[Clinical analysis of preimplantation genetic diagnosis with HLA matching for beta-thalassemia]

OBJECTIVE

To investigate the efficacy and feasibility of preimplantation genetic diagnosis(PGD)with human leukocyte antigen(HLA)matching for beta-thalassemia.

METHODS

A total of 43 referred beta-thalassemia couples, with at least on child in need of hematopoietic stem cell transplantation(HSCT), underwent PGD for HLA matching at the First Affiliated Hospital of Sun Yat-sen University from 2010 to 2015. PGD cycles of these couples were retrospectively analyzed, and 15 infants born from PGD-HLA were followed up.

RESULTS

A total of 84 oocyte retrieval cycles were performed, providing 14±7 oocytes per cycle. Fifty nine embryos biopsied cycles were done, including 24 cleavage stage and 35 blastocyst stage biopsy cycles. In cleavage stage, 259 embryos were biopsied, 93.4%(242/259)of them with conclusive molecular diagnosis, and the percentage of unaffected embryos(normo-homozygote and heterozygote)was 71.4%(185/259). The percentage of HLA matched unaffected embryos was 9.3%(24/259). In blastocyst stage, 306 embryos were biopsied, while 93.8%(287/306)of them were conclusive, and the percentage of unaffected embryos was 70.6%(216/306). The percentage of HLA matched unaffected embryos in blastocyst stage biopsy was 14.4%(44/306), which was higher than in cleavage stage biopsy(P< 0.05). Forty three female carriers underwent 48 embryo transfer cycles including 3 fresh and 45 frozen-thawed embryo transfer cycles. Three fresh embryo transfer cycles were done after cleavage stage biopsy, resulted in a birth of healthy twins born at 36 weeks' gestation. All the embryos were frozen after blastocyst biopsied. Totally, 54 frozen-thawed embryos that were transferred in 45 frozen-thawed embryo transfer cycles included 25 embryo from cleavage stage biopsy and 29 embryo from blastocyst stage biopsy, and 42 of them were HLA matched. Clinical pregnancy rate and implantation rate per cycle in frozen-thawed embryo transfer were 38%(17/45)and 37%(20/54)respectively. A total of 15 infants were born, 2 were from a fresh embryo transfer cycle, and 13 were from frozen-thawed embryo transfer cycles. RESULTS of prenatal diagnosis from delivered cases were matched to that of PGD. Four sick children have been cured by HSCT from these HLA matched born siblings.

CONCLUSION

PGD with HLA matching is an established method for conceiving a child who may donate hematopoietic stem cells to save an ill sibling.

[Composition of potassium channels in normal rat coronary smooth muscle cells and activation effects of docosahexaenoic acid]

OBJECTIVE

To investigate the composition of potassium channels in normal rat coronary smooth muscle cells (CASMCs) and the activation effects of docosahexaenoic acid (DHA).

METHODS

CASMCs were isolated by enzyme digestion.Effects of different types of potassium channel blockers and/or DHA on potassium channels currents were studied by whole-cell patch clamp technique.

RESULTS

Potassium currents were significantly increased with 5 μmol/L DHA perfusion (P<0.05). The current density was increased from (52.80±6.68) pA/pF to (110.09±13.39) pA/pF (P<0.05) after DHA perfusion when the stimulation voltage was 100 mV.Compared with baseline, potassium currents were significantly decreased by various inhibitor perfusion (tetraethylammonium: (49.63±5.75) pA/pF vs. (13.96±2.18) pA/pF; ibritoxin: (50.67±7.89) pA/pF vs. (26.53±4.68) pA/pF; TRAM-34: (52.60±7.02) pA/pF vs. (46.05±7.60) pA/pF; apamin: (51.97±3.83) pA/pF vs. (44.89±5.04) pA/pF; 4-aminopyridine: (51.19±3.44) pA/pF vs. (29.92±2.81) pA/pF; glyburide: (49.67±1.77) pA/pF vs. (49.61±1.87) pA/pF, all P<0.05). In presence of different inhibitors, potassium channel current densities were increased after DHA perfusion except tetraethylammonium (tetraethylammonium: ( 12.79±1.89) pA/pF; ibritoxin: (67.08±5.54) pA/pF; TRAM-34: (117.91±21.79) pA/pF; apamin: (108.33±7.06) pA/pF; 4-aminopyridine: (127.73±20.56) pA/pF; glyburide: (121.53±13.83) pA/pF, all P<0.05 compared with baseline).

