Dosimetric Evaluation and Reproducibility of Breath-hold Plans in Intensity Modulated Proton Therapy: An Initial Clinical Experience.

Purpose: Breath-hold (BH) technique can mitigate target motion, minimize target margins, reduce normal tissue doses, and lower the effect of interplay effects with intensity-modulated proton therapy (IMPT). This study presents dosimetric comparisons between BH and nonbreath-hold (non-BH) IMPT plans and investigates the reproducibility of BH plans using frequent quality assurance (QA) computed tomography scans (CT). Methods and Materials: Data from 77 consecutive patients with liver (n = 32), mediastinal/lung (n = 21), nonliver upper abdomen (n = 20), and malignancies in the gastroesophageal junction (n = 4), that were treated with a BH spirometry system (SDX) were evaluated. All patients underwent both BH CT and 4-dimensional CT simulations. Clinically acceptable BH and non-BH plans were generated on each scan, and dose-volume histograms of the 2 plans were compared. Reproducibility of the BH plans for 30 consecutive patients was assessed using 1 to 3 QA CTs per patient and variations in dose-volume histograms for deformed target and organs at risk (OARs) volumes were compared with the initial CT plan. Results: Use of BH scans reduced initial and boost target volumes to 72% ± 20% and 70% ± 17% of non-BH volumes, respectively. Additionally, mean dose to liver, stomach, kidney, esophagus, heart, and lung V20 were each reduced to 71% to 79% with the BH technique. Similarly, small and large bowels, heart, and spinal cord maximum doses were each lowered to 68% to 84%. Analysis of 62 QA CT scans demonstrated that mean target and OAR doses using BH scans were reproducible to within 5% of their nominal plan values. Conclusions: The BH technique reduces the irradiated volume, leading to clinically significant reductions in OAR doses. By mitigating tumor motion, the BH technique leads to reproducible target coverage and OAR doses. Its use can reduce motion-related uncertainties that are normally associated with the treatment of thoracic and abdominal tumors and, therefore, optimize IMPT delivery.

Deletion of protein tyrosine phosphatase SHP-1 restores SUMOylation of podocin and reverses the progression of diabetic kidney disease.

Both clinical and experimental data suggest that podocyte injury is involved in the onset and progression of diabetic kidney disease (DKD). Although the mechanisms underlying the development of podocyte loss are not completely understood, critical structural proteins such as podocin play a major role in podocyte survival and function. We have reported that the protein tyrosine phosphatase SHP-1 expression increased in podocytes of diabetic mice and glomeruli of patients with diabetes. However, the in vivo contribution of SHP-1 in podocytes is unknown. Conditional podocyte-specific SHP-1-deficient mice (Podo-SHP-1-/-) were generated to evaluate the impact of SHP-1 deletion at four weeks of age (early) prior to the onset of diabetes and after 20 weeks (late) of diabetes (DM; Ins2+/C96Y) on kidney function (albuminuria and glomerular filtration rate) and kidney pathology. Ablation of the SHP-1 gene specifically in podocytes prevented and even reversed the elevated albumin/creatinine ratio, glomerular filtration rate progression, mesangial cell expansion, glomerular hypertrophy, glomerular basement membrane thickening and podocyte foot process effacement induced by diabetes. Moreover, podocyte-specific deletion of SHP-1 at an early and late stage prevented diabetes-induced expression of collagen IV, fibronectin, transforming growth factor-ß, transforming protein RhoA, and serine/threonine kinase ROCK1, whereas it restored nephrin, podocin and cation channel TRPC6 expression. Mass spectrometry analysis revealed that SHP-1 reduced SUMO2 post-translational modification of podocin while podocyte-specific deletion of SHP-1 preserved slit diaphragm protein complexes in the diabetic context. Thus, our data uncovered a new role of SHP-1 in the regulation of cytoskeleton dynamics and slit diaphragm protein expression/stability, and its inhibition preserved podocyte function preventing DKD progression.

Enhanced SHP-1 Expression in Podocyturia Is Associated with Kidney Dysfunction in Patients with Diabetes.

