The Haemostatic Mechanism and Menstruation: The Role of Intra-Uterine Contraceptive Devices

The haemostatic mechanism of 40 female patients undergoing menstruation, 20 with intra-uterine devices (IUCD) and 20 without (Control), were studied. The patients’ coagulation profiles, fibrinolytic system and platelet functions were studied before and after hysterectomy. Platelet survival times and platelet consumption was determined using 51Cr. labelled autologous platelets. Patients who menstruated during the study had their pads collected and radioactivity measured. Histology, autoradiography and scintillation counting was performed on uteri obtained from a hysterectomy performed towards the end of the platelet survival study period. There were no significant differences in the coagulation, fibrinolytic and platelet function tests in these 2 groups, though in each group there were the expected changes after operation.

Platelet survival time, consumption and radioactivity in the tampons showed no significant differences between the IUCD and control groups, although there were 6 patients with low platelet survival times in the IUCD group. Resected uteri showed surprising lack of concentration of platelets which may have been due in part to loss of blood at operation and handling of the uterus. Surprisingly, in the control patients, platelet survival time in response to the severe haemosatic challenge of menstruation were normal. However in the IUCD group, 6 patients showed shortening of platelet survival. Also surprisingly and equally in both control and IUCD groups, was the small amount of platelet related radioactivity in the menstruating fluid.

Weed presence altered biotic stress and light signaling in maize even when weeds were removed early in the critical weed-free period

Weed presence early in the life cycle of maize (typically, from emergence through the 8 to 12 leaf growth stage) can reduce crop growth and yield and is known as the critical weed-free period (CWFP). Even if weeds are removed during or just after the CWFP, crop growth and yield often are not recoverable. We compared transcriptome responses of field-grown hybrid maize at V8 in two consecutive years among plants grown under weed-free and two weed-stressed conditions (weeds removed at V4 or present through V8) using RNAseq analysis techniques. Compared with weed-free plant responses, physiological differences at V8 were identified in all weed-stressed plants and were most often associated with altered photosynthetic processes, hormone signaling, nitrogen use and transport, and biotic stress responses. Even when weeds were removed at V4 and tissues sampled at V8, carbon: nitrogen supply imbalance, salicylic acid signals, and growth responses differed between the weed-stressed and weed-free plants. These underlying processes and a small number of developmentally important genes are potential targets for decreasing the maize response to weed pressure. Expression differences of several novel, long noncoding RNAs resulting from exposure of maize to weeds during the CWFP were also observed and could open new avenues for investigation into the function of these transcription units.

Foliar Glyphosate Treatment Alters Transcript and Hormone Profiles in Crown Buds of Leafy Spurge and Induces Dwarfed and Bushy Phenotypes throughout its Perennial Lifecycle

Leafy spurge ( L.) is an invasive weed of North America and its perennial nature attributed to underground adventitious buds (UABs) that undergo seasonal cycles of para-, endo-, and ecodormancy. Recommended rates of glyphosate (∼1 kg ha) destroy aboveground shoots but plants still regenerate vegetatively; therefore, it is considered glyphosate-tolerant. However, foliar application of glyphosate at higher rates (2.2-6.7 kg ha) causes sublethal effects that induce UABs to produce stunted, bushy phenotypes. We investigated the effects of glyphosate treatment (±2.24 kg ha) on vegetative growth, phytohormone, and transcript profiles in UABs under controlled environments during one simulated seasonal cycle. Because shoots derived from UABs of foliar glyphosate-treated plants produced stunted, bushy phenotypes, we could not directly determine if these UABs transitioned through seasonally induced endo- and ecodormancy. However, transcript abundance for leafy spurge dormancy marker genes and principal component analyses suggested that UABs of foliar glyphosate-treated plants transitioned through endo- and ecodormancy. Glyphosate treatment increased shikimate abundance in UABs 7 d after treatment; however, the abundance of shikimate gradually decreased as UABs transitioned through endo- and ecodormancy. The dissipation of shikimate over time suggests that glyphosate's target site was no longer affected, but these changes did not reverse the altered phenotypes observed from UABs of foliar glyphosate-treated leafy spurge. Transcript profiles further indicated that foliar glyphosate treatment significantly affected phytohormone biosynthesis and signaling, particularly auxin transport; gibberellic acid, abscisic acid and jasmonic acid biosynthesis; ethylene responses; and detoxification and cell cycle processes in UABs. These results correlated well with the available phytohormone profiles and altered phenotypes.

Comparison of phytohormone levels and transcript profiles during seasonal dormancy transitions in underground adventitious buds of leafy spurge

Leafy spurge (Euphorbia esula L.) is an herbaceous perennial weed that maintains its perennial growth habit through generation of underground adventitious buds (UABs) on the crown and lateral roots. These UABs undergo seasonal phases of dormancy under natural conditions, namely para-, endo-, and ecodormancy in summer, fall, and winter, respectively. These dormancy phases can also be induced in growth chambers by manipulating photoperiod and temperature. In this study, UABs induced into the three phases of dormancy under controlled conditions were used to compare changes in phytohormone and transcriptome profiles. Results indicated that relatively high levels of ABA, the ABA metabolite PA, and IAA were found in paradormant buds. When UABs transitioned from para- to endodormancy, ABA and PA levels decreased, whereas IAA levels were maintained. Additionally, transcript profiles associated with regulation of soluble sugars and ethylene activities were also increased during para- to endodormancy transition, which may play some role in maintaining endodormancy status. When crown buds transitioned from endo- to ecodormancy, the ABA metabolites PA and DPA decreased significantly along with the down-regulation of ABA biosynthesis genes, ABA2 and NCED3. IAA levels were also significantly lower in ecodormant buds than that of endodormant buds. We hypothesize that extended cold treatment may trigger physiological stress in endodormant buds, and that these stress-associated signals induced the endo- to ecodormancy transition and growth competence. The up-regulation of NAD/NADH phosphorylation and dephosphorylation pathway, and MAF3-like and GRFs genes, may be considered as markers of growth competency.

Coal-Bed Methane Water: Effects on Soil Properties and Camelina Productivity

Every year, the production of coal-bed natural gas in the Powder River Basin results in the discharge of large amounts of coal-bed methane water (CBMW) in Wyoming; however, no sustainable disposal methods for CBMW are currently available. A greenhouse study was conducted to evaluate the potential to use CBMW as a source of irrigation water for camelina [ (L.) Crantz]. We assessed the effects of three CBMW concentrations (0% [1:0], 50% [1:1], and 100% [0:1] tap water to CBMW) on selected soil properties, growth, seed oil, and fatty acid composition of three camelina cultivars: Blaine Creek, Ligena, and Pronghorn. The 100% CBMW reduced seed and estimated biofuel yields by 24 and 23%, respectively, but increased the oil content by 3%, relative to the control. Additionally, the 100% CBMW visibly affected soil through formation of surface crust due to elevated levels of sodium (653 mg Na kg). The 50% CBMW had no significant effects on the seed yield, estimated biofuel yield, and oil content, but the soil Na levels were still high (464 mg kg), which could pose a long-term impact on soil structure. The CBMW tended to reduce the total saturated fatty acid, but it had no significant effects on the total monounsaturated or polyunsaturated fatty acids of camelina seeds. Overall, CBMW diluted with an equal amount of good-quality water could be used to irrigate camelina in the short term. Afterward, only good-quality water would have to be used until the accumulated dissolved solids are flushed out.

Development and dissection of diagnostic SNP markers for the downy mildew resistance genes Pl Arg and Pl 8 and maker-assisted gene pyramiding in sunflower (Helianthus annuus L.)