CONCLUSIONS

Large-conductance calcium-activated potassium channel and voltage-gated potassium channel are the major constituents of potassium channels in CASMCs.DHA can activate potassium channels in CASMCs, mainly the large conductance calcium-activated potassium channel, thus dilate coronary arteries.

[A comparation of efficacy between unilateral laminectomy approach bilateral decompression and traditional total laminectomy decompression in the treatment of lumbar spinal stenosis]

OBJECTIVES

To compare the efficacy between unilateral laminectomy approach bilateral decompression and traditional total laminectomy decompression in the treatment of graft bone fusion and internal fixation for degenerative lumbar spinal stenosis with the unilateral symptoms.

METHOD

From January 2013 to December 2014, a total of 40 patients with unilateral symptoms of lumbar spinal stenosis were treated in Department of Spinal Surgery Bozhou People's Hospital of Anhui Province. Twenty patients(group A ) were treated by severe symptoms unilateral facetectomy and resection of superior articular and laminectomy and lateral recess decompression, interbody fusion, pedicle screw fixation.Twenty patients(group B ) were treated by total laminectomy interbody fusion and pedicle screw fixation.The time of operation, blood loss of the two groups were recorded.At the same time the visual analog scale (VAS), Oswestry disability index(ODI), Japanese Orthopaedic Association Scores(JOA) before and after operation (3, 6 , 12months) were recorded retrospectively. The effect of surgery were evaluated and compared.

RESULT

The VAS, JOA, and ODI of group A preoperation is respectively have no significant differences with the group B (P>0.05). The operation time, blood loss in operation of group A was respectively(133.2±25.3) min, (415.0±42.1) ml, significant differences with the group B[(491.0±46.3)ml; (156.2±28.5) min, P<0.05)]. The VAS, JOA, ODI of group A had no significant differences with the group B (P>0.05) at 3, 6 months after operation.The VAS, JOA, ODI of group A was respectively (3.0±0.6), (25.3±5.1), (16.5±1.5)scores, had significant differences with the group B and preoperation (P<0.05) at 12 months after operation. The radiographic data showed that the interbody fusion rate of group A was 100%, and group B was 95%, had significant differences by statistical analysis (P<0.05) at 12 months afer operation.

CONCLUSION

The improved unilateral laminectomy approach and bilateral decompression have less operation time and blood loss, more satisfactory for the lumbar spinal stenosis patients with the unilateral severe symptoms, the other side moderate stenosis and mild symptoms.The efficacy of lumbar stability and bilateral decompression is better by operation of improved unilateral approach.

[Genotype and phenotype of female Dravet syndrome with PCDH19 mutations]

OBJECTIVE

To explore the genotype and phenotype of female Dravet syndrome (DS) patients with PCDH19 mutations.

METHOD

Clinical data of all DS patients seen at Pediatric Department of Peking University First Hospital from February 2005 to May 2015 were prospectively collected. Genomic DNAs were extracted from the patients and their family members. Female DS patients without SCN1A mutation were enrolled. PCR and Sanger sequencing were performed to identify PCDH19 mutations. Clinical data of DS patients with PCDH19 mutations were summarized.