Background: Diabetic kidney disease (DKD) remains the leading cause of end stage kidney disease worldwide. Despite significant advances in kidney care, there is a need to improve noninvasive techniques to predict the progression of kidney disease better for patients with diabetes. After injury, podocytes are shed in urine and may be used as a biologic tool. We previously reported that SHP-1 is upregulated in the kidney of diabetic mice, leading to podocyte dysfunction and loss. Our objective was to evaluate the expression levels of SHP-1 in urinary podocytes and kidney tissues of patients with diabetes. Methods: In this prospective study, patients with and without diabetes were recruited for the quantification of SHP-1 in kidney tissues, urinary podocytes, and peripheral blood monocytes. Immunochemistry and mass spectrometry techniques were applied for kidney tissues. Urinary podocytes were counted, and expression of SHP-1 and podocyte markers were measured by quantitative PCR. Results: A total of 66 participants (diabetic n=48, nondiabetic n=18) were included in the analyses. Diabetes was associated with increased SHP-1 expression in kidney tissues (P=0.03). Nephrin and podocin mRNA was not significantly increased in urinary podocytes from patients with diabetes compared with those without diabetes, whereas levels of SHP-1 mRNA expression significantly correlated with HbA1c and estimated glomerular filtration rate (eGFR). Additionally, follow-up (up to 2 years post recruitment) evaluation indicated that SHP-1 mRNA expression continued to increase with eGFR decline. Conclusions: Levels of SHP-1 in urinary podocytes may serve as an additional marker of glomerular disease progression in this population.

Inwardly rectifying potassium channels mediate polymyxin-induced nephrotoxicity.

Polymyxin antibiotics are often used as a last-line defense to treat life-threatening Gram-negative pathogens. However, polymyxin-induced kidney toxicity is a dose-limiting factor of paramount importance and can lead to suboptimal treatment. To elucidate the mechanism and develop effective strategies to overcome polymyxin toxicity, we employed a whole-genome CRISPR screen in human kidney tubular HK-2 cells and identified 86 significant genes that upon knock-out rescued polymyxin-induced toxicity. Specifically, we discovered that knockout of the inwardly rectifying potassium channels Kir4.2 and Kir5.1 (encoded by KCNJ15 and KCNJ16, respectively) rescued polymyxin-induced toxicity in HK-2 cells. Furthermore, we found that polymyxins induced cell depolarization via Kir4.2 and Kir5.1 and a significant cellular uptake of polymyxins was evident. All-atom molecular dynamics simulations revealed that polymyxin B1 spontaneously bound to Kir4.2, thereby increasing opening of the channel, resulting in a potassium influx, and changes of the membrane potential. Consistent with these findings, small molecule inhibitors (BaCl2 and VU0134992) of Kir potassium channels reduced polymyxin-induced toxicity in cell culture and mouse explant kidney tissue. Our findings provide critical mechanistic information that will help attenuate polymyxin-induced nephrotoxicity in patients and facilitate the design of novel, safer polymyxins.

PAX2 + Mesenchymal Origin of Gonadal Supporting Cells Is Conserved in Birds.

During embryonic gonadal development, the supporting cell lineage is the first cell type to differentiate, giving rise to Sertoli cells in the testis and pre-granulosa cells in the ovary. These cells are thought to direct other gonadal cell lineages down the testis or ovarian pathways, including the germline. Recent research has shown that, in contrast to mouse, chicken gonadal supporting cells derive from a PAX2/OSR1/DMRT1/WNT4 positive mesenchymal cell population. These cells colonize the undifferentiated genital ridge during early gonadogenesis, around the time that germ cells migrate into the gonad. During the process of somatic gonadal sex differentiation, PAX2 expression is down-regulated in embryonic chicken gonads just prior to up-regulation of testis- and ovary-specific markers and prior to germ cell differentiation. Most research on avian gonadal development has focused on the chicken model, and related species from the Galloanserae clade. There is a lack of knowledge on gonadal sex differentiation in other avian lineages. Comparative analysis in birds is required to fully understand the mechanisms of avian sex determination and gonadal differentiation. Here we report the first comparative molecular characterization of gonadal supporting cell differentiation in birds from each of the three main clades, Galloanserae (chicken and quail), Neoaves (zebra finch) and Palaeognathe (emu). Our analysis reveals conservation of PAX2+ expression and a mesenchymal origin of supporting cells in each clade. Moreover, down-regulation of PAX2 expression precisely defines the onset of gonadal sex differentiation in each species. Altogether, these results indicate that gonadal morphogenesis is conserved among the major bird clades.

