Placenta Accreta Spectrum in Normal Situated Placenta and Unscarred Uterus.

Placenta accreta, one of the morbidly adherent placenta components and currently known as placenta accreta spectrum (PAS), is a condition characterized by abnormal adherence of the placenta to the uterine wall. This can lead to significant blood loss and may lead to high morbidity and mortality rates for the mother. It is a failure of placenta separation during the third stage of labor, which is thought to be high prevalence in those with previous cesarean delivery, especially with the presence of placenta previa. However, PAS is possible in cases of a normally-situated placenta without previous cesarean delivery. We reported an interesting case of a 41-year-old woman, gravida 8 para 7, admitted to the labor room for augmentation of labor, who needed emergency lower segment cesarean section. The incidental finding of PAS was made intraoperatively and was complicated with a hysterectomy. PAS in a normally situated placenta (upper segment) in a virgin abdomen that has been discovered during emergency lower segment cesarean section could cause a nightmare to the obstetrician as it leads to massive postpartum hemorrhage, ureteric injury, and high maternal morbidity and mortality.

Vegetation-fire feedbacks increase subtropical wildfire risk in scrubland and reduce it in forests.

Climate dictates wildfire activity around the world. But East and Southeast Asia are an apparent exception as fire-activity variation there is unrelated to climatic variables. In subtropical China, fire activity decreased by 80% between 2003 and 2020 amid increased fire risks globally. Here, we assessed the fire regime, vegetation structure, fuel flammability and their interactions across subtropical Hubei, China. We show that tree basal area (TBA) and fuel flammability explained 60% of fire-frequency variance. Fire frequency and fuel flammability, in turn, explained 90% of TBA variance. These results reveal a novel system of scrubland-forest stabilized by vegetation-fire feedbacks. Frequent fires promote the persistence of derelict scrubland through positive vegetation-fire feedbacks; in forest, vegetation-fire feedbacks are negative and suppress fire. Thus, we attribute the decrease in wildfire activity to reforestation programs that concurrently increase forest coverage and foster negative vegetation-fire feedbacks that suppress wildfire.

Immune-mediated oral mucosal pathology: a comprehensive review and update for clinicians. Part I.

The oral mucosa can be involved in a wide variety of mucocutaneous conditions that may present primarily in the mouth or affect other cutaneous or mucosal sites. Many of these conditions are immune mediated and typically present as inflammatory mucosal pathology. Patients experiencing such conditions usually seek medical evaluation and treatment due to the associated pain and discomfort and occasionally taste disturbance or dysphagia and the overall deterioration in the oral health-related quality of life. These conditions share some common features and there could be some overlapping in their clinical presentation, which can lead to delays in diagnosis and proper management of patients. Clinicians dealing with such disorders, including dermatologists, need to be aware of the oral manifestations of mucocutaneous conditions, their clinical features, underlying mechanisms, diagnostic approaches, and treatment options, as well as the recent advances in the research on these conditions. This review provides a comprehensive, evidence-based reference for clinicians, with updated insights into a group of immune mediated conditions known to cause oral mucosal pathology. Part one will cover oral lichen planus, erythema multiforme and systemic lupus erythematosus, while part two will cover pemphigus vulgaris and mucous membrane pemphigoid, recurrent aphthous stomatitis, in addition to the less common disorders linear IgA disease, dermatitis herpetiformis and epidermolysis bullosa.

[Further progress of the etiology,diagnosis and treatment of peripheral precocious puberty].

Peripheral precocious puberty(PPP),also known as puberty independent from hypothalamic-pituitary axis activation,is stimulated by hormones from other sources, with only partial sexual characteristics development but without mature sexual function. The secondary sexual characteristics development occurs before 7.5 years of age in girls and before 9 years of age in boys. Clinical manifestations are diverse, and PPP has varied etiology including congenital adrenal hyperplasia, McCune-Albright syndrome, ovarian cyst, adrenal tumor, ovarian tumor, testicular tumor, human chorionic gonadotropin producing tumor, familial male precocious puberty, aromatase excess syndrome, and environmental estrogen. Early identification of etiology, accurate differential diagnosis and prenatal gene screening play a significant role in the prevention, diagnosis and treatment of the disease.

[Research progresses on interventions of obesity in children and adolescents].