RESULT

Five different heterozygous PCDH19 mutations were identified in six unrelated patients of 75 SCN1A-negative female DS patients (8%), among whom five patients had de novo mutations and one patient's mutation was inherited from her affected mother. Three missense mutations and two insertion mutations were all located in exon 1. Mean age of onset of the six patients with PCDH19 mutations was 6.8 months (range 5-9 months). Onset of seizures were triggered by fever in four patients, after vaccination in one and without fever in one. Generalized tonic clonic seizure (GTCS) was the first seizure type in four patients and focal seizure with secondary generalized tonic clonic seizures in the remaining two. During the course, all patients presented multiple seizure types including generalized tonic clonic seizures and focal seizures in all six patients, myoclonic seizures in three, absence seizures and atonic seizures in one respectively. In all patients, seizures manifested fever-sensitive and in clusters. Seizures were always in brief duration, in most less than 5 minutes, except one experienced twice status epilepticus triggered by fever. Six patients had development delay after the seizure onset, two with autism spectrum disorder, three with ataxia.

CONCLUSION

PCDH19 is another important gene of DS after SCN1A, mutations mainly occurred de novo. PCDH19 gene mutation should be routinely screened in female DS patients without SCN1A mutation. The clinical features of female DS patients with PCDH19 mutations include that the main seizures types are generalized tonic clonic seizures and focal seizures, seizures occurr in clusters and fever-sensitive, short seizure duration, rare status epilepticus, common development delay and some may manifest autism spectrum disorders.

[The clinical, radiological and prognostic factor analysis of medullary infarction]

OBJECTIVE

To investigate the clinical and radiological features of medullary infarction (MI), and to compare the clinical characteristics of lateral medullary infarction (LMI) and medial medullary infarction (MMI).

METHODS

Patients diagnosed as acute MI who were treated from January 2009 to December 2014 in Department of Neurology, Peking University Third Hospital, were retrospectively enrolled in the study and data were analyzed including risk factors, clinical features, laboratory findings, radiological characteristics, etiology and outcomes.

RESULTS

A total of 62 cases of MI were enrolled with 48 cases of LMI and 14 cases of MMI , including 2 cases of bilateral MMI. The mean onset age of LMI and MMI was 60.2±12.3 and 56.9±14.2, respectively. The frequently affected location of LMI was the middle and upper part of medulla [40 cases (83.3%)]. The common symptoms and signs of LMI were dizzy (38 cases , 79.2%), sensory disturbance (33 cases , 68.8%), dysarthria ( 32 cases , 66.7%), dysphagia (30 cases , 62.5%), diminished pharyngeal reflex (30 cases, 62.5%), Horner's sign (29 cases, 60.4%), ataxia (26 cases, 54.2%) and nausea or vomiting (25 cases, 52.1%). The frequently affected location of MMI was the upper part of medulla (13 cases, 92.9%). The common symptoms and signs of MMI were motor dysfunction (12 cases, 85.7%), sensory disturbances (11 cases, 78.6%), dizzy (10 cases, 71.4%) and dysarthria (10 cases, 71.4%). Infarctions caused by atherosclerosis were found in 35 cases of LMI (72.9%) and 12 cases of MMI (85.7%). Five cases (10.4%) of LMI died in hospital, while 1 case (7.1%) of MMI died in hospital. No lesion was found in 16 cases (25.8%) by MRI-DWI within the first 24 hours of onset.

CONCLUSIONS

Our study showes that the mean onset age of LMI is older than that of MMI. The lesion of LMI is frequently located in the upper and middle medulla, whereas the lesion of MMI is mostly in the upper medulla. The prognosis of LMI is worse than that of MMI. Atherosclerosis of the vertebral arteries is the predominant vascular pathology in MI.