Interlaboratory bias of albuminuria and proteinuria in hypertensive pregnancy.

BACKGROUND: Measurement of proteinuria in women with hypertensive disorders of pregnancy is of major importance in the diagnosis and management of preeclampsia. Urinary protein/creatinine ratio, which is commonly used to detect kidney damage in preeclampsia, suffers from important analytical limitations, including poor harmonization of results between laboratories. Adoption of albuminuria could help reduce interlaboratory bias, since methods used to quantify it are better harmonized. METHODS: A total of 27 urinary samples collected from hypertensive women evaluated for preeclampsia were sent to four different clinical laboratories in Canada. Urinary proteins and albumin as well as urinary creatinine were measured in duplicates in one batch to calculate protein/creatinine (PCR) and albumin/creatinine (ACR) ratio. Statistical analyses were done to evaluate interlaboratory variability of urinary proteins and urinary albumin. RESULTS: Interlaboratory bias for urinary proteins ranged from 64.7% at low concentration to 3.9% at higher concentrations. In contrast, urinary albumin interlaboratory bias ranged from 29.2% to 4% from low to high concentrations. Coefficient of variation for urinary proteins reached a maximum of 91.5% in lower concentration while urinary albumin highest value was 42.7%. When looking at PCR and ACR ratio, eight samples had PCR measurement range that contained the diagnostic threshold used to detect kidney damage in HDP (30 mg/mmol), while only four samples had ACR ratio measurement range that contained the diagnostic threshold used outside of pregnancy in Canada (2 mg/mmol). CONCLUSION: Interlaboratory bias was lower for urinary albumin measurement compared to urinary proteins in hypertensive women evaluated for preeclampsia. Better harmonization with the use of albumin instead of protein measurement would reduce instances where results of different laboratories lead to opposite diagnosis of kidney damage in pregnancy.

Albumin/Creatinine Ratio for the Detection of Significant Proteinuria of Preeclampsia in Hospitalized Hypertensive Women.

OBJECTIVE: Preeclampsia is a hypertensive disorder of pregnancy associated with proteinuria detected by 24-hour urine collection (≥0.3 g/24 h) or protein/creatinine ratio (≥30 mg/mmol). The albumin/creatinine ratio (ACR) is used outside pregnancy to detect abnormal amounts of albumin in the urine, but there is little data on its value in pregnancy. Our objective was to determine the diagnostic threshold for ACR to detect significant proteinuria in women investigated for preeclampsia. METHODS: A prospective observational study involving 99 hypertensive women (≥140/90 mm Hg) over 20 weeks gestation who were hospitalized at 2 Canadian tertiary centres. A 24-hour urine collection and a morning urine sample were collected. The optimal ACR threshold was determined by a receiver operating characteristic (ROC) curve using the 24-hour collection as the reference test; sensitivity and specificity analyses were performed. Maternal and perinatal characteristics were extracted from medical records. RESULTS: Of the 87 women who had completed urine collection, 74 (85%) had an initial diagnosis of preeclampsia and 63 (72%) had significant proteinuria confirmed by 24-hour collection. The area under the morning ROC curve was 0.92 (95% CI 0.86-0.98) and the optimal threshold obtained for the ACR was 9 mg/mmol, with a sensitivity and specificity of 84% (95% CI 73-92) and 88% (95% CI 68-97), respectively. CONCLUSION: Our results suggest that an ACR threshold of 9 mg/mmol on a morning urine sample can be used to detect significant proteinuria of preeclampsia in hospitalized hypertensive women.

Functional genomics and gene-environment interaction highlight the complexity of congenital heart disease caused by Notch pathway variants.

