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In this paper, a new apodized fiber Bragg grating (FBG) structure, the Chebyshev apodization, is proposed. The Chebyshev polynomial distribution has been widely used for the optimal design of antennas and filters, but it has not been used for designing FBGs. Unlike the function of traditional Gaussian-apodized FBGs, the Chebyshev polynomial is a discrete function. We demonstrate a new methodology for designing Chebyshev-apodized FBGs: the grating region is divided by discrete n sections with uniform gratings, while the index change is used to express the Chebyshev polynomial. We analyze the Chebyshev-apodized FBGs by using coupled mode theory and the piecewise-uniform approach. The reflection spectrum and the dispersion of Chebyshev-apodized FBGs are calculated and compared with those of Gaussian FBGs. Moreover, a sidelobe suppression level (SSL), a parameter of the Chebyshev polynomial, along with the maximum ac-index change of FBGs are analyzed. Assume that the grating length is 20mm, SSL is 100 dB, the section number is 40, and the maximum ac-index change is 2 × 10-4. The reflection spectrum of Chebyshev apodized FBGs shows flattened sidelobes with an absolute SSL of -95.9 dB (corresponding to SSL=100 dB). The simulation results reveal that at the same full width at half maximum, the Chebyshev FBGs have lower sidelobe suppression than the Gaussian FBGs, but their dispersion is similar. We demonstrate the potential of using Chebyshev-apodized FBGs in optical filters, dispersion compensators, and sensors; Chebyshev apodization can be applied in the design of periodic dielectric waveguides.

Abnormal angiogenesis and regression of the diseased retinal vasculature are key processes associated with ischemic retinopathies, but the underlying mechanisms that regulate vascular remodeling remain poorly understood. Here, we confirmed the specific expression of semaphorin 3G (Sema3G) in retinal endothelial cells (ECs), which was required for vascular remodeling and the amelioration of ischemic retinopathy. We found that Sema3G was elevated in the vitreous fluid of patients with proliferative diabetic retinopathy (PDR) and in the neovascularization regression phase of oxygen-induced retinopathy (OIR). Endothelial-specific Sema3G knockout mice exhibited decreased vessel density and excessive matrix deposition in the retinal vasculature. Moreover, loss of Sema3G aggravated pathological angiogenesis in mice with OIR. Mechanistically, we demonstrated that HIF-2α directly regulated Sema3G transcription in ECs under hypoxia. Sema3G coordinated the functional interaction between β-catenin and VE-cadherin by increasing β-catenin stability in the endothelium through the neuropilin-2 (Nrp2)/PlexinD1 receptor. Furthermore, Sema3G supplementation enhanced healthy vascular network formation and promoted diseased vasculature regression during blood vessel remodeling. Overall, we deciphered the endothelium-derived Sema3G-dependent events involved in modulating physiological vascular remodeling and regression of pathological blood vessels for reparative vascular regeneration. Our findings shed light on the protective effect of Sema3G in ischemic retinopathies.