Childhood and adolescent obesity has become a global epidemic. The interventions mainly include lifestyle intervention, medication treatment and bariatric surgery. Among them, lifestyle intervention, especially intensive lifestyle intervention with participation of family members, is the first-line treatment for obesity in children and adolescents. Both medication and bariatric surgery are adjuvant treatments for severely obese children and adolescents. Currently, metformin is the most widely used drug for the treatment of obesity in children and adolescents in both China and other countries; orlistat and liraglutide are also the drugs that are safe and often used in other countries; other drugs are not recommended. As a tertiary prevention and treatment strategy for obesity, bariatric surgery should be carried out on the basis of good compliance from both the children and their family members, with the cooperation of multiple disciplines. Sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) are the most common types of procedure performed. Meanwhile, as a new treatment method, intra-gastric balloon procedure needs to be paid more attention to its efficacy and safety.

[Progress in research of etiology of childhood obesity based on interaction between genes and environment].

Childhood obesity is a global public health problem, which can not only endangers children's health, but also might be an important cause of chronic diseases in adulthood. In recent years, with the in-depth development of precision medicine research, more and more research evidences have shown that there are interactions between environmental factors, such as early intrauterine environment, children's diet, physical activity and children's gene factor on the incidence of childhood obesity, which can result in or inhibit the incidence and development of childhood obesity. This paper summarizes the progress in research in this field to reveal the effects and potential mechanisms of genetic factors and environmental factors on the incidence of childhood obesity in order to provide reference for the precise prevention and control of childhood obesity under different genetic backgrounds.

Discrepant serological findings in SARS-CoV-2 PCR-negative hospitalized patients with fever and acute respiratory symptoms during the pandemic.

Coronavirus Disease 2019 (COVID-19) serology has an evolving role in the diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, its use in hospitalized patients with acute respiratory symptoms remains unclear. Hospitalized patients with acute respiratory illness admitted to an isolation ward were recruited. All patients had negative nasopharyngeal swab polymerase chain reaction (PCR) for SARS-CoV-2. Serological studies using four separate assays (cPass: surrogate neutralizing enzyme-linked immunosorbent assay [ELISA]; Elecsys: N-antigen based chemiluminescent assay; SFB: S protein flow-based; epitope peptide-based ELISA) were performed on stored plasma collected from patients during the initial hospital stay, and a convalescent visit 4-12 weeks later. Of the 51 patients studied (aged 54, interquartile range 21-84; 62.7% male), no patients tested positive on the Elecsys or cPass assays. Out of 51 patients, 5 had antibodies detected on B-cell Epitope Assay and 3/51 had antibodies detected on SFB assay. These 8 patients with positive serological test to COVID-19 were more likely to have a high-risk occupation (p = 0.039), bacterial infection (p = 0.028), and neutrophilia (p = 0.013) during their initial hospital admission. Discrepant COVID-19 serological findings were observed among those with recent hospital admissions and bacterial infections. The positive serological findings within our cohort raise important questions about the interpretation of sero-epidemiology during the current pandemic.

Effects of urea-treated oil palm frond on nutrient composition and in vitro rumen fermentation using goat rumen fluid.

Ammoniation of oil palm frond (OPF) with non-protein nitrogen (N) sources has been shown to improve the nutritional value and digestibility of OPF in ruminants. This study evaluated the effect of treating OPF without (control) or with different urea levels (1%-5%) on chemical composition and in vitro gas production, digestibility and fermentation properties using goat rumen fluids. The results showed that the treated OPF with urea (1%-5%) had significantly lower (p < 0.05) dry matter (DM), organic matter (OM) and ash contents than that of the control. The crude protein (CP) content of treated OPF increased (linear p < 0.05; quadratic p < 0.05) with increasing levels of urea inclusion (1%-5%), whereas the contents of neutral detergent fibre (NDF) and acid detergent lignin (ADL) were significantly (p < 0.05) decreased. The CH4 (ml/500 mg DM incubated) production decreased (linear p < 0.05) with increasing levels of urea inclusion in treated OPF silage. However, in vitro DM and OM degradability were significantly (p < 0.05) increased by higher inclusion levels of urea (4% and 5%). OPF treated with 4% or 5% urea also revealed significantly (p < 0.05) higher total volatile fatty acids and ammonia-N than the control and OPFs treated with 1%-3% urea. Ammoniation of OPF with urea improved its nutritional value and in vitro rumen fermentation profiles in goats. The impact was more pronounced for 4% or 5% urea-treated OPF.

Density Functional Theory Study of 12mer Single-Strand Guanine Oligomer and Associated Muon Hyperfine Interaction.

