Histological analysis of an alkaline based tissue clearing technique for fetal musculoskeletal tissue / Análisis histológico de una técnica de limpieza de tejido de base alcalina para tejido musculoesquelético fetal

SUMMARY: Tissue clearing techniques are frequently used in the observation and description of anatomical structures and pathways without altering the three-dimensional layout of the anatomical specimen. Tissue optical clearing promotes preservation of three-dimensional structures, which allows the study of the internal anatomy in its original position and original spatial interaction. Among these techniques, Potassium Hydroxide (KOH) maceration clearing is one of the most widely used. However, the histological changes of tissue after KOH maceration have yet to be fully understood. Our aim is to describe the microscopical differences between macerated and normal tissue. To better understand said changes, two human fetuses with a gestation period of 16 to 28 weeks were cleared and processed for histological analysis. Microtome slides of the fetuses' lower limbs were obtained and stained with Hematoxylin & Eosin, Periodic Acid Schiff (PAS), and Masson's trichrome with the purpose of observing the histological and macromolecule composition changes in cleared tissue. Remarkable differences at a histological level regarding the composition of the cellular structures, since diaphanized tissues showed a predominance of extracellular matrix composed of collagen fibers with the absence of most of the nucleated cellular tissue. Phospholipid's saponification, nucleic acids degradation and a change on proteins structural properties are the main factors inducing clearing. At the same time, molecular stability of collagen in alkaline conditions allows the specimen to maintain its shape after the process.

RESUMEN: Las técnicas de limpieza de tejido se utilizan con frecuencia en la observación y descripción de estructuras y vías anatómicas sin alterar el diseño tridimensional de la muestra anatómica. El aclaramiento óptico de tejidos promueve la preservación de estructuras tridimensionales, lo que permite el estudio de la anatomía interna en su posición original y la interacción espacial original. Entre estas técnicas, el aclarado por maceración con Hidróxido de Potasio (KOH) es una de las más utilizadas. Sin embargo, los cambios histológicos del tejido después de la maceración con KOH aún no se han entendido por completo. Nuestro objetivo es describir las diferencias microscópicas entre el tejido macerado y el normal. Para entender mejor dichos cambios, dos fetos humanos con un período de gestación de 16 a 28 semanas fueron aclarados y procesados para análisis histológicos. Se obtuvieron microtomos de las extremidades inferiores de los fetos y se tiñeron con hematoxilina y eosina, ácido peryódico de Schiff (PAS) y tricrómico de Masson con el fin de observar los cambios histológicos y de composición de macromoléculas en el tejido aclarado. Diferencias notables a nivel histológico en cuanto a la composición de las estructuras celulares, ya que los tejidos diafanizados mostraban un predominio de matriz extracelular compuesta por fibras de colágeno con ausencia de la mayor parte del tejido celular nucleado. La saponificación de los fosfolípidos, la degradación de los ácidos nucleicos y un cambio en las propiedades estructurales de las proteínas son los principales factores que inducen la depuración. Al mismo tiempo, la estabilidad molecular del colágeno en condiciones alcalinas permite que la muestra mantenga su forma después del proceso.

Estudio piloto de los factores de riesgo en la preeclampsia / Pilot study of risk factors in pre-eclampsia

La preeclampsia es una patología que surge de forma desconocida comprometiendo el estado de salud del binomio materno ­ neonatal, provocando daño multiorgánico. La característica principal es la relación con múltiples factores de riesgo tales como la hipertensión en familiares de primer grado, obesidad, alimentación, falta de controles obstétricos durante la gestación, entre otros; Objetivo: Validar el cuestionario diseñado para evaluar los factores que influyen en preclamsia, Determinar los factores de riesgo que influyen en su incidencia. Materiales y métodos: Se aplico una metodología cuanti cualitativa, corte transversal, exploratorio; la validación se efectuó a través del juicio de expertos, utilizando dos tipos de instrumentos uno para cada tipo de investigación, se valoran por separado, en el plan piloto se utiliza parte de la muestra seleccionada para la investigación macro. En el caso de la cualitativa se utiliza una técnica de entrevista a saturación, con una investigación de tipo fenomenológica, organizada por categorías. Resultados: El instrumento cuantitativo obtiene un puntaje 93% de confiabilidad, con un alfa de crombach de 0,7, el instrumento cualitativo 95%, dentro de los factores de riesgo se distingue los trastornos hipertensivos del embarazo, se asocia con un espectro de gravedad que va desde la hipertensión leve inducida por el embarazo hasta la eclampsia. Conclusión: Durante el estudio piloto se obtiene los datos con rapidez y efectividad, no existen conflictos en su comprensión, su confiabilidad garantiza el trabajo científico, la validación de instrumentos justifica el proceso, de inicio resultó conflictivo por la ausencia de instrumentos para medir los factores que influyen en esta patología, se encuentran los valores causales y en especial en las vivencias de cada uno de los actores e involucrados, La preeclampsia es un fenómeno frecuente cuya patología conlleva graves complicaciones para la madre y el feto con este tipos de estudio se aporta a su control y erradicación(AU)

