Isolation and characterization of CCoAOMT in interspecific hybrid of Acacia auriculiformis x Acacia mangium--a key gene in lignin biosynthesis.

This study was directed at the understanding of the function of CCoAOMT isolated from Acacia auriculiformis x Acacia mangium. Full length cDNA of the Acacia hybrid CCoAOMT (AhCCoAOMT) was 1024-bp long, containing 750-bp coding regions, with one major open reading frame of 249 amino acids. On the other hand, full length genomic sequence of the CCoAOMT (AhgflCCoAOMT) was 2548 bp long, containing three introns and four exons with a 5' untranslated region (5'UTR) of 391 bp in length. The 5'UTR of the characterized CCoAOMT gene contains various regulatory elements. Southern analysis revealed that the Acacia hybrid has more than three copies of the CCoAOMT gene. Real-time PCR showed that this gene was expressed in root, inner bark, leaf, flower and seed pod of the Acacia hybrid. Downregulation of the homologous CCoAOMT gene in tobacco by antisense (AS) and intron-containing hairpin (IHP) constructs containing partial AhCCoAOMT led to reduction in lignin content. Expression of the CCoAOMT in AS line (pART-HAS78-03) and IHP line (pART-HIHP78-06) was reduced respectively by 37 and 75% compared to the control, resulting in a decrease in the estimated lignin content by 24 and 56%, respectively. AhCCoAOMT was found to have altered not only S and G units but also total lignin content, which is of economic value to the pulp industry. Subsequent polymorphism analysis of this gene across eight different genetic backgrounds each of A. mangium and A. auriculiformis revealed 47 single nucleotide polymorphisms (SNPs) in A. auriculiformis CCoAOMT and 30 SNPs in A. mangium CCoAOMT.

Hypertension, fetal growth restriction and obstructive sleep apnoea in pregnancy.

OBJECTIVE: To test the hypothesis that obstructive sleep apnoea (OSA) is more common in pregnancies complicated by hypertensive disease and fetal growth restriction. STUDY DESIGN: An observational study comparing pregnant women with these two complications with normal pregnant women and non-pregnant women in two UK maternity hospitals. Each participant completed a sleep apnoea questionnaire and underwent nocturnal oxygen saturation monitoring. RESULTS: Using a strict definition of obstructive sleep apnoea confirmed by oxygen saturation monitoring only two mild cases were seen, 0/50 non-pregnant women, 1/69 of normal pregnant women, 0/48 women with various types of hypertensive disease, and 1/33 women carrying fetuses affected with fetal growth restriction. Even using less strict definitions and self-reported sleepiness scores there was no relation between sleep apnoea and either fetal growth restriction or hypertensive diseases. CONCLUSION: Obstructive sleep apnoea is at most a rare cause of either growth restriction or hypertensive disease in pregnancy.

Does initial routine use of a compression garment reduce the risk of lower limb lymphedema after gynecological cancer treatment? A randomized pilot study in an Asian institution and review of the literature.

This is a randomized pilot study evaluating the effectiveness of customized compression garments (CG) in reducing the risk of lower limb lymphedema (LLL) in gynecological cancer patients. Patients who completed pelvic node dissection or radiation were routinely educated on reducing the risk of LLL by good skin care and manual lymphatic massage. After baseline lower limb volume perometry and clinical assessment, they were randomized to customized compression garment (CG) for 6 weeks (26 patients) or observation (30 patients). Both groups were followed up for 2 years and the primary outcome was the development of LLL. LLL incidence in the control group was 13.3% (4 of 30 patients) compared to 7.7% (2 of 26 patients) in the CG group. However the difference was not statistically significant (P=0.496). In the control group, 10.7% (3/28) who underwent node dissection developed LLL vs 7.7% (2/26) in the CG group. Among patients with node dissection plus radiation, LLL incidence was 14.3% (1/7) in the control group vs 12.5% (1/8) in the CG group. The mean onset of LLL was 12 months; compliance to CG wearing was high and QOL scores were similar in both groups. Customized low-compression CG worn for 6 weeks may have a possible benefit in reducing the risk of LLL when added to patient education on risk reduction although statistic significance was not achieved in this small pilot study. A larger multi-center study would be justified to expand these findings.

Morphometric evidence that villous development and fetoplacental angiogenesis are compromised by intrauterine growth restriction but not by pre-eclampsia.

The aim of this study was to compare morphometric measures of villous development, villous capillarization, fetoplacental angiogenesis and capillary lumen remodelling in normal pregnancies with those complicated by intrauterine growth restriction (IUGR) with and without preeclampsia (PE). To this end, term placentas from control pregnancies (n = 9) and cases of IUGR alone (n = 5), PE alone (n = 5) and IUGR with PE (n = 5) provided random samples of tissue. These were fixed in formalin and Masson trichrome-stained wax sections were analysed stereologically. Overall growth of peripheral villi and fetal capillaries was assessed by estimating total volumes, surface areas and lengths. Villous capillarization was monitored using volume, surface and length densities and capillary:villus surface and length ratios. Measures of villous maturation and capillary lumen remodelling comprised mean cross-sectional areas, perimeters and shapes (perimeter(2)/area). Between-group comparisons were drawn using two-way analysis of variance. IUGR was associated with abnormal growth of villi and fetal capillaries. Reduced villous growth was not accompanied by changes in measures of villous capillarization or maturation and reduced capillary growth was not accompanied by changes in lumen calibre or shape. In contrast, PE was not associated with any main or interaction effects on placental morphometry. It is concluded that IUGR, but not PE, is associated with impoverished villous development and fetoplacental angiogenesis. The latter is due to production of fewer and/or shorter capillary segments (rather than a decrease in capillary calibre), does not affect villous capillarization and is not accompanied by luminal remodelling.