CRISPR/Cas-based mRNA imaging has been developed to labeling of high-abundance mRNAs. A lack of non-genetically encoded mRNA-tagged imaging tools has limited our ability to explore the functional distributions of endogenous low-abundance mRNAs in cells. Here, we developed a CRISPR-Sunspot method based on the SunTag signal amplification system that allows efficient imaging of low-abundance mRNAs with CRISPR/Cas9. Methods: We created a stable TRE3G-dCas9-EGFP cell line and generated an Inducible dCas9-EGFP imaging system for assessment of two factors, sgRNA and dCas9, which influence imaging quality. Based on SunTag system, we established a CRISPR-Sunspot imaging system for amplifying signals from single-molecule mRNA in live cells. CRISPR-Sunspot was used to track co-localization of Camk2a mRNA with regulatory protein Xlr3b in neurons. CRISPR-Sunspot combined with CRISPRa was used to determine elevated mRNA molecules. Results: Our results showed that manipulating the expression of fluorescent proteins and sgRNA increased the efficiency of RNA imaging in cells. CRISPR-Sunspot could target endogenous mRNAs in the cytoplasm and amplified signals from single-molecule mRNA. Furthermore, CRISPR-Sunspot was also applied to visualize mRNA distributions with its regulating proteins in neurons. CRISPR-Sunspot detected the co-localization of Camk2a mRNA with overexpressed Xlr3b proteins in the neuronal dendrites. Moreover, we also manipulated CRISPR-Sunspot to detect transcriptional activation of target gene such as HBG1 in live cells. Conclusion: Our findings suggest that CRISPR-Sunspot is a novel applicable imaging tool for visualizing the distributions of low-abundance mRNAs in cells. This study provides a novel strategy to unravel the molecular mechanisms of diseases caused by aberrant mRNA molecules., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Blood-brain barrier (BBB) dysfunction has been suggested to play an important role in epilepsy. However, the mechanism mediating the transition from cerebrovascular damage to epilepsy remains unknown. Here, we report that endothelial cyclin-dependent kinase 5 (CDK5) is a central regulator of neuronal excitability. Endothelial-specific Cdk5 knockout led to spontaneous seizures in mice. Knockout mice showed increased endothelial chemokine (C-X-C motif) ligand 1 (Cxcl1) expression, decreased astrocytic glutamate reuptake through the glutamate transporter 1 (GLT1), and increased glutamate synaptic function. Ceftriaxone restored astrocytic GLT1 function and inhibited seizures in endothelial Cdk5-deficient mice, and these effects were also reversed after silencing Cxcl1 in endothelial cells and its receptor chemokine (C-X-C motif) receptor 2 (Cxcr2) in astrocytes, respectively, in the CA1 by AAV transfection. These results reveal a previously unknown link between cerebrovascular factors and epileptogenesis and provide a rationale for targeting endothelial signaling as a potential treatment for epilepsy., (© 2019 Liu et al.)

Anxiety disorders are the most prevalent psychiatric disorders, but their pathogenic mechanism remains poorly understood. Here, we report that transmembrane protein 74 (TMEM74), which contains two putative transmembrane domains and exhibits high levels of mRNA in the brain, is closely associated with the pathogenesis of anxiety disorders. TMEM74 was decreased in the serum of patients with anxiety and the basolateral amygdaloid nucleus (BLA) in chronic stress mice. Furthermore, genetic deletion of Tmem74 or selective knockdown of Tmem74 in BLA pyramidal neurons resulted in anxiety-like behaviors in mice. Whole-cell recordings in BLA pyramidal neurons revealed lower hyperpolarization-activated cation current (I h ) and greater input resistance and excitability in Tmem74 -/- neurons than in wild-type neurons. Accordingly, surface expression of hyperpolarization-activated cyclic nucleotide-gated 1 (HCN1) channels was also lower in the BLA of Tmem74 -/- mice. The I h current blocker ZD7288 mimicked these effects in BLA pyramidal neurons in wild-type mice but not in Tmem74 -/- mice. Consistent with the improvement in anxiety-like behaviors, Tmem74 overexpression restored HCN1 channel trafficking and pyramidal neuron excitability in the BLA of Tmem74 -/- and chronic stress mice. Mechanistically, we demonstrate that interactions between Tmem74 and HCN1 are physiologically relevant and that transmembrane domain 1 (TM1) is essential for the cellular membrane localization of Tmem74 to enhance I h . Together, our findings suggest that Tmem74 coupling with HCN1 acts as a critical component in the pathophysiology of anxiety and is a potential target for new treatments of anxiety disorders.

Prolonged occlusion of multiple microvessels causes microvascular injury. G protein-coupled receptor 124 (GPR124) has been reported to be required for maintaining central nervous system (CNS) angiogenesis and blood-brain barrier integrity. However, the molecular mechanisms by which GPR124 regulates pericytes during ischemia have remained elusive. Methods : A microsphere embolism-induced ischemia model was used to evaluate the expression of GPR124 following microsphere embolism. Immunocytochemistry and stochastic optical reconstruction microscopy imaging were used to assess the expression and distribution of GPR124 in human brain vascular pericytes (HBVPs) and after the treatment with 3-morpholino-sydnonimine (SIN-1) or oxygen-glucose deprivation (OGD). The effect of GPR124 knockdown or overexpression on HBVP migration was analyzed in vitro using wound healing assays and a microfluidic device. GPR124 loss-of-function studies were performed in HBVPs and HEK293 cells using CRISPR-Cas9-mediated gene deletion. Time-lapse imaging was used to assess dynamic changes in the formation of filopodia in an individual cell. Finally, to explore the functional domains required for GPR124 activity, deletion mutants were constructed for each of the N-terminal domains. Results : GPR124 expression was increased in pericytes following microsphere embolism. Morphological analysis showed localization of GPR124 to focal adhesions where GPR124 bound directly to the actin binding protein vinculin and upregulated Cdc42. SIN-1 or OGD treatment redistributed GPR124 to the leading edges of HBVPs where GPR124 signaling was required for pericyte filopodia formation and directional migration. Partial deletion of GPR124 domains decreased SIN-1-induced filopodia formation and cell migration. Conclusion : Taken together, our results provide the first evidence for a role of GPR124 in pericyte migration under ischemic conditions and suggest that GPR124 was essential for Cdc42 activation and filopodia formation., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.