Density functional theory method at the B3LYP/6-31G level was used to determine the structure of 12mer single-strand guanine oligomers. The length and width of the optimized structure are 38.7 and 18.2 Å, respectively, and the observed high-resolution transmission electron microscopy image of the 12mer single-strand guanine sample shows similar oligomer dimensions with the calculated ones. Both HOMO and LUMO are significantly delocalized, and the calculated HOMO-LUMO gap is 3.31 eV. A total of 96 muonium trapping sites at C2, C4, C5, C6, C8, N3, N7, and O6 were investigated. All 12 C8 sites have lower energy than the other 84 sites and are clustered in the energy-muon hyperfine coupling constant scatter plot. The calculated muon hyperfine coupling constant at C8 sites range from 384.6 to 481.1 MHz, and the corresponding estimated ALC-µSR resonance for |ΔM| = 1 range from 1.419 to 1.775 T.

Comparing flipped classroom and conventional live demonstration for teaching orthodontic wire-bending skill.

Flipped classroom may overcome weaknesses of live demonstration in teaching orthodontic wire-bending. This study aims to compare the effectiveness between flipped classroom and live demonstration in transferring skills for fabricating Adams clasp. Forty third-year undergraduate dental students were assigned to two groups. The students in group LD (n = 20) attended a live demonstration while students in group FC (n = 20) attended a flipped classroom. Both groups were taught on skills to fabricate Adams clasp in a standardised way. Each student from both groups were asked to submit an Adams clasp for a blinded quality assessment by two trained and calibrated assessors using a 18-item rubric, followed by validated students' satisfaction questionnaires to evaluate their perceived satisfaction on the teaching method received. A crossover study was then conducted three weeks later where LD attended a flipped classroom while FC attended a live demonstration. Students' satisfaction questionnaires were again collected from each student for blinded analysis. Mean scores for the quality of Adams clasp were 9.775 and 9.125 for LD and FC, respectively. No significant difference was detected between the two groups. Statistically significant association was found for one statement on the questionnaire, "I found the classroom arrangements conducive for the wire-bending activity" (p = 0.010). No significant differences were found between the two groups for other statements (p > 0.05). In conclusion, within the limitations of the study, flipped classroom is equally effective as conventional live demonstration in transferring orthodontic wire-bending skills for fabrication of Adams clasp. However, students perceived the classroom arrangements during the flipped classroom significantly more conducive for teaching orthodontic wire-bending.

The study of border zone formation in ischemic heart using electro-chemical coupled computational model.

Myocardial infarction (MI) is the most common cause of a heart failure, which occurs due to myocardial ischemia leading to left ventricular (LV) remodeling. LV remodeling particularly occurs at the ischemic area and the region surrounds it, known as the border zone. The role of the border zone in initiating LV remodeling process urges the investigation on the correlation between early border zone changes and remodeling outcome. Thus, this study aims to simulate a preliminary conceptual work of the border zone formation and evolution during onset of MI and its effect towards early LV remodeling processes by incorporating the oxygen concentration effect on the electrophysiology of an idealized three-dimensional LV through electro-chemical coupled mathematical model. The simulation result shows that the region of border zone, represented by the distribution of electrical conductivities, keeps expanding over time. Based on this result, the border zone is also proposed to consist of three sub-regions, namely mildly, moderately, and seriously impaired conductivity regions, which each region categorized depending on its electrical conductivities. This division could be used as a biomarker for classification of reversible and irreversible myocardial injury and will help to identify the different risks for the survival of patient. Larger ischemic size and complete occlusion of the coronary artery can be associated with an increased risk of developing irreversible injury, in particular if the reperfusion treatment is delayed. Increased irreversible injury area can be related with cardiovascular events and will further deteriorate the LV function over time.

Density Functional Theory Studies of the Electronic Structure and Muon Hyperfine Interaction in [Au25(SR)18]0 and [Au25(SeR)18]0 Nanoclusters.

Density functional theory computational investigation was performed to study the electronic structures, muon sites, and the associated hyperfine interactions in [Au25(SR)18]0 and [Au25(SeR)18]0 where R is phenylethane. The calculated electronic structures show inhomogeneous spin density distribution and are also affected by different ligands. The two most stable muon sites near Au atoms in the thiolated system are MAu11 and MAu6. When the thiolate ligands were replaced by selenolate ligands, the lowest energy positions of muons moved to MAu6 and MAu5. Muons prefer to stop inside the Au12 icosahedral shell, away from the central Au and the staple motifs region. Muonium states at phenyl ring and S/Se atoms in the ligand were found to be stable and the Fermi contact fields are much larger as compared to the field experienced by muons near Au atoms.

