Pannexin 3 deletion reduces fat accumulation and inflammation in a sex-specific manner.

BACKGROUND: Pannexin 3 (PANX3) is a channel-forming glycoprotein that enables nutrient-induced inflammation in vitro, and genetic linkage data suggest that it regulates body mass index. Here, we characterized inflammatory and metabolic parameters in global Panx3 knockout (KO) mice in the context of forced treadmill running (FEX) and high-fat diet (HFD). METHODS: C57BL/6N (WT) and KO mice were randomized to either a FEX running protocol or no running (SED) from 24 until 30 weeks of age. Body weight was measured biweekly, and body composition was measured at 24 and 30 weeks of age. Male WT and KO mice were fed a HFD from 12 to 28 weeks of age. Metabolic organs were analyzed for a panel of inflammatory markers and PANX3 expression. RESULTS: In females there were no significant differences in body composition between genotypes, which could be due to the lack of PANX3 expression in female white adipose tissue, while male KOs fed a chow diet had lower body weight and lower fat mass at 24 and 30 weeks of age, which was reduced to the same extent as 6 weeks of FEX in WT mice. In addition, male KO mice exhibited significantly lower expression of multiple pro-inflammatory genes in white adipose tissue compared to WT mice. While on a HFD body weight differences were insignificant, multiple inflammatory genes were significantly different in quadriceps muscle and white adipose tissue resulting in a more anti-inflammatory phenotype in KO mice compared to WT. The lower fat mass in male KO mice may be due to significantly fewer adipocytes in their subcutaneous fat compared to WT mice. Mechanistically, adipose stromal cells (ASCs) cultured from KO mice grow significantly slower than WT ASCs. CONCLUSION: PANX3 is expressed in male adult mouse adipose tissue and may regulate adipocyte numbers, influencing fat accumulation and inflammation.

Timing of delivery in women with prior uterine rupture: a decision analysis.

Background: Uterine rupture is an obstetric complication with high rates of associated maternal and neonatal morbidity and mortality. However, limited guidance for the timing of delivery in women with a history of prior uterine rupture exists.Objective: To determine the optimal gestational age of delivery in women with prior uterine rupture.Study design: A decision-analytic model was built using TreeAge software to compare the outcomes of repeat cesarean delivery when performed at 32, 33, 34, 35, or 36 weeks gestation in a theoretical cohort of 1000 women with prior uterine rupture. Strategies involved expectant management until a later gestational age accounting for the risks of spontaneous uterine rupture, spontaneous labor, uterine rupture following spontaneous labor, and stillbirth during each successive week that a woman was still pregnant. Maternal outcomes included uterine rupture, hysterectomy, and death. Neonatal outcomes included hypoxic-ischemic encephalopathy, cerebral palsy, and death. Probabilities were derived from the literature and total quality-adjusted life years (QALYs) were calculated. Sensitivity analyses were used to vary model inputs to investigate the robustness of our baseline assumptions.Results: In our theoretical cohort of 1000 pregnant women with a history of prior uterine rupture, cesarean delivery at 34 weeks maximized maternal and neonatal QALYs. Compared to delivery at 36 weeks, delivery at 34 weeks would prevent 38.6 uterine ruptures, 0.079 maternal deaths, 6.10 hysterectomies, and 12.1 neonatal deaths but results in 4.70 more cases of cerebral palsy. Univariate sensitivity analysis found that repeat cesarean at 34 weeks remained the optimal strategy until the probability of spontaneous repeat uterine rupture (baseline estimate: 0.68%) fell below 0.2% or rose above 0.9%, at which point, a strategy of delivery at 35 or 32 weeks became optimal, respectively. However, Monte Carlo simulation demonstrated that delivery at 35 weeks was the optimal strategy 37% of the time, whereas 34 weeks was the optimal strategy 17% of the time.Conclusion: The optimal time for repeat cesarean delivery in women with prior uterine rupture appears to be between 34-0/7 and 35-6/7 weeks gestation.

Pannexin 1 regulates adipose stromal cell differentiation and fat accumulation.