The proper interactions between blood vessels and neurons are critical for maintaining the strength of neural circuits and cognitive function. However, the precise molecular events underlying these interactions remain largely unknown. Here, we report that the selective knockout of semaphorin 3G (Sema3G) in endothelial cells impaired hippocampal-dependent memory and reduced dendritic spine density in CA1 neurons in mice; these effects were reversed after restoration of Sema3G levels in the hippocampus by AAV transfection. We further show that Sema3G increased excitatory synapse density via neuropilin-2/PlexinA4 signaling and through activation of Rac1. These results provide the first evidence that, in the central nervous system, endothelial Sema3G serves as a vascular-derived synaptic organizer that regulates synaptic plasticity and hippocampal-dependent memory. Our findings highlight the role of vascular endothelial cells in regulating cognitive function through intercellular communication with neurons in the hippocampus., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Grb2-associated-binding protein 1 (Gab1) is a docking/scaffolding molecule known to play an important role in cell growth and survival. Here, we report that Gab1 is decreased in cholinergic neurons in Alzheimer's disease (AD) patients and in a mouse model of AD. In mice, selective ablation of Gab1 in cholinergic neurons in the medial septum impaired learning and memory and hippocampal long-term potentiation. Gab1 ablation also inhibited SK channels, leading to an increase in firing in septal cholinergic neurons. Gab1 overexpression, on the other hand, improved cognitive function and restored hippocampal CaMKII autorphosphorylation in AD mice. These results suggest that Gab1 plays an important role in the pathophysiology of AD and may represent a novel therapeutic target for diseases involving cholinergic dysfunction.

Objective: Hyponatremia is one of the most frequently encountered electrolyte disorder in small cell lung cancer (SCLC) patients. It was shown that some SCLC cell lines could produce atrial natriuretic peptide (ANP) and arginine vasopressin (AVP). The aim of the study was to assess the secretion of ANP, AVP and their relative contributions to hyponatremia in SCLC patients, especially in patients with brain metastases., Patients and Methods: In total, 194 SCLC patients including 51 patients with brain metastases were collected. The levels of ANP and AVP were measured with radioimmunoassay kits. And then their associations with serum sodium were investigated. The progression-free survival (PFS) was compared between the hyponatremia group and the normal serum sodium group., Results: Serum sodium was negatively correlated with the plasma levels of ANP (r=-0.171, p=0.017) and AVP (r = -0.244, p=0.001) in all SCLC patients. In the brain metastatic subgroup, there was also a negative correlation between serum sodium and ANP (r=-0.399, p=0.004), while there was no correlation between serum sodium and AVP (r=-0.232, p=0.101). The occurrence rate of hyponatremia (serum sodium values below 135 mmol/l) in patients with brain metastases (21/51, 41.18%) was higher than that in patients without brain metastases (37/143, 25.87%) (p=0.040). The progression-free survival (PFS) in the hyponatremia group was significantly shorter than that in patients of the group without hyponatremia (p=0.010). Moreover, compared with patients which regained normal serum sodium after the treatment, the PFS of patients still with hyponatremia after the treatment was significantly shorter (p=0.049)., Conclusions: ANP might play a leading role in the formation of hyponatremia of SCLC patients with brain metastases. Correcting hyponatremia timely and appropriately could improve SCLC patients' prognosis.