Validity and reproducibility of the 3D VECTRA photogrammetric surface imaging system for the maxillofacial anthropometric measurement on cleft patients.

OBJECTIVES: To validate the accuracy and reproducibility of linear measurements of three-dimensional (3D) images and to compare the measurements with the direct anthropometry method on cleft lip and palate (CLP) patients. MATERIALS AND METHODS: Nineteen linear facial measurements were derived from 16 standardized surface landmarks obtained from 37 cleft patients (20 males, 17 females; mean age 23.84 years, standard deviation ± 6.02). They were taken manually with calipers and were compared with the digitally calculated distance on the 3D images captured using the VECTRA-M5 360° Imaging System with pre-marked landmarks. Another pair of 19 linear measurements were computed on the 3D images 2 weeks apart for intra- and inter-observer agreements. Statistical analyses used were paired t test, the Bland-Altman analysis, and the intra-class correlation coefficient (ICC) index. RESULTS: Most of the linear measurements showed no statistically significant differences between the proposed method and direct anthropometry linear measurements. Nevertheless, bias of the 3D imaging system is present in the linear measurements of the nose width and the upper vermillion height. The measurements' mean biases were within 2 mm, but the 95% limit of agreement was more than 2 mm. Intra- and inter-observer measurements generally showed good reproducibility. Four inter-observer measurements, the upper and lower face heights, nose width, and pronasale to left alar base were clinically significant. CONCLUSIONS: Measurements obtained from this 3D imaging system are valid and reproducible for evaluating CLP patients. CLINICAL RELEVANCE: The system is suitable to be used in a clinical setting for cleft patients. However, training of the operator is strictly advisable.

Disseminated thymic B-cell lymphoma in a Holstein heifer.

A 19-mo-old Holstein heifer was inactive and dyspneic. Physical examination revealed wheezing, exophthalmos, a cervical mass, and lymphadenopathy. Cytology of the cervical mass and lymph nodes showed predominantly large atypical lymphocytes. Lactate dehydrogenase and thymidine kinase activities were elevated. Although nested PCR for bovine leukemia virus (BLV) using blood was positive, quantitative PCR showed a low number of provirus copies. Autopsy revealed enlargement of most lymph nodes examined, as well as white masses of various sizes in muscles of the left hindlimb and thoracic and abdominal organs. Histopathology revealed severe infiltration with neoplastic lymphocytes in these organs. The cervical mass was immune-positive for B-cell markers. The final diagnosis was thymic B-cell lymphoma with BLV infection.

Chemerin affects the metabolic and proliferative capabilities of chondrocytes by increasing the phosphorylation of AKT/ERK.

OBJECTIVE: The purpose of the present study was to explore the mechanism of action of the adipokine chemerin in osteoarthritis (OA) by means of an in vitro OA model. MATERIALS AND METHODS: Primary chondrocytes were isolated from normal rats. The chondrocytes were stimulated with interleukin 1 beta (IL-1ß, 10 µg/L) to establish a model of induced OA. Chemerin was administered to cells of this model. After culture of the chondrocytes in the presence of chemerin for 48 h, the expression of the genes related to OA occurrence and protection, matrix metalloproteinase-1 (MMP-1), matrix metalloproteinase-3 (MMP-3), and matrix metalloproteinase-13 (MMP-13) was examined. Western blot was then performed to analyze the phosphorylation of the AKT and extracellular signal-regulated kinase (ERK) proteins in chondrocytes. RESULTS: Stimulation of chondrocytes with IL-1ß markedly reduced the proliferative capability of chondrocytes. Chemerin (5 µM) also significantly decreased the proliferative capability of chondrocytes. The combined administration of IL-1ß and chemerin induced an even greater reduction in the proliferative capability of chondrocytes. Polymerase chain reaction (PCR) results showed that both IL-1ß and chemerin reduced the expression of the protective genes in OA (MMP-1, MMP-3, and MMP-13). Also, the stimulation with IL-1ß and chemerin significantly enhanced the phosphorylation of AKT/ERK in chondrocytes. CONCLUSIONS: This adipokine induces changes in the metabolic and proliferative capabilities of chondrocytes by increasing the phosphorylation of AKT/ERK, thereby inducing OA or aggravating the symptoms of OA.

Identifying Potential Therapeutics for Osteoporosis by Exploiting the Relationship between Mevalonate Pathway and Bone Metabolism.

