Combined effects of age and polymorphisms in Notch3 in the pathogenesis of cerebral infarction disease.

Cerebral infarction disease is a severe hypoxic ischemic tissue necrosis in the brain, often leading to long-term functional disability and residual impairments. The Notch signaling pathway plays key roles in proliferation and survival of the stem/progenitor cells of the central and peripheral nervous systems. Notch3 is an important member of the pathway, but the relationships between the genetic abnormalities and cerebral infarction disease still remain unclear. The aim of this work was to evaluate variations in Notch3 gene for their possible associations with the cerebral infarction disease. We sequenced the Notch3 gene for 260 patients with cerebral infarction disease, 300 normal controls with old ages and 300 normal controls with younger ages, and identified the variations. The statistical analyses were conducted using Chi-Square Tests as implemented in SPSS (version 19.0). The Hardy-Weinberg equilibrium test of the population was carried out using the online software OEGE. Six variations, including rs1044116, rs1044009, rs1044006, rs10408676, rs1043996 and rs16980398 within or near the Notch3 gene, were found. The genetic heterozygosity of rs1044116, rs1044009, rs1044006, and rs1043996 was very high, whereas that of rs10408676 and rs16980398 was very low. Statistical analyses showed that rs1044009 and rs1044006 were associated with the risk of cerebral infarction disease in the Chinese Han agedness population. The SNPs rs1044009 and rs1044006 in the Notch3 gene were associated with the risk of cerebral infarction diseases in the Chinese Han agedness population.

Inherited neurovascular diseases affecting cerebral blood vessels and smooth muscle.

Neurovascular diseases are among the leading causes of mortality and permanent disability due to stroke, aneurysm, and other cardiovascular complications. Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and Marfan syndrome are two neurovascular disorders that affect smooth muscle cells through accumulation of granule and osmiophilic materials and defective elastic fiber formations respectively. Moyamoya disease, hereditary hemorrhagic telangiectasia (HHT), microcephalic osteodysplastic primordial dwarfism type II (MOPD II), and Fabry's disease are disorders that affect the endothelium cells of blood vessels through occlusion or abnormal development. While much research has been done on mapping out mutations in these diseases, the exact mechanisms are still largely unknown. This paper briefly introduces the pathogenesis, genetics, clinical symptoms, and current methods of treatment of the diseases in the hope that it can help us better understand the mechanism of these diseases and work on ways to develop better diagnosis and treatment.

Identification of two novel critical mutations in PCNT gene resulting in microcephalic osteodysplastic primordial dwarfism type II associated with multiple intracranial aneurysms.

Microcephalic osteodysplastic primordial dwarfism type II (MOPD II) is a highly detrimental human autosomal inherited recessive disorder. The hallmark characteristics of this disease are intrauterine and postnatal growth restrictions, with some patients also having cerebrovascular problems such as cerebral aneurysms. The genomic basis behind most clinical features of MOPD II remains largely unclear. The aim of this work was to identify the genetic defects in a Chinese family with MOPD II associated with multiple intracranial aneurysms. The patient had typical MOPD II syndrome, with subarachnoid hemorrhage and multiple intracranial aneurysms. We identified three novel mutations in the PCNT gene, including one single base alteration (9842A>C in exon 45) and two deletions (Del-C in exon 30 and Del-16 in exon 41). The deletions were co-segregated with the affected individual in the family and were not present in the control population. Computer modeling demonstrated that the deletions may cause drastic changes on the secondary and tertiary structures, affecting the hydrophilicity and hydrophobicity of the mutant proteins. In conclusion, we identified two novel mutations in the PCNT gene associated with MOPD II and intracranial aneurysms, and the mutations were expected to alter the stability and functioning of the protein by computer modeling.

Transcriptional Factor Snail Mediates Epithelial-Mesenchymal Transition in Human Bronchial Epithelial Cells Induced by Silica.