Diagnostic DNA markers are an invaluable resource in breeding programs for successful introgression and pyramiding of disease resistance genes. Resistance to downy mildew (DM) disease in sunflower is mediated by Pl genes which are known to be effective against the causal fungus, Plasmopara halstedii. Two DM resistance genes, Pl _Arg and Pl ₈ , are highly effective against P. halstedii races in the USA, and have been previously mapped to the sunflower linkage groups (LGs) 1 and 13, respectively, using simple sequence repeat (SSR) markers. In this study, we developed high-density single nucleotide polymorphism (SNP) maps encompassing the Pl _arg and Pl ₈ genes and identified diagnostic SNP markers closely linked to these genes. The specificity of the diagnostic markers was validated in a highly diverse panel of 548 sunflower lines. Dissection of a large marker cluster co-segregated with Pl _Arg revealed that the closest SNP markers NSA_007595 and NSA_001835 delimited Pl _Arg to an interval of 2.83 Mb on the LG1 physical map. The SNP markers SFW01497 and SFW06597 delimited Pl ₈ to an interval of 2.85 Mb on the LG13 physical map. We also developed sunflower lines with homozygous, three gene pyramids carrying Pl _Arg , Pl ₈ , and the sunflower rust resistance gene R ₁₂ using the linked SNP markers from a segregating F₂ population of RHA 340 (carrying Pl ₈ )/RHA 464 (carrying Pl _Arg and R ₁₂ ). The high-throughput diagnostic SNP markers developed in this study will facilitate marker-assisted selection breeding, and the pyramided sunflower lines will provide durable resistance to downy mildew and rust diseases.

Genetics and mapping of a novel downy mildew resistance gene, Pl(18), introgressed from wild Helianthus argophyllus into cultivated sunflower (Helianthus annuus L.)

A novel downy mildew resistance gene, Pl(18), was introgressed from wild Helianthus argophyllus into cultivated sunflower and genetically mapped to linkage group 2 of the sunflower genome. The new germplasm, HA-DM1, carrying Pl(18) has been released to the public. Sunflower downy mildew (DM) is considered to be the most destructive foliar disease that has spread to every major sunflower-growing country of the world, except Australia. A new dominant downy mildew resistance gene (Pl 18) transferred from wild Helianthus argophyllus (PI 494573) into cultivated sunflower was mapped to linkage group (LG) 2 of the sunflower genome using bulked segregant analysis with 869 simple sequence repeat (SSR) markers. Phenotyping 142 BC1F2:3 families derived from the cross of HA 89 and H. argophyllus confirmed the single gene inheritance of resistance. Since no other Pl gene has been mapped to LG2, this gene was novel and designated as Pl (18). SSR markers CRT214 and ORS203 flanked Pl(18) at a genetic distance of 1.1 and 0.4 cM, respectively. Forty-six single nucleotide polymorphism (SNP) markers that cover the Pl(18) region were surveyed for saturation mapping of the region. Six co-segregating SNP markers were 1.2 cM distal to Pl(18), and another four co-segregating SNP markers were 0.9 cM proximal to Pl(18). The new BC2F4-derived germplasm, HA-DM1, carrying Pl(18) has been released to the public. This new line is highly resistant to all Plasmopara halstedii races identified in the USA providing breeders with an effective new source of resistance against downy mildew in sunflower. The molecular markers that were developed will be especially useful in marker-assisted selection and pyramiding of Pl resistance genes because of their close proximity to the gene and the availability of high-throughput SNP detection assays.

Phytohormone balance and stress-related cellular responses are involved in the transition from bud to shoot growth in leafy spurge

BACKGROUND

Leafy spurge (Euphorbia esula L.) is an herbaceous weed that maintains a perennial growth pattern through seasonal production of abundant underground adventitious buds (UABs) on the crown and lateral roots. During the normal growing season, differentiation of bud to shoot growth is inhibited by physiological factors external to the affected structure; a phenomenon referred to as paradormancy. Initiation of shoot growth from paradormant UABs can be accomplished through removal of the aerial shoots (hereafter referred to as paradormancy release).

RESULTS

In this study, phytohormone abundance and the transcriptomes of paradormant UABs vs. shoot-induced growth at 6, 24, and 72 h after paradormancy release were compared based on hormone profiling and RNA-seq analyses. Results indicated that auxin, abscisic acid (ABA), and flavonoid signaling were involved in maintaining paradormancy in UABs of leafy spurge. However, auxin, ABA, and flavonoid levels/signals decreased by 6 h after paradormancy release, in conjunction with increase in gibberellic acid (GA), cytokinin, jasmonic acid (JA), ethylene, and brassinosteroid (BR) levels/signals. Twenty four h after paradormancy release, auxin and ABA levels/signals increased, in conjunction with increase in GA levels/signals. Major cellular changes were also identified in UABs at 24 h, since both principal component and Venn diagram analysis of transcriptomes clearly set the 24 h shoot-induced growth apart from other time groups. In addition, increase in auxin and ABA levels/signals and the down-regulation of 40 over-represented AraCyc pathways indicated that stress-derived cellular responses may be involved in the activation of stress-induced re-orientation required for initiation of shoot growth. Seventy two h after paradormancy release, auxin, cytokinin, and GA levels/signals were increased, whereas ABA, JA, and ethylene levels/signals were decreased.

CONCLUSION

Combined results were consistent with different phytohormone signals acting in concert to direct cellular changes involved in bud differentiation and shoot growth. In addition, shifts in balance of these phytohormones at different time points and stress-related cellular responses after paradormancy release appear to be critical factors driving transition of bud to shoot growth.

Heart rate variability in neonates of type 1 diabetic pregnancy

BACKGROUND

Cardiomyopathy is a common finding in offspring of pre-gestational type 1 diabetic pregnancy. Echocardiographic and biochemical evidence of fetal cardiac dysfunction have also been reported. Studies suggest that offspring of diabetic mothers (ODM) undergo a fetal programming effect due to the hyperglycaemic intrauterine milieu which increases their risk of cardiovascular morbidity in adult life. Decreased neonatal heart rate variability (HRV) has been described in association with in-utero growth restriction, prematurity, sudden infant death syndrome and congenital heart disease. The effect of in-utero exposure to hyperglycaemia in diabetic pregnancy on neonatal HRV is unknown.

AIMS

Our aim was to determine if neonatal HRV differs between normal and diabetic pregnancy.

STUDY DESIGN AND SUBJECTS

This was a prospective observational study of 38 patients with pregestational type 1 diabetes and 26 controls. HRV assessment was performed using Powerlab (ADI Instruments Ltd).

OUTCOME MEASURES

Heart rate variability assessment and cord blood sampling for pH and glucose were performed for all neonates. Maternal glycaemic control was assessed via measurement of glycosylated haemoglobin in each trimester in the diabetic cohort.

RESULTS

Neonates of diabetic mothers had evidence of altered heart rate variability, with increased low frequency to high frequency ratio (LF: HF), suggestive of a shift towards sympathetic predominance (p<0.05). This altered HRV was significantly related to fetal acidaemia, cord blood glucose values and maternal glycaemic control during pregnancy (p<0.05).

CONCLUSION

Neonates of pregestational diabetic pregnancy have altered HRV which is related to maternal hyperglycaemia, fetal acidaemia and fetal glycaemia. Exposure of the developing heart to fluctuations in maternal glycaemia with subsequent alterations in HRV may explain why infants of diabetic mothers are at greater risk of cardiovascular disease in later life.

The Effects of Fetal Gender on Maternal and Fetal Insulin Resistance

OBJECTIVE

Gender plays a role in the development of a number of cardiovascular and metabolic diseases and it has been suggested that females may be more insulin resistant in utero. We sought to assess the relationship between infant gender and insulin resistance in a large pregnancy cohort.

STUDY DESIGN

This is a secondary analysis of a cohort from the ROLO randomized control trial of low GI diet in pregnancy. Serum insulin, glucose and leptin were measured in early pregnancy and at 28 weeks. At delivery cord blood C-peptide and leptin were measured. A comparison of maternal factors, fetal biometry, insulin resistance and leptin was made between male and female offspring. A multivariate regression model was built to account for the possible effects of maternal BMI, birthweight and original study group assignment on findings.

