Non-invasive prenatal testing for trisomies 21, 18 and 13: clinical experience from 146,958 pregnancies

OBJECTIVES

To report the clinical performance of massively parallel sequencing-based non-invasive prenatal testing (NIPT) in detecting trisomies 21, 18 and 13 in over 140,000 clinical samples and to compare its performance in low-risk and high-risk pregnancies.

METHODS

Between 1 January 2012 and 31 August 2013, 147,314 NIPT requests to screen for fetal trisomies 21, 18 and 13 using low-coverage whole-genome sequencing of plasma cell-free DNA were received. The results were validated by karyotyping or follow-up of clinical outcomes.

RESULTS

NIPT was performed and results obtained in 146,958 samples, for which outcome data were available in 112,669 (76.7%). Repeat blood sampling was required in 3213 cases and 145 had test failure. Aneuploidy was confirmed in 720/781 cases positive for trisomy 21, 167/218 cases positive for trisomy 18 and 22/67 cases positive for trisomy 13 on NIPT. Nine false negatives were identified, including six cases of trisomy 21 and three of trisomy 18. The overall sensitivity of NIPT was 99.17%, 98.24% and 100% for trisomies 21, 18 and 13, respectively, and specificity was 99.95%, 99.95% and 99.96% for trisomies 21, 18 and 13, respectively. There was no significant difference in test performance between the 72,382 high-risk and 40,287 low-risk subjects (sensitivity, 99.21% vs. 98.97% (P = 0.82); specificity, 99.95% vs. 99.95% (P = 0.98)). The major factors contributing to false-positive and false-negative NIPT results were maternal copy number variant and fetal/placental mosaicism, but fetal fraction had no effect.

CONCLUSIONS

Using a stringent protocol, the good performance of NIPT shown by early validation studies can be maintained in large clinical samples. This technique can provide equally high sensitivity and specificity in screening for trisomy 21 in a low-risk, as compared to high-risk, population.

A novel FBN1 heterozygous mutation identified in a Chinese family with autosomal dominant Marfan syndrome

The purpose of this study was to identify the clinical features and mutations in the fibrillin-1 gene (FBN1) in a large Chinese family with autosomal dominant Marfan syndrome (MFS). Seventeen members from a Chinese family of 4 generations were included in the study. All members underwent complete ophthalmic examination. Molecular genetic analysis was performed on all subjects. All exons of FBN1 were amplified by polymerase chain reaction, sequenced, and the sequences were compared with a reference database. Variations were evaluated in family members as well as 100 normal controls. Changes in structure and function of the protein induced by amino acid variation were predicted by bioinformatic analysis. Ectopia lentis, dolichostenomelia, arachnodactyly, and tall stature were present in all patients diagnosed with MFS. The novel heterozygous missense mutation c.2243 T>G (p.C781W) in exon 19 of FBN1 was identified in all 5 patients, but not in other family members or 100 normal controls. This mutation caused an amino acid substitution of cysteine to tryptophan at position 781 (p.C781W) of the FBN1 protein. This mutation occurred in a highly conserved region and may cause structural and functional changes in the protein according to our bioinformatic analysis. Our results suggest that the novel mutation C781W of FBN1 is responsible for the pathogenesis of MFS in this pedigree.

Knockdown of H19 enhances differentiation capacity to epidermis of parthenogenetic embryonic stem cells

Parthenogenetic embryonic stem (pES) cells are pluripotent stem cells derived from artificially activated oocytes without embryo destruction, thus eliciting less ethic concerns, and have been demonstrated promising for autologous stem cell therapy. However, pES cells could carry inappropriate imprinting such as relatively high expression of H19, a paternal imprinted gene, and may negatively influence their lineage differentiation. We show that knockdown of H19 by shRNA in mouse pES cells does not alter self-renewal and expression of genes associated with pluripotency. We find that down-regulation of H19 promotes differentiation of pES cells to epidermis. In addition, H19 depletion also facilitates differentiation of pES cells to cardiomyocytes and strong heart-like beating. Our data support the notion that reduction of H19 improves pES cell differentiation in the lineages of ectoderm and mesoderm, and provide further evidence suggesting that defective imprinting can be manipulated to allow potential application of pES cells for stem cell therapy.

Rotavirus in organ transplantation: drug-virus-host interactions

Although rotavirus is usually recognized as the most common etiology of diarrhea in young children, it can in fact cause severe diseases in organ transplantation recipients irrespective of pediatric or adult patients. This comprehensive literature analysis revealed 200 cases of rotavirus infection with 8 related deaths in the setting of organ transplantation been recorded. Based on published cohort studies, an average incidence of 3% (187 infections out of 6176 organ recipients) was estimated. Rotavirus infection often causes severe gastroenteritis complications and occasionally contributes to acute cellular rejection in these patients. Immunosuppressive agents, universally used after organ transplantation to prevent organ rejection, conceivably play an important role in such a severe pathogenesis. Interestingly, rotavirus can in turn affect the absorption and metabolism of particular immunosuppressive medications via several distinct mechanisms. Even though rotaviral enteritis is self-limiting in general, infected transplantation patients are usually treated with intensive care, rehydration and replacement of nutrition, as well as applying preventive strategies. This article aims to properly assess the clinical impact of rotavirus infection in the setting of organ transplantation and to disseminate the interactions among the virus, host and immunosuppressive medications.

Studies on expression of p14ARF and MDM2 in human thyroid neoplasms

AIM

We sought to evaluate the expression and clinical significance of p14ARF and MDM2 proteins in thyroid neoplasm.

METHODS

Immunohistochemical streptavidin-peroxidase (S-P) method was used to detect the expression of p14ARF and MDM2 proteins in 78 cases of papillary thyroid carcinoma (PTC), 34 cases of papillary thyroid microcarcinoma (PTMC) and 45 cases of thyroid adenoma.

RESULTS

The expression of p14ARF and MDM2 protein differed significantly (P<0.01) among three group. The positivity rate of p14ARF protein in PTC was significantly lower than that in thyroid adenoma (P=0.002) and PTMC (P=0.008). While the positivity rate of MDM2 protein in PTC was significantly higher than that in thyroid adenoma (P=0.000) and PTMC (P=0.009). There was a significant correlation found between the expressions of p14ARF and MDM2 proteins in PTC (P=0.013) and PTMC (P=0.012). Also, a significant correlation was found between p14ARF protein expression and lymph node metastasis in PTC (P=0.011).

CONCLUSION

It was concluded that p14ARF and MDM2 proteins might be involved in the induction and development of PTC and PTMC whereas p14ARF also had diagnostic value in determining the biological behavior of PTC.

Pharmacokinetics of cefquinome in tilapia (Oreochromis niloticus) after a single intramuscular or intraperitoneal administration

The pharmacokinetics of cefquinome was studied in plasma after a single dose (10 mg/kg) of intramuscular (i.m.) or intraperitoneal (i.p.) administration to tilapia (Oreochromis niloticus) in freshwater at 30 °C. Ten fish per sampling point were examined after treatment. The data were fitted to two-compartment open models following both routes of administration. The estimates of total body clearance (CL/F), volume of distribution (Vd/F), and absorption half-life (T1/2ka ) were 0.049 and 0.037 L/h/kg, 0.41 and 0.33 L/kg, and 0.028 and 0.035 h following i.m. and i.p. administration, respectively. After i.m. injection, the elimination half-life (T1⁄2β ) was calculated to be 5.81 h, the maximum plasma concentration (Cmax ) to be 49.40 μg/mL, the time to peak plasma cefquinome concentration (Tmax ) to be 0.14 h, and the area under the plasma concentration-time curve (AUC) to be 204.6 μg h/mL. Following i.p. administration, the corresponding estimates were 6.05 h, 44.39 μg/mL, 0.17 h and 267.8 μg h/mL. The minimum inhibitory concentrations of cefquinome, determined for 30 strains of Streptococcus agalactiae isolated from diseased tilapia, ranged from 0.015 to 0.12 μg/mL. Results from these studies support that 10 mg cefquinome/kg body weight daily could be expected to control tilapia bacterial pathogens inhibited in vitro by a minimal inhibitory concentration value of ≤2 μg/mL.