Differentiating origins of outflow tract ventricular arrhythmias: a comparison of three different electrocardiographic algorithms

Our objective is to evaluate the accuracy of three algorithms in differentiating the origins of outflow tract ventricular arrhythmias (OTVAs). This study involved 110 consecutive patients with OTVAs for whom a standard 12-lead surface electrocardiogram (ECG) showed typical left bundle branch block morphology with an inferior axis. All the ECG tracings were retrospectively analyzed using the following three recently published ECG algorithms: 1) the transitional zone (TZ) index, 2) the V₂ transition ratio, and 3) V₂ R wave duration and R/S wave amplitude indices. Considering all patients, the V₂ transition ratio had the highest sensitivity (92.3%), while the R wave duration and R/S wave amplitude indices in V₂ had the highest specificity (93.9%). The latter finding had a maximal area under the ROC curve of 0.925. In patients with left ventricular (LV) rotation, the V₂ transition ratio had the highest sensitivity (94.1%), while the R wave duration and R/S wave amplitude indices in V₂ had the highest specificity (87.5%). The former finding had a maximal area under the ROC curve of 0.892. All three published ECG algorithms are effective in differentiating the origin of OTVAs, while the V₂ transition ratio, and the V₂ R wave duration and R/S wave amplitude indices are the most sensitive and specific algorithms, respectively. Amongst all of the patients, the V₂ R wave duration and R/S wave amplitude algorithm had the maximal area under the ROC curve, but in patients with LV rotation the V₂ transition ratio algorithm had the maximum area under the ROC curve.

[Distribution of human papillomavirus (HPV) among HPV positive cervical adenocarcinoma cases detected by laser capture microdissection(LCM)]

OBJECTIVE

To investigate the distribution of human papillomavirus (HPV) in the diseased areas cut from HPV-positive cervical adenocarcinoma (ADC) detected by laser capture microdissection (LCM).

METHODS

Paraffin-embedded specimens diagnosed as ADC between 2005 and 2010 were collected from 9 hospitals in 7 regions across China. HPV genotyping was conducted on paraffin sections using sandwich technique and LCM in order to identify HPV infection in the tumor tissues. HE and p16 immunohistochemistry staining were performed to make histological diagnosis.

RESULTS

A total of 169 cervical adenocarcinoma cases were recruited, including 94 cases of mucinous adenocarcinoma (ADC-CX), 9 cases of adenosquamous carcinoma (ASC), 19 cases of minimal deviation adenocarcinoma (ADC-MIN), 14 cases of clear cell adenocarcinoma (ADC-CC), 8 cases of endometrioid adenocarcinoma (ADC-ENDO), 9 cases of serous adenocarcinoma (ADC-SER) and 16 cases of adenocarcinoma not otherwise specified (ADC-NOS). Fourteen types of high risk HPV were detected in the whole tissue section (WTS). HPV16 was the most common type, and the second was HPV18 and HPV52, respectively. Compared with WTS, the HPV-positive rate detected by LCM was lower. The HPV positive rates were significantly different among different subtypes of cervical adenocarcinoma (P<0.001). After LCM, the HPV positive rate was 50.8% and 66.7% in the single infection and multiple, infection groups respectively (P=0.14). The positive rates of p16 was significantly different among different subtypes of cervical adenocarcinoma (P<0.001). p16-positive rate was 73.9% in the HPV-positive samples after LCM, significantly higher than the 38.5% of negative samples (P<0.001).

CONCLUSIONS

Laser capture dissection technique can more precisely reflect the HPV distribution in cervical adenocarcinomas. The etiological association between HPV infection and cervical adenocarcinoma occurrence is not as close as that reported in the literature.

Strong correlation between early stage atherosclerosis and electromechanical coupling of aorta

Atherosclerosis is the underlying cause of cardiovascular diseases that are responsible for many deaths in the world, and the early diagnosis of atherosclerosis is highly desirable. The existing imaging methods, however, are not capable of detecting the early stage of atherosclerosis development due to their limited spatial resolution. Using piezoresponse force microscopy (PFM), we show that the piezoelectric response of an aortic wall increases as atherosclerosis advances, while the stiffness of the aorta shows a less evident correlation with atherosclerosis. Furthermore, we show that there is strong correlation between the coercive electric field necessary to switch the polarity of the artery and the development of atherosclerosis. Thus by measuring the electromechanical coupling of the aortic wall, it is possible to probe atherosclerosis at the early stage of its development, not only improving the spatial resolution by orders of magnitude, but also providing comprehensive quantitative information on the biomechanical properties of the artery.