RESULTS

A total of 582 women were included in this secondary analysis, of whom 304 (52.2%) gave birth to male and 278 (47.8%) gave birth to female infants. Compared to male infants at birth, female infants were significantly lighter, (3945 ± 436 vs. 4081± 549g, p<0.001), shorter in length (52.36 ± 2.3 vs. 53.05 ± 2.4cm, p<0.001) and with smaller head circumferences (35.36 ± 1.5 vs. 36.10 ± 1.1cm, p<0.001) than males. On multiple regression analysis, women pregnant with female fetuses were less insulin resistant in early pregnancy, i.e. had lower HOMA indices (B = -0.19, p = 0.01). Additionally female fetuses had higher concentrations of both cord blood leptin and C-peptide at birth when compared to male offspring (B = 0.38, p<0.001 and B = 0.31, p = 0.03 respectively).

CONCLUSION

These findings suggest gender is a risk factor for insulin resistance in-utero. Additionally, carrying a female fetus decreases the risk of insulin resistance in the mother, from as early as the first trimester.

Glyphosate's impact on vegetative growth in leafy spurge identifies molecular processes and hormone cross-talk associated with increased branching

BACKGROUND

Leafy spurge (Euphorbia esula) is a perennial weed that is considered glyphosate tolerant, which is partially attributed to escape through establishment of new vegetative shoots from an abundance of underground adventitious buds. Leafy spurge plants treated with sub-lethal concentrations of foliar-applied glyphosate produce new vegetative shoots with reduced main stem elongation and increased branching. Processes associated with the glyphosate-induced phenotype were determined by RNAseq using aerial shoots derived from crown buds of glyphosate-treated and -untreated plants. Comparison between transcript abundance and accumulation of shikimate or phytohormones (abscisic acid, auxin, cytokinins, and gibberellins) from these same samples was also done to reveal correlations.

RESULTS

Transcriptome assembly and analyses confirmed differential abundance among 12,918 transcripts (FDR ≤ 0.05) and highlighted numerous processes associated with shoot apical meristem maintenance and stem growth, which is consistent with the increased number of actively growing meristems in response to glyphosate. Foliar applied glyphosate increased shikimate abundance in crown buds prior to decapitation of aboveground shoots, which induces growth from these buds, indicating that 5-enolpyruvylshikimate 3-phosphate (EPSPS) the target site of glyphosate was inhibited. However, abundance of shikimate was similar in a subsequent generation of aerial shoots derived from crown buds of treated and untreated plants, suggesting EPSPS is no longer inhibited or abundance of shikimate initially observed in crown buds dissipated over time. Overall, auxins, gibberellins (precursors and catabolites of bioactive gibberellins), and cytokinins (precursors and bioactive cytokinins) were more abundant in the aboveground shoots derived from glyphosate-treated plants.

CONCLUSION

Based on the overall data, we propose that the glyphosate-induced phenotype resulted from complex interactions involving shoot apical meristem maintenance, hormone biosynthesis and signaling (auxin, cytokinins, gibberellins, and strigolactones), cellular transport, and detoxification mechanisms.

Glyphosate's impact on vegetative growth in leafy spurge identifies molecular processes and hormone cross-talk associated with increased branching

BACKGROUND

Leafy spurge (Euphorbia esula) is a perennial weed that is considered glyphosate tolerant, which is partially attributed to escape through establishment of new vegetative shoots from an abundance of underground adventitious buds. Leafy spurge plants treated with sub-lethal concentrations of foliar-applied glyphosate produce new vegetative shoots with reduced main stem elongation and increased branching. Processes associated with the glyphosate-induced phenotype were determined by RNAseq using aerial shoots derived from crown buds of glyphosate-treated and -untreated plants. Comparison between transcript abundance and accumulation of shikimate or phytohormones (abscisic acid, auxin, cytokinins, and gibberellins) from these same samples was also done to reveal correlations.

RESULTS

Transcriptome assembly and analyses confirmed differential abundance among 12,918 transcripts (FDR ≤ 0.05) and highlighted numerous processes associated with shoot apical meristem maintenance and stem growth, which is consistent with the increased number of actively growing meristems in response to glyphosate. Foliar applied glyphosate increased shikimate abundance in crown buds prior to decapitation of aboveground shoots, which induces growth from these buds, indicating that 5-enolpyruvylshikimate 3-phosphate (EPSPS) the target site of glyphosate was inhibited. However, abundance of shikimate was similar in a subsequent generation of aerial shoots derived from crown buds of treated and untreated plants, suggesting EPSPS is no longer inhibited or abundance of shikimate initially observed in crown buds dissipated over time. Overall, auxins, gibberellins (precursors and catabolites of bioactive gibberellins), and cytokinins (precursors and bioactive cytokinins) were more abundant in the aboveground shoots derived from glyphosate-treated plants.

CONCLUSION

Based on the overall data, we propose that the glyphosate-induced phenotype resulted from complex interactions involving shoot apical meristem maintenance, hormone biosynthesis and signaling (auxin, cytokinins, gibberellins, and strigolactones), cellular transport, and detoxification mechanisms.

Sesquiterpene Lactone Composition of Wild and Cultivated Sunflowers and Biological Activity against an Insect Pest

Sesquiterpene lactones in sunflowers, Helianthus spp., are important to interactions with pathogens, weeds, and insects. Across a broad range of Helianthus annuus, differences in composition of sesquiterpene lactones extracted from disc florets were found between wild and cultivated sunflowers and also between distinct groups of inbreds used to produce sunflower hybrids. Discriminant function analysis showed the presence and relative abundance of argophyllone B, niveusin B, and 15-hydroxy-3-dehydrodesoxyfruticin were usually (75%) effective at classifying wild sunflowers, cultivated inbreds, and hybrids. Argophyllone B reduced the larval mass of the sunflower moth, Homeosoma electellum, by >30%, but only at a dose greater than that found in florets. Low doses of mixed extracts from cultivated florets produced a similar (≈40%) reduction in larval mass, suggesting combinations of sesquiterpene lactones act additively. Although the results support a role for sesquiterpene lactones in herbivore defense of cultivated sunflowers, additional information is needed to use these compounds purposefully in breeding.

Impact of probiotics in women with gestational diabetes mellitus on metabolic health: a randomized controlled trial

OBJECTIVE

Probiotics are live microorganisms that may confer health benefits on the host. Recent trials of probiotic use among healthy pregnant women demonstrate potential for improved glycemic control. The aim of this study was to investigate the effects of a probiotic capsule intervention on maternal metabolic parameters and pregnancy outcome among women with gestational diabetes.

STUDY DESIGN

This double-blind placebo-controlled randomized trial recruited pregnant women with a new diagnosis of gestational diabetes or impaired glucose tolerance following a 3-hour 100-g glucose tolerance test. Women were randomized to a daily probiotic (Lactobacillus salivarius UCC118) or placebo capsule from diagnosis until delivery. Fasting blood samples were collected at baseline and 4-6 weeks after capsule commencement for analysis of glucose, insulin, c-peptide, and lipids. The primary outcome was difference in fasting glucose postintervention, first analyzed on an intention-to-treat basis and followed by per-protocol analysis that excluded women commenced on pharmacological therapy (insulin or metformin). Secondary outcomes were changes in insulin, c-peptide, homeostasis model assessment and lipids, requirement for pharmacological therapy, and neonatal anthropometry.