BACKGROUND: Osteoporosis is a silent skeletal disease characterized by low bone mass and destruction of skeletal microarchitecture, leading to an increased fracture risk. This occurs due to an imbalance in bone remodelling, whereby the rate of bone resorption is greater than bone formation. Mevalonate pathway, previously known to involve in cholesterol synthesis, is an important regulatory pathway for bone remodelling. OBJECTIVE: This review aimed to provide an overview of the relationship between mevalonate pathway and bone metabolism, as well as agents which act through this pathway to achieve their therapeutic potential. DISCUSSION: Mevalonate pathway produces farnesyl pyrophosphate and geranylgeranyl pyrophosphate essential in protein prenylation. An increase in protein prenylation favours bone resorption over bone formation. Non-nitrogen containing bisphosphonates inhibit farnesyl diphosphate synthase which produces farnesyl pyrophosphate. They are used as the first line therapy for osteoporosis. Statins, a well-known class of cholesterol-lowering agents, inhibit 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase, the rate-determining enzyme in the mevalonate pathway. It was shown to increase bone mineral density and prevent fracture in humans. Tocotrienol is a group of vitamin E commonly found in palm oil, rice bran and annatto bean. It causes degradation of HMG-CoA reductase. Many studies demonstrated that tocotrienol prevented bone loss in animal studies but its efficacy has not been tested in humans. CONCLUSION: Mevalonate pathway can be exploited to develop effective antiosteoporosis agents.

HIV, HBV and HCV in people who inject drugs and are placed on methadone maintenance therapy, Yangon, Myanmar.

Setting: Two drug treatment centres (DTCs) for people who inject drugs (PWID) and are enrolled in methadone maintenance therapy (MMT), Yangon, Myanmar. Objectives: To determine, in PWID enrolled for MMT from 2015 to 2017, 1) testing uptake and results for human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV); 2) risk factors for infection; and 3) retention in care and risk factors for loss to follow-up (LTFU). Design: Cohort study using secondary data. Results: Of 642 PWID, 578 (90.0%) were tested for HIV, HBV and/or HCV. Overall, 404 (69.9%) were infected: 316 (78.2%) had one infection and the remainder had dual/triple infections. Testing uptake was generally better in 2015 and 2016 than in 2017. Prevalence of HIV infection was 15-17%, for HBV it was 4-7%, and for HCV it was 68-76%. Age >30 years, being single and duration of drug use were independent risk factors for infection. Retention in MMT at 6 months was 76% and declined thereafter. Experimental use of drugs and needle sharing were independent risk factors for LTFU. Conclusion: PWID enrolled in MMT in Yangon had high rates of HIV, HBV and HCV, and retention in care declined with time. Ways to improve individual tracing, programmatic retention and linkage to care are needed.

Contexte : Deux centres de traitement de l'addiction (DTC) pour les utilisateurs de drogues injectables (PWID) qui sont enrôlés dans un traitement d'entretien à la méthadone (MMT), Yangon, Myanmar.Objectif : Déterminer parmi les PWID enrôlés en MMT de 2015 à 2017 1) la couverture et les résultats des tests de virus de l'immunodéficience humaine (VIH), de l'hépatite B (HBV) et de l'hépatite C (HCV) ; 2) les facteurs de risque d'infection ; et 3) la rétention en soins et les facteurs de risque de pertes de vue (LTFU).Schéma : Etude de cohorte basée sur des données secondaires.Résultats : Il y a eu 642 PWID, dont 578 (90,0%) ont été testés pour le VIH, le HBV et/ou le VHC. Au total, 404 (69,9%) étaient infectés ; 316 (78,2%) avaient une seule infection et le reste avait deux ou trois infections. La couverture des tests a généralement été meilleure en 2015 et 2016 qu'en 2017. La prévalence de l'infection a été de 15­17% pour le VIH, de 4­7% pour le HBV et de 68­76% pour le HCV. Un âge > 30 ans, le fait d'être célibataire et la durée de la consommation de drogues ont été des facteurs de risque indépendants d'infection. La rétention en MMT à 6 mois a été de 76% et a décliné ensuite. L'usage expérimental de drogues et le partage d'aiguilles ont été des facteurs de risque indépendants de LTFU.Conclusion : Les PWID enrôlés en MMT à Yangon ont eu des taux élevés de VIH, d'HBV et d'HCV et la rétention en soins a décliné avec le temps. Il faut trouver des stratégies visant à améliorer le suivi individuel, la rétention dans le programme et les liens avec la prise en charge.