Association of MMP3 genotype with susceptibility to frozen shoulder: a case-control study in a Chinese Han population

Genetic factors may play an important role in frozen shoulder etiology, which may involve matrix metalloproteinase-3 (MMP3) gene polymorphisms. In this study, we examined single nucleotide polymorphisms in MMP3 for their association with frozen shoulder susceptibility in a Chinese Han population. The rs591058, rs650108, and rs679620 polymorphisms in the MMP3 gene were genotyped in 112 subjects diagnosed as having frozen shoulder and in 143 healthy controls. rs650108 was found to be significantly associated with an increased risk of frozen shoulder. For other single nucleotide polymorphisms, no statistically significant associations with frozen shoulder were found. In conclusion, our data demonstrated that the MMP3 rs650108 variant was significantly associated with increased frozen shoulder susceptibility in a Chinese Han population.

Amorphous mixed-metal hydroxide nanostructures for advanced water oxidation catalysts

The design of highly efficient, durable, and earth-abundant catalysts for the oxygen evolution reaction (OER) is crucial in order to promote energy conversion and storage processes. Here, we synthesize amorphous mixed-metal (Ni-Fe) hydroxide nanostructures with a homogeneous distribution of Ni/Fe as well as a tunable Ni/Fe ratio by a simple, facile, green and low-cost electrochemical technique, and we demonstrate that the synthesized amorphous nanomaterials possess ultrahigh activity and super long-term cycle stability in the OER process. The amorphous Ni0.71Fe0.29(OH)x nanostructure affords a current density of 10 mA cm(-2) at an overpotential of a mere 0.296 V and a small Tafel slope of 58 mV dec(-1), while no deactivation is detected in the CV testing even up to 30 000 cycles, which suggests the promising application of these amorphous nanomaterials in electrochemical oxidation. Meanwhile, the distinct catalytic activities among these amorphous Ni-Fe hydroxide nanostructures prompts us to take notice of the composition of the alloy hydroxides/oxides when studying their catalytic properties, which opens an avenue for the rational design and controllable preparation of such amorphous nanomaterials as advanced OER electrocatalysts.

A flexible, transparent and super-long-life supercapacitor based on ultrafine Co3O4 nanocrystal electrodes

Flexible and transparent supercapacitors, as advanced energy storage devices, are essential for the development of innovative wearable electronics because of their unique optical and mechanical qualities. However, all previous designs are based on carbon-based nanostructures like carbon nanotubes and graphene, and these devices usually have poor or short cycling lives. Here, we demonstrate a high-performance, flexible, transparent, and super-long-life supercapacitor made from ultrafine Co3O4 nanocrystals synthesized using a novel process involving laser ablation in liquid. The fabricated flexible and transparent pseudocapacitor exhibits a high capacitance of 177 F g(-1) on a mass basis and 6.03 mF cm(-2) based on the area of the active material at a scan rate of 1 mV s(-1), as well as a super-long cycling life with 100% retention rate after 20 000 cycles. An optical transmittance of up to 51% at a wavelength of 550 nm is achieved, and there are not any obvious changes in the specific capacitance after bending from 0° to 150°, even after bending over 100 times. The integrated electrochemical performance of the Co3O4-based supercapacitor is greatly superior to that of the carbon-based ones reported to date. These findings open the door to applications of transition metal oxides as advanced electrode materials in flexible and transparent pseudocapacitors.