Epithelial-mesenchymal transition (EMT) plays an important role in fibrotic diseases. We have previously showed that silica induces EMT in human bronchial epithelial cells (BECs); however, the underlying mechanism of silica-induced EMT is poorly understood. In the present study, we investigated the role of Snail in silica-induced EMT in human BECs in vitro. Human BECs were treated with silica at various concentrations and incubation times. Then MTT assay, western blot, electrophoretic mobility shift assay (EMSA), and small interfering RNA (siRNA) transfection were performed. We found that silica increased the expression and DNA binding activity of Snail in human BECs. SNAI siRNA inhibited the silica-induced expression of Snail. Moreover, SNAI siRNA upregulated the expression of epithelial marker E-cadherin, but attenuated the expression of mesenchymal marker α-smooth muscle actin and vimentin in silica-stimulated cells. These results suggest that Snail mediates the silica-induced EMT in human BECs.

Perceptions towards online learning among medical students during the COVID-19 pandemic.

Social distancing has been essential during the COVID-19 pandemic to slow the spread of the disease. Online learning ensures students can participate in learning activities while also maintaining a physical distance from other students. Although online learning was used to prevent the spread of COVID-19, the development of online learning has also been promoted. Here, we sought to explore the perceptions and responses of students to online learning during the pandemic using a cross-sectional study. Electronic questionnaire was used for data collection. Statistical analyses were performed for 1614 valid questionnaires and P < 0.05 was considered statistically significant. Overall, COVID-19 had more effect on female students, such as fear of COVID-19 (2.4 times higher than the number of male students) and length of time spent learning (H = 42.449, P < 0.05). However, the higher the students' grades were, the less the impact of COVID-19. For the style of lessons, all students would prefer shorter lessons (P < 0.05). Female and fifth-grade students were more prefer combined online and face-to-face learning, and male and freshmen students were more likely to prefer face-to-face learning after the pandemic. More than 50% of students thought the main advantage of online learning was convenience, with low efficiency being a disadvantage. The main factors negatively influencing online learning were eyestrain, poor network connections, and poor learning environments at home. In conclusion, synchronous online and face-to-face learning may become more common in future curricula, however the efficiency of online learning and the female students more attentions.

Structural Genomic Analysis of SARS-CoV-2 and Other Coronaviruses.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative agent of the coronavirus disease 2019 (COVID-19) pandemic. In this study, we conducted a comparative analysis of the structural genes of SARS-CoV-2 and other CoVs. We found that the sequence of the E gene was the most evolutionarily conserved across 200 SARS-CoV-2 isolates. The E gene and M gene sequences of SARS-CoV-2 and NC014470 CoV were closely related and fell within the same branch of a phylogenetic tree. The absolute diversity of E gene and M gene sequences of SARS-CoV-2 isolates was similar to that of common CoVs (C-CoVs) infecting other organisms. The absolute diversity of the M gene sequence of the KJ481931 CoV that can infect humans was similar to that of SARS-CoV-2 and C-CoVs infecting other organisms. The M gene sequence of KJ481931 CoV (infecting humans), SARS-CoV-2 and NC014470 CoV (infecting other organisms) were closely related, falling within the same branch of a phylogenetic tree. Patterns of variation and evolutionary characteristics of the N gene and S gene were very similar. These data may be of value for understanding the origins and intermediate hosts of SARS-CoV-2.

Comparative analysis of SARS-CoV-2 and its receptor ACE2 with evolutionarily related coronaviruses.

The pandemic COVID-19 is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and it is spreading very rapidly worldwide. To date, the origin and intermediate hosts of SARS-CoV-2 remain unclear. In this study, we conducted comparative analysis among SARS-CoV-2 and non-SARS-CoV-2 coronavirus strains to elucidate their phylogenetic relationships. We found: 1, the SARS-CoV-2 strains analyzed could be divided into 3 clades with regional aggregation; 2, the non-SARS-CoV-2 common coronaviruses that infect humans or other organisms to cause respiratory syndrome and epizootic catarrhal gastroenteritis could also be divided into 3 clades; 3, the hosts of the common coronaviruses closest to SARS-CoV-2 were Apodemus chevrieri (a rodent), Delphinapterus leucas (beluga whale), Hypsugo savii (bat) , Camelus bactrianus (camel) and Mustela vison (mink); and 4, the gene sequences of the receptor ACE2 from different hosts could also be divided into 3 clades. The ACE2 gene sequences closest to that of humans in evolution include those from Nannospalax galili (Upper Galilee mountains blind mole rat), Phyllostomus discolor (pale spear-nosed bat), Mus musculus (house mouse), Delphinapterus leucas (beluga whale), and Catharus ustulatus (Swainson's thrush). We conclude that SARS-CoV-2 may have evolved from a distant common ancestor with the common coronaviruses but not a branch of any of them, implying that the prevalent pandemic COVID-19 agent SARS-CoV-2 may have existed in a yet to be identified primary host for a long time.