Marco de referencia: Dos centros de tratamiento de la drogadicción destinados a las personas que consumen drogas inyectables, inscritas en el tratamiento de mantenimiento con metadona de Yangon, en Birmania.Objetivos: Determinar en las personas que consumen drogas inyectables inscritas en el programa de mantenimiento con metadona del 2015 al 2017 las siguientes características: 1) la utilización de las pruebas diagnósticas de la infección por el virus de la inmunodeficiencia humana (VIH), el virus de la hepatitis B (VHB) y de la hepatitis C (VHC) y sus resultados; 2) los factores de riesgo de contraer la infección; y 3) la proporción de retención en la atención y los factores de riesgo de pérdida durante el seguimiento.Método: Estudio de cohortes a partir de datos secundarios.Resultados: Se inscribieron en los centros 642 consumidores de drogas inyectables, de los cuales 578 (90,0%) recibieron las pruebas diagnósticas del VIH, el VHB o el VHC. En general, 404 personas estaban infectadas (69,9%), de las cuales 316 padecían una monoinfección (78,2%) y el resto una infección doble o triple. En general, la utilización de las pruebas fue mayor en el 2015 y el 2016 que en el 2017. La prevalencia de infección por el VIH fue de 15% a 17%, por el VHB fue de 4% a 7% y por el VHC de 68% a 76%. Los factores de riesgo independientes de padecer una infección fueron la edad superior a los 30 años, el hecho de no tener pareja y la duración del consumo de drogas. La retención en el tratamiento de mantenimiento con metadona a los 6 meses fue 76% y en adelante disminuyó. Los factores de riesgo independientes de pérdida durante el seguimiento fueron el consumo experimental de drogas y el uso compartido de agujas.Conclusión: Las personas que consumen drogas inyectables que se inscriben en el programa de mantenimiento con metadona en Yangon exhibieron tasas altas de infección por el VIH, el VHB y el VHC y su retención en la atención disminuyó con el transcurso del tiempo. Se precisan estrategias que mejoren el seguimiento individual, la retención en los programas y la vinculación con la atención.

Anthropometric and Reproductive Factors among Newly- Diagnosed Breast Cancer Patients and Healthy Women: A Case-Control Study.

The objective of this case-control study was to determine anthropometric and reproductive factors associated with the development of breast cancer among women. Fifty-six newly diagnosed breast cancer patients were recruited from the Oncology Clinic, Universiti Sains Malaysia (USM), and 56 healthy female hospital employees were recruited as controls. Socio-demographic and reproductive data were obtained using a standard questionnaire. Anthropometric factors (body weight, height, body fat percentage, visceral fat and waist and hip circumference) were assessed. A high waist circumference (adjusted OR= 1.04, [95% CI: 1.00, 1.09]) and being more than 30 years of age at rst full-term pregnancy (adjusted OR=3.77, [95% CI: 1.10, 12.90]) were predictors of breast cancer development. The results of this study indicate that weight and reproductive health management should be emphasized for breast cancer prevention in Malaysia.

Does high-density lipoprotein protect vascular function in healthy pregnancy?

The maternal adaptation to pregnancy includes hyperlipidaemia, oxidative stress and chronic inflammation. In non-pregnant individuals, these processes are usually associated with poor vascular function. However, maternal vascular function is enhanced in pregnancy. It is not understood how this is achieved in the face of the adverse metabolic and inflammatory environment. Research into cardiovascular disease demonstrates that plasma HDL (high-density lipoprotein), by merit of its functionality rather than its plasma concentration, exerts protective effects on the vascular endothelium. HDL has vasodilatory, antioxidant, anti-thrombotic and anti-inflammatory effects, and can protect against endothelial cell damage. In pregnancy, the plasma HDL concentration starts to rise at 10 weeks of gestation, peaking at 20 weeks. The initial rise in plasma HDL occurs around the time of the establishment of the feto-placental circulation, a time when the trophoblast plugs in the maternal spiral arteries are released, generating oxidative stress. Thus there is the intriguing possibility that new HDL of improved function is synthesized around the time of the establishment of the feto-placental circulation. In obese pregnancy and, to a greater extent, in pre-eclampsia, plasma HDL levels are significantly decreased and maternal vascular function is reduced. Wire myography studies have shown an association between the plasma content of apolipoprotein AI, the major protein constituent of HDL, and blood vessel relaxation. These observations lead us to hypothesize that HDL concentration, and function, increases in pregnancy in order to protect the maternal vascular endothelium and that in pre-eclampsia this fails to occur.