Congenital heart disease (CHD) is the most common birth defect and brings with it significant mortality and morbidity. The application of exome and genome sequencing has greatly improved the rate of genetic diagnosis for CHD but the cause in the majority of cases remains uncertain. It is clear that genetics, as well as environmental influences, play roles in the aetiology of CHD. Here we address both these aspects of causation with respect to the Notch signalling pathway. In our CHD cohort, variants in core Notch pathway genes account for 20% of those that cause disease, a rate that did not increase with the inclusion of genes of the broader Notch pathway and its regulators. This is reinforced by case-control burden analysis where variants in Notch pathway genes are enriched in CHD patients. This enrichment is due to variation in NOTCH1. Functional analysis of some novel missense NOTCH1 and DLL4 variants in cultured cells demonstrate reduced signalling activity, allowing variant reclassification. Although loss-of-function variants in DLL4 are known to cause Adams-Oliver syndrome, this is the first report of a hypomorphic DLL4 allele as a cause of isolated CHD. Finally, we demonstrate a gene-environment interaction in mouse embryos between Notch1 heterozygosity and low oxygen- or anti-arrhythmic drug-induced gestational hypoxia, resulting in an increased incidence of heart defects. This implies that exposure to environmental insults such as hypoxia could explain variable expressivity and penetrance of observed CHD in families carrying Notch pathway variants.

Effects of Postmastectomy Radiation Therapy on Immediate Tissue Expander and Acellular Dermal Matrix Reconstruction: Results of a Prospective Clinical Trial.

PURPOSE: Postmastectomy radiation therapy (PMRT) delivered to an immediate reconstruction increases the risk of surgical complications. Although acellular dermal matrix (ADM) has been used with immediate tissue expander (TE) reconstruction to improve cosmetic outcomes and minimize capsular contracture, there is a paucity of data on this approach in the setting of PMRT. METHODS AND MATERIALS: Thirty-two patients with stage I to III breast cancer were treated with mastectomy, immediate TE-ADM reconstruction, and PMRT between 2009 and 2012 in a prospective single-arm study. The primary objective was the "success" rate, determined by the number of patients at 2 years after PMRT having an intact final reconstruction, no major complications, and a cosmetic outcome rated by a physician as excellent or good. RESULTS: The median follow-up was 24 months. Final reconstruction status was known in 31 of 32 patients (96.9%; 1 patient left the country) and completed in 29 of 31 patients (93.5%; implant, n = 26; flap, n = 1; both, n = 2; none, n = 2). At 2 years, 6 patients were unevaluable (metastatic disease, n = 3; withdrawn consent, n = 1; left the country, n = 2). Of 26 evaluable patients, the success rate was 65.4% (17 of 26). Lack of success was the result of "fair" cosmesis (n = 2), infection (n = 2), severe capsular contracture (n = 1), major revision (n = 2), and no final reconstruction (n = 2). Most patients had good-to-excellent 2-year overall cosmesis based on patient perception (15; 62.5%) and physician evaluation (19; 79.2%). CONCLUSIONS: To the best of our knowledge, this is the first dedicated prospective trial evaluating long-term cosmetic and complication outcomes in patients treated with immediate TE-ADM reconstruction followed by PMRT. Most patients (65.4%) met the success criteria in this prospective single-arm series. The great majority (93.5%) achieved final reconstruction; most had good-to-excellent overall cosmetic outcomes (79.2%). The results with longer follow-up will be of interest, and further investigation of strategies to optimize reconstruction with PMRT are warranted.

Gene-environment interaction impacts on heart development and embryo survival.

Congenital heart disease (CHD) is the most common type of birth defect. In recent years, research has focussed on identifying the genetic causes of CHD. However, only a minority of CHD cases can be attributed to single gene mutations. In addition, studies have identified different environmental stressors that promote CHD, but the additive effect of genetic susceptibility and environmental factors is poorly understood. In this context, we have investigated the effects of short-term gestational hypoxia on mouse embryos genetically predisposed to heart defects. Exposure of mouse embryos heterozygous for Tbx1 or Fgfr1/Fgfr2 to hypoxia in utero increased the incidence and severity of heart defects while Nkx2-5+/- embryos died within 2 days of hypoxic exposure. We identified the molecular consequences of the interaction between Nkx2-5 and short-term gestational hypoxia, which suggest that reduced Nkx2-5 expression and a prolonged hypoxia-inducible factor 1α response together precipitate embryo death. Our study provides insight into the causes of embryo loss and variable penetrance of monogenic CHD, and raises the possibility that cases of foetal death and CHD in humans could be caused by similar gene-environment interactions.

NAD Deficiency, Congenital Malformations, and Niacin Supplementation.