Associations of CXCL1 gene 5'UTR variations with ovarian cancer.

BACKGROUND: There are about 2.4 hundred thousand new cases and 1.5 hundred thousand deaths of ovarian cancer (OC) annually in the world. Chronic inflammation is a risk factor for OC. C-X-C motif chemokine ligand 1 (CXCL1) defects may facilitate inflammation and transactivate EGFR in ovarian cancer, but the precise haplotypes associated with the potential diseases remained largely unknown. In this work, we characterized CXCL1 gene variations to elucidate their possible associations with OC. METHODS: We analyzed the CXCL1 gene for 300 OC patients with 400 healthy participants as controls. The statistical analyses and Hardy-Weinberg equilibrium tests of the patients and control populations were conducted using the SPSS software (version 19.0) and Plink (version 1.9). RESULTS: The variants rs11547681, rs201090116, rs199791199, rs181868085, rs4074 and rs1814092 within or near the CXCL1 gene were characterized. The genetic heterozygosity of rs11547681 and rs4074 was very high. Statistical analysis showed that the variant rs11547681 in the gene was closely associated with the risk of OC in the Chinese Han population, although this variant was not associated with FIGO stages or pathological grades of the patients. CONCLUSIONS: Rs11547681 in CXCL1 gene was associated with the risk of OC in the Chinese Han population.

Isobaric Tags for Relative and Absolute Quantitation in Proteomic Analysis of Potential Biomarkers in Invasive Cancer, Ductal Carcinoma In Situ, and Mammary Fibroadenoma.

OBJECTIVES: Breast malignancy is a serious threat to women's health around the world. Following the rapid progress in the field of cancer diagnostics and identification of pathological markers, breast tumor treatment methods have been greatly improved. However, for invasive, ductal carcinomas and mammary fibroadenoma, there is an urgent demand for better breast tumor-linked biomarkers. The current study was designed to identify diagnostic and/or therapeutic protein biomarkers for breast tumors. METHODS: A total of 140 individuals were included, comprising 35 healthy women, 35 invasive breast cancers (IBC), 35 breast ductal carcinomas in situ (DCIS), and 35 breast fibroadenoma patients. Isobaric tags for relative and absolute quantitation (iTRAQ) proteomic analysis was employed to characterize differentially expressed proteins for potential biomarkers in IBC, DCIS, and fibroadenomas by comparisons with their matched adjacent tissues and/or normal breast tissues. The public databases Metascape and String were used for bioinformatic analyses. RESULTS: Using the proteomics approach, we identified differentially expressed proteins in tissues of different breast tumors compared to normal/adjacent breast tissues, including 100 in IBC, 52 in DCIS, and 44 in fibroadenoma. Among the 100 IBC differentially expressed proteins, 37 were found to be specific to this type of cancer only. Additionally, four proteins were specifically expressed in DCIS and four in fibroadenoma. Compared to corresponding adjacent tissues and normal breast tissues, 18 step-changing proteins were differentially expressed in IBC, 14 in DCIS, and 13 in fibroadenoma, respectively. Compared to DCIS and normal breast tissues, 65 proteins were differentially expressed in IBC with growing levels of malignancy. CONCLUSIONS: The identified potential protein biomarkers may be used as diagnostic and/or therapeutic targets in breast tumors.

Identification of epigenetic factor KAT2B gene variants for possible roles in congenital heart diseases.

Congenital heart disease (CHD) is a group of anatomic malformations in the heart with high morbidity and mortality. The mammalian heart is a complex organ, the formation and development of which are strictly regulated and controlled by gene regulatory networks of many signaling pathways such as TGF-ß. KAT2B is an important histone acetyltransferase epigenetic factor in the TGF-ß signaling pathway, and alteration in the gene is associated with the etiology of cardiovascular diseases. The aim of this work was to validate whether KAT2B variations might be associated with CHD. We sequenced the KAT2B gene for 400 Chinese Han CHD patients and evaluated SNPs rs3021408 and rs17006625. The statistical analyses and Hardy-Weinberg equilibrium tests of the CHD and control populations were conducted by the software SPSS (version 19.0) and PLINK. The experiment-wide significance threshold matrix of LD correlation for the markers and haplotype diagram of LD structure were calculated using the online software SNPSpD and Haploview software. We analyzed the heterozygous variants within the CDS region of the KAT2B genes and found that rs3021408 and rs17006625 were associated with the risk of CHD.

Clinical and genetic study of a novel mutation in the REEP1 gene.

OBJECTIVE: To examine the gene mutation associated with clinical phenotype from a Chinese kindred with autosomal dominant hereditary spastic paraplegia (ADHSP). METHOD: To perform linkage analysis and mutation detection. For two affected individual of the family, clinical analysis, electrophysiological examination, and MRI of brain and spinal cord were also performed. RESULT: A novel splice-site mutation (REEP1 c417+1g>a) was identified. Central motor conduction time to the first metatarsal interosseus and anterior tibial muscles were clearly prolonged. Thoracic cord atrophy was found from T1 to T10. CONCLUSION: Our study supports that mutations in REEP1 cause ADHSP and demonstrates genetic heterogeneity in ADHSP. Synapse

Nonsense mutation in the CRYBB2 gene causing autosomal dominant progressive polymorphic congenital coronary cataracts.

PURPOSE: We sought to identify the genetic defect in a large, five-generation Chinese family with autosomal dominant progressive polymorphic congenital coronary cataracts and to examine the clinical features in detail. METHODS: Clinical and ophthalmologic examinations were conducted on family members. All members were genotyped with microsatellite markers at loci previously associated with cataracts. Two-point LOD scores were calculated using a linkage package after genotyping. A mutation was detected by direct sequencing and verified by denaturing high-performance liquid chromatography (DHPLC). RESULTS: Clinical observations showed that all affected family members had progressive polymorphic coronary cataracts. Linkage analysis was obtained at markers, D22S303 (LOD score [Z]=2.11, recombination fraction [theta]=0.0) and D22S1167 (Z=1.20, theta=0.0). Haplotype analysis indicated that the cataract gene was closely linked with these two markers. Sequencing the betaB-crystallin gene (CRYBB2) revealed a C --> T transition in exon 6, which changed a codon from Gln to a stop codon (P.Q155X). This mutation cosegregated with all affected individuals and was not observed in any unaffected family member or 100 normal, unrelated individuals. CONCLUSIONS: This study identified a mutation in CRYBB2 in a large Chinese family with autosomal dominant progressive polymorphic congenital coronary cataracts. These results provide evidence that CRYBB2 is a pathogenic gene for congenital cataracts; at the same time, congenital cataracts are a clinically and genetically heterogeneous lens condition.

A new mutation in BFSP2 (G1091A) causes autosomal dominant congenital lamellar cataracts.

PURPOSE: We sought to identify the genetic defect in a four-generation Chinese family with autosomal dominant congenital lamellar cataracts and demonstrate the functional analysis with biosoftware of a candidate gene in the family. METHODS: Family history data were recorded. Clinical and ophthalmologic examinations were performed on family members. All the members were genotyped with microsatellite markers at loci considered to be associated with cataracts. Two-point LOD scores were calculated by using the Linkage Software after genotyping. A mutation was detected by using gene-specific primers in direct sequencing. Wild type and mutant proteins were analyzed with Online Bio-Software. RESULTS: Affected members of this family had lamellar cataracts. Linkage analysis was obtained at markers D3S2322 (LOD score [Z]=7.22, recombination fraction [theta]=0.0) and D3S1541 (Z=5.42, theta=0.0). Haplotype analysis indicated that the cataract gene was closely linked to these two markers. Sequencing the beaded filament structural protein 2 (BFSP2) gene revealed a G>A transversion in exon 5, which caused a conservative substitution of Arg to His at codon 339 (P.R339H). This mutation cosegregated with the disease phenotype in all affected individuals and was not observed in the unaffected family members or in 100 normal, unrelated individuals. Bioinformatic analyses showed that a highly conserved region was located around Arg339. Data generated with Online Bio-Software revealed that the mutation altered the protein's hydrophobicity, hydrophobic moment, and chaperone and regulation activities. CONCLUSIONS: This is the first reported case of a congenital lamellar cataract phenotype associated with the mutation of Arg339His (P.R339H) in BFSP2. It highlights the physiologic importance of the beaded filament protein and demonstrates a possible mechanism of action for the mutant gene.