Preeclampsia is a pathology that arises in an unknown way, compromising the health status of the maternal-neonatal binomial, causing multi-organ damage. The main characteristic is the relationship with multiple risk factors such as hypertension in first degree relatives, obesity, diet, lack of obstetric controls during pregnancy, among others; Objective: to validate the questionnaire designed to evaluate the factors that influence preeclampsia, to determine the risk factors that influence its incidence. Materials and methods: A quantitative, qualitative, cross-sectional, exploratory methodology was applied; The validation was carried out through the judgment of experts, using two types of instruments, one for each type of research, they are valued separately, in the pilot plan part of the selected sample is used for the macro research. In the case of qualitative, a saturation interview technique is used, with a phenomenological type investigation, organized by categories. Results: The quantitative instrument obtains a 93% reliability score, with a crombach alpha of 0.7, the qualitative instrument 95%, within the risk factors distinguishes hypertensive disorders of pregnancy, it is associated with a spectrum of severity ranging from mild pregnancy-induced hypertension to eclampsia. Conclusion: During the pilot study the data is obtained quickly and effectively, there are no conflicts in its understanding, its reliability guarantees scientific work, the validation of instruments justifies the process, initially it was conflictive due to the absence of instruments to measure the factors that influence this pathology, are the causal values ​​and especially in the experiences of each of the actors and involved, Preeclampsia is a frequent phenomenon whose pathology entails serious complications for the mother and the fetus with this type of study is provided to its control and eradication(AU)

A guideline for femoral nerve block with the age-related formulas obtained from the distances between the femoral nerve and surface anatomical landmarks in fetal cadavers / Una guía para el bloqueo del nervio femoral con fórmulas relacionadas con la edad obtenidas a partir de las distancias entre el nervio femoral y los puntos de referencia anatómicos superficiales en cadáveres fetales

SUMMARY: The femoral nerve (FN) is used for nerve block in many surgeries and provides effective postoperative analgesics in the pediatric population. However, although there are sufficient anatomical maps and signs for femoral nerve blockades in adults, there is not enough information for the pediatric group. Therefore, in our study, we tried to determine an effective area for safe block blocking with the help of bone structures in order to perform effective blockade in younger age groups. The study was conducted on 60 lower limbs. The exit point of the FN was identified. The measurements were examined in two regards, namely the level of the FN and the relationship of the FN with the surrounding structures. For the right and left sides, all the parameters showed increases with age. A significant relationship was found between all the parameters of the fetal cadavers (p<0.01). It was determined that there was a strong correlation between all parameters related to FN and surrounding bone structures (p<0.01). Sex was not found to be significantly related to the other parameters (p<0.05 Among all the fetal cadavers, high-level division was observed in six limbs (10 %), mid-level division in 33 limbs (55 %), and lower-level division in 21 limbs (35 %). Gestational age-based regression equations from my study showed that the site of the blockage could be effectively performed with the aid of palpable bone structures from the outside without the need for technical assistance.