Objective: The current meta-analysis evaluated the association between vitamin B12 intake and blood vitamin B12 level and colorectal cancer (CRC) risk., Design: The PubMed and EMBASE databases were searched. A dose-response analysis was performed with generalized least squares regression, with the relative risk (RR) and 95 % CI as effect values., Setting: The meta-analysis included seventeen studies., Subjects: A total of 10 601 patients., Results: The non-linear dose-response relationship between total vitamin B12 intake and CRC risk was insignificant (P=0·690), but the relationship between dietary vitamin B12 intake and CRC risk was significant (P<0·001). Every 4·5 μg/d increment in total and dietary vitamin B12 intake was inversely associated with CRC risk (total intake: RR=0·963; 95 % CI 0·928, 0·999; dietary intake: RR=0·914; 95 % CI 0·856, 0·977). The inverse association between vitamin B12 intake and CRC risk was also significant when vitamin B12 intake was over a dosage threshold, enhancing the non-linear relationship. The non-linear dose-response relationship between blood vitamin B12 level and CRC risk was insignificant (P=0·219). There was an insignificant association between every 150 pmol/l increment in blood vitamin B12 level and CRC risk (RR=1·023; 95 % CI 0·881, 1·187)., Conclusions: Our meta-analysis indicates that evidence supports the use of vitamin B12 for cancer prevention, especially among populations with high-dose vitamin B12 intake, and that the association between CRC risk and total vitamin B12 intake is stronger than between CRC risk and dietary vitamin B12 intake only.

Objective: To identify the pathogenic mutation underlying Lowe syndrome in a Chinese family., Methods: After obtaining written informed consent of all participating individuals, peripheral blood samples were collected from 11 family members, including one affected male and three obligate female carriers, and an amniotic fluid sample was obtained from a pregnant carrier female in the family. Genomic DNA was extracted using the standard SDS-proteinase K-phenol/chloroform method. Linkage analysis was carried out using microsatellite markers flanking the OCRL gene. All OCRL exons and their flanking intronic sequences were PCR-amplified and sequenced for the proband. Restriction analysis was performed to confirm the pathogenic mutation. Prenatal genetic testing was carried out by combining haplotype analysis, DNA sequencing and restriction analysis., Results: Linkage analysis showed that the affected male and three obligate carrier females shared a same haplotype. Sequence analysis in the proband revealed a nonsense mutation c.2032C→T (p.R678X) in exon 18 of the OCRL gene. Restriction analysis showed that the mutation was present in the proband and three obligate carriers, but not in the other 7 available family members. This nonsense mutation was not found in the amniotic fluid sample., Conclusion: A recurrent OCRL nonsense mutation was found to be the pathogenic mutation in the Chinese family and the fetus didn't carry the mutation.

Background: Crohn's disease (CD) patients may be at increased risk for the development of Hodgkin's lymphoma (HL) or non-Hodgkin's lymphoma (NHL), either through exposure to immunosuppressive medications or due to their underlying chronic inflammatory illness. There are limited data regarding the natural history of CD following treatment of lymphoma. We present a series of CD patients who were treated for lymphoma and describe the natural history of their CD following lymphoma treatment., Methods: Retrospective case series from three academic referral centers was used. All CD patients with a history of lymphoma were identified. Demographic data, CD medication exposure, and surgical procedures before and after lymphoma treatment were recorded., Results: Nine CD patients with a history of lymphoma were identified. Eight individuals received chemotherapy, while one patient was observed without treatment. Eight patients remained free of lymphoma for a mean of 72.8 months (range 1-276 months). The ninth patient had recurrence of his HL 3 years after lymphoma diagnosis. Following lymphoma treatment, two patients had quiescent CD with no specific therapy. Three patients demonstrated significant clinical relapse of their CD and a fourth patient developed CD after treatment of her lymphoma, which ultimately required long-term immunomodulator therapy with 6-mercaptopurine or methotrexate in the first three patients, and azathioprine in the fourth. Four patients required CD surgery after lymphoma treatment., Conclusion: We report on the clinical course of CD in patients who develop lymphoma. Significant clinical relapse of CD following successful medical treatment of lymphoma occurred frequently in patients with a history of this neoplasm., (Copyright © 2011 Crohn's & Colitis Foundation of America, Inc.)