Pannexin 1 (Panx1) is a channel-forming glycoprotein important in paracrine signaling and cellular development. In this study, we discovered that mice globally lacking Panx1 (KO) have significantly greater total fat mass and reduced lean mass compared to wild type (WT) mice under a normal diet. Despite having higher fat content, Panx1 KO mice on a high fat diet exhibited no differences in weight gain and blood markers of obesity as compared to WT controls, except for an increase in glucose and insulin levels. However, metabolic cage data revealed that these Panx1 KO mice display significantly increased activity levels, higher ambulatory activity, and reduced sleep duration relative to their WT littermates on a high-fat diet. To uncover the cellular mechanism responsible for the increased fat content in the KO, we isolated primary cultures of adipose-derived stromal cells (ASCs) from WT and KO fat pads. In WT ASCs we observed that Panx1 protein levels increase upon induction into an adipogenic lineage. ASCs isolated from Panx1 KO mice proliferate less but demonstrate enhanced adipogenic differentiation with increased intracellular lipid accumulation, glycerol-3-phosphate dehydrogenase (GPDH) enzyme activity, and adipokine secretion, as compared to WT ASCs. This was consistent with the increased adipocyte size and decreased adipocyte numbers observed in subcutaneous fat of the Panx1 KO mice compared to WT. We concluded that Panx1 plays a key role in adipose stromal cells during the early stages of adipogenic proliferation and differentiation, regulating fat accumulation in vivo.

Trisomy 13 and the risk of gestational hypertensive disorders: a population-based study.

PURPOSE: To describe the rate and severity of gestational hypertensive disorders (GHDs) in pregnancies complicated by trisomy 13 (T13). MATERIALS AND METHODS: Retrospective cohort study of singleton deliveries in California from 2005 to 2008 using vital statistics and ICD-9 data. We were interested in gestational hypertension (gHTN), preeclampsia with and without severe features (sPREX and PREX), and gestational age at delivery. Pregnancies and maternal complications affected by prenatally diagnosed T13 were compared to unaffected pregnancies. Regression models were used to compute adjusted odds ratios for pregnancy outcomes by T13 status. RESULTS: Of the 2,029,004 deliveries, 142 women had prenatally diagnosed T13. A diagnosis of GHD occurred in 26.8% of the T13 pregnancies versus 6% of the non-T13 pregnancies (p < .001). This remained true for gHTN (9.2% versus 3.2%, p=.001), PREX (12% versus 2.2%, p < .001), and sPREX (8.5% versus 0.9%, p < .001). After adjusting for confounders, T13 pregnancies were 6.3-times more likely to be affected by GHD, and 12.5-times more likely to have sPREX. Delivery <37 and <32 weeks in the setting of GHD was 14.1-times and 11.2-times likely among women with T13. CONCLUSIONS: Women with T13 pregnancies were significantly more likely to have gHTN, preeclampsia, sPREX, and to deliver <32 weeks.

The Effects of Turner Syndrome, 45,X on Obstetric and Neonatal Outcomes: A Retrospective Cohort Evaluation.

Objective This study aims to evaluate the perinatal and neonatal outcomes associated with prenatal diagnosis of 45,X, both with and without fetal cardiac anomalies. Study Design A retrospective cohort of singleton pregnancies in California, 2005 to 2008, using vital statistics and International Classification of Diseases, Ninth Revision data, identifying prenatally diagnosed 45,X. Outcomes included preterm delivery, preeclampsia, intrauterine fetal demise (IUFD), cesarean section, small for gestational age (SGA), neonatal death, and infant death. Bivariate and multivariate analyses were used to compare pregnancies and neonates with and without 45,X. Prenatally diagnosed cardiac anomalies were also considered. Results Of the 2,029,000 deliveries, 138 had prenatally diagnosed 45,X. Out of these 138 deliveries, 22 had a prenatally diagnosed cardiac anomaly. Compared with unaffected pregnancies, those with fetal 45,X had higher rates of preterm delivery (19.5 vs. 9.9%, p = 0.001), cesarean section (44.2 vs. 30.2%, p < 0.0001), and SGA (21.5 vs. 6.3%, p < 0.0001). The affected cohort had no IUFDs. Neonatal death was 14.5 times higher in the 45,X cohort (p < 0.0001). Of only infants with cardiac anomalies, neonatal death was significantly more likely in those with 45,X (p = 0.005). In adjusted analysis, risk of SGA (< 3rd percentile), neonatal death, and infant death remained increased for infants with 45,X while controlling for fetal cardiac anomalies. Conclusion Prenatally diagnosed 45,X was associated with increased risk of cesarean section, and adverse neonatal outcomes, including mortality.

The impact of prenatally diagnosed Klinefelter Syndrome on obstetric and neonatal outcomes.