RESULTS

Of 149 women recruited and randomized, there were no differences between the probiotic and placebo groups in postintervention fasting glucose (4.65 ± 0.49 vs 4.65 ± 0.53 mmol/L; P = 373), requirement for pharmacological therapy (17% vs 14%; P = .643), or birthweight (3.57 ± 0.64 vs 3.60 ± 0.57 kg; P = .845). Among 100 women managed with diet and exercise alone, fasting plasma glucose decreased significantly within both the probiotic (4.76 ± 0.45 to 4.57 ± 0.42 mmol/L; P < .001) and placebo (4.85 ± 0.58 to 4.58 ± 0.45 mmol/L; P < .001) groups, but the levels between groups did not differ (P = .316). The late gestation-related rise in total and low-density lipoprotein (LDL) cholesterol was attenuated in the probiotic vs the placebo group (+0.27 ± 0.48 vs +0.50 ± 0.52 mmol/L total cholesterol, P = .031; +0.08 ± 0.51 vs +0.31 ± 0.45 mmol/L LDL cholesterol, P = .011). No differences were noted between groups in other metabolic parameters or pregnancy outcome.

CONCLUSION

A probiotic capsule intervention among women with abnormal glucose tolerance had no impact on glycemic control. The observed attenuation of the normal pregnancy-induced rise in total and LDL cholesterol following probiotic treatment requires further investigation, particularly in this obstetric group at risk of future metabolic syndrome.

The resemblance and disparity of gene expression in dormant and non-dormant seeds and crown buds of leafy spurge (Euphorbia esula)

BACKGROUND

Leafy spurge (Euphorbia esula L.) is a herbaceous perennial weed and dormancy in both buds and seeds is an important survival mechanism. Bud dormancy in leafy spurge exhibits three well-defined phases of para-, endo- and ecodormancy; however, seed dormancy for leafy spurge is classified as physiological dormancy that requires after-ripening and alternating temperature for maximal germination. Overlaps in transcriptome profiles between different phases of bud and seed dormancy have not been determined. Thus, we compared various phases of dormancy between seeds and buds to identify common genes and molecular processes, which should provide new insights about common regulators of dormancy.

RESULTS

Cluster analysis of expression profiles for 201 selected genes indicated bud and seed samples clustered separately. Direct comparisons between buds and seeds are additionally complicated since seeds incubated at a constant temperature of 20°C for 21 days (21d C) could be considered paradormant (Para) because seeds may be inhibited by endosperm-generated signals, or ecodormant (Eco) because seeds germinate after being subjected to alternating temperature of 20:30°C. Since direct comparisons in gene expression between buds and seeds were problematic, we instead examined commonalities in differentially-expressed genes associated with different phases of dormancy. Comparison between buds and seeds ('Para to Endo buds' and '21d C to 1d C seeds'), using endodormant buds (Endo) and dormant seeds (1d C) as common baselines, identified transcripts associated with cell cycle (HisH4), stress response/transcription factors (ICE2, ERFB4/ABR1), ABA and auxin response (ABA1, ARF1, IAA7, TFL1), carbohydrate/protein degradation (GAPDH_1), and transport (ABCB2). Comparison of transcript abundance for the 'Eco to Endo buds' and '21d C to 1d C seeds' identified transcripts associated with ABA response (ATEM6), auxin response (ARF1), and cell cycle (HisH4). These results indicate that the physiological state of 21d C seeds is more analogous to paradormant buds than that of ecodormant buds.

CONCLUSION

Combined results indicate that common molecular mechanisms associated with dormancy transitions of buds and seeds involve processes associated with ABA and auxin signaling and transport, cell cycle, and AP2/ERF transcription factors or their up-stream regulators.

Obstetric and metabolic implications of excessive gestational weight gain in pregnancy

OBJECTIVE

To compare maternal characteristics, obstetric outcomes and insulin resistance in a cohort of women subdivided into those who did and those who did not exceed the Institute of Medicine (IOM) gestational weight gain guidelines.

METHODS

This is a prospective study of 621 women without diabetes. Concentrations of glucose, insulin and leptin were measured in early pregnancy and at 28 weeks. Ultrasound at 34 weeks assessed fetal anthropometry including abdominal wall width (AAW). At delivery birthweight was recorded and fetal glucose, C-peptide and leptin measured in cord blood. Insulin resistance was calculated using the HOMA equation. Outcomes in those who did and did not exceed IOM guidelines were compared.

RESULTS

Overall, 267 women (43%) exceeded IOM guidelines and 354 (57%) did not. On 34-week ultrasound women with excessive weight gain had higher fetal weights (2681 ± 356 g vs. 2574 ± 331, P = 0.001) and fetal adiposity (AAW) (5.29 ± 1.3 vs. 4.8 ± 1.2, P = 0.001). Infant birthweight and birthweight centiles were also higher in those who exceeded the guidelines. There was no difference between the two groups in maternal insulin resistance in early pregnancy, but by 28 weeks those with excessive weight gain had higher maternal HOMA indices and higher maternal leptin concentrations.

CONCLUSION

Excessive maternal gestational weight gain has significant implications for infant growth and adiposity, with potential implications for later adult health.

Impact of a low glycemic index diet in pregnancy on markers of maternal and fetal metabolism and inflammation

This is a secondary analysis of 621 women in ROLO study, a randomized control trial of low glycemic index (GI) diet in pregnancy to prevent the recurrence of macrosomia, which aims to assess the effect of the diet on maternal and fetal insulin resistance, leptin, and markers of inflammation. In early pregnancy and at 28 weeks, serum was analyzed for insulin, leptin, tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6). At delivery, cord blood concentrations of leptin, TNF-α, IL-6, and C-peptide were recorded. We found no difference between those who did or did not receive low GI advice with respect to the concentrations of any marker in early pregnancy, at 28 weeks or in cord blood. Women in the intervention arm of the study did have a lower overall rise in insulin concentrations from early pregnancy to 28 weeks gestation, P = .04. Of the women in the intervention arm, 20% were in the highest quartile for insulin change (28-week insulin - insulin at booking) compared to 29% of controls (P = .02). In conclusion, a low GI diet in pregnancy has little effect on leptin and markers of inflammation although an attenuated response to the typical increase in insulin resistance seen in pregnancy with advancing gestation was seen in those who received the low GI advice.

Eclampsia: trends in incidence and outcomes over 30 years

OBJECTIVE

This study set out to describe the incidence, mortality rates, and treatment of eclampsia over a 30-year period in a large urban population.

STUDY DESIGN

A detailed report of all pregnancies delivered in the Dublin area from 1977 to 2006 was reviewed for incidence, mortality, and treatment of eclampsia. Almost all pregnancies in this area are managed at one of three major obstetric hospitals. All offer comprehensive antenatal care and operate a restrictive policy to magnesium sulfate prophylaxis, in which MgSO4 is reserved for patients with severe preeclampsia or who have already had an eclamptic seizure.

RESULTS

During the 30-year study period, there were a total of 626,929 deliveries. Of the 247 cases of eclampsia (3.9/10,000 deliveries) and four maternal deaths (0.63/100,000 deliveries) attributed to eclampsia, none received MgSO4. The mortality rate due to eclampsia was 1.6% (4/247). The use of MgSO4 increased significantly from 11% (13/115) in the first decade of the study to 88.1% (67/76) in the last decade (p < 0.001). The incidence of eclampsia decreased from 5.4/10,000 in the first decade to 3.5/10,000 in the final decade of the study (p < 0.0001).

CONCLUSION

Over the study period, MgSO4 has become the leading antiseizure medication used, and this has led to a significant decrease in rates of eclampsia.