Analysis of optical waveguides with thin metal films is studied by the multidomain pseudospectral frequency-domain (PSFD) method. Calculated results for both guiding and leaky modes are precise by means of the PSFD based on Chebyshev-Lagrange interpolating polynomials with modified perfectly matched layer (MPML). By introducing a suitable boundary condition for the dielectric-metallic interface, the stability and the spectrum convergence characteristic of the PSFD-MPML method can be sustained. The comparison of exact solutions of highly sensitive surface plasmon modes in 1D dielectric-metal waveguides and those calculated by our PSFD-MPML demonstrates the validity and usefulness of the proposed method. We also apply the method to calculate the effective refractive indices of an integrated optical waveguide with deposition of the finite gold metal layer which induces the hybrid surface plasmon modes. Furthermore, the 2-D optical structures with gold films are investigated to exhibit hybrid surface plasmon modes of wide variations. We then apply hybrid surface plasmon modes to design novel optical components-mode selective devices and the polarizing beam splitter.

Objective: To increase the success rate of prenatal diagnosis for classical phenylketonuria(PKU)., Methods: Three new short tandem repeat (STR) markers (PAH26, PAH32 and PAH9) within and surrounding phenylalanine hydroxylase(PAH) gene were selected for amplified fragment length polymorphism. The allele frequencies and polymorphism information contests (PIC) were determined in Chinese population., Results: The PIC of these three new STR markers was 0.518 (PAH26), 0.413 (PAH32) and 0.362 (PAH9) respectively. There was linkage disequilibrium between PAH9 marker and PAH-STR marker (TCTA)n in the intron 3 of PAH gene. The linkage phase of the mutant genes and the markers was established using the combination of PAH-STR, PAH26 and PAH32 in 95% families. Prenatal diagnosis was performed successfully with these markers in four cases., Conclusion: By selecting or combining the three STR markers, the mutant genes could be distinguished from the normal allele in up to 95% of families with classical PKU.

Objective: To understand the correlation of lower serum folate, and red blood cell (RBC) folate level with birth defects including unexplained recurrent pregnancy loss, and to evaluate the role of RBC folate level as a suitable marker for folate supplement., Methods: Two hundred and ninety-nine non-pregnant women at child-bearing age with a birth defect history were selected as birth defect group. The levels of serum and RBC folate, and serum vitamin B(12) were determined. By comparing with the group of non-pregnant women at child-bearing age without any birth defect history (control group), we evaluated the correlation between lower serum folate, RBC folate level and main kinds of birth defects including unexplained recurrent pregnancy loss. And the levels of serum and RBC folate of birth defect group were also determined and compared before and after oral folate intake (5 mg/d) for one month., Results: The serum folate level of birth defect group was not different from the control group (17 - 26 vs 14 nmol/L, P > 0.05). The RBC folate level of birth defect group except the urinary defect was significantly lower compared with the control group (233 - 547 vs 689 nmol/L, P < 0.05). After the oral folate intake (5 mg/d), the serum folate level of unexplained recurrent pregnancy loss group and neural tube defects group were significantly increased than before [(22 +/- 9) vs (27 +/- 12) nmol/L, (19 +/- 10) vs (25 +/- 18) nmol/L; P < 0.05]. The RBC folate level of unexplained recurrent pregnancy loss group and congenital heart defect group were significantly increased than before [(374 +/- 275) vs (567 +/- 397) nmol/L, (322 +/- 205) vs (527 +/- 351) nmol/L, P < 0.05]., Conclusion: RBC folate level is more closely correlated than serum folate level with the incidence of main birth defect.