Opening the band gap of graphene through silicon doping for the improved performance of graphene/GaAs heterojunction solar cells

Graphene has attracted increasing interest due to its remarkable properties. However, the zero band gap of monolayered graphene limits it's further electronic and optoelectronic applications. Herein, we have synthesized monolayered silicon-doped graphene (SiG) with large surface area using a chemical vapor deposition method. Raman and X-ray photoelectron spectroscopy measurements demonstrate that the silicon atoms are doped into graphene lattice at a doping level of 2.7-4.5 at%. Electrical measurements based on a field effect transistor indicate that the band gap of graphene has been opened via silicon doping without a clear degradation in carrier mobility, and the work function of SiG, deduced from ultraviolet photoelectron spectroscopy, was 0.13-0.25 eV larger than that of graphene. Moreover, when compared with the graphene/GaAs heterostructure, SiG/GaAs exhibits an enhanced performance. The performance of 3.4% silicon doped SiG/GaAs solar cell has been improved by 33.7% on average, which was attributed to the increased barrier height and improved interface quality. Our results suggest that silicon doping can effectively engineer the band gap of monolayered graphene and SiG has great potential in optoelectronic device applications.

Topological centrality-based identification of hub genes and pathways associated with acute viral respiratory infection in infants

The objective of this study was to identify hub genes and pathways associated with acute respiratory infection (ARI) in infants based on gene expression profiles. Differentially expressed genes (DEGs) between ARI and normal (controls) infants were identified based on linear modeling of the microarray data using Limma package. A protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes/proteins and clusters were obtained by employing the molecular complex detection algorithm. Topological centrality was applied to characterize the biological importance of genes in the network. Functional enrichment analysis of the genes was performed based on the expression analysis systematic explore test. In total, 116 DEGs between ARI and controls were identified. Of the 61 nodes and 189 edges in the PPI network generated with the DEGs, three clusters were mined. Six hub genes namely RPL6, RPL3, EEF1B2, RPL15, EEF1A1, and RPS2, which were identified based on the topological centrality measures, were evaluated further. Functional enrichment analysis revealed that DEGs were significantly enriched in terms of Gene Ontology translational elongation, structural constituent of ribosome, and cytosol. The most significant term of pathway analysis was "ribosome". In summary, this study suggests RPL6, RPL3, and RPL15 as hub genes and the ribosome pathway to be significantly associated with viral ARI in infants, which might also be used as potential markers for the viral etiology.

Communication: Fragment-based Hamiltonian model of electronic charge-excitation gaps and gap closure

Capturing key electronic properties such as charge excitation gaps within models at or above the atomic scale presents an ongoing challenge to understanding molecular, nanoscale, and condensed phase systems. One strategy is to describe the system in terms of properties of interacting material fragments, but it is unclear how to accomplish this for charge-excitation and charge-transfer phenomena. Hamiltonian models such as the Hubbard model provide formal frameworks for analyzing gap properties but are couched purely in terms of states of electrons, rather than the states of the fragments at the scale of interest. The recently introduced Fragment Hamiltonian (FH) model uses fragments in different charge states as its building blocks, enabling a uniform, quantum-mechanical treatment that captures the charge-excitation gap. These gaps are preserved in terms of inter-fragment charge-transfer hopping integrals T and on-fragment parameters U((FH)). The FH model generalizes the standard Hubbard model (a single intra-band hopping integral t and on-site repulsion U) from quantum states for electrons to quantum states for fragments. We demonstrate that even for simple two-fragment and multi-fragment systems, gap closure is enabled once T exceeds the threshold set by U((FH)), thus providing new insight into the nature of metal-insulator transitions. This result is in contrast to the standard Hubbard model for 1d rings, for which Lieb and Wu proved that gap closure was impossible, regardless of the choices for t and U.