The transcriptomes of dormant leafy spurge seeds under alternating temperature are differentially affected by a germination-enhancing pretreatment

Seed dormancy is an important stage in the life cycle of many non-domesticated plants, often characterized by the temporary failure to germinate under conditions that normally favor the process. Pre-treating dormant imbibed seeds at a constant temperate accelerated germination of leafy spurge seeds under alternating temperatures. However, dormant seeds will also germinate without a pre-treatment, albeit at a much slower rate, which gives rise to longer periods of imbibition before germination. Transcriptome analyses on seeds exposed to prolonged imbibition highlighted pathways associated with phenylpropanoid biosynthesis and interacting networks of genes involved in plant defense. In addition to the many pathways associated with phenylpropanoid biosynthesis enriched with down-regulated genes upon germination, there were also numerous pathways enriched with up-regulated genes associated with energy metabolism, such as glycolysis. Transcriptome data further suggest that metabolism and signaling by the plant hormones ethylene, gibberellin, and abscisic acid are involved in the developmental transition from dormancy to germination. More specifically, sub-network enrichment analysis identified ABI3 as a central hub of a sub-network at germination including several down-regulated genes such as DELLA (i.e., RGL2), which represses gibberellin signaling processes required for germination. The 595-fold increase in the expression of ACC oxidase (ACO4) at germination also suggests an important role for ethylene biosynthesis in germinating leafy surge seeds. Furthermore, the 10-578-fold difference in expression of many genes such as HY5 and Histone H3 between two populations at germination, which were treated with and without a constant temperature germination-enhancing pretreatment, revealed disparate impacts on various biosynthetic, growth, signaling, and response processes. Overall, our results indicate a constant temperature pretreatment (20°C for 21d) is not required for germination of leafy spurge seeds at an alternating temperature. However, the presence or absence of the pretreatment does affect the rate of germination and the germination transcriptional programs.

Induction of endodormancy in crown buds of leafy spurge (Euphorbia esula L.) implicates a role for ethylene and cross-talk between photoperiod and temperature

Leafy spurge is a model for studying well-defined phases of dormancy in underground adventitious buds (UABs) of herbaceous perennial weeds, which is a primary factor facilitating their escape from conventional control measures. A 12-week ramp down in both temperature (27 → 10 °C) and photoperiod (16 → 8 h light) is required to induce a transition from para- to endo-dormancy in UABs of leafy spurge. To evaluate the effects of photoperiod and temperature on molecular networks of UABs during this transition, we compared global transcriptome data-sets obtained from leafy spurge exposed to a ramp down in both temperature and photoperiod (RDtp) versus a ramp down in temperature (RDt) alone. Analysis of data-sets indicated that transcript abundance for genes associated with circadian clock, photoperiodism, flowering, and hormone responses (CCA1, COP1, HY5, MAF3, MAX2) preferentially increased in endodormant UABs. Gene-set enrichment analyses also highlighted metabolic pathways involved in endodormancy induction that were associated with ethylene, auxin, flavonoids, and carbohydrate metabolism; whereas, sub-network enrichment analyses identified hubs (CCA1, CO, FRI, miR172A, EINs, DREBs) of molecular networks associated with carbohydrate metabolism, circadian clock, flowering, and stress and hormone responses. These results helped refine existing models for the transition to endodormancy in UABs of leafy spurge, which strengthened the roles of circadian clock associated genes, DREBs, COP1-HY5, carbohydrate metabolism, and involvement of hormones (ABA, ethylene, and strigolactones). We further examined the effects of ethylene by application of 1-aminocyclopropane-1-carboxylate (ACC) to paradormant plants without a ramp down treatment. New vegetative growth from UABs of ACC-treated plants resulted in a dwarfed phenotype that mimicked the growth response in RDtp-induced endodormant UABs. The results of this study provide new insights into dormancy regulation suggesting a short-photoperiod treatment provides an additive cross-talk effect with temperature signals that may impact ethylene's effect on AP2/ERF family members.

Apparent improvement in survival for carcinoma of the cervix following the introduction of chemoradiation--a Will Rogers phenomenon

The improved survival for bulky cervical cancers (> 4cm) reported with combination platinum based chemoradiation (1999) prompted a move away from surgery as these cases frequently received adjuvant radiotherapy and were exposed to the morbidity of multimodality treatment. The period pre-1999 (Group 1) was compared with post-1999 (Group 2) when chemoradiation was the preferred treatment for bulky operable cervical cancer. Significantly more cases were treated surgically among Group 1 compared with Group 2 (79% vs. 62%; P < 0.001). Switching from surgery to radiotherapy improved survival in both treatment categories (73% vs. 78% and 37% vs. 44%, respectively) but with no improvement in overall survival (70%/ov.s 70%). Survival (86%) was similar in both groups among surgically treated women with tumors < 4 cm, but significantly more in Group 2 with negative nodes received postoperative adjuvant chemoradiotherapy (Groups 1 vs. 2; 16% vs.37.5%: P < 0.001) and overall the surgically treated patients received more not less multimodality treatment (46.5% vs. 59%; P = 0.7).

Low glycaemic index diet in pregnancy to prevent macrosomia (ROLO study): randomised control trial

OBJECTIVE

To determine if a low glycaemic index diet in pregnancy could reduce the incidence of macrosomia in an at risk group.

DESIGN

Randomised controlled trial.

SETTING

Maternity hospital in Dublin, Ireland.

PARTICIPANTS

800 women without diabetes, all in their second pregnancy between January 2007 to January 2011, having previously delivered an infant weighing greater than 4 kg.

INTERVENTION

Women were randomised to receive no dietary intervention or start on a low glycaemic index diet from early pregnancy.

MAIN OUTCOMES

The primary outcome measure was difference in birth weight. The secondary outcome measure was difference in gestational weight gain.

RESULTS

No significant difference was seen between the two groups in absolute birth weight, birthweight centile, or ponderal index. Significantly less gestational weight gain occurred in women in the intervention arm (12.2 v 13.7 kg; mean difference -1.3, 95% confidence interval -2.4 to -0.2; P=0.01). The rate of glucose intolerance was also lower in the intervention arm: 21% (67/320) compared with 28% (100/352) of controls had a fasting glucose of 5.1 mmol/L or greater or a 1 hour glucose challenge test result of greater than 7.8 mmol/L (P=0.02).

CONCLUSION

A low glycaemic index diet in pregnancy did not reduce the incidence of large for gestational age infants in a group at risk of fetal macrosomia. It did, however, have a significant positive effect on gestational weight gain and maternal glucose intolerance.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN54392969.

Selection and validation of endogenous reference genes for qRT-PCR analysis in leafy spurge (Euphorbia esula)

Quantitative real-time polymerase chain reaction (qRT-PCR) is the most important tool in measuring levels of gene expression due to its accuracy, specificity, and sensitivity. However, the accuracy of qRT-PCR analysis strongly depends on transcript normalization using stably expressed reference genes. The aim of this study was to find internal reference genes for qRT-PCR analysis in various experimental conditions for seed, adventitious underground bud, and other organs of leafy spurge. Eleven candidate reference genes (BAM4, PU1, TRP-like, FRO1, ORE9, BAM1, SEU, ARF2, KAPP, ZTL, and MPK4) were selected from among 171 genes based on expression stabilities during seed germination and bud growth. The other ten candidate reference genes were selected from three different sources: (1) 3 stably expressed leafy spurge genes (60S, bZIP21, and MD-100) identified from the analyses of leafy spurge microarray data; (2) 3 orthologs of Arabidopsis “general purpose” traditional reference genes (GAPDH_1, GAPDH_2, and UBC); and (3) 4 orthologs of Arabidopsis stably expressed genes (UBC9, SAND, PTB, and F-box) identified from Affymetrix ATH1 whole-genome GeneChip studies. The expression stabilities of these 21 genes were ranked based on the C_T values of 72 samples using four different computation programs including geNorm, Normfinder, BestKeeper, and the comparative ΔC_T method. Our analyses revealed SAND, PTB, ORE9, and ARF2 to be the most appropriate reference genes for accurate normalization of gene expression data. Since SAND and PTB were obtained from 4 orthologs of Arabidopsis, while ORE9 and ARF2 were selected from 171 leafy spurge genes, it was more efficient to identify good reference genes from the orthologs of other plant species that were known to be stably expressed than that of randomly testing endogenous genes. Nevertheless, the two newly identified leafy spurge genes, ORE9 and ARF2, can serve as orthologous candidates in the search for reference genes from other plant species.