Objective: Mucopolysaccharidosis type II (MPS II, Hunter syndrome, OMIM 309900) is an X-linked recessive lysosomal storage disease resulting from a deficiency of iduronte-2-sulphate sulphatase (IDS). The present study aimed to establish an enzyme assay method for IDS activity for carrying out postnatal and prenatal diagnosis of MPS II by means of IDS activity assay on plasma, uncultured chorionic villi (CV) and cultured amniotic fluid cells (AF cell) using a new synthesized substrate., Methods: A fluorigenic substrate (4-methylumbelliferyl-alpha-iduronate-2-sulphate, MU-alpha-Idu-2S) was used for the assay of IDS activity. IDS activity in plasma was determined for diagnosis of the proband. Prenatal diagnosis in 10 pregnancies at risk was carried out according to IDS activity on uncultured CV at 11th week or on cultured AF cell at 18th week of gestation. At the same time, IDS activity was also determined in the maternal plasmas to observe the change of IDS activity in pregnancy. The fetal sex determination was performed by PCR amplification of the ZFX/ZFY genes., Result: The IDS activity in plasma of normal controls and obligate heterozygotes were 240.2 - 668.2 nmol/(4 hxml) and 88.7 - 547.9 nmol/(4 hxml), respectively, while the enzyme activities in plasmas were in the range of 0.3 - 18.6 nmol/(4 hxml) in affected male. The IDS activities were 37.2 - 54.9 nmol/(4 hxmg protein) and 21.4 - 74.4 nmol/(4 hxmg protein) in CV and cultured AF cells respectively. Out of 50 suspected cases, 46 were diagnosed as having MPS II and 4 were excluded. Prenatal diagnosis was performed on 10 pregnancies at risk. Four of 5 male fetuses [IDS activity were 4.7, 1.8, 7.0 nmol/(4hxmg protein) in CV, 0.6 nmol/(4 hxmg protein) in AF cell] were diagnosed as having MPS II and the other 5 fetuses were normal females [IDS activity were: 48.7, 5.9, 25.2 nmol/(4 hxmg protein) in CV, 55.2, 40.9 nmol/(4 hxmg protein) in AF cell]. Increased IDS activity was observed in plasma of the pregnant women with unaffected fetuses, while the IDS activity decreased in pregnancies with affected fetuses. IDS activity of one female fetus was very low [5.9 nmol/(4 hxmg protein)], but the IDS activity in maternal plasmas increased, this fetus was a normal female., Conclusions: The method using a synthesized fluorigenic 4-methylumbelliferyl-substrate was a sensitive, rapid and convenient assay of IDS activity and was reliable for early prenatal diagnosis. Determination of fetal sex would be helpful in excluding the female fetus with low IDS activity from being considered as an affected male fetus. It would be further helpful if IDS activity in maternal plasma was taken into account.

Objective: To discuss the differential diagnosis of the hydatidiform mole and a coexisting fetus, to study the prenatal diagnosis and the clinical management of a twin pregnancy consisting of a complete mole and coexisting fetus (CMCF)., Methods: Two cases of CMCF were reported retrospectively., Results: In the first case, the hydatidiform mole and a coexisting fetus was found by B mode ultrasound at the 10th gestational week, the patient asked to terminate the pregnancy. The interphase FISH and karyotype analysis of the normal villi and the mole showed both of them were diploid, thus the CMCF was diagnosed. In the second case, the hydatidiform mole and a coexisting fetus was found by B mode ultrasound at the 21st gestational week. Transabdominal chorionic villi sampling and amniocentesis was performed, interphase FISH and karyotype analysis of the mole and the amniotic fluid showed both of them were diploid, thus the CMCF was diagnosed prenatally. The pregnancy was continued and premature rupture of membrane happened at the 28th gestational week, the cesarean section was performed. The neonate was healthy. The karyotype analysis of the placenta and the neonate was accordant with the prenatal diagnosis., Conclusions: As long as the hydatidiform mole and a coexisting fetus was found the prenatal diagnosis must be performed in order to differentiate the CMCF and the partial hydatidiform mole (PHM). The transabdominal chorionic villi sampling and the amniocentesis were ideal methods, interphase FISH and karyotype analysis of the mole and the amniotic fluid should be performed. If both of them were diploid, the CMCF could be diagnosed. The clinical management of CMCF should be done individually. If both of them were triploid, the PHM could be diagnosed.

Objective: To set up a fluorescent in situ hybridization (FISH) based method to detect the gene-deleted female carriers of Duchenne/Becker muscular dystrophy (DMD/BMD)., Methods: Multiplex polymerase chain reaction was used to identify the gene deletion DMD/BMD probands and their female relatives were checked by double-color FISH., Results: Two probands whose exon 46 of dystrophin gene was deleted, one had a positive pedigree and the other was a sporatic patient. In the case of the positive pedigree, four carriers were detected. In the case of the sporatic family, FISH showed that the mother of the proband was a somatic mosaicism., Conclusion: Combined with multiplex PCR, double-color FISH is a simple, fast, directly visual and accurate method. It is feasible to identify the carrier status of the female relatives of the gene deletion DMD/BMD probands. The detection of the somatic mosaicism is a prominent feature of FISH.