RESUMEN: El nervio femoral (NF) se utiliza para el bloqueo nervioso en muchas cirugías y proporciona analgesia posoperatoria eficaz en la población pediátrica. Sin embargo, aunque existen suficientes mapas anatómicos y signos de bloqueo del NF en los individuos adultos, no hay suficiente información para el grupo pediátrico. Se intentó determinar una área exacta para el bloqueo del NF junto con estructuras óseas para realizar un bloqueo efectivo. El estudio se realizó en 60 miembros inferiores. Se identificó el punto de salida del NF. Las mediciones se realizaron en dos puntos, nivel del NF y la relación de éste con las estructuras circundantes. Para los lados derecho e izquierdo, todos los parámetros mostraron incrementos con la edad. Se encontró una relación significativa entre todos los parámetros de los cadáveres fetales (p<0,01). Se determinó que existía una fuerte correlación entre todos los parámetros relacionados con el NF y las estructuras óseas circundantes (p <0,01). No se encontró que el sexo se relacionara significativamente con los otros parámetros (p<0,05 Entre todos los cadáveres fetales se observó un alto nivel de división en seis miembros (10 %), una división de nivel medio en 33 miembros (55 %) y división de nivel inferior en 21 miembros (35 %). Las ecuaciones de regresión basadas en la edad gestacional del estudio mostraron que el sitio de bloqueo se podría realizar eficazmente con la ayuda de estructuras óseas palpables desde el exterior sin necesidad de asistencia técnica.

Autopsies and placental examinations of perinatal fetal deaths: a clinicopathological analysis of 105 cases / 中华病理学杂志

Objective: To summarize the clinicopathological factors related to perinatal fetal death and to evaluate importance of fetal autopsy and placental pathology. Methods: The clinicopathological data of 105 perinatal fetal deaths in Beijing Haidian Maternal and Child Health Hospital from November 2012 to December 2020 were retrospectively analyzed. Relevant literature was also reviewed. Results: The maternal age of the deceased fetuses ranged from 22 to 43 years with the average (31.35±4.04 years), and the gestational weeks were 28-40+6 weeks. Among them, 101 were singleton cases and 4 twin cases. 103 fetuses died in uterus and 2 died during delivery. Relevant factors analysis of the 105 perinatal fetal deaths showed that 86 cases (81.9%, 86/105) were related to umbilical cord/placental abnormality, 10 cases (9.5%, 10/105) uterine infection, 6 cases (5.7%, 6/105) fetal factors, 1 case was fetal maternal blood transfusion syndrome, 1 case twin blood transfusion syndrome, and 1 case died of complete uterine rupture. Among the 86 cases related to umbilical cord/placental abnormality, the diagnosis was most often based on the gross examination of placenta. The most common cause of death was umbilical cord torsion with thin root, followed by placental abruption, tight umbilical cord winding, vascular rupture and umbilical cord true knot. The morphology of placenta revealed mainly functional changes. Among the 10 cases related to intrauterine infections, the placenta generally showed lobular placental edema. The morphological characteristics of ascending infection were mainly acute chorioamnionitis, and the morphological characteristics of blood-borne infection were mainly acute or chronic villitis, as well as villous interstitial inflammation. Identification of viral inclusions suggested viral etiology, while the final diagnosis was relied on laboratory testing. Among the 6 cases related to fetal abnormality, the diagnostic value of placenta was limited and the diagnosis could be made with fetal autopsy. Conclusion: The causes of perinatal fetal death are complex, diverse, and often the synergistic result of multiple factors. Fetal autopsy and placental pathology are the key technical means to identify the cause of death and deserve more attention and utilization.

Which fetal growth charts should be used? A retrospective observational study in China / 中华医学杂志(英文版)

