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Nanbert Zhong

Publications and source records attributed to Nanbert Zhong.

17 recordsLinked to original sources
PubMed2006

N-terminal segments are the functional domains of CLN3-encoded battenin for protein interactions.

OBJECTIVE: Batten disease (BD), the juvenile form of neuronal ceroid lipofuscinosis (NCLs), is pathological characterized by finding lysosomal storage of autofluorescent lipofuscins with unique ultrastructural profiles. The gene underlying BD is designated CLN3 and encodes a protein, Battenin, of unknown function that localizes in lysosomes and/or mitochondria. Previously, we hypothesized that Battenin associates with other membrane protein(s) to form a membrane complex. Dysfunction of this complex could result in the pathological changes of BD, and possibly in other NCLs. Two such membranous proteins, the slow and fast Battenin-interactive proteins (BIPs and BIPf) of unknown functions, have been identified. In this study, we have characterized the functional domains of Battenin that interact with both BIP proteins. METHODS: Protein-protein interactions with a yeast two-hybrid system were employed. A "deletion assay" was employed to localize the interactive segment(s). Different lengths of cDNA sequences lacking exon 1-5 were used to express CLN3-encoded proteins lacking N-terminal segments in the yeast two-hybrid system. N-terminal exons of CLN3 were deleted with PCR-cloning strategies. RESULTS: We eliminated the possibility of interacting domains from the exon 7-encoded region because both Battenin and mBattenin interact with the BIP proteins. We have shown that peptide sequences encoded by exons 2 and 4 of CLN3 gene include the functional domains by which Battenin interacts with the BIP proteins. CONCLUSION: Our studies provide evidence that the N-terminus of Battenin is the functional domain for these protein interactions.

DNA, Complementary↗
PubMed2006

Genotype-phenotype analyses of classic neuronal ceroid lipofuscinosis (NCLs): genetic predictions from clinical and pathological findings.

OBJECTIVE: Genotype-phenotype associations were studied in 517 subjects clinically affected by classical neuronal ceroid lipofuscinosis (NCL). METHODS: Genetic loci CLN1-3 were analyzed in regard to age of onset, initial neurological symptoms, and electron microscope (EM) profiles. RESULTS: The most common initial symptom leading to a clinical evaluation was developmental delay (30%) in NCL1, seizures (42.4%) in NCL2, and vision problems (53.5%) in NCL3. Eighty-two percent of NCL1 cases had granular osmiophilic deposits (GRODs) or mixed-GROD-containing EM profiles; 94% of NCL2 cases had curvilinear (CV) or mixed-CV-containing profiles; and 91% of NCL3 had fingerprint (FP) or mixed-FP-containing profiles. The mixed-type EM profile was found in approximately one-third of the NCL cases. DNA mutations within a specific CLN gene were further correlated with NCL phenotypes. Seizures were noticed to associate with common mutations 523G>A and 636C>T of CLN2 in NCL2 but not with common mutations 223G>A and 451C>T of CLN1 in NCL1. Vision loss was the initial symptom in all types of mutations in NCL3. Surprisingly, our data showed that the age of onset was atypical in 51.3% of NCL1 (infantile form) cases, 19.7% of NCL2 (late-infantile form) cases, and 42.8% of NCL3 (juvenile form) cases. CONCLUSION: Our data provide an overall picture regarding the clinical recognition of classical childhood NCLs. This may assist in the prediction and genetic identification of NCL1-3 via their characteristic clinical features.

Age of Onset↗
PubMed2006

Chromosomal abnormalities and adverse pregnancy outcome with maternal serum second trimester triple screening test for fetal Down syndrome in 4,860 Chinese women.