Nutrient biomarkers and vascular risk factors in subtypes of mild cognitive impairment: a cross-sectional study

OBJECTIVE

To investigate the interrelationships among blood nutrient biomarkers, the Framingham Stroke Risk Profile (FSRP), and cognitive impairment features in mild cognitive impairment (MCI) subjects and to verify whether nutrient biomarkers and FSRP are risk factors for MCI.

METHODS

According to the criteria for MCI developed by Petersen, 81 subjects aged 50-80 years were divided into a normal control group (NC group, n = 36) and an MCI group (n = 45). Then, the MCI group was divided into an amnestic MCI (a-MCI) and a multidomain MCI (md-MCI) group. All subjects were administered a comprehensive health history to calculate their FSRP score and a thorough neuropsychological assessment of four cognitive domains. Blood samples from all subjects were collected to measure the nutrient biomarkers.

RESULTS

FSRP score was not only associated with memory function, but also with executive function, which itself had a negative relationship with eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and total n-3 polyunsaturated fatty acids (n-3PUFAs) levels, and a positive relationship with the ratio of n-6 PUFAs to n-3 PUFAs(n6/n3). Compared with the NC group, the concentrations of EPA, DHA, 25-hydroxy vitamin D (25OHD), and folate and the ratio of n3/n6 in the md-MCI group were significantly lower. In the a-MCI group, only DHA concentrations and the ratio of n3/n6 were significantly lower. After adjustment for potential confounding variables, low education level [Adjusted OR=8.71 (95%CI: 1.83-41.50), p trend = 0.007], decreased plasma 25OHD [Adjusted OR = 4.41 (95% CI: 1.08-17.94), p trend=0.04] and decreased plasma DHA [Adjusted OR = 6.69 (95% CI: 1.37-32.72), p = 0.02] were associated with a higher risk of MCI.

CONCLUSIONS

Several nutrient biomarkers in MCI patients, especially in md-MCI patients, were lower compared with healthy controls, suggesting that lower 25OHD and DHA levels are risk factors for MCI. However, we found no evidence that FSRP is an early biomarker of MCI.

Reagent concentration dependent variations in the stability and photoluminescence of silica-coated ZnO nanorods

ZnO nanorods produced hydrothermally, using different precursor concentrations, show strikingly different morphologies and photoluminescence properties after encapsulation in silica. These differences are traced to differences in the nanorod growth chemistry.

A novel mutation of PAX6 identified in a Chinese twin family with congenital aniridia complicated with nystagmus

Genetic variations within the paired box gene 6 (PAX6) gene are associated with congenital aniridia. To detect the genetic defects in a Chinese twin family with congenital aniridia and nystagmus, exons of PAX6 were amplified by polymerase chain reaction (PCR), sequenced and compared with a reference database. Six members from the family of three generations were included in the study. The twins' father presented with congenital aniridia, nystagmus and cataract at birth, while the twins presented with congenital aniridia and nystagmus. A novel mutation c.888 insA in exon 10 of PAX6 was identified in all affected individuals. This study suggests that the novel mutation c.888 insA is likely responsible for the pathogenesis of the congenital aniridia and nystagmus in this pedigree. To the best of our knowledge, this is the first report of this mutation in PAX6 gene in pedigree with aniridia. Furthermore, no PAX6 gene defect was reported in twins with congenital aniridia.

Arrays of nanorods composed of ZnO nanodots exhibiting enhanced UV emission and stability

A novel one-step coating and assembly approach for fabricating well-defined ZnO nanodot/SiO₂ nanorod arrays by hydrolysis-recrystallization growth from 1-D ZnO nanorods is described. The resultant composite nanorod arrays exhibit much enhanced UV emission efficiencies and excellent stability, and thus offer particular promise for application in UV emission devices operating in harsh environments.

A novel NF1 frame-shift mutation (c.702_703delGT) in a Chinese family with neurofibromatosis type 1

This study aimed to characterize the clinical features of a Chinese pedigree with neurofibromatosis type 1 (NF1) and to identify mutations in the NF1 gene. In this three-generation family containing 8 members, 5 had been diagnosed with NF1 and the others were asymptomatic. All members of the family underwent complete medical examinations. Molecular genetic analyses were performed on all subjects included in the study. All exons of NF1 were amplified by polymerase chain reaction, sequenced, and compared with a reference database. Possible changes in function of the protein induced by amino acid variants were predicted by bioinformatic analysis. In this family, the 5 patients presented different clinical phenotypes, but all manifested typical café-au-lait macules. One novel frame-shift mutation, c.702_703delGT, in exon 7 of NF1 was identified in all affected family members, but not in the unaffected family members or in 102 normal controls. This mutation generates a premature stop codon at amino acid position 720. Additionally, a synonymous mutation c.702 G>A was found in 3 family members, including 2 affected and 1 normal individuals. In conclusion, our study suggests that a novel c.702_703delGT frame-shift mutation in NF1 is likely to be responsible for the pathogenesis of NF1 in this family. To the best of our knowledge, it is the first time that a c.702_703delGT mutation has been identified in a family with neurofibromatosis type 1.

Expression features of CXCR5 and its ligand, CXCL13 associated with poor prognosis of advanced colorectal cancer

OBJECTIVE

CXCL13 plays a unique role in the trafficking and homing of B1 cells associated with its cognate receptor, CXCR5. The CXCR5-CXCL13 axis has been previously demonstrated to be a poor prognosis factor in malignancies. However, the clinical significance of the CXCR5-CXCL13 expression in colorectal cancer carcinoma (CRC) remains unclear. The aim of this study was to investigate the CXCR5-CXCL13 expression in CRC and determine its correlation with the progression and prognosis of the tumor.

PATIENTS AND METHODS

A total of 144 paraffin-embedded specimens with advanced colon cancer were assessed for CXCR5 and CXCL13 by immunohistochemistry. Patients' long-term survival was also monitored. There were significant differences in lymph node metastasis (p = 0.0066), neural invasion (p = 0.0061) and neural invasion (p = 0.0001) between high and low expression of CXCR5.

RESULTS

There were significant differences in distant metastasis (p = 0.0261), TNM stage (p = 0.0409), differentiation (p < 0.0001) and neural invasion of the CXCL13. Both CXCR5 and CXCL13 was associated with poor correlation with the overall survival (OS) and relapse-free survival (RFS).

CONCLUSIONS

Our data suggest that the CXCR5 and CXCL13 may play a crucial role in the development, metastasis and relapse of advanced colon cancer. They can be used as prognostic markers of colon cancer in clinical practice.

Abnormalities in whole-brain functional connectivity observed in treatment-naive post-traumatic stress disorder patients following an earthquake

BACKGROUND

Convergent studies have highlighted the dysfunction of the amygdala, prefrontal cortex and hippocampus in post-traumatic stress disorder (PTSD). However, only a few studies have investigated the functional connectivity between brain regions in PTSD patients during the resting state, which may improve our understanding of the neuropathophysiology of PTSD. The aim of this study was to investigate patterns of whole-brain functional connectivity in treatment-naive PTSD patients without co-morbid conditions who experienced the 8.0-magnitude earthquake in the Sichuan province of China.

METHOD

A total of 72 PTSD patients and 86 trauma-exposed non-PTSD controls participated in the resting-state functional magnetic resonance imaging study. All these subjects were recruited from the disaster zone of the 2008 Sichuan earthquake. Functional connectivities between 90 paired brain regions in PTSD patients were compared with those in trauma-exposed non-PTSD controls. Furthermore, Pearson correlation analysis was performed between significantly abnormal connectivities in PTSD patients and their clinician-administered PTSD scale (CAPS) scores.

RESULTS

Compared with non-PTSD controls, PTSD patients showed weaker positive connectivities between the middle prefrontal cortex (mPFC) and the amygdala, hippocampus, parahippocampal gyrus and rectus, as well as between the inferior orbitofrontal cortex and the hippocampus. In addition, PTSD patients showed stronger negative connectivity between the posterior cingulate cortex (PCC) and the insula. The CAPS scores in PTSD patients correlated negatively with the connectivity between the amygdala and the mPFC.

CONCLUSIONS

PTSD patients showed abnormalities in whole-brain functional connectivity, primarily affecting the connectivities between the mPFC and limbic system, and connectivity between the PCC and insula.