BACKGROUND@#The fetal growth charts in widest use in China were published by Hadlock >35 years ago and were established on data from several hundred of American pregnant women. After that, >100 fetal growth charts were published around the world. We attempted to assess the impact of applying the long-standing Hadlock charts and other charts in a Chinese population and to compare their ability to predict newborn small for gestational age (SGA).@*METHODS@#For this retrospective observational study, we reviewed all pregnant women ( n  = 106,455) who booked prenatal care with ultrasound measurements for fetal biometry at the Shenzhen Maternity and Child Healthcare Hospital between 2012 and 2019. A fractional polynomial regression model was applied to generate Shenzhen fetal growth chart ranges for head circumference (HC), biparietal diameter (BPD), abdominal circumference (AC), and femur length (FL). The differences between Shenzhen charts and published charts were quantified by calculating the Z -score. The impact of applying these published charts was quantified by calculating the proportions of fetuses with biometric measurements below the 3rd centile of these charts. The sensitivity and area under the receiver operating characteristic curves of published charts to predict neonatal SGA (birthweight <10th centile) were assessed.@*RESULTS@#Following selection, 169,980 scans of fetal biometry contributed by 41,032 pregnancies with reliable gestational age were analyzed. When using Hadlock references (<3rd centile), the proportions of small heads and short femurs were as high as 8.9% and 6.6% in late gestation, respectively. The INTERGROWTH-21st standards matched those of our observed curves better than other charts, in particular for fat-free biometry (HC and FL). When using AC<10th centile, all of these references were poor at predicting neonatal SGA.@*CONCLUSIONS@#Applying long-standing Hadlock references could misclassify a large proportion of fetuses as SGA. INTERGROWTH-21st standard appears to be a safe option in China. For fat-based biometry, AC, a reference based on the Chinese population is needed. In addition, when applying published charts, particular care should be taken due to the discrepancy of measurement methods.

Prenatal diagnosis and genetic analysis of three fetuses with paternal chromosomal simplex 3q microduplication syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the phenotypic characteristics of paternal chromosomal simplex 3q microduplication syndrome.@*METHODS@#Amniotic fluid samples of 3 fetuses from a same couple were subjected to prenatal diagnosis through combined high-resolution chromosomal G-banding karyotyping and chromosomal microarray analysis (CMA). Peripheral blood samples were also collected the couple for the determination of parental origin.@*RESULTS@#The karyotypes of all three fetuses were 46,XN,dup(3)(q25q26.1), and their CMA results were arr[hg19]3q25.33q26.1(159 336 333-166 924 969)×3. The duplication in the three fetuses have all derived from their father. No anomaly with found with the mother by CMA .@*CONCLUSION@#Through combined G-banded chromosomal karyotyping and CMA assay, a paternally derived 3q25.33-q26.1 microduplication has been identified, which has enabled genetic counseling for this couple.

Diagnosis a fetus with Coffin-Siris syndrome due to variant of SMARCA4 gene by whole exome sequencing / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical phenotype and genetic basis for a fetus suspected for Coffin-Siris syndrome.@*METHODS@#Chromosomal microarray analysis (CMA) and whole exome sequencing (WES) were carried out for the fetus. Candidate variant was verified by Sanger sequencing.@*RESULTS@#Prenatal ultrasound at 23rd gestational week has revealed fetal ventriculomegaly. No abnormality was found by CMA, while WES revealed that the fetus has harbored a de novo heterozygous c.2851G>A (p.G951R) variant of the SMARCA4 gene, which was predicted to be pathogenic.@*CONCLUSION@#Genetic testing should be considered for fetuses featuring progressive widening of lateral cerebral ventricles.

Ultrasonographic phenotype and genetic analysis of fetuses with 17q12 microdeletion / 中华医学遗传学杂志

OBJECTIVE@#To analyze the ultrasonographic phenotype and result of genetic testing in six fetuses carrying a 17q12 microdeletion.@*METHODS@#Chromosomal microarray analysis (CMA) was carried out for 6200 pregnant women undergoing prenatal diagnosis from December 2016 to May 2021.@*RESULTS@#CMA has identified 6 fetuses with a microdeletion in the 17q12 region, which spanned approximately 1.4 Mb and encompassed at least 13 OMIM genes. All fetuses have shown bilateral renal parenchymal echo enhancement. Four fetuses also had other ultrasonographic phenotypes. The parents of 4 fetuses had refused parental verification, whilst the remaining two fetuses were confirmed to be de novo in origin.@*CONCLUSION@#The prenatal ultrasonographic phenotype of 17q12 microdeletion is mainly enhanced bilateral renal parenchymal echos. CMA can facilitate detection of the 17q12 microdeletion.

Prenatal genetic diagnosis for fetuses with anomalies revealed by fetal echocardiography / 中华医学遗传学杂志

OBJECTIVE@#To carry out amniocyte karyotyping analysis and chromosomal microarray analysis (CMA) for women with anomalies revealed by fetal echocardiography.@*METHODS@#From January 2019 to December 2021, genetic testing was carried out for 205 fetuses including 97 with soft marker anomalies and 108 with structural heart abnormalities. Among these, 138 only had abnormal fetal echocardiography, whilst 38 and 29 were complicated with extracardiac soft marker anomalies and extracardiac structural malformation, respectively.@*RESULTS@#No significant difference was detected in the detection rate of genetic anomalies between fetuses with heart-related soft markers and those with abnormal heart structures (P > 0.05). Compared with those with abnormal fetal echocardiography alone, the detection rates of chromosomal aneuploidies in those with abnormal extracardiac soft markers or abnormal extracardiac structures were significantly higher (P < 0.05). Twenty-eight chromosomal aneuploidies (including a rare mosaicism), 2 balanced translocations and 1 supernumerary marker chromosome were detected by karyotyping analysis. Twenty-seven aneuploidies, 19 copy number variations (CNVs) and 1 uniparental disomy were detected by CMA.@*CONCLUSION@#Prenatal diagnosis has attached great importance to the suggestive role of fetal heart-related soft markers, and chromosomal aneuploidies are more common among fetuses with abnormal extracardiac soft markers and extracardiac structural abnormalities. Chromosomal Karyotyping is useful for the detection of balanced translocations and mosaicisms. CMA is helpful for the detection of CNVs. Identification of the genetic causes can facilitate genetic counseling for the affected couples.

Distribution of variants of 88 recessive genetic disease-related genes among 1314 individuals from Chenzhou, China / 中华医学遗传学杂志

OBJECTIVE@#To determine the carrier rate for common recessive genetic diseases in Chenzhou region in order to provide a reference for carrier screening in this region.@*METHODS@#Targeted capture and high-throughput sequencing were carried out to detect potential variants of 79 genes associated with 88 recessive genetic diseases. Couples at risk were provided with prenatal diagnosis upon their subsequent pregnancies.@*RESULTS@#A total of 1314 individuals were enrolled, among whom 355 (27.02%) were found to be carrier for at least one disease. The carrier rates for 8 diseases have exceeded 1%, with the most common two including thalassemia (11.72%, 154/1314) and autosomal recessive deafness (5.48%, 72/1314). Ten couples were found to be at risk for producing affected offspring. Among these, five females were carriers for X-linked recessive genetic diseases. Following genetic counseling, seven couples had accepted prenatal diagnosis, and 3 affected fetuses were diagnosed.@*CONCLUSION@#The disease types and pathogenic variants of Chenzhou region have differed from previously reported. Further research is required to validate the above finding with a larger populations.

Genetic analysis and prenatal diagnosis of a fetus with Xq25 microduplication / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a fetus with structural brain abnormalities.@*METHODS@#The karyotypes of the fetus and its parents were analyzed by conventional G-banding. Chromosome microarray analysis (CMA) was carried out to detect chromosomal microdeletion and microduplication.@*RESULTS@#No kartotypic abnormality was detected in the fetus and its parents. CMA has identified a 194 kb microduplication at Xq25 in the fetus, which encompassed exons 4-35 of the STAG2 gene and was derived from its mother.@*CONCLUSION@#The Xq25 duplication encompassing part of the STAG2 gene probably underlay the brain malformation in the fetus.

Analysis of TUBB2B gene variant in a fetus with complex cortical dysplasia with other brain malformations-7 / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a fetus with dysgenesis of corpus callosum and other brain malformations.@*METHODS@#Whole exome sequencing was carried out for the fetus and its parents. Suspected pathogenic variants were verified by Sanger sequencing.@*RESULTS@#A novel de novo missense variant c.758T>A (p.L253Q) of the TUBB2B gene was identified, which was unreported previously. Based on the guidelines from the American College of Medical Genetics, the c.758T>A variant was predicted to be likely pathogenic. Bioinformatics analysis predicted that the leucine at position 253 was highly conserved among various species, and the c.758T>A variant may impact the formation of hydrogen bonds between Leu253 and Asp249 and Met257 residues, which in turn may affect the combination of GTP/GDP and function of the TUBB2B protein.@*CONCLUSION@#The c.758T>A variant of the TUBB2B gene probably underlay the fetal malformations in this Chinese family. Above discovery has enriched the spectrum of TUBB2B gene variants and provided a basis for genetic counseling and prenatal diagnosis.