OBJECTIVE: To investigate the efficiency of maternal serum triple screening for the genetic abnormality in second-trimester and the morbidity of adverse pregnancy outcome in false positive results of the test. METHODS: A total of 4,680 pregnant women with singleton pregnancies assigned in Obs & Gyn Hospital, Fudan University, underwent triple screening test (alpha fetoprotein, AFP; human chorionic gonadotropin, HCG and unconjugated estriol, uE3) by fluorescence enzyme immunoassay between 2003 and 2005. The valid MoM (Multiples of Median) value of mid-trimester serum AFP, uE3, and hCG and risk assessments was provided by Beckman Coulter Co. when applied in the prenatal Down syndrome screening service. The study compares the incidence of chromosomal abnormalities with Down syndrome in screen positive women and compares to the MoM value established in the literature. The risks of having a fetus with congenital abnormalities or of developing obstetric complications in the screen positive women with their matched controls. RESULTS: The MoM values for the triple tests of our study are similar to established values of literature. Only 51.01% women with pregnancies agree to receive screening. Amniocentesis utilization rate was 55.12% in the screen-positive pregnancies. The false positive rate was 6.89% and the median of maternal age of the women was 28.13 (range 19 to 49) years old. Chromosomal abnormalities were identified in 21 pregnancies, including 9 cases of trisomy 21. The detection rate was 77.77%. Pregnancies with positive screening results had a significantly higher risk of adverse outcomes than those with negative results (P< 0.05). Whereas there was no difference in the incidences of fetal congenital appearance or skeleton abnormality. CONCLUSION: Adjusting MoM values of local unaffected populations is limited to increasing the detection rate. Because chromosomal defects have variable exhibitions, amniocentesis utilization is still a choice for screen-positive pregnancies. Screen-positive pregnancies had increased risk of chromosomal abnormalities.

Adult↗
PubMed2006

Study of microsatellite instability in epithelial ovarian tumors.

OBJECTIVE: To evaluate the frequency of MSI in epithelial ovarian tumors and its relationship with clinicopathologic features. METHODS: Ninety fresh specimens of epithelial ovarian tumors, including 74 primary and 16 secondary tumors, were collected. Microsatellite analysis was carried out using 5 mono-and dinucleotide markers from the National Cancer Institute Consensus Panel by fluorescence-labeled polymerase chain reaction. RESULTS: Of 90 epithelial ovarian tumors analyzed, 18 demonstrated a high level of microsatellite instability (MSI-H), 30 demonstrated a low level of microsatellite instability (MSI-L), and the remaining 42 exhibited microsatellite stability (MSS). Frequency of microsatellite instability (MSI) at loci BAT-25 was higher than that at any other loci. No correlation was found between MSI level and patient age, tumor type, tumor differentiation (P>0.05). But the microsatellite instability-high phenotype correlates with clinical stage. It tended to occur more frequently in early-stage tumors (P=0.03). CONCLUSION: The frequent MSI in epithelial ovarian tumors suggests that it is an early event to involve in the development of epithelial ovarian tumors.

Adult↗
PubMed2006

No mutation was detected in the LMNA gene among sporadic Charcot-Marie-Tooth patients.

OBJECTIVE: To intensively investigate sporadic CMT patients, we have analyzed the LMNA gene in this study in a series of 32 unrelated CMT patients. METHODS: Twelve exons of the LMNA gene were amplified from genetic DNA. PCR products of each exon were analyzed by single strand conformational polymorphism (SSCP). RESULTS: No abnormal SSCP pattern, suggesting no mutation in our CMT patients, was detected. CONCLUSION: The CMT diseases resulted from the mutations of LMNA gene were rare.

Charcot-Marie-Tooth Disease↗
PubMed2006

Clinical and genetic features of DYT1 and DYT5.

Dystonia is a syndrome which is characterized by sustained muscle contractions, producing twisting, repetitive, and patterned movements, or abnormal postures. According to genetic basis, dystonia is classified into 13 subtypes. We mainly discussed two subtypes, DYT1 and DYT5, in this review. Early-onset primary dystonia is caused by the mutation of DYT1 gene, which leads to TORSINA abnormal. GTP cyclohydrolase 1 (GTPCH1)-deficient DRD (DYT5) is caused by the mutations of GCH1 gene. By genetic testing, we can confirm clinical diagnosis of each subtype and develop prenatal diagnosis for it.

Dystonia Musculorum Deformans↗
PubMed2006

Principal genetic syndromes and autism: from phenotypes, proteins to genes.

Autism is a neurodevelopmental disorder characterized by impairments in social skills, language, and behavior. It is now clear that autism is not a disease, but a syndrome characterized by phenotypic and genetic complexity. The etiology of autism is still poorly understood. Available evidence from a variety of sources strongly suggests that many genetic disorders are frequently associated with autism for their similar phenotypes. Based on this fact, this review begins by highlighting several principal genetic syndromes consistently associated with autism (fragile X, tuberous sclerosis, Angelman syndrome, Pader-Willi syndrome, Rett syndrome, Down syndrome and Turner syndrome). These genetic disorders include both chromosome disorders and single gene disorders. By comparing the similar phenotype, protein marker and candidate genes, we might make some breakthrough in the mechanism of autism and other genetic disorders.