Stereological investigation of placental morphology in pregnancies complicated by pre-eclampsia with and without intrauterine growth restriction.

The aim of this study was to quantify placental morphology in pregnancies complicated by pre-eclampsia with and without intrauterine growth restriction. Particular attention is given to the dimensions and composition of peripheral (intermediate+terminal) villi. Placentae from 9 control pregnancies, 5 cases of pre-eclampsia, 5 cases of intrauterine growth restriction and 5 cases of pre-eclampsia with intrauterine growth restriction were randomly sampled for location and position. Formalin-fixed, wax-embedded sections stained by the Masson trichrome method were subjected to stereological analysis in order to quantify the volumes of placental components and the surfaces and derived diameters for peripheral villi and fetal capillaries. Group comparisons were drawn using two-way analysis of variance. Fetal weights were reduced in all complicated pregnancies but only intrauterine growth restriction was accompanied by a significantly smaller placenta. Pre-eclampsia was not associated with main effects on placental morphology and (except for trophoblast thickness) there were no interaction effects involving pre-eclampsia. In contrast, intrauterine growth restriction was associated with a placenta which had reduced volumes of intervillous space and all types of villi (stem, intermediate, terminal). The impoverished growth of peripheral villi affected all tissues (trophoblast, stroma, capillaries) and was accompanied by smaller exchange surface areas and a thicker trophoblastic epithelium. The derived mean diameters of villi and capillaries were not affected. It is concluded that intrauterine growth restriction, but not pre-eclampsia, is associated with substantial changes in placental morphology including impoverished growth of villi and fetal vasculature. These changes are likely to reduce placental oxygen diffusive conductances and contribute to fetal hypoxic stress.

Functional magnetic resonance imaging (magnetization transfer) and stereological analysis of human placentae in normal pregnancy and in pre-eclampsia and intrauterine growth restriction.

Magnetic resonance imaging provides a non-invasive method for investigating functional changes in the human placenta in vivo. In this study, we combine a magnetic resonance imaging technique called magnetization transfer with established stereological methods in order to analyse and compare placentae from normal (16-36 weeks of gestation) and complicated (pre-eclampsia, intrauterine growth restriction) pregnancies. Magnetization transfer provided an in vivo measure of the ratio of bound protons:total protons and stereological analysis of histological sections was used to estimate a residual:total volume ratio (the ratio of non-vascular volume to total placental volume). Statistical comparisons were drawn using tests for related samples (longitudinal data) or one-way analysis of variance (cross-sectional data). We found no significant differences in magnetization transfer between gestational age groups or between uncomplicated pregnancies and pregnancies complicated by pre-eclampsia or intrauterine growth restriction. In comparable groups of different subjects, stereological analyses also failed to demonstrate significant differences in residual:total volume ratios. We conclude that [a] the ratio of non-vascular volume:total placental volume does not alter between 16 and 36 weeks of normal gestation, and [b] this integrated response is also conserved in pre-eclampsia and intrauterine growth restriction.

Prognosis in isolated gastroschisis with bowel dilatation: a systematic review.

OBJECTIVES: To investigate prognosis of the fetus with isolated gastroschisis and bowel dilatation from a systematic review of the literature. We aimed to compare the incidence of (a) intrauterine death, (b) death within 4 weeks of delivery, (c) bowel resection, (d) length of time to oral feeds and (e) time as inpatient in fetuses with gastroschisis with and without evidence of bowel dilatation. METHODS: Literature was identified by searching two bibliographical databases between 1980 and 2007. Studies were assessed for quality and stratified according to the definition of bowel dilatation. The data extracted were inspected for clinical and methodological heterogeneity. RESULTS: The search strategy yielded 1335 potentially relevant citations. Full manuscripts were retrieved for 92 citations. 10 studies (273 patients) were finally included in the systematic review. No difference was found between groups for death within 4 weeks of delivery (OR = 0.62 (95% CI 0.11 to 3.32); heterogeneity p = 0.39) or bowel resection (OR = 3.35 (95% CI 0.82 to 13.74); heterogeneity p = 0.39). There were insufficient data to compare the risk of intrauterine death and length of time to oral feeds. The mean inpatient stay was not significantly different between groups (OR = 16.63 (95% CI 0.98 to 32.28); heterogeneity p = 0.23). CONCLUSION: Current available evidence suggests that fetuses with isolated gastroschisis and bowel dilatation are not at increased risk of adverse perinatal outcome compared to those without bowel dilatation. However, there is a paucity of studies, and a randomised controlled trial is urgently needed.

No correlation between ultrasound placental grading at 31-34 weeks of gestation and a surrogate estimate of organ function at term obtained by stereological analysis.

We test the experimental hypothesis that early changes in the ultrasound appearance of the placenta reflect poor or reduced placental function. The sonographic (Grannum) grade of placental maturity was compared to placental function as expressed by the morphometric oxygen diffusive conductance of the villous membrane. Ultrasonography was used to assess the Grannum grade of 32 placentas at 31-34 weeks of gestation. Indications for the scans included a history of previous fetal abnormalities, previous fetal growth problems or suspicion of IUGR. Placentas were classified from grade 0 (most immature) to grade III (most mature). We did not exclude smokers or complicated pregnancies as we aimed to correlate the early appearance of mature placentas with placental function. After delivery, microscopical fields on formalin-fixed, trichrome-stained histological sections of each placenta were obtained by multistage systematic uniform random sampling. Using design-based stereological methods, the exchange surface areas of peripheral (terminal and intermediate) villi and their fetal capillaries and the arithmetic and harmonic mean thicknesses of the villous membrane (maternal surface of villous trophoblast to adluminal surface of vascular endothelium) were estimated. An index of the variability in thickness of this membrane, and an estimate of its oxygen diffusive conductance, were derived secondarily as were estimates of the mean diameters and total lengths of villi and fetal capillaries. Group comparisons were drawn using analysis of variance. We found no significant differences in placental volume or composition or in the dimensions or diffusive conductances of the villous membrane. Subsequent exclusion of smokers did not alter these main findings. Grannum grades at 31-34 weeks of gestation appear not to provide reliable predictors of the functional capacity of the term placenta as expressed by the surrogate measure, morphometric diffusive conductance.

Prognosis for the co-twin following single-twin death: a systematic review.

BACKGROUND: Following single-twin death, the perinatal mortality and morbidity for the surviving co-twin is increased but difficult to quantify. We present data on prognosis from a systematic review. OBJECTIVES: We aimed to determine the incidence of a) co-twin death, b) neurological abnormality and c) preterm delivery for the surviving co-twin following single-twin death after 14 weeks of gestation. SEARCH STRATEGY: Literature was identified by searching two bibliographical databases and specialist journals between 1990 and 2005. SELECTION CRITERIA: The selected studies of > or = 5 cases reported on perinatal death and/or neurodevelopmental delay of the surviving co-twin. DATA COLLECTION AND ANALYSIS: Studies were assessed for quality and data extracted to allow computation of rates. The data were inspected for heterogeneity using a Forrest plot and examined statistically using the chi-square test. Data from individual studies were pooled within subgroups defined by prognosis. MAIN RESULTS: The search strategy yielded 632 potentially relevant citations. Full manuscripts were retrieved for 54 citations and 28 studies were finally included in the review. Following the death of one twin, the risk of monochorionic and dichorionic co-twin demise was 12% (95% CI 7-11) and 4% (95% CI 2-7), respectively. The risk of neurological abnormality in the surviving monochorionic and dichorionic co-twin was 18% (95% CI 11-26) and 1% (95% CI 0-7), respectively. The risk of preterm delivery was 68% (95% CI 56-78) and 57% (95% CI 34-77), respectively. Where there was comparative data within studies, the odds of monochorionic co-twin intrauterine death was six times that of dichorionic twins (OR 6.04 [95% CI 1.84-19.87]). Neurological abnormality was also higher in monochorionic compared with dichorionic pregnancies (OR 4.07 [95% CI 1.32-12.51]). AUTHOR'S CONCLUSIONS: More prospective research is required to inform decision making on this subject, especially with data that allow stratification based upon chorionicity.

Laser ablation of foetal microcystic lung lesion: successful outcome and rationale for its use.

OBJECTIVE: A foetus with an echodense, microcystic lung lesion complicated by non-immune hydrops has a high mortality rate. Because of the limited treatment options available, laser ablation was offered in an attempt to reduce the size of the lesion and reduce hydrops fetalis. METHODS AND RESULTS: A 25-year-old nulliparous woman presented at 21 weeks gestation. Ultrasound revealed a male foetus with a large microcystic right sided lung lesion that completely occupied the right hemithorax causing marked mediastinal deviation. The foetus was hydropic with polyhydramnios. Percutaneous laser ablation of the large microcystic lung lesion was performed under direct ultrasound control. At a power setting of 45 W, and using a 400 microm Nd:YAG laser fibre, the core of the lesion was photocoagulated in pulses lasting 5 s at 5 s intervals. The total target dose was 1683 J. This led to a marked but temporary reduction in amniotic fluid volume. The patient was commenced on sulindac and amniodrainage was performed at 27 weeks as reaccumulation of the polyhydramnios occurred. Pre-eclampsia complicated the pregnancy at 38 weeks gestation and an emergency caesarean section was performed. The baby underwent a thoracotomy and lobectomy at 48 h of age, made a good recovery, and is currently well 8 weeks post-delivery. CONCLUSIONS: In cases of cystic lung lesion complicated by hydrops, laser ablation should be considered as a treatment option.