Practice of clinical application of noninvasive prenatal testing based on cell-free fetal DNA / 中华医学遗传学杂志

OBJECTIVE@#To assess the application value of noninvasive prenatal testing (NIPT) based on cell-free fetal DNA.@*METHODS@#The results of 2777 cases of basic and extended NIPT were retrospectively analyzed. The clinical data and outcome of pregnancy were analyzed, in addition with the diagnosis rate and testing efficiency.@*RESULTS@#Among the 2777 pregnant women, 1192 (42.9%) had accepted basic NIPT and 1585 (57.1%) accepted extended NIPT. With a failure rate of 0.1%, 8 and 6 cases were reported respectively as high-risk pregnancies for trisomy 21 and sex chromosomal abnormalities. Other genetic abnormalities were detected in 32 cases. The positive predictive value for trisomy 21 was 85.7%, and one case of 47,XXX was diagnosed among 3 women with high risks for sex chromosomal abnormalities. For those with a high risk for other genetic abnormalities, pregnant diagnosis rates of basic and extended NIPT were 71.4% (5/7) and 68.2% (15/22), respectively. Seven copy number variations (CNVs) were confirmed, including one pathogenic CNV, one likely pathogenic CNV and 5 variants of unknown significance. Among 6 cases with high-risk of maternal CNVs, 5 fetuses and the mothers were confirmed to be carriers. No CNV was detected in the remainder fetus by chromosomal microarray analysis, while its mother was a carrier of the corresponding CNV.@*CONCLUSION@#NIPT has shown a relatively high positive predictive value for the screening of trisomy 21 and maternal CNVs but with a limited efficiency for the discovery of fetal CNVs. For other genetic abnormalities signaled by NIPT, informed choice by the pregnant women during pre-testing consultation is recommended. Invasive prenatal diagnosis should be considered in the combination of NIPT reports and fetal ultrasound, while the residual risks should be fully informed.

Prenatal ultrasonographic manifestations and genetic analysis of eight fetuses with 16p11.2 microdeletions / 中华医学遗传学杂志

OBJECTIVE@#To analyze the intrauterine phenotype and genotype of eight fetuses carrying a 16p11.2 microdeletion.@*METHODS@#5100 fetuses undergoing routine prenatal diagnosis were subjected to single nucleotide polymorphism-based microarray (SNP-array) analysis. Fetuses harboring a 16p11.2 microdeletion were analyzed for their ultrasonographic characteristics.@*RESULTS@#Eight fetuses were found to harbor a microdeletion in the 16p11.2 region. Among these, six had a typical 500-600 kb deletion, while the remaining two had an atypical 220 kb deletion at the distal part of 16p11.2. Four fetuses showed vertebral malformations, two had mild left ventriculomegaly, one had hydrocephalus, and one had pulmonary valve stenosis with regurgitation. The parents of five fetuses have accepted pedigree verification, and the results confirmed that the 16p11.2 microdeletions carried by fetuses all had a de novo origin.@*CONCLUSION@#The intrauterine phenotypes of fetuses carrying a 16p11.2 microdeletion may be variable, and the deletion can be effectively detected with the SNP-array assay.

Analysis of HNF1B gene variant in a fetus featuring infantile polycystic kidney disease / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a fetus featuring infantile polycystic kidney disease (IPKD).@*METHODS@#Following elective abortion, fetal tissue and peripheral blood samples of its parents were collected for the extraction of genomic DNA. Whole exome sequencing was carried out to detect potential variants correlated with the phenotype.@*RESULTS@#The fetus was found to harbor a heterozygous c.1370C>T (p.P457L) variant of the HNF1B gene, which was unreported previously. The same variant was not detected in either parent.@*CONCLUSION@#The heterozygous c.1370C>T (p.P457L) variant of the HNF1B gene probably underlay the IPKD in this fetus. Above finding has enabled genetic counseling and prenatal diagnosis for the family.