Fetal death in twins

OBJECTIVE

To examine the pattern and prospective risk of intrauterine fetal death (IUFD) in twin pregnancy by chorionicity.

DESIGN

Retrospective cohort analysis.

SETTING

Large national tertiary referral center.

POPULATION

All consecutive twin deliveries (1997-2006) ≥24 weeks.

METHODS

Retrospective review of all consecutive twin deliveries over 10 years to identify patterns of IUFD in twins and calculate gestation-specific prospective risks of IUFD. Fetal death was defined as intrauterine demise of a fetus ≥24weeks, intertwin birthweight discordance as ≥20% difference and growth restriction as birthweight <5(th) centile. Chorionicity was confirmed by postnatal placental examination.

MAIN OUTCOME MEASURES

Fetal death.

RESULTS

1094 twin pairs including 276 monochorionic-diamniotic (MCDA) (25.3%) and 818 dichorionic-diamniotic (DCDA) twin pregnancies (74.7%) were studied. Twenty-nine fetal deaths occurred affecting 22 twin pregnancies. The incidence of IUFD (death of one or both fetuses) in MCDA twin pregnancies was three times that in DCDA pregnancies [11/276 (3.9)% vs. 11/818 (1.3%) p<0.001]. The majority of deaths in MCDA twins were associated with twin-twin transfusion syndrome (TTTS) prior to 30 weeks. In normally grown twins the prospective risk of IUFD was similarly low in MCDA and DCDA pregnancies after 34 weeks but in pregnancies complicated by abnormal growth, the prospective risk of IUFD was 3.4 in MCDA and 2.0 in DCDA pregnancies.

CONCLUSION

Twin pregnancies complicated by growth restriction or growth discordance were associated with a high risk of IUFD, particularly in affected MCDA twins. Conversely, in normally grown twins the risk was similarly low in MCDA and DCDA pregnancies after 34 weeks.

Current trends in Irish perinatal mortality

This was a retrospective review of normally formed perinatal deaths among 176,620 births at the National Maternity Hospital (1984-2007). Prelabor stillbirths were categorised by presumed cause of death including unexplained, intrauterine growth retardation (IUGR), placental abruption, red cell alloimmunisation (RCA) and deaths related to prematurity. Peripartum deaths included intrapartum and first week neonatal deaths. The post-mortem rate, initially almost 100%, fell to 60%. Data were analysed using the Mantel-Haenszel chi square test for trends. In the study period there was a significant reduction in the PNM, largely because of a fall in death related to prematurity, term peripartum death, death at 42 weeks or greater, placental abruption, death related to IUGR and RCA (P < 0.01). Overall the unexplained still birth rate was unchanged throughout the study period (p = 0.8) despite a highly significant (p < 0.001) increase in obstetric intervention particularly induction of labor and caesarean section.

Initial changes in the transcriptome of Euphorbia esula seeds induced to germinate with a combination of constant and diurnal alternating temperatures

We investigated transcriptome changes in Euphorbia esula (leafy spurge) seeds with a focus on the effect of constant and diurnal fluctuating temperature on dormancy and germination. Leafy spurge seeds do not germinate when incubated for 21 days at 20 degrees C constant temperatures, but nearly 30% germinate after 21 days under fluctuating temperatures 20:30 degrees C (16:8 h). Incubation at 20 degrees C for 21 days followed by 20:30 degrees C resulted in approximately 63% germination in about 10 days. A cDNA microarray representing approximately 22,000 unique sequences was used to profile transcriptome changes in the first day after transfer of seeds from constant to alternating temperature conditions. Functional classification based on MIPS and gene ontology revealed active metabolism including up-regulation of energy, protein synthesis, and signal transduction processes. Down-regulated processes included translation elongation, translation, and some biosynthetic processes. Subnetwork analysis identified genes involved in abscisic acid, sugar, and circadian clock signaling as key regulators of physiological activity in seeds soon after the transfer to alternating conditions.

Low temperatures impact dormancy status, flowering competence, and transcript profiles in crown buds of leafy spurge

Leafy spurge (Euphorbia esula) is an herbaceous perennial weed that produces vegetatively from an abundance of underground adventitious buds. In this study, we report the effects of different environmental conditions on vegetative production and flowering competence, and determine molecular mechanisms associated with dormancy transitions under controlled conditions. Reduction in temperature (27-10 degrees C) and photoperiod (16-8 h) over a 3-month period induced a para- to endo-dormant transition in crown buds. An additional 11 weeks of cold (5-7 degrees C) and short-photoperiod resulted in accelerated shoot growth from crown buds, and 99% floral competence when plants were returned to growth-promoting conditions. Exposure of paradormant plants to short-photoperiod and prolonged cold treatment alone had minimal affect on growth potential and resulted in ~1% flowering. Likewise, endodormant crown buds without prolonged cold treatment displayed delayed shoot growth and ~2% flowering when returned to growth-promoting conditions. Transcriptome analysis revealed that 373 and 260 genes were differentially expressed (P < 0.005) during para- to endo-dormant and endo- to eco-dormant transitions, respectively. Transcripts from flower competent vs. non-flower competent crown buds identified 607 differentially expressed genes. Further, sub-network analysis identified expression targets and binding partners associated with circadian clock, dehydration/cold signaling, phosphorylation cascades, and response to abscisic acid, ethylene, gibberellic acid, and jasmonic acid, suggesting these central regulators affect well-defined phases of dormancy and flowering. Potential genetic pathways associated with these dormancy transitions and flowering were used to develop a proposed conceptual model.

Cerebral palsy following neonatal hypoxic seizures in singleton term infants: the influence of parity

This was a retrospective review of term singleton neonates (> 37 weeks) with early onset seizures, with and without encephalopathy, from 1989 through 2000. Our aim was to examine the relationship between antepartum and intrapartum obstetric events, neonatal hypoxic seizures and subsequent neurological impairment of 77,838 infants, the incidence of seizures was significantly higher among primiparas (2.4/1000; 67/31,729) compared with multiparas (0.35/1000; 16/46,109)(p < 0.001). Compared with multiparas, seizures with encephalopathy occurred more frequently among primiparas (0.8/1000; 26/31,729) vs. multiparas (0.2/1000; 8/46,109), were more commonly associated with unexplained intrapartum hypoxia (0.6/1000, n = 20 vs.0.04/ 1000, n = 2) and the incidence of cerebral palsy, 45% (9/20) vs. 0% (0/2) was significantly higher(p < 0.001). Seizures with encephalopathy (0.2/1000 vs.0.13/1000) and cerebral palsy (33%) had a similar incidence in primiparas and multiparas following a sentinel event. Neonatal seizures with encephalopathy, related to intrapartum events, were 4 times more common following first delivery and associated with a 9 fold higher incidence of cerebral palsy, implicating primiparous labor in the development of cerebral palsy.

Recurrence of fetal macrosomia in non-diabetic pregnancies

Fetal macrosomia (birth weight >/=4,500 g) is known to increase a number of adverse maternal and perinatal outcomes. Although there is a clear association between maternal diabetes mellitus and fetal macrosomia, the majority of macrosomic infants are born to non-diabetic mothers. We wished to determine the recurrence rate of macrosomia in non-diabetic pregnancy and to see if a history of multiple prior macrosomic infants confers additional risk. A retrospective analysis of 14,461 term, singleton, infants born to non-diabetic mothers in 1997 and 1998 was performed, using a computerised hospital database. Among 14,461 term pregnancies, 529 infants (3.7%) were macrosomic, and the incidence was significantly higher in parous women (4.6%) compared with nulliparas (2.4%, p < 0.0001). Over the next 5 years, 164 of these women returned for another delivery. Women with a history of one macrosomic infant are at significantly increased risk of another macrosomic infant in a subsequent pregnancy (OR 15.8, 95% CI 11.45 - 21.91, p < 0.0001). For women with two or more macrosomic infants, the risk is even greater (OR 47.4, 95% CI 19.9 - 112.89, p < 0.0001). Macrosomia was associated with increased rates of instrumental delivery and anal sphincter injury regardless of parity, and additionally with increased rates of caesarean delivery and shoulder dystocia among nulliparas. Overall, 88% of women who laboured with a macrosomic infant achieved vaginal delivery.