Objective: To investigate the optimal method of screening for Down's syndrome (DS) with maternal serum mankers., Methods: Screening by maternal serum markers for Down's syndrome was offered to all 2886 pregnant women in Peking Union Medical Hospital during 1996.11-2001.3. Alpha-fetoprotein (AFP), human chorionic gonadotrophin (free beta-HCG) were used as markers during the first year of pregnancy. Alpha-fetoprotein, free human chorionic gonadotrophin (HCG) and pregnancy-associated plasma protein A (PAPP-A) were used as mid pregnancy and first-trimester markers in next three years. Amniocentesis and (CVS) were done in those defined as risk cases., Results: The detection rate of Down's syndrome by maternal serum markers was 3.8% (11/2886). The proportion of false positive results in group of triple markers (alpha FP, free beta-HCG, PAPP-A) was 5%., Conclusions: The PAPP-A was a good marker to detect Down's syndrome in early pregnancy and may be used to predict the outcome during mid trimester of pregnancy. The AFP and free beta-HCG can be useful markers to detect Down's syndrome and fetal abnormality. While prenatal diagnostics can be shifted to an early pregnant period.

A continuous dimensional electrophoretic method was used in 15 urine samples of clinically diagnosed mucopolysaccharidoses I or IV. Twelve of the 15 were glycosaminoglycans band positive. Of the 12 one was KS band positive but methyl toluidine blue test was negative. The other 11 were positive with both methods. Prenatal diagnosis was done in 10 cases during their next pregnancy with the same method on the amniotic fluid. Two affected fetuses were diagnosed and proved, one after induced abortion and the other after full-term delivery.

Prenatal diagnosis of hemophilia A and B was carried out in our hospital by DNA analysis in early and late villi and amniotic cells. Fifteen women with family history of hemophilia were studied by different sets of DNA probes and restrictive enzymes from Nov. 1986 to March 1989. Two of the 15 women were proved not carriers by blood sample assaying. Two did not show sites of polymorphism and another was not reported owing too small a DNA sample of amniotic cells. Among other 10 cases, 4 were proven normal male fetus, 1 proven affected male fetus was induced, and 5 were proven female fetus with 2 carriers.

The BcII polymorphism within DXS52 (St14) was reported. It was composed of 4 allelic fragments, 4.0 kb, 3.3 kb, 3.0 kb and 2.3 kb. The frequency of these fragment were 0.09, 0.12, 0.44 and 0.35 respectively in the Chinese. The polymorphism provided the PIC of 0.66. DNA analysis of families with hemophilia A showed that the confidence of the RFLPs was the same as the TaqI/St14 RFLPs and for carrier detection the former is much better than that of the TaqI/St14 RFLPs.

The genomic DNA fragment St14 (DXS52) is located in q28 region of X chromosome that also contains the hemophilia A locus. The RFLPs of St14/Taq I in Chinese were studied. The frequency of allele 7A (3.6 kb) is 31%, which is obviously different from the data reported abroad. By use of the RFLPs, 8 families with hemophilia A were analysed, including 1 case for first trimester prenatal diagnosis at risk of hemophilia A.

The amount of fetal-maternal transfusion during invasive intrauterine diagnostic instrumentation was determined by measuring the increase in maternal serum alpha-fetoprotein (delta AFP) caused by the procedure. Fetal liver biopsy or fetoscopy for purposes other than blood sampling caused a mean delta AFP of 11.4 ng/ml and 34.2 ng/ml, respectively. Fetoscopy with fetal blood sampling produced a mean delta AFP of 211.8 ng/ml, while fetoscopy followed by placentesis caused a mean delta AFP of 462.8 ng/ml (representing a 1.07 ml fetal-maternal transfusion). Although this magnitude of fetal-maternal transfusion is an acceptable risk for the fetus, it is a sufficient transfusion to cause blood cell antigen sensitization.

We report an apparently balanced reciprocal t(4q;5q) translocation ascertained coincidentally on amniocentesis in a phenotypically normal male fetus and found to be inherited in his mother and maternal grandmother. No banding study was available at the time of the amniocentesis, and the chromosomal status of his parents was unknown. Because of the possibility that this finding might be a de novo, unbalanced translocation, the pregnancy was terminated. Subsequently, the translocation was found to be apparently balanced, but so unequal that both unbalanced translocation products are presumed to be lethal. Thus, it is predicted that only carriers and normal individuals will be conceived and viable in this family. We are unaware of previously observations on a similar (4q;5a) translocation.