A rare PAX6 mutation in a Chinese family with congenital aniridia

Aniridia is an autosomal dominant disorder characterized by the complete or partial loss of the iris and is almost associated with mutations in the paired box gene 6 (PAX6). We examined three generations of a Chinese family with congenital aniridia and observed genetic defects. Exons of PAX6 from 12 family members were amplified by polymerase chain reaction, sequenced, and compared with reference sequences in NCBI reference sequence database (http://www.ncbi.nlm.nih.gov/nuccore/NG_008679.1?from=5001&to=38170&report=genbank). A rare mutation c.2T>A (M1K) in exon 4 of PAX6 was identified in all affected family members but not in unaffected family members. Our results suggest that the c.2T>A (M1K) mutation may be responsible for the pathogenesis of congenital aniridia in this family. To our knowledge, this is the first report of the M1K mutation in PAX6 in a Chinese family with this disease and the second report worldwide.

Effects of Fetal and Neonatal Murine Peripheral Blood Mononuclear Cells Infusion on MicroRNA-145 Expression in Renal Vascular Smooth Muscle Cells in MRL/lpr Mice

For patients with refractory systemic lupus erythematosus, current medications are insufficient to control their condition, and new treatments are necessary. We aimed to evaluate the therapeutic effect of fetal and neonatal murine peripheral blood (FNPB) mononuclear cells and their impact on microRNA-145 (miR-145) in renal vascular smooth muscle cells (VSMCs) of MRL/lpr lupus-prone mice. MRL/lpr mice aged 20 weeks were randomized to 3 groups of 15 (control group, radiation group, infusion group). The renal tissues were subjected to pathological examination. In situ hybridization assay was applied to measure miR-145 expression in renal vessels of MRL/lpr mice. The infusion group had significantly better results for pathological renal tissue lesions than either the control or radiation group. In MRL/lpr mice, there was positive expression of miR-145 in renal VSMCs, although the expression of miR-145 was not discernible in renal vascular intima and adventitia. The miR-145 expression in renal VSMCs in the infusion group was significantly higher than in the control or radiation group, and higher in the radiation group than in the control group; however, the difference was not statistically significant. The increased expression of miR-145 in renal VSMCs might be one of the mechanisms supporting FNPB as a therapy for lupus nephritis; it also suggests that the miR-145 in renal vessels might be a new target for treatment of lupus nephritis.

SERS detection of R6G based on a novel graphene oxide/silver nanoparticles/silicon pyramid arrays structure

We present a novel surface-enhanced Raman scattering (SERS) substrate based on graphene oxide/silver nanoparticles/silicon pyramid arrays structure (GO/Ag/PSi). The SERS behaviors are discussed and compared by the detection of R6G. Based on the contrast experiments with PSi, GO/PSi, Ag/PSi and GO/AgA/PSi as SERS substrate, the perfect bio-compatibility, good homogeneity and chemical stability were confirmed. We also calculated the electric field distributions using Finite-difference time-domain (FDTD) analysis to further understand the GO/Ag/PSi structure as a perfect SERS platform. These experimental and theoretical results imply that the GO/Ag/PSi with regular pyramids array is expected to be an effective substrate for label-free sensitive SERS detections in areas of medicine, food safety and biotechnology.

Inheritance of balanced translocation t(17; 22) from a Down syndrome mother to a phenotypically normal daughter

We report that a 30-year-old woman with mental retardation was referred for prenatal diagnoses during pregnancy. An ultrasound scan showed that the heart structure and function of the fetus were normal. Cytogenetic analysis showed that the female karyotype was 47,XX, t(17; 22) (q21; q11), +21. The woman's husband had a normal male karyotype and was phenotypically normal. During this first pregnancy, an amniocentesis, which was done at 19 weeks, revealed that the fetal karyotype was 46,XX, t(17; 22) (q21; q11). Fluorescence in situ hybridization testing of amniotic fluid gave a normal result for chromosome 21. The child was a phenotypically normal female baby.

Seroprevalence of Toxoplasma gondii infection in pigs in Jilin Province, Northeastern China

In the present study, a total of 1,235 porcine serum samples were collected from 9 counties in Jilin Province (40°52'~46°18'N,121°38'~131°19'E), northeastern China from August to October 2013, and the seroprevalence of Toxoplasma gondii infection was tested by indirect haemagglutination assay (IHA). The results showed that antibodies to T. gondii were found in 19.1% (95% confidence interval [CI], 16.9% to 21.3%), with higher seroprevalence in the breeding boars (28.6%, 95% CI, 20.0% to 37.2%), and breeding sows (32.0%, 95% CI, 25.2% to 38.9%). No significant difference was found among the slaughter pigs, fattening pigs and the piglets. These results indicated that infection with T. gondii in pigs is widespread in Jilin province, and is of public health concern.

Cloning and characterization of a farnesyl pyrophosphate synthase from Matricaria recutita L. and its upregulation by methyl jasmonate

Matricaria recutita (L.), commonly known as chamomile, is one of the most valuable medicinal plants because it synthesizes a large number of pharmacologically active secondary metabolites known as α-bisabolol and chamazulene. Although the plant has been well characterized in terms of chemical constituents of essential oil as well as pharmacological properties, little is known about the genes responsible for biosynthesis of these compounds. In this study, we report a new full-length cDNA encoding farnesyl diphosphate synthase (FPS), a key enzyme in the pathway of biosynthesis of isoprenoids, from M. recutita. The cDNA of MrFPS comprises 1032 bp and encodes 343 amino acid residues with a calculated molecular mass of 39.4 kDa. The amino acid sequence homology and phylogenetic analysis indicated that MrFPS belongs to the plant FPS super-family and is closely related to FPS from the Asteraceae family. Expression of the MrFPS gene in Escherichia coli yielded FPS activity. Using real-time quantitative PCR, the expression pattern of the MrFPS gene was analyzed in different tissues of M. recutita as well as in response to methyl jasmonate. The expression analysis demonstrated that MrFPS expression varies in different tissues (with maximal expression in flowers and stems) and was significantly elevated in response to methyl jasmonate. This study will certainly enhance our understanding of the role of MrFPS in the biosynthesis and regulation of valuable secondary metabolites in M. recutita at a molecular level.

imDC: an ensemble learning method for imbalanced classification with miRNA data

Imbalances typically exist in bioinformatics and are also common in other areas. A drawback of traditional machine learning methods is the relatively little attention given to small sample classification. Thus, we developed imDC, which uses an ensemble learning concept in combination with weights and sample misclassification information to effectively classify imbalanced data. Our method showed better results when compared to other algorithms with UCI machine learning datasets and microRNA data.

Molecular cloning and characterization of the full-length Hsp90 gene from Matricaria recutita

Heat shock protein 90 (Hsp90) is one of the most abundant and conserved chaperone proteins and plays important roles in plant growth and responses to environmental stimuli. However, little is known regarding the sequence and function of Hsp90s in Matricaria recutita. In the present study, we cloned the full-length cDNA sequence of the hsp90 gene from this species. Using rapid amplification of cDNA ends technologies with 2 degenerate primers that were designed based on the hsp90 gene sequence from other members of Asteraceae, we isolated and characterized an Hsp90 homolog gene from M. recutita (Mr-Hsp90). The full-length Mr-hsp90 cDNA sequence, containing 2097 base pairs, encodes a protein of 698 amino acids. Based on amino acid sequence identity, Mr-Hsp90 showed high similarity to other cloned Hsp90 proteins. The Mr-Hsp90 protein was closely clustered with the Lactuca sativa in a phylogenetic tree. These results indicate that the cloned sequence of Mr-Hsp90 is a member of the Hsp90 family, which is reported for the first time in M. recutita. Next, we conducted a salt stress experiment to determine the protein's function under salt stress conditions. Survival of chamomile seedlings subjected to heat-shock pretreatment was significantly increased compared with groups that had not undergone heat-shock pretreatment in a salt stress environment. This indicates that Mr-Hsp90 plays an important role in the salt resistance of chamomile seedlings.

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.

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.