Clinical and genetic study of SPG6 mutation in a Chinese family with hereditary spastic paraplegia.

Mutations in the NIPA1 gene cause autosomal dominant hereditary spastic paraplegia (ADHSP). To date, little is known about the relationship between genotype-phenotype correlation. In order to examine the gene mutation associated with the genotype-phenotype of Chinese kindred with ADHSP, linkage analysis and mutation detection were performed. For affected family members, clinical analysis, electrophysiological examination and MRI of the brain and spinal cord were also performed. Every effected patient had a c316 (G106R) mutation in the NIPA1 gene. Neurophysiological examination revealed decreased amplitude of compound muscle action potentials (CMAP) from the tibial and peroneal motor nerves in most patients. Sensory nerve action potential (SNAP) from the tibialis nerve was not elicited in most patients. Central motor conduction time (CMCT) to the abductor pollicis brevis muscle (APB), first metatarsal interosseus muscle (FMI) and anterior tibial muscle (AT) were either absent or clearly prolonged in all patients. Spinal cord MRI showed different levels of atrophy in every affected individual. These lesions present an increased spot or patch signal on transverse axis T2WI and an intense signal of continual longitudinal strip on the anteroposterior axis. Our study supports that mutations in the NIPA1 gene cause ADHSP and further demonstrates genotype-phenotype correlations in SPG6.

RBPJ polymorphisms associated with cerebral infarction diseases in Chinese Han population: A Clinical Trial/Experimental Study (CONSORT Compliant).

TRIAL DESIGN: Cerebral small vessel diseases (CSVDs) are a group of brain pathological processes involving cerebral small arteries, brain venules, and capillaries. The recombination signal-binding protein Jκ (RBPJ) is implicated in the pathogenesis of these diseases but its actual roles need confirmation. The aim of this work was to evaluate variations in RBPJ gene for their possible associations with the disease. METHODS: The RBPJ gene was sequenced for 400 patients with cerebral infarction disease and 600 normal controls. The statistical analyses and Hardy-Weinberg equilibrium tests of the patients and control populations were conducted using the SPSS software (version 19.0) and Plink (version 1.9), Haploview software, and online software SNPSpD. RESULTS: We characterized variants rs2871198, rs1397731, rs3822223, rs2077777, rs2270226, and rs2788861 within or near the RBPJ gene. The genetic heterozygosity of rs2871198, rs1397731, rs3822223, rs2077777, and rs2270226 was very high. Statistical analysis showed that the variants rs2270226 and rs2077777 in the gene were associated with the risk of cerebral infarction diseases in the Chinese Han population. CONCLUSIONS: rs2270226 and rs2077777 in the RBPJ gene were associated with the risk of cerebral infarction diseases in the Chinese Han population.

Rs2459976 in ZW10 gene associated with congenital heart diseases in Chinese Han population.

Congenital heart diseases (CHD) are a large group of prevalent and complex anatomic malformations of the heart, with the genetic basis remaining largely unknown. Since genes or factors associated with the differentiation of human embryonic stem (HES) cells would affect the development of all embryonic tissues, including cardiac progenitor cells, we postulated their potential roles in CHD. In this study, we focused on ZW10, a kinetochore protein involved in the process of proper chromosome segregation, and conducted comparative studies between CHD patients and normal controls matched in gender and age in Chinese Han populations. We identified three variations in the ZW10 gene, including rs2885987, rs2271261 and rs2459976, which all had high genetic heterozygosity. Association analysis of these genetic variations with CHD showed correlation between rs2459976 and the risk of CHD. We conclude that rs2459976 in the ZW10 gene is associated with CHD in Chinese Han populations.

A novel mutation in the EXT2 gene identified in two unrelated Chinese families with hereditary multiple exostoses.

Hereditary multiple exostoses (HME) is an autosomal dominant disorder characterized by benign bone tumors. In this report, we describe two unrelated Chinese families with HME. Linkage analysis and mutation detection was performed. Clinical analysis was also performed for some affected individual in both families. Linkage with the EXT2 was established in both families. A novel mutation, c505 G > T, was identified in both families. Further allelic heterogeneity of EXT2 was demonstrated by the intrafamilial and interfamilial variability in clinical phenotype.