Correlation of perineal outcome at first and second vaginal deliveries

Perineal outcome in 1000 consecutive term non instrumental second vaginal deliveries was correlated with first delivery method and perineal outcome. Our aim was to determine the relationship between perineal outcome at first and second vaginal deliveries. Overall 75% of first non instrumental vaginal deliveries required sutures. Sutures were required at second delivery in 12% (24 of 199) of cases not sutured at first delivery compared with 60.4% (485 of 801) of those sutured. The rate of second perineal repair correlated with method of first delivery and perineal outcome, instrumental delivery--66.2% (145 of 219), first episiotomy-68.4% (238 of 348) and first sutured tear--43.6% (102 of 234). The incidence of third /fourth degree tear at first delivery was 1.3% (13/1000) (one recurred at second forceps delivery), compared with 0.6% at second delivery. First delivery outcome should be considered when conducting a second delivery as sixty per cent of women require perineal repair following repair at first delivery.

Trends in intrapartum fetal death, 1979-2003

OBJECTIVES

This study was undertaken to analyze trends in intrapartum fetal death and rates of perinatal autopsy over a 25-year period in Dublin, Ireland.

STUDY DESIGN

A retrospective multicenter analysis of 508,342 nonanomalous infants 500 g or more, delivering in 3 tertiary-referral university institutions between 1979-2003.

RESULTS

There has been a significant downward trend in the rate of intrapartum fetal death over the past 25 years (P < .0001). Nulliparous labors were statistically more likely to be complicated by an intrapartum fetal demise than parous labors (odds ratio, 1.49; 95% confidence interval [CI], 1.16-1.92; P = .0018). Intrapartum deaths secondary to hypoxia fell significantly over the study period (P < .0001). Infants of multiple gestations were twice as likely to die in labor as singletons (odds ratio, 2.2; 95% CI, 1.22-3.74; P = .0058). Rates of perinatal autopsy fell significantly over the 25 years studied (P < .0001).

CONCLUSION

There has been a significant fall in rates of intrapartum fetal death. This has primarily resulted from a reduction in deaths attributable to intrapartum hypoxia. Infants of multiple gestations still retain a significantly higher chance of intrapartum death. The fall in uptake rates of perinatal autopsy in recent years is concerning.

Epistatic interactions of three loci regulate flowering time under short and long daylengths in a backcross population of rice

The short-day plant rice varies greatly in photoperiod sensitivity (PS) for flowering. The hybrid F(1) from a cross between the day-neutral pure line EM93-1 and the weedy rice accession SS18-2 had stronger PS than SS18-2. Some BC(1) (EM93-1/F(1)) segregates were even more sensitive to photoperiod than the F(1), as indicated by later flowering or no flowering after 250 days under a 14-h long daylength. A genome-wide scan identified the quantitative trait loci Se (7.1), Se (7.2) and Se (8) for PS from the BC(1) population, with all alleles that inhibit flowering derived from SS18-2. These three loci regulate the time of flowering under long daylength through their main effects, and di- and trigenic epistases. Under a 10-h short daylength, the regulation is through Se (7.1) and Se (8) main effects and digenic epistases involving all three loci. The short daylength not only nullified the main effect of Se (7.2), but also changed its epistatic effects from inhibiting flowering under long daylength to promoting flowering. The epistases indicate that genes underlying the three PS loci work in the same pathway for the control of flowering. Many non-flowered BC(1)s were the trigenic heterozygote; this suggests that the three PS loci are also involved in genetic control of critical daylength.

Unexplained Prelabor Uterine Rupture in a Term Primigravida

BACKGROUND

Uterine rupture is a catastrophic obstetric complication. The main risk factor is a scarred uterus, usually secondary to a previous cesarean delivery. Uterine rupture in a primigravid woman is a very rare event.

CASE

A 33-year-old primigravida presented at term with severe abdominal pain, signs of hemodynamic instability, and fetal bradycardia. She was not in labor, and the fetal heart tones disappeared before a cesarean could be performed. After a failed attempt at induction, exploratory laparotomy was performed for worsening maternal hemodynamic status. A complete rupture of the posterior uterine wall was found with a well-grown fetus free in the abdominal cavity. The uterus was repaired in two layers, and the patient did well postoperatively.

CONCLUSION

We report the rare occurrence of a spontaneous uterine rupture in a nonlaboring primigravid with no known risk factors. The differential diagnosis of this presentation includes concealed placental abruption, subhepatic hematoma with or without liver rupture, splenic rupture, rupture of the broad ligament, and rupture of a uterine vein. Although uterine rupture occurs more commonly in the multiparous population, it cannot be assumed that the primigravid uterus is immune to rupture.

Isolation of three dormancy QTLs as Mendelian factors in rice

Seed dormancy is a key adaptive trait under polygenic control in many plants. We introduced the chromosomal regions containing the dormancy QTLs qSD1, qSD7-1, and qSD12 from an accession of weedy rice into a nondormant genetic background to examine component genetic effects and their interactions with time of afterripening (DAR). A BC4F2 plant, which was heterozygous for the three loci, was selected to develop the BC4F3 population. Single point analysis detected only qSD7-1 and qSD12 (R2 = 38-72%) at 10, 30, and 50 DAR in the population. However, multiple linear regression analysis detected genetic effects of the three QTLs and their trigenic epistasis, an environmental effect of DAR (E), and interactions of E with qSD12 and with the qSD1 x qSD7-1 and qSD7-1 x qSD12 epistases. The linear model demonstrates that QTL main effects varied with DAR, and that some epistasis or epistasis-by-DAR interactions partially counteract the main effects. The three QTLs were isolated as single Mendelian factors from the BC4F3 population and estimated for component genic effects based on the BC4F4 populations. Isolation improved estimation of the qSD1 effect and confirmed the major effect of qSD12. The qSD1 and qSD12 loci displayed a gene-additive effect. The qSD7-1, which was further narrowed to a chromosomal region encompassing the red pericarp color gene Rc, displayed gene additive and dominant effects.

Outcome of Second Delivery After Prior Macrosomic Infant in Women With Normal Glucose Tolerance

OBJECTIVE

Our aim was to estimate the obstetric outcome of second delivery in women with normal glucose tolerance whose first fetus was macrosomic (fetal weight >/= 4,500 g).

METHODS

Primiparas delivering a macrosomic infant during the years 1997-2000 were identified from a hospital computer database, and the obstetric outcome of a second delivery was analyzed up until June 2003. A control group (birth weight 3,000-3,500 g) served for comparison.

RESULTS

Among 13,020 first pregnancies, 301 (2.3%) were macrosomic. A similar proportion in the macrosomic group, 156 of 301 (52%), and control group, 171 of 300 (57%), returned for second delivery (P = .252). Compared with controls, first macrosomic deliveries were characterized by higher rates of operative delivery, anal sphincter injury, and shoulder dystocia. At second delivery, 32% of neonates in the macrosomic group and 0.3% in the control group weighed 4,500 g or more (P < .001). More prelabor cesareans were performed in the macrosomic group compared with controls (27 of 156, 17.3%, compared with 8 of 171, 4.7%; P < .001). Among 104 women in the macrosomic group who labored after first vaginal delivery, 99% (103 of 104) delivered vaginally again compared with 44% (11 of 25) who labored after primiparous cesarean delivery (P < .001), which compares with 97% (146 of 150) and 77% (10 of 13), respectively, in the control group.