BACKGROUND: Congenital malformations can be manifested as combinations of phenotypes that co-occur more often than expected by chance. In many such cases, it has proved difficult to identify a genetic cause. We sought the genetic cause of cardiac, vertebral, and renal defects, among others, in unrelated patients. METHODS: We used genomic sequencing to identify potentially pathogenic gene variants in families in which a person had multiple congenital malformations. We tested the function of the variant by using assays of in vitro enzyme activity and by quantifying metabolites in patient plasma. We engineered mouse models with similar variants using the CRISPR (clustered regularly interspaced short palindromic repeats)-Cas9 system. RESULTS: Variants were identified in two genes that encode enzymes of the kynurenine pathway, 3-hydroxyanthranilic acid 3,4-dioxygenase (HAAO) and kynureninase (KYNU). Three patients carried homozygous variants predicting loss-of-function changes in the HAAO or KYNU proteins (HAAO p.D162*, HAAO p.W186*, or KYNU p.V57Efs*21). Another patient carried heterozygous KYNU variants (p.Y156* and p.F349Kfs*4). The mutant enzymes had greatly reduced activity in vitro. Nicotinamide adenine dinucleotide (NAD) is synthesized de novo from tryptophan through the kynurenine pathway. The patients had reduced levels of circulating NAD. Defects similar to those in the patients developed in the embryos of Haao-null or Kynu-null mice owing to NAD deficiency. In null mice, the prevention of NAD deficiency during gestation averted defects. CONCLUSIONS: Disruption of NAD synthesis caused a deficiency of NAD and congenital malformations in humans and mice. Niacin supplementation during gestation prevented the malformations in mice. (Funded by the National Health and Medical Research Council of Australia and others.).

Associations of Maternal Leptin with Neonatal Adiposity Differ according to Pregravid Weight.

BACKGROUND: During pregnancy, maternal circulating leptin is released by maternal adipose tissue and the placenta, and may have a role in fetal development. OBJECTIVES: We investigated maternal leptinemia and glycemia associations with neonatal adiposity, taking into account pregravid weight status. METHODS: We included 235 pregnant women from the Genetics of Glucose Regulation in Gestation and Growth prospective cohort with data: blood samples collected during the 2nd trimester, an oral glucose tolerance test (OGTT), and the measured leptin and glucose levels. As an integrated measure of maternal leptin exposure, we calculated the area under the curve for maternal leptin at the OGTT (AUCleptin). Within 72 h of delivery, we measured the triceps, biceps, subscapular, and suprailiac skinfold thicknesses (SFTs); the sum of these SFTs represented neonatal adiposity. We conducted a regression analysis to assess the maternal metabolic determinants of neonatal adiposity, adjusting for parity, smoking status, maternal triglyceride levels, gestational weight gain, placental weight, delivery mode, neonate sex, and gestational age at delivery. RESULTS: The pregravid BMI of the participating women was 23.3 (21.2-27.0). In the 2nd trimester, maternal AUCleptin was 1,292.0 (767.0-2,222.5) (ng × min)/mL, and fasting glucose levels were 4.2 ± 0.4 mmol/L. At delivery, the neonatal sum of 4 SFTs was 17.9 ± 3.3 mm. Higher maternal leptinemia was associated with higher neonatal adiposity (ß = 4.23 mm [SE = 1.77] per log-AUCleptin; p = 0.02) in mothers with a BMI ≥25, independently of confounders and maternal glycemia, but not in mothers with a BMI <25. Higher maternal fasting glucose was associated with higher neonatal adiposity (ß = 0.88 mm [SE = 0.30] per SD glucose; p = 0.005) in mothers with a BMI <25, independently of confounders and maternal leptinemia. CONCLUSION: Maternal leptinemia may be associated with neonatal adiposity in offspring from overweight/obese mothers, independently of maternal glycemia.

"Homophobia hurts": Mourning as resistance to violence in South Africa.

Much has been written on the successful lesbian, gay, bisexual, transgender, and intersex movement in South Africa, and the resulting institutionalization of sexual minority rights. Comparatively less has been written about the forms of activism undertaken specifically by Black lesbians that are not oriented toward legal change. In this article, I assert the need to examine public demonstrations of mourning as an act of Black lesbian resistance to violence in South Africa. Based on in-depth interviews with members of Free Gender, a Black lesbian organization, I argue that members' conceptualizations of mourning as providing community support force a reconsideration of what it means to be human. In order to grasp the decolonial potential of Free Gender's activism, I draw on Sylvia Wynter's argument that a singular Western bourgeois conception of human has come to dominate globally.

Gestational stress induces the unfolded protein response, resulting in heart defects.

Congenital heart disease (CHD) is an enigma. It is the most common human birth defect and yet, even with the application of modern genetic and genomic technologies, only a minority of cases can be explained genetically. This is because environmental stressors also cause CHD. Here we propose a plausible non-genetic mechanism for induction of CHD by environmental stressors. We show that exposure of mouse embryos to short-term gestational hypoxia induces the most common types of heart defect. This is mediated by the rapid induction of the unfolded protein response (UPR), which profoundly reduces FGF signaling in cardiac progenitor cells of the second heart field. Thus, UPR activation during human pregnancy might be a common cause of CHD. Our findings have far-reaching consequences because the UPR is activated by a myriad of environmental or pathophysiological conditions. Ultimately, our discovery could lead to preventative strategies to reduce the incidence of human CHD.

Diarrhea-predominant irritable bowel syndrome: Diagnosis, etiology, and new treatment considerations.

PURPOSE: To provide an overview of irritable bowel syndrome (IBS), specifically the efficacy and tolerability of treatment options for diarrhea-predominant IBS (IBS-D). DATA SOURCES: Research articles available via PubMed were reviewed. CONCLUSIONS: IBS is a chronic multifactorial disorder that has a negative impact on patient-related quality of life. Genetic factors, psychosociologic factors, alterations in the gut microbiota, and changes in immune, motor, and sensory responses to various stimuli all may be involved in the development of IBS. While pharmacologic therapies for IBS-D have historically been limited (e.g., alosetron), newer therapies (eluxadoline and rifaximin), both approved in the United States in 2015, may be considered for appropriate patients for the management of IBS-D. IMPLICATIONS FOR PRACTICE: Nurse practitioners play an important role in the diagnosis, care, and management of patients with IBS-D. The goals of therapy should be to reach a correct diagnosis before initiating therapy, provide reassurance to the patient, educate the patient on potential treatment options, improve IBS-D symptoms, minimize risk of harm with treatment, and maximize patient-related quality of life. The authors present a treatment algorithm to guide nurse practitioners on the management of patients with IBS-D.

Higher maternal leptin levels at second trimester are associated with subsequent greater gestational weight gain in late pregnancy.

BACKGROUND: Excessive gestational weight gain (GWG) is associated with adverse pregnancy outcomes. In non-pregnant populations, low leptin levels stimulate positive energy balance. In pregnancy, both the placenta and adipose tissue contribute to circulating leptin levels. We tested whether maternal leptin levels are associated with subsequent GWG and whether this association varies depending on stage of pregnancy and on maternal body mass index (BMI). METHODS: This prospective cohort study included 675 pregnant women followed from 1(st) trimester until delivery. We collected anthropometric measurements, blood samples at 1(st) and 2(nd) trimester, and clinical data until delivery. Maternal leptin was measured by ELISA (Luminex technology). We classified women by BMI measured at 1(st) trimester: BMI < 25 kg/m(2) = normal weight; 25 ≤ BMI < 30 kg/m(2) = overweight; and BMI ≥ 30 kg/m(2) = obese. RESULTS: Women gained a mean of 6.7 ± 3.0 kg between 1(st) and 2(nd) trimester (mid pregnancy GWG) and 5.6 ± 2.5 kg between 2(nd) and the end of 3(rd) trimester (late pregnancy GWG). Higher 1(st) trimester leptin levels were associated with lower mid pregnancy GWG, but the association was no longer significant after adjusting for % body fat (%BF; ß = 0.38 kg per log-leptin; SE = 0.52; P = 0.46). Higher 2(nd) trimester leptin levels were associated with greater late pregnancy GWG and this association remained significant after adjustment for BMI (ß = 2.35; SE = 0.41; P < 0.0001) or %BF (ß = 2.01; SE = 0.42; P < 0.0001). In BMI stratified analyses, higher 2(nd) trimester leptin levels were associated with greater late pregnancy GWG in normal weight women (ß = 1.33; SE = 0.42; P =0.002), and this association was stronger in overweight women (ß = 2.85; SE = 0.94; P = 0.003--P for interaction = 0.05). CONCLUSIONS: Our results suggest that leptin may regulate weight gain differentially at 1(st) versus 2(nd) trimester of pregnancy: at 2(nd) trimester, higher leptin levels were associated with greater subsequent weight gain--the opposite of its physiologic regulation in non-pregnancy--and this association was stronger in overweight women. We suspect the existence of a feed-forward signal from leptin in second half of pregnancy, stimulating a positive energy balance and leading to greater weight gain.