The value of re-sampling for patients who had failed non-invasive prenatal testing due to low cell-free fetal DNA fraction / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of re-sampling for patients who had failed non-invasive prenatal testing (NIPT) due to low cell-free fetal DNA (cffDNA) fraction.@*METHODS@#Clinical data of 20 387 patients undergoing NIPT test was reviewed. The patients were re-sampled when initial blood test did not yield a result due to cffDNA fraction. The results were analyzed, and the outcome of pregnancy was followed up.@*RESULTS@#Among all samples, 17 (0.08%) had failed to yield a result due to low cffDNA fraction, all of which accepted re-sampling. A result was attained in 16 cases, with a success rate of 94.12%. Only one sample had failed the re-test.@*CONCLUSION@#For patients who had failed the initial NIPT due to low cffDNA fraction, re-sampling should be considered with gestational week and ultrasound results taken into consideration.

Genetic analysis of a fetus with mosaicism of 13q inversion duplication / 中华医学遗传学杂志

OBJECTIVE@#To report on a case of mosaicism 13q inversion duplication, analyze its mechanism, and discuss the correlation between its genotype and phenotype.@*METHODS@#Amniotic fluid and umbilical cord blood were collected at 23 and 32 weeks of gestation, respectively. Combined with G-banding chromosome karyotyping analysis, single nucleotide polymorphism array (SNP-array) and fluorescence in situ hybridization (FISH) were used to confirm the result.@*RESULTS@#The karyotype of the fetus was determined as 47,XY,+inv dup(13)(q14.3q34)/46,XY. After careful counseling, the couple decided to continue with the pregnancy, and had given birth to a boy at 40 weeks' gestation. Except for a red plaque (hemangioma) on the nose bridge, no obvious abnormality (intelligence to be evaluated) was discovered.@*CONCLUSION@#To provide reference for clinical genetic counseling and risk assessment, the location and proportion of new centromere formation should be fully considered in the case of mosaicism 13q inversion duplication.

Comparison of biological characteristics of placenta mesenchymal stem cells derived from fetus / 生物工程学报

Mesenchymal stem cells (MSCs) have broad application potentials in regenerative medicine and translational medicine. Obtaining large quantities of primary-cultured MSCs and select the most suitable cell origin for targeted diseases are critical to research. To select the most suitable seed cells of MSCs from different origins for clinical treatment and research, biological characteristics of MSCs from human umbilical cord and placenta were compared. These include cell morphology, surface marker expression, differentiation and karyotype. Transcriptome sequencing of four MSCs from fetus were performed and the results were analyzed from the perspective of proliferation and cytokine secretion. The results revealed that MSCs from umbilical cord (UC), amniotic membrane (AM), chorionic membrane (CM), chorionic villi (CV) and deciduae (DC) met the minimum standards of the International Society of Cell Therapy (ISCT) in 2006 and had the general characteristics of stem cells. Karyotype analysis showed that MSCs derived from UC, AM, CM and CV were all from fetus except that the DC-MSCs were from mother. Transcriptome sequencing analysis showed that hMSCs from umbilical cord and placenta had similar gene expression patterns, while different expression patterns were observed in specific genes involved in cell cycle, cell division, cell death, cell growth and development. These genes play important roles in transcriptional regulation, DNA repair, DNA replication and chromosome stability, which were momentous components of cellular or subcellular fraction movement, cell communication, cell tissue protrusions, cytokine secretion and hormone metabolism. Transcriptome sequencing analysis explained the differences in biological characteristics among MSCs from different sources, while verification experiments based on the transcriptome sequencing results showed that the proliferation and cytokine secretion capabilities of MSCs from different sources were significantly different. In all, UC-MSCs and CV-MSCs with stronger proliferation and higher levels of paracrine factors secretion may show their respective advantages in treating diseases.

Retroperitoneal fetus in fetu in a 65-year-old man

Fetus in fetu (FIF) is a rare congenital anomaly in which a malformed fetus is incorporated within the body of its twin. It was first described in the late 18th century and has an incidence of 1:500,000 live births. In most cases, the diagnosis is made in infants or young adults. To date, the oldest patient reported in the literature was 47 years old. We describe the case of a 65-year-old patient with FIF, now the oldest reported in the literature. Our patient meets all the diagnostic criteria for FIF, including the presence of a limb in advanced formation inside the lesion. The treatment was surgical excision. FIF should be considered in the differential diagnosis of abdominal masses, typically recognized in infancy. Symptoms arise from mass effects. Surgical resection should be performed due to the potential for malignant transformation.