OBJECTIVE: The objective of this study was to examine the obstetric and neonatal outcomes as well as the as the associated hospital costs for pregnancies complicated by prenatally diagnosed Klinefelter Syndrome, 47,XXY. STUDY DESIGN: We conducted a retrospective cohort study of all of the singleton deliveries in California from 2005 to 2008 using vital statistics and ICD-9 data, specifically identifying cases of fetal Klinefelter Syndrome. Specifically, we were interested in the outcomes of preterm delivery, preeclampsia, intrauterine fetal demise, cesarean delivery, neonatal death, respiratory distress syndrome (RDS), small for gestational age, large for gestational age, neonatal death, and infant death. Bivariate and multivariate analyses were used to compare pregnancies and neonates affected by prenatally diagnosed Klinefelter Syndrome to those that were not affected with 47,XXY. RESULTS: There were 2,029,000 deliveries in the cohort, including 52 women with prenatally diagnosed 47,XXY. Advanced maternal age, completion of 12th grade, and private insurance were all associated with a prenatal diagnosis of Klinefelter Syndrome. Compared to unaffected deliveries, pregnancies complicated by prenatally diagnosed Klinefelter Syndrome had higher rates of preterm delivery (23.1% vs 9.9%, p=0.0004), cesarean delivery (50.0% vs 30.2%, p=0.004), and RDS (9.6% vs 1.2%, p=<0.0001). Infants with 47,XXY were markedly more likely to be small for gestational age, including less than the 10th, 5th and 3rd percentile (aOR 5.86 (95% CI 2.99, 11.46), 6.03 (95% CI 2.52, 14.43), and 8.28 (95% CI 3.22, 21.25), p≤0.001). Rates of neonatal death were 9.5 times higher (1.9% vs 0.2% p<0.0001) in the 47,XXY cohort, and rates of infant death were more than 50 times higher (5.8% vs 0.1%, p<0.0001). In the adjusted analysis, prenatally diagnosed 47,XXY was associated with increased odds of preterm delivery <32 weeks (OR 6.81, 95% CI 2. .38, 19.52), IVH (OR 9.08, 95% CI 1.22, 67.7), RDS (OR 8.32, 95% CI 3.22, 21.49), neonatal death (OR 9.77, 1.33, 71.79), and infant death (OR 62.73, 95% CI 19.34, 203.4). CONCLUSION: Pregnancies affected by prenatally diagnosed Klinefelter Syndrome are at an increased risk of adverse fetal and neonatal outcomes. These findings may be helpful when counseling families with pregnancies affected by fetal 47,XXY.

When is the optimal time to deliver late preterm IUGR fetuses with abnormal umbilical artery Dopplers?

OBJECTIVE: To determine the optimal timing of delivery in late preterm intrauterine growth restriction (IUGR) fetuses with abnormal umbilical artery Doppler (UAD) indices. METHODS: A decision-analytic model was built to determine the optimal gestational age (GA) of delivery in a theoretic cohort of 10 000 IUGR fetuses with elevated UAD systolic/diastolic ratios diagnosed at 34 weeks. All inputs were derived from the literature. Strategies involving expectant management accounted for the probabilities of stillbirth, spontaneous delivery and induction of labor for UAD absent or reversed end-diastolic flow (AREDF) at each successive week. Outcomes included short- and long-term neonatal morbidity and mortality with quality-adjusted life years (QALYs) generated based on these outcomes. Base case, sensitivity analyses and a Monte Carlo simulation were performed. RESULTS: The optimal GA for delivery is 35 weeks, which minimized perinatal deaths and maximized total QALYs. Earlier delivery became optimal once the risk of stillbirth was threefold our baseline assumption; our model was also robust until the risk of AREDF at 35 weeks was half our baseline assumption, after which delivery at 36 weeks was preferred. Delivery at 35 weeks was the optimal strategy in 77% of trials in Monte Carlo multivariable sensitivity analysis. CONCLUSIONS: Weighing the risks of iatrogenic prematurity against the poor outcomes associated with AREDF, the ideal GA to deliver late preterm IUGR fetuses with elevated UAD indices is 35 weeks.

Maternal and fetal outcomes of pancreatitis in pregnancy.

OBJECTIVE: This study examined maternal and neonatal outcomes that are associated with pancreatitis in pregnancy, in particular preeclampsia. STUDY DESIGN: We conducted a retrospective cohort study of all singleton nonanomalous pregnancies in California from 2005-2008 with an identification of all cases of pancreatitis. Outcomes of interest included preeclampsia, intrauterine fetal death, preterm delivery, and neonatal or infant death. Univariate and multivariable analyses were then conducted to examine the association of pancreatitis in pregnancy and maternal characteristics and fetal outcomes. RESULTS: Our cohort of 2,039,870 pregnant women included 342 women (0.017%) with pancreatitis. Pancreatitis in pregnancy was not associated significantly with neonatal or infant death. When assessing fetal outcomes, pancreatitis was associated with preterm delivery, small for gestational age, jaundice, respiratory distress syndrome, and intrauterine fetal death (P < .001). Of note, pregnancy-associated pancreatitis was found to be associated with preeclampsia and severe preeclampsia in both univariate (P < .001) and multivariate analysis after we controlled for potential confounders (odds ratio, 4.21 [95% confidence interval, 2.99-5.93]; odds ratio, 7.85 [95% confidence interval, 5.03-12.24], respectively). CONCLUSION: We found that pancreatitis in pregnancy was associated with several adverse maternal outcomes; in particular, a strong association existed with preeclampsia, which has its own implications and complications surrounding pregnancy management. Pancreatitis in pregnancy was also associated with increased risk for preterm delivery but not neonatal or infant death, which is consistent with the literature.

Cost-Effectiveness Analysis of Latent versus Active Labor Hospital Admission for Medically Low-Risk, Term Women.

OBJECTIVE: To assess the outcomes and costs of hospital admission during the latent versus active phase of labor. Latent labor hospital admission has been consistently associated with elevated maternal risk for increased interventions, including epidural anesthesia and cesarean delivery, longer hospital stay, and higher utilization of hospital resources. METHODS: A cost-effectiveness model was built to simulate a theoretic cohort of 3.2 million term, medically low-risk women either being admitted in latent labor (< 4 cm dilation) or delaying admission until active labor (≥ 4 cm dilation). Outcomes included epidural use, mode of delivery, stillbirth, maternal death, and costs of care. All probability, cost, and utility estimates were derived from the literature, and total quality-adjusted life years were calculated. Sensitivity analyses and a Monte Carlo simulation were used to investigate the robustness of model assumptions. RESULTS: Delaying admission until active labor would result in 672,000 fewer epidurals, 67,232 fewer cesarean deliveries, and 9.6 fewer maternal deaths in our theoretic cohort as compared to admission during latent labor. Additionally, delaying admission results in a cost savings of $694 million annually in the United States. Sensitivity analyses indicated the model was robust within a wide range of probabilities and costs. Monte Carlo simulation found that delayed admission was the optimal strategy in 76.79 percent of trials. CONCLUSION: Delaying admission until active labor is a dominant strategy, resulting in both better outcomes and lower costs. Issues related to clinical translation of these findings are explored.

What is the optimal gestational age for women with gestational diabetes type A1 to deliver?

OBJECTIVE: Type A1 gestational diabetes mellitus (A1GDM), also known as diet-controlled gestational diabetes, is associated with an increase in adverse perinatal outcomes such as macrosomia and Erb palsy. However, it remains unclear when to deliver these women because optimal timing of delivery requires balancing neonatal morbidities from early term delivery against the risk of intrauterine fetal demise (IUFD). We sought to determine the optimal gestational age (GA) for women with A1GDM to deliver. STUDY DESIGN: A decision-analytic model was built to compare the outcomes of delivery at 37-41 weeks in a theoretical cohort of 100,000 women with A1GDM. Strategies involving expectant management until a later GA accounted for probabilities of spontaneous delivery, indicated delivery, and IUFD during each week. GA-associated risks of neonatal complications included cerebral palsy, infant death, and Erb palsy. Probabilities were derived from the literature, and total quality-adjusted life years were calculated. Sensitivity analyses were used to investigate the robustness of the baseline assumptions. RESULTS: Our model showed that induction at 38 weeks maximized quality-adjusted life years. Within our cohort, delivery at 38 weeks would prevent 48 stillbirths but lead to 12 more infant deaths compared to 39 weeks. Sensitivity analysis revealed that 38 weeks remains the optimal timing of delivery until IUFD rates fall <0.3-fold of our baseline assumption, at which point expectant management until 39 weeks is optimal. CONCLUSION: By weighing the risks of IUFD against infant deaths and neonatal morbidities from early term delivery, we determined that the ideal GA for women with A1GDM to deliver is 38 weeks.

Nitric oxide is less effective at inhibiting neointimal hyperplasia in spontaneously hypertensive rats.

Exogenous administration of nitric oxide (NO) markedly decreases neointimal hyperplasia following arterial injury in several animal models. However, the effect of NO on neointimal hyperplasia in hypertension remains unknown. Here, we employ the spontaneously hypertensive rat (SHR) strain, inbred from Wistar Kyoto (WKY) rats, and the carotid artery balloon injury model to assess the effects of NO on neointimal hyperplasia development. 2weeks after arterial injury, we showed that both rat strains developed similar levels of neointimal hyperplasia, but local administration of NO was less effective at inhibiting neointimal hyperplasia in the SHR compared to WKY rats (58% vs. 79%, P<0.001). Interestingly, local administration of NO did not affect systemic blood pressure in either rat strain. Compared to WKY, the SHR displayed more proliferation in the media and adventitia following balloon injury, as measured by BrdU incorporation. The SHR also showed more inflammation in the adventitia after injury, as well as more vasa vasorum, than WKY rats. NO treatment reduced the vasa vasorum in the SHR but not WKY rats. Finally, while NO decreased both injury-induced proliferation and inflammation in the SHR, it did not return these parameters to levels seen in WKY rats. We conclude that NO is less effective at inhibiting neointimal hyperplasia in the SHR than WKY rats. This may be due to increased scavenging of NO in the SHR, leading to diminished bioavailability of NO. These data will help to develop novel NO-based therapies that will be equally effective in both normotensive and hypertensive patient populations.

Antioxidants modulate the antiproliferative effects of nitric oxide on vascular smooth muscle cells and adventitial fibroblasts by regulating oxidative stress.

BACKGROUND: S-nitrosothiols (SNO) release nitric oxide (NO) through interaction with ascorbic acid (AA). However, little is known about their combined effect in the vasculature. The aim of this study was to investigate the effect of AA on SNO-mediated NO release, proliferation, cell cycle progression, cell death, and oxidative stress in vascular cells. METHODS: Vascular smooth muscle cells and adventitial fibroblasts harvested from the aortae of Sprague-Dawley rats were treated with AA, ± S-nitrosoglutathione (GSNO), or ± diethylenetriamine NONOate (DETA/NO). NO release, proliferation, cell cycle progression, cell death, and oxidative stress were determined by the Griess reaction, [(3)H]-thymidine incorporation, flow cytometry, trypan blue exclusion, and 5-(and-6)chloromethyl-2',7'dichlorodihydrofluorescein staining, respectively. RESULTS: AA increased NO release from GSNO 3-fold (P < .001). GSNO and DETA/NO significantly decreased proliferation, but AA abrogated this effect (P < .05). Mirroring the proliferation data, changes in cell cycle progression induced by GSNO and DETA/NO were reversed by the addition of AA. GSNO- and DETA/NO-mediated increases in oxidative stress were significantly decreased by the addition of AA (P < .001). CONCLUSIONS: Despite causing increased NO release from GSNO, AA reduced the antiproliferative and cell cycle effects of GSNO and DETA/NO through the modulation of oxidative stress.

Insights into the effect of nitric oxide and its metabolites nitrite and nitrate at inhibiting neointimal hyperplasia.

OBJECTIVE: Periadventitial delivery of the nitric oxide (NO) donor PROLI/NO following arterial injury effectively inhibits neointimal hyperplasia. Given the short half-life of NO release from PROLI/NO, our goal was to determine if inhibition of neointimal hyperplasia by PROLI/NO was due to NO, or its metabolites nitrite and nitrate. METHODS AND RESULTS: In vitro, the NO donor DETA/NO inhibited proliferation of rat aortic vascular smooth muscle cells (RASMC), but neither nitrite nor nitrate did. In vivo, following rat carotid artery balloon injury or injury plus the molar equivalents of PROLI/NO, nitrite, or nitrate (n=8-11/group), PROLI/NO was found to provide superior inhibition of neointimal hyperplasia (82% inhibition of intimal area, and 44% inhibition of medial area, p<0.001). Only modest inhibition was noted with nitrite or nitrate (45% and 41% inhibition of intimal area, and 31% and 29% inhibition of medial area, respectively, p<0.001). No effects on blood pressure were noted with any treatment groups. In vivo, only PROLI/NO inhibited cellular proliferation and increased arterial lumen area compared to injury alone (p<0.001). However, all three treatments inhibited inflammation (p<0.001). CONCLUSIONS: PROLI/NO was more effective at inhibiting neointimal hyperplasia following arterial injury than nitrite or nitrate. However, modest inhibition of neointimal hyperplasia was observed with nitrite and nitrate, likely secondary to anti-inflammatory actions. In conclusion, we have demonstrated that the efficacy of NO donors is primarily due to NO production and not its metabolites, nitrite and nitrate.