CONCLUSION

Despite a one-third recurrence of macrosomia, first vaginal delivery of a macrosomic infant was associated with a high incidence of second vaginal delivery. Conversely, primiparous macrosomic cesarean delivery conveyed a high risk (56%) for repeat intrapartum cesarean whether macrosomia recurred or not.

LEVEL OF EVIDENCE

II-2.

Dormancy genes from weedy rice respond divergently to seed development environments

Genes interacting with seed developmental environments control primary dormancy. To understand how a multigenic system evolved to adapt to the changing environments in weedy rice, we evaluated genetic components of three dormancy QTL in a synchronized nondormant genetic background. Two genetically identical populations segregating for qSD1, qSD7-1, and qSD12 were grown under greenhouse and natural conditions differing in temperature, relative humidity, and light intensity during seed development. Low temperatures tended to enhance dormancy in both conditions. However, genotypes responded to the environments divergently so that two populations displayed similar distributions for germination. Additive and/or dominance effects of the three loci explained approximately 90% of genetic variances and their epistases accounted for the remainder in each environment. The qSD1 and qSD7-1 main effects were increased, while the qSD12 additive effect was decreased by relatively low temperatures. Both gene main and epistatic effects were involved in G x E interactions, which in magnitude were greater than environmental main effect. The divergent responses of dormancy genes observed in this simple multigenic system presumably have selective advantages in natural populations adapted to changing environments and hence represent a genetic mechanism stabilizing the dormancy level of weedy rice ripened in different seasons or temperature regimes.

Phenotypic selection for dormancy introduced a set of adaptive haplotypes from weedy into cultivated rice

Association of seed dormancy with shattering, awn, and black hull and red pericarp colors enhances survival of wild and weedy species, but challenges the use of dormancy genes in breeding varieties resistant to preharvest sprouting. A phenotypic selection and recurrent backcrossing technique was used to introduce dormancy genes from a wild-like weedy rice to a breeding line to determine their effects and linkage with the other traits. Five generations of phenotypic selection alone for low germination extremes simultaneously retained dormancy alleles at five independent QTL, including qSD12 (R(2) > 50%), as determined by genome-wide scanning for their main and/or epistatic effects in two BC(4)F(2) populations. Four dormancy loci with moderate to small effects colocated with QTL/genes for one to three of the associated traits. Multilocus response to the selection suggests that these dormancy genes are cumulative in effect, as well as networked by epistases, and that the network may have played a "sheltering" role in maintaining intact adaptive haplotypes during the evolution of weeds. Tight linkage may prevent the dormancy genes from being used in breeding programs. The major effect of qSD12 makes it an ideal target for map-based cloning and the best candidate for imparting resistance to preharvest sprouting.

A set of three genes regulates photoperiodic responses of flowering in rice (Oryza sativa)

Differentiation in photoperiodic response of flowering has been key to the evolution and wide geographic distribution of rice, an essentially short-day plant. Crosses were made such that the hybrid F1 plants flower later than the late-flowering parents to investigate the genetic basis underlying this differentiation. From initial experiments, three major genes for flowering time were identified from four naturally occurring variants under natural long-day conditions. An F2-derived trigenic mutant line bred-true for a day-neutral response was selected and used as the recipient to synchronize the genetic background for the major genes. Experiments conducted under various daylengths indicated that these genes are responsible for photoperiodic sensitivity and the trihybrid has a critical daylength between 13.5 and 14 h. The three genes regulate photoperiodic responses qualitatively and quantitatively through complementary and other epistatic effects, respectively. The complementation suggests that the three genes act in a linear manner to repress the transition from the vegetative to reproductive phases under long daylengths. This set of genes also provides a model to understand the genetic mechanism underlying the elongated vegetative growth period in the F1 generation, which is usually an obstacle to the use of heterosis, and the selection for early maturation in rice breeding.

Genetic analysis of adaptive syndromes interrelated with seed dormancy in weedy rice (Oryza sativa)

Seed dormancy in rice interrelates to the weedy characteristics shattering, awn, black hull color, and red pericarp color. A cross between the weedy strain SS18-2 and the breeding line EM93-1 was developed to investigate the genetic basis and adaptive significance of these interrelationships. These characteristics or their components differed in average degree of dominance from -0.8 to 1.5, in heritability from 0.5 to 0.96, and in their contribution to phenotypic or genotypic variation in dormancy by up to 25%. Five dormancy, four shattering, and three awn-length quantitative trait loci (QTLs) were detected in the BC1 population replicated in 2 years. Two QTLs for hull color were identified, and the SS18-2-derived and EM93-1-derived alleles increased the intensity of black, and red or yellow pigmentations, respectively. The only QTL for pericarp color co-located with the red pericarp gene Rc, with the SS18-2-derived allele increasing the intensity of black and red pigmentations. Four of the five dormancy QTLs were flanked or bracketed by one to four QTLs for the interrelated characteristics. The QTL organization pattern indicates the central role of seed dormancy in adaptive syndromes for non-domesticated plants, implies that the elimination of dormancy from cultivars could arise from the selections against multiple interrelated characteristics, and challenges the use of dormancy genes at these loci in breeding varieties for resistance to pre-harvest sprouting (PHS). However, another QTL (qSD12) provides candidate gene(s) for PHS resistance because it has a large effect in the population and it is independent of the loci for interrelated characteristics.

Term neonatal asphyxial seizures and peripartum deaths: lack of correlation with a rising cesarean delivery rate

OBJECTIVE

The purpose of this analysis was to study the relationship between an increasing cesarean delivery rate and term neonatal seizures and peripartum deaths.

STUDY DESIGN

This was a retrospective analysis of annually collated institutional data on cesarean delivery and perinatal outcome.

RESULTS

Of 77,350 women who delivered at 37 weeks' gestation or more through 12 years (1989 to 2000), the cesarean rate increased from 6.9% to 15.1%; perinatal mortality at term, average 3.1/1000, was unchanged. The cesarean rate for nulliparas doubled from 8.3% to 17.5%. The overall neonatal term seizure rate (overall 1.3/1000; and for nulliparas 2.5/1000) did not change. The overall peripartum death rate (0.8/1000) was unchanged, although the rate for nulliparas (1.5/1000) showed a significant decline. Overall seizure rate in nulliparas was 5-fold higher than in multiparas; presumed intrapartum asphyxia was associated with 84% of both seizures and neonatal deaths in nulliparas. Among 2547 prelabor cesarean deliveries, there were no peripartum deaths and one neonatal seizure, an incidence comparable with that in multiparas who labored.

CONCLUSION

Despite a greater than 2-fold rise in cesarean section rate, the seizure rate and overall peripartum death rate at term did not alter significantly. Neonatal seizures occurred 5 times more often following first deliveries.

Multiple loci and epistases control genetic variation for seed dormancy in weedy rice (Oryza sativa)

Weedy rice has much stronger seed dormancy than cultivated rice. A wild-like weedy strain SS18-2 was selected to investigate the genetic architecture underlying seed dormancy, a critical adaptive trait in plants. A framework genetic map covering the rice genome was constructed on the basis of 156 BC(1) [EM93-1 (nondormant breeding line)//EM93-1/SS18-2] individuals. The mapping population was replicated using a split-tiller technique to control and better estimate the environmental variation. Dormancy was determined by germination of seeds after 1, 11, and 21 days of after-ripening (DAR). Six dormancy QTL, designated as qSD(S)-4, -6, -7-1, -7-2, -8, and -12, were identified. The locus qSD(S)-7-1 was tightly linked to the red pericarp color gene Rc. A QTL x DAR interaction was detected for qSD(S)-12, the locus with the largest main effect at 1, 11, and 21 DAR (R(2) = 0.14, 0.24, and 0.20, respectively). Two, three, and four orders of epistases were detected with four, six, and six QTL, respectively. The higher-order epistases strongly suggest the presence of genetically complex networks in the regulation of variation for seed dormancy in natural populations and make it critical to select for a favorable combination of alleles at multiple loci in positional cloning of a target dormancy gene.