[EXT1 and EXT2 mutation identified by denaturing high performance liquid chromatograph in three families with hereditary multiple exostoses].

OBJECTIVE: To develop a new denaturing high performance liquid chromatograph (DHPLC)-based method to screen patients with EXT gene mutation and to study the gene mutation in three families with multiple exostoses. METHODS: All the exons of EXT gene, including the intro-exon boundaries, were amplified by PCR. Linkage analysis and DHPLC screening were carried out to identify the mutations. DNA sequencing was used to confirm the mutations. RESULTS: Two known splice site mutations, IVS2+1 G to A and IVS7+1 G to T, and two SNPs have been detected in EXT2 or EXT1 gene. CONCLUSION: The transversions of IVS2+1 G to A and IVS7+1 G to T in EXT2 gene are suggested to be the disease-causing mutations and the DHPLC is a high throughout, sensitive, simple, quick, economical method to screen gene mutation in hereditary multiple exostosis.

Characterization of soluble N-ethylmaleimide-sensitive factor attachment protein receptor gene STX18 variations for possible roles in congenital heart diseases.

Congenital heart disease (CHD) is among the most prevalent and complex congenital anatomic malformations in newborns. Interactions of cardiac progenitor with a broad range of cellular regulatory factors play key roles in the formation of mammalian heart and pathogenesis of CHD. STX18 is a soluble N-ethylmaleimide-sensitive factor attachment protein receptor, which is involved in numeral cellular activities such as organelle assembly and the cell cycle. The aim of this work was to find evidence on whether STX18 variations might be associated with CHD in Chinese Han populations. We evaluated SNPs rs2044, rs33952588, rs61740788, rs12504020 and rs12644497, which are located within the exon or intron sequences of the STX18 gene, for 310 Chinese Han CHD patients and 400 non-CHD controls. Using SPSS software (version 19.0) and the online software OEGE, we conducted statistical analyses and Hardy-Weinberg equilibrium test, respectively. Among the five SNPs identified in the STX18 gene, rs33952588 and rs61740788 had very low genetic heterozygosity. In contrast, the genetic heterozygosity of the remaining three variations rs12504020 and rs12644497 near the 5'UTR and rs2044 within 3'UTR of the STX18 gene was considerably high. Analysis of associations of these genetic variations with the risk of CHD showed that rs12644497 (P value=0.017<0.05) was associated with the risk of CHD, specifically VSD and ASD, whereas rs12504020 (P value=0.560>0.05) and rs2044 (P value=0.972>0.05) were not. The SNP rs12644497 in the STX18 gene was associated with CHD in Chinese Han populations.

[Expectant therapy versus curettage for retained products of conception after second trimester termination of pregnancy: analysis of outcomes and complications].

OBJECTIVE: To evaluate the prognosis and complications of expectant therapy and curettage for retained product of conception (RPOC) after second trimester termination of pregnancy (TOP). METHODS: A total of 270 patients with RPOC following second trimester TOP in Nanfang Hospital between January, 2014 and December, 2015 were included in this study. The duration of vaginal bleeding time and menstruation recovery interval were compared between patients receiving expectant therapy and curettage for RPOC, and binary logistic regression was used to assess the risk factors for complications in bivariate and multivariate analyses. RESULTS: The duration of vaginal bleeding time was significantly longer in expectant therapy group than in curettage group (P=0.005), while the menstruation recovery interval did not differ significantly between the two groups. The incidence of vaginal bleeding time for over 42 days was significantly higher in curettage group than in expectant therapy group (P=0.040), and the incidence of a menstruation recovery interval beyond 60 days was comparable between them. The incidence of complications was significantly higher in curettage group than in expectant therapy group either with adjustment of age, gravidity, parity, history of uterine surgery status, gestational age, type of indications, regimens for TOP and induction-abortion interval (OR=18.26 [95% CI: 3.57-93.42], P<0.001) or without adjustment (OR=10.60, [95% CI: 2.36-47.66], P=0.002). CONCLUSION: Expectant therapy and curettage for RPOC after second trimester TOP have comparable prognosis, but curettage is associated with a significantly higher rate of complications.