Complete Duplication Research Articles

Morphologic and functional evaluation of duplicated renal collecting systems with MR urography: A descriptive analysis

PurposeTo describe the morphology and function of duplicated collecting systems in pediatric patients undergoing functional MR urography (fMRU). MethodsThis is a HIPAA compliant IRB approved retrospective study of all patients with duplicated renal collecting systems undergoing fMRU at our institution between 2010 and 2017. Two pediatric radiologists evaluated the studies to determine the presence, morphology and function of duplicated collecting systems using both T2-weighted and dynamic post-contrast fat saturated T1-weighted images. Assessed morphologic features included pelvic and calyceal dilation, partial or complete ureteral duplication, ureteral dilation, ectopic ureteral insertion and ureteroceles. Functional analysis was carried out per moiety. ResultsA total of 86 examinations (63 girls; 23 boys), median age 2.6 years (Standard Deviation 6.4 years, interquartile range: 0.4–10.3 years) and 107 kidneys (39 right; 30 left and 19 bilateral), which yielded 214 evaluable moieties, were included in the final sample. One hundred and sixty-three (76.1%) of the moieties had normal morphological features and normal functional results (average calyceal transit time and renal transit time of 2 min 28 s and 3 min 16 s, respectively). The remaining 51 moieties (23.8%) were hypoplastic or dysplastic. Seventy-seven (35.9%) had pelvic and calyceal dilation. Slightly more than half of the kidneys had complete ureteral duplication (60/107; 56%); 50 (50/107, 46.7%) had ectopic ureters (23 intra- and 27 extravesical) and 9 (9/107, 8.4%) had ureteroceles. ConclusionfMRU provides comprehensive information regarding the morphology and function of duplicated renal collecting systems in children. In particular, fMRU is useful for assessing barely or non-functioning renal poles and ectopic ureters.

Replication origin licensing deficiency and genome instability during cell cycle re‐entry from quiescence

Metazoan cells transition between active cell division cycles and periods of quiescence during development, regeneration, and homeostasis. Prior to cell division, DNA replication initiates during S phase at thousands of origins to ensure timely and complete genome duplication. Each origin that initiates must have been already licensed for replication in the preceding G1 phase by the DNA loading of Minichromosome Maintenance (MCM) complexes. Insufficient origin licensing in G1 causes incomplete replication and is associated with hypersensitivity to replication stress and DNA damage. We hypothesize that physiological differences in G1 length or G1 starting point impact origin licensing dynamics, and that such differences affect genome stability. We have explored origin licensing parameters in the first G1 phase during cell cycle re‐entry from quiescence relative to the G1 phases following mitosis in actively proliferating cells. We used single cell flow cytometry and live cell imaging to define the relationships among cell cycle re‐entry, G1 length, origin licensing dynamics and replication stress in untransformed human epithelial cells. Despite spending a long time in G1 phase, cells re‐entering the cell cycle are significantly underlicensed in the first cell cycle but not the second or subsequent cell cycles. Cells enter their first S phase before licensing is complete and are then hypersensitive to replication stress. Thus, G1 phase upon cell cycle re‐entry is characterized by slow (or delayed) origin licensing and an apparently weak licensing checkpoint. Strikingly, repeated transitions into and out of quiescence and active proliferation exacerbate replication stress and cause hypersensitivity to replication inhibitors Therefore, the transition from quiescence to active division is a particularly sensitive time for genome stability, and the number of transitions into and out of quiescence may play a role in long term cell viability and genome stability.Support or Funding InformationThe UNC Flow Cytometry Core Facility is supported in part by P30 CA016086. This work was supported by a fellowship from the NSF (DGE‐1144081) to J.P.M and by grants from the NIH to J.G.C. (GM083024 and GM102413).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Structure-Specific Endonucleases and the Resolution of Chromosome Underreplication.

Complete genome duplication in every cell cycle is fundamental for genome stability and cell survival. However, chromosome replication is frequently challenged by obstacles that impede DNA replication fork (RF) progression, which subsequently causes replication stress (RS). Cells have evolved pathways of RF protection and restart that mitigate the consequences of RS and promote the completion of DNA synthesis prior to mitotic chromosome segregation. If there is entry into mitosis with underreplicated chromosomes, this results in sister-chromatid entanglements, chromosome breakage and rearrangements and aneuploidy in daughter cells. Here, we focus on the resolution of persistent replication intermediates by the structure-specific endonucleases (SSEs) MUS81, SLX1-SLX4 and GEN1. Their actions and a recently discovered pathway of mitotic DNA repair synthesis have emerged as important facilitators of replication completion and sister chromatid detachment in mitosis. As RS is induced by oncogene activation and is a common feature of cancer cells, any advances in our understanding of the molecular mechanisms related to chromosome underreplication have important biomedical implications.

Origin Firing Regulations to Control Genome Replication Timing.

Complete genome duplication is essential for genetic homeostasis over successive cell generations. Higher eukaryotes possess a complex genome replication program that involves replicating the genome in units of individual chromatin domains with a reproducible order or timing. Two types of replication origin firing regulations ensure complete and well-timed domain-wise genome replication: (1) the timing of origin firing within a domain must be determined and (2) enough origins must fire with appropriate positioning in a short time window to avoid inter-origin gaps too large to be fully copied. Fundamental principles of eukaryotic origin firing are known. We here discuss advances in understanding the regulation of origin firing to control firing time. Work with yeasts suggests that eukaryotes utilise distinct molecular pathways to determine firing time of distinct sets of origins, depending on the specific requirements of the genomic regions to be replicated. Although the exact nature of the timing control processes varies between eukaryotes, conserved aspects exist: (1) the first step of origin firing, pre-initiation complex (pre-IC formation), is the regulated step, (2) many regulation pathways control the firing kinase Dbf4-dependent kinase, (3) Rif1 is a conserved mediator of late origin firing and (4) competition between origins for limiting firing factors contributes to firing timing. Characterization of the molecular timing control pathways will enable us to manipulate them to address the biological role of replication timing, for example, in cell differentiation and genome instability.

The cervical function and pregnancy outcomes after hysteroscopic resection of the complete uterine septum, duplicate cervix and vaginal septum

ObjectiveTo evaluate cervical function and pregnancy outcomes after hysteroscopic resection of the complete uterine septum, duplicate cervix and vaginal septum with Metzenbaum scissors. MethodsBetween January 2010 and December 2016, 13 patients admitted to the Department of Obstetrics and Gynecology of Sir Run Run Shaw Hospital with complete uterine septum, duplicate cervix and vaginal septum, were enrolled into this study. The cervical and corporal septum was cut by Metzenbaum scissors, and residual septum was cut by micro scissors under hysteroscopy. The vaginal septum was cut with the unipolar electric knife. ResultsThe operation time was about 10 ± 1.31 min. All the 13 patients present normal uterine cavities without scar formation under hysteroscopy at 3 months after operation, there was mild adhesions between anterior and posterior intrauterine wall on 2 cases. After operation, there were 13 pregnancies naturally conceived in 11 patients, 10 deliveries. The live birth rate was 76.92%, the early miscarriage rate was 23.08%. The cesarean section rate was 30%, the vaginal delivery rate was 70%, and all were term births. ConclusionThe operation was simple, convenient, and fast, without any complications and cervical insufficiency. It was easy to have vaginal deliveries.

The Cdk8/19-cyclin C transcription regulator functions in genome replication through metazoan Sld7

Accurate genome duplication underlies genetic homeostasis. Metazoan Mdm2 binding protein (MTBP) forms a main regulatory platform for origin firing together with Treslin/TICRR and TopBP1 (Topoisomerase II binding protein 1 (TopBP1)–interacting replication stimulating protein/TopBP1-interacting checkpoint and replication regulator). We report the first comprehensive analysis of MTBP and reveal conserved and metazoa-specific MTBP functions in replication. This suggests that metazoa have evolved specific molecular mechanisms to adapt replication principles conserved with yeast to the specific requirements of the more complex metazoan cells. We uncover one such metazoa-specific process: a new replication factor, cyclin-dependent kinase 8/19–cyclinC (Cdk8/19-cyclin C), binds to a central domain of MTBP. This interaction is required for complete genome duplication in human cells. In the absence of MTBP binding to Cdk8/19-cyclin C, cells enter mitosis with incompletely duplicated chromosomes, and subsequent chromosome segregation occurs inaccurately. Using remote homology searches, we identified MTBP as the metazoan orthologue of yeast synthetic lethal with Dpb11 7 (Sld7). This homology finally demonstrates that the set of yeast core factors sufficient for replication initiation in vitro is conserved in metazoa. MTBP and Sld7 contain two homologous domains that are present in no other protein, one each in the N and C termini. In MTBP the conserved termini flank the metazoa-specific Cdk8/19-cyclin C binding region and are required for normal origin firing in human cells. The N termini of MTBP and Sld7 share an essential origin firing function, the interaction with Treslin/TICRR or its yeast orthologue Sld3, respectively. The C termini may function as homodimerisation domains. Our characterisation of broadly conserved and metazoa-specific initiation processes sets the basis for further mechanistic dissection of replication initiation in vertebrates. It is a first step in understanding the distinctions of origin firing in higher eukaryotes.

Unusual Recto-colonic Tubular Duplication in a Female Neonate

Complete tubular colonic duplication is exceedingly rare. A second ectopic opening in the perineum other than a normally cited anus could be an unusual presentation. We report an unusual case of recto-colonic duplication in a 16-day-old girl who presented with fecal discharge from a vestibular opening in addition to a normally situated anus. The diagnosis of total recto-colonic tubular duplication associated with a rectovestibular fistula and a normal anus was confirmed by barium enema and computed tomography scan with double contrast. At operation, we performed a long transanal incision of the common septum to create an anastomosis between the normal and duplicated colon with complete submucosal excision of the rectovestibular fistula. The patient was doing well at 3-year follow-up examination.

Unusual Recto-colonic Tubular Duplication in a Female Neonate

Complete tubular colonic duplication is exceedingly rare. A second ectopic opening in the perineum other than a normally cited anus could be an unusual presentation. We report an unusual case of recto-colonic duplication in a 16-day-old girl who presented with fecal discharge from a vestibular opening in addition to a normally situated anus. The diagnosis of total recto-colonic tubular duplication associated with a rectovestibular fistula and a normal anus was confirmed by barium enema and computed tomography scan with double contrast. At operation, we performed a long transanal incision of the common septum to create an anastomosis between the normal and duplicated colon with complete submucosal excision of the rectovestibular fistula. The patient was doing well at 3-year follow-up examination.

Diprosopus: a review of the aetiology and case report of early surgery in a 7-week-old infant with partial facial duplication

Diprosopus is a rare craniofacial anomaly and is considered a subgroup of conjoined twinning. It encompasses a broad spectrum of duplications from single structure doubling to two completely formed heads on one neck. The aetiology of diprosopus remains a controversial topic, and many hypotheses exist. A multifactorial causal relationship is feasible because of the coexistence of other internal system anomalies of cardiac, gastrointestinal, neurological and respiratory origin. Ovid and PubMed databases were searched, using the key words: “diprosopus”, “craniofacial duplication” and “duplicated mandible”. The identified literature and key referenced articles therein were examined. The purpose was to consolidate the existing body of knowledge on the aetiology and management of diprosopus in order to improve our understanding of this rare condition. Our case report is relatively unique in that it represents a complete duplication of the mandible. Other tissues that were duplicated include the tongue, floor of mouth and the lower lip. It was hypothesised that associated growth abnormalities of the facial skeleton could undergo spontaneous correction if the duplicated mandible and associated tissues were excised early. On review, surgery is the only treatment that can offer functional, aesthetic and psychological improvement. Most patients who were offered surgery (in the reviewed literature) had a partial facial duplication. Surgery is usually deferred until the patient is older when more soft tissue is available to perform the reconstruction and when there would possibly be less growth restriction due to growth centre manipulation. This finding on the timing of surgery was in direct conflict with our hypothesis. Level of Evidence: Level V, therapeutic study.

Urologic Complications After Transplantation of Kidneys With Duplicated Ureter: A Retrospective Study

BackgroundDuplication of ureters is a common anatomic abnormality and occurs in 0.7% to 1% of the general population. In this article we focus on the safety of using of kidneys with complete ureteral duplication, provided no hydronephrosis or ureterocele was present in the donor. MethodsFrom 1998 to March 2018 there were 1965 kidneys transplanted at our institution, including 27 kidneys with duplicated ureter, which corresponds to incidence of 1.4%. Patients' medical records, surgery protocols, and Poltransplant registries were searched for urinary complications. ResultsIn the double ureter group, urologic complications occurred in 4 patients (15.4%). Similarly, severe urinary complications developed in 4 patients from the control group (17.4%). ConclusionsTransplantation of kidneys with duplicated ureters appears to be a safe and feasible procedure.

Slc:Hartley guinea pigs frequently possess duplication of the caudal vena cava.

The formation of the caudal vena cava is a complex process involving development, regression, and anastomosis. In mammals, the normal caudal vena cava runs to the right side of the abdominal aorta, while duplication of the caudal vena cava has been identified as a congenital abnormality in both companion animals and humans. The present study demonstrates that Slc:Hartley guinea pigs frequently possess asymptomatic duplicated caudal vena cava. The prevalence was 30% and 24% for males and females, respectively, with no sex-related differences. In accordance with Saad et al. (2012)’s criteria, duplicated caudal vena cava were classified into two distinct variations. The dominant variation was a complete duplication without iliac anastomosis where the left caudal vena cava continued from the left common iliac vein and joined the left renal vein; the left renal vein ran to the right to join the right caudal vena cava. The alternative variation was an incomplete duplication where the left caudal vena cava joined the right infrarenal caudal vena cava at a more cranial point than in normal cases; the renal segment was unchanged. Iliac anastomosis was not found in any cases. Duplicated caudal vena cava neither affected the body weight nor the kidney weight. In conclusion, Slc:Hartley guinea pigs frequently possess asymptomatic duplicated caudal vena cava in the absence of iliac anastomosis and appear to be a novel and useful animal model for duplicated caudal vena cava in animals and humans.

Diastematomyelia- a rare ultrasound diagnosis of spinal dysraphism

Introduction Diastematomyelia is a rare congenital anomaly where there is complete or partial duplication of the spinal cord as a result of a fibrous, cartilaginous or osseous spur. By 1994 only 100 cases had been reported worldwide. Diagnosis, if prenatal, is usually late 3rd trimester. This poster depicts a case study illustrating ultrasound appearances at 17 weeks gestation and prenatal diagnosis of Diastematomyelia at 24 weeks describing Epidemiology, Presentation, Associated Anomalies, Ultrasound appearances, Treatment and Prognosis. Rationale Due to the infrequent presentation and low recorded incidence of Diastematomyelia, limited literature is available on this condition. The purpose of this poster is to rectify this dilemma. Objectives 1. To raise awareness of the sonographic appearance of the extremely rare Diastematomyelia. 2. To disseminate the importance of an early diagnosis to promote ‘Best Practice Care’ and better patient outcomes. 3. To encourage sonographers to be vigilant and ensure thorough scanning. Method -A thorough obstetric ultrasound examination concentrating on morphology was performed utilising a Toshiba Aplio unit and 10 MHZ and 3.5MHZ curved array transducers. -Maternal and fetal structures were interrogated and documented paying particular attention to the transverse, longitudinal and coronal images of the fetal spine, skin-line and fetal cranium when a spinal abnormality was suspected. -Ultrasound appearances were compared with normal anatomy. Results Identification of an additional spinal cord posterior ossification centre is pathognomic for ultrasound antenatal diagnosis of Diastematomyelia. Conclusions The resultant significance of this poster research is to promote earlier diagnosis of this fetal anomaly and associated abnormalities assisting parents with informed decisions concerning obstetric care if their baby is affected by Diastematomyelia.

LAPAROSCOPIC REIMPLANTATION FOR THE MANAGEMENT OF URETERAL DUPLICATIONS WITH PRIMARY MEGAURETERS IN CHILDREN

Ureteral duplication is an abnormality of the urogenital tract, which may be presented in about 0,8% of the population. However, in some cases, a complete doubling of the collective system is combined with such defects as megaureter, ureterocele, vesicoureteral reflux, urinary incontinence, and others. Currently, there are several treatment options for children with urological pathology in the doubling of the kidneys. Depending on the type of pathology and the functional state of the affected segment, this can be both organ-bearing operations (heminephrouretherectomy), and reconstructive plastic interventions - ureterocystoneoimplantation of the one ureter or both ureters by a “single unit”, as well as the formation of inter-uterine anastomoses. In recent years, there was appeared the possibility to use endovideosurgical technologies for the reconstruction of the urinary tract. The article presents the experience of using laparoscopic reimplantation of the ureter in the correction of various variants of defects in doubling the upper urinary tract in children. But on the other hand, complete ureteral duplication can be detected in the association with ureter hydronephrosis, ureterocele, and ectopic ureters. Another common disease, which can coexist with duplication is vesicoureteral reflux (VUR).

Pattern and prognostic value of FLT3-ITD mutations in Chinese de novo adult acute myeloid leukemia.

FMS‐like tyrosine kinase 3 (FLT3) is one of the most frequently mutated genes in hematological malignancies. FLT3 internal tandem duplication (FLT3‐ITD) mutations located in juxtamembrane domain (JMD) and tyrosine kinase domain 1 (TKD1) regions account for two‐thirds of all FLT3 mutations. The outcome of patients remains unsatisfactory, with low survival rates. It is not yet known whether the different mutations within the FLT3 gene are all associated with patient outcome. In addition, the cause of FLT3‐ITD in‐frame duplication events remains unknown. Although there are some published studies investigating the FLT3‐ITD mutation and its clinical implications in Chinese acute myeloid leukemia (AML) patients, sample sizes tend to be small and detailed molecular profiles of FLT3 mutations are lacking in these studies. In our study, 227 FLT3‐ITD sequences were analyzed from 227 Chinese de novo AML patients. ITD were next classified into 3 types based on molecular profiles of insertion DNA sequences: DNA complete duplication (type I), DNA partial duplication (type II) and complete random sequence (type III). From the 154 patients, we confirmed that high ITD allelic ratio (≥.5) and allogeneic stem cell transplant treatment under CR1 are independent prognostic factors. We also presented evidence that ITD integration sites in the hinge region or beta1‐sheet region are an unfavorable prognostic factor in adult AML patients with FLT3‐ITD mutations. These findings may help to decipher the mechanisms of FLT3‐ITD in‐frame duplication events and stratify patients when considering different therapeutic combinations.

Uterus with Cervical Duplication and a Longitudinal Vaginal Septum: A Case Report

Objective: To present a rare uterine anomaly characterized by a complete longitudinal vaginal septum and duplicate cervices leading to a joined endocervical canal and a uterus lacking abnormalities and demonstrate a total laparoscopic hysterectomy and longitudinal septum dissection.

THORACOSCOPIC TREATMENT IN NEWBORN WITH EXTENDED TUBULAR ESOPHAGEAL DUPLICATION

We present a case of complete extended tubular esophageal duplication in a newborn without concomitant abnormal development. Esophageal duplication is diagnosed based on the clinical picture, direct laryngoscopy, esophagography and contrastenhanced computed tomography. The esophageal duplication was removed by thoracoscopy, isolation from the pharynx was performed via a separate dissection on the neck.

ADGRE1 (EMR1, F4/80) Is a Rapidly-Evolving Gene Expressed in Mammalian Monocyte-Macrophages.

The F4/80 antigen, encoded by the Adgre1 locus, has been widely-used as a monocyte-macrophage marker in mice, but its value as a macrophage marker in other species is unclear, and has even been questioned. ADGRE1 is a seven transmembrane G protein-coupled receptor with an extracellular domain containing repeated Epidermal Growth Factor (EGF)-like calcium binding domains. Using a new monoclonal antibody, we demonstrated that ADGRE1 is a myeloid differentiation marker in pigs, absent from progenitors in bone marrow, highly-expressed in mature granulocytes, monocytes, and tissue macrophages and induced by macrophage colony-stimulating factor (CSF1) treatment in vivo. Based upon these observations, we utilized RNA-Seq to assess the expression of ADGRE1 mRNA in bone marrow or monocyte-derived macrophages (MDM) and alveolar macrophages from 8 mammalian species including pig, human, rat, sheep, goat, cow, water buffalo, and horse. ADGRE1 mRNA was expressed by macrophages in each species, with inter-species variation both in expression level and response to lipopolysaccharide (LPS) stimulation. Analysis of the RNA-Seq data also revealed additional exons in several species compared to current Ensembl annotations. The ruminant species and horses appear to encode a complete duplication of the 7 EGF-like domains. In every species, Sashimi plots revealed evidence of exon skipping of the EGF-like domains, which are highly-variable between species and polymorphic in humans. Consistent with these expression patterns, key elements of the promoter and a putative enhancer are also conserved across all species. The rapid evolution of this molecule and related ADGRE family members suggests immune selection and a role in pathogen recognition.

Positive selection in coding regions and motif duplication in regulatory regions of bottlenose dolphin MHC class II genes.

The vertebrate immune response is mediated through highly adaptive, quickly evolving cell surface receptors, the major histocompatibility complex (MHC). MHC molecules bind and present a diverse array of pathogenic molecules and trigger a cascade of defenses. Use of MHC variation as a marker for population health has also evolved quickly following advances in sequencing methods. We applied a combination of traditional and next generation sequencing methodology to characterize coding (peptide binding region) and regulatory (proximal promoter) sequence variation in MHC Class II DQA and DQB genes between estuarine and coastal populations of the bottlenose dolphin, Tursiops truncatus, an apex predator whose health status is indicative of anthropogenic impacts on the ecosystem. The coding regions had 10 alleles each at DQA and DQB; the promoters had 6 and 7 alleles at DQA and DQB, respectively with variation within key regulatory motifs. Positive selection was observed for the coding regions of both genes while both coding and promoter regions exhibited geographic differences in allele composition that likely indicates diversifying selection across habitats. Most notable was the discovery of a complete duplication of a 14-bp T-box motif in the DQA promoter. Four class II promoter regions (DQA, DQB, DRA, DRB) were characterized in species from four cetacean families (Delphinidae, Monodontidae, Lipotidae, and Physeteridae) and revealed substantial promoter structural diversity across this order. Peptide binding regions may not be the only source of adaptive potential within cetacean MHC for responding to pathogenic threats. These findings are the first analysis of cetacean MHC regulatory motifs, which may divulge unique immunogenetic strategies among cetaceans and reveal how MHC transcriptional control continues to evolve. The combined MHC regulatory and coding data provide new genetic context for distinct vulnerability profiles between coastal and estuarine populations, which are key concerns for health and risk management.

The helicase Pif1 functions in the template switching pathway of DNA damage bypass.

Replication of damaged DNA is challenging because lesions in the replication template frequently interfere with an orderly progression of the replisome. In this situation, complete duplication of the genome is ensured by the action of DNA damage bypass pathways effecting either translesion synthesis by specialized, damage-tolerant DNA polymerases or a recombination-like mechanism called template switching (TS). Here we report that budding yeast Pif1, a helicase known to be involved in the resolution of complex DNA structures as well as the maturation of Okazaki fragments during replication, contributes to DNA damage bypass. We show that Pif1 expands regions of single-stranded DNA, so-called daughter-strand gaps, left behind the replication fork as a consequence of replisome re-priming. This function requires interaction with the replication clamp, proliferating cell nuclear antigen, facilitating its recruitment to damage sites, and complements the activity of an exonuclease, Exo1, in the processing of post-replicative daughter-strand gaps in preparation for TS. Our results thus reveal a novel function of a conserved DNA helicase that is known as a key player in genome maintenance.

A Rare Case of Double-System With Ectopic Ureteral Openings Into Vagina

The presence of an ectopic ureter may be indicated by continuous wetting, despite a normal voiding pattern, especially in girls. In most cases, an ectopic ureter is associated with a duplex collecting system and complete ureteral duplication. A 5-year-old girl presented with urinary incontinence regardless of the successful toilet training and a suspicion of left duplex kidney on a previous ultrasound. Contrast-enhanced computed tomography revealed a double left kidney with double ureters, both inserting together into the vagina. The surgical treatment consisted in the “en block” reimplantation of the ectopic ureters into the bladder, with complete resolution of the symptoms. The reported case does not represent just a typical presentation of a single ectopic ureter, as the duplex kidney system had ectopic both ipsilateral ureters (with insertion into the vagina). This case reminds us that congenital abnormalities of the genito-urinary tract should be considered in case of urinary incontinence and recurrent urinary tract infections.