Genetics of Glucose regulation in Gestation and Growth (Gen3G): a prospective prebirth cohort of mother-child pairs in Sherbrooke, Canada.

PURPOSE: We initiated the Genetics of Glucose regulation in Gestation and Growth (Gen3G) prospective cohort to increase our understanding of biological, environmental and genetic determinants of glucose regulation during pregnancy and their impact on fetal development. PARTICIPANTS: Between January 2010 and June 2013, we invited pregnant women aged ≥ 18 years old who visited the blood sampling in pregnancy clinic in Sherbrooke for their first trimester clinical blood samples: 1034 women accepted to participate in our cohort study. FINDINGS TO DATE: At first and second trimester, we collected demographics and lifestyle questionnaires, anthropometry measures (including fat and lean mass estimated using bioimpedance), blood pressure, and blood samples. At second trimester, women completed a full 75 g oral glucose tolerance test and we collected additional blood samples. At delivery, we collected cord blood and placenta samples; obstetrical and neonatal clinical data were abstracted from electronic medical records. We also collected buffy coats and extracted DNA from maternal and/or offspring samples (placenta and blood cells) to pursue genetic and epigenetic hypotheses. So far, we have found that low adiponectin and low vitamin D maternal levels in first trimester predict higher risk of developing gestational diabetes. FUTURE PLANS: We are now in the phase of prospective follow-up of mothers and offspring 3 and 5 years postdelivery to investigate the consequences of maternal dysglycaemia during pregnancy on offspring adiposity and metabolic profile. TRIAL REGISTRATION NUMBER: NCT01623934.

Preeclampsia is associated with an increased pro-inflammatory profile in newborns.

Hypertensive disorders of pregnancy (HDP) lead to high rates of maternal and fetal morbidity. Existing studies on inflammatory marker TNFα in HDP offspring are inconsistent. We performed a population-based cohort study of 636 pregnancies, including normotensive (NT) women and women with preeclampsia (PE) or gestational hypertension (GH). TNFα was measured in maternal blood in the first and second trimesters and in cord blood at the time of delivery. Cord blood TNFα was higher in offspring delivered of women with PE (6.53 [4.94-8.38]pg/mL) versus those delivered of NT women (5.13 [4.11-6.72]pg/mL; p=0.01), independent of confounders. Maternal TNFα levels were not different among groups (p>0.1) in either the first or second trimester.

Cited2 is required in trophoblasts for correct placental capillary patterning.

CITED2 is a transcriptional co-factor with important roles in many organs of the developing mammalian embryo. Complete deletion of this gene causes severe malformation of the placenta, and results in significantly reduced embryonic growth and death from E14.5. The placenta is a complex organ originating from cells derived from three lineages: the maternal decidua, the trophectoderm, and the extra-embryonic mesoderm. Cited2 is expressed in many of these cell types, but its exact role in the formation of the placenta is unknown. Here we use a conditional deletion approach to remove Cited2 from overlapping subsets of trophectoderm and extra-embryonic mesoderm. We find that Cited2 in sinusoidal trophoblast giant cells and syncytiotrophoblasts is likely to have a non-cell autonomous role in patterning of the pericytes associated with the embryonic capillaries. This function is likely to be mediated by PDGF signaling. Furthermore, we also identify that loss of Cited2 in syncytiotrophoblasts results in the subcellular mislocalization of one of the major lactate transporters in the placenta, SLC16A3 (MCT4). We hypothesize that the embryonic growth retardation observed in Cited2 null embryos is due in part to a disorganized embryonic capillary network, and in part due to abnormalities of the nutrient transport functions of the feto-maternal interface.