Angelman Syndrome↗
PubMed2006

Mutation frequency for Charcot-Marie-Tooth disease type 1 in the Chinese population is similar to that in the global ethnic patients.

PURPOSE: To investigate the genetic loci/mutations among the Chinese Charcot-Marie-Tooth disease type 1 (CMT1), which accounts for approximately 70% of Charcot-Marie-Tooth; and to study the genetic heterogeneity and mutation frequency. METHODS: CMT1A duplication and mutations at loci of MPZ, Cx32/GJB1, EGR2, and LITAF/SIMPLE were analyzed among 32 clinically diagnosed CMT1 patients of Chinese ancestry. RESULTS: The CMT1A duplication was detected in 62.5% (20/32) CMT1 patients. This duplication accounts for the major mutation for Chinese CMT1. Among 12 cases that have no CMT1A duplication detected, three point mutations including one (3.1%) in MPZ and two (6.3%) in Cx32 were identified. No mutation was detected in genes PMP22, EGR2 and LITAF among the remaining nine (28.1%) CMT1 patients. CONCLUSION: The mutation frequency for the Chinese CMT1 is similar to that seen in the global ethnic population. Molecular testing of the CMT1A duplication, along with the loci of MPZ and Cx32, may detect the majority of Chinese CMT1 patients.

Amino Acid Substitution↗
PubMed2006

[The emphases and basic procedures of genetic counseling in psychotherapeutic model].

The emphases and basic procedures of genetic counseling are all different with those in old models. In the psychotherapeutic model, genetic counseling will not only focus on counselees' genetic disorders and birth defects, but also their psychological problems. "Client-centered therapy" termed by Carl Rogers plays an important role in genetic counseling process. The basic procedures of psychotherapeutic model of genetic counseling include 7 steps: initial contact, introduction, agendas, inquiry of family history, presenting information, closing the session and follow-up.

Family↗
PubMed2005

Novel progerin-interactive partner proteins hnRNP E1, EGF, Mel 18, and UBC9 interact with lamin A/C.

The Hutchinson-Gilford progeria syndrome (HGPS or progeria) is an apparent accelerated aging disorder of childhood. Recently, HGPS has been characterized as one of a growing group of disorders known as laminopathies, which result from genetic defects of the lamin A/C (LMNA) gene. The majority of HGPS mutant alleles involve a silent mutation, c.2063C>T resulting in G608G, that generates a cryptic splicing site in exon 11 of LMNA and consequently truncates 50 amino acids near the C-terminus of pre-lamin A/C. To explore possible mechanisms underlying the development of HGPS, we began a search for proteins that would uniquely interact with progerin (the truncated lamin A in HGPS) using a yeast two-hybrid system. Four new progerin interactive partner proteins were identified that had not been previously found to interact with lamin A/C: hnRNP E1, UBC9 (ubiquitin conjugating enzyme E2I), Mel-18, and EGF1. However, using control and progeria fibroblasts, co-immunoprecipitation studies of endogenous proteins did not show differential binding affinity compared to normal lamin A/C. Thus, we did not find evidence for uniquely interacting partner proteins using this approach, but did identify four new lamin A/C interactive partners.

Cell Nucleus↗
PubMed2005

Prenatal diagnostic testing for infantile and late-infantile neuronal ceroid lipofusinoses (NCL) using allele specific primer extension (ASPE).

Infantile (INCL, NCL1) and late-infantile (LINCL, NCL2) neuronal ceroid lipofuscinoses have been found to result from genetic deficiency of genes CLN(1 ) and CLN(2), respectively. The application of molecular analyses can facilitate prenatal diagnosis for families affected by NCL1 or NCL2, in which the familial mutation(s) have been identified. Molecular testing with allele-specific primer extension and DNA sequencing was performed in nine pregnancies, four from two NCL1 families and five from five NCL2 families. Lysosomal enzyme activity assays were carried out as well.Four fetuses from three pregnancies in NCL1 families were found to be carriers for a mutation 451C-T in the CLN(1) gene and one was normal. Prenatal testing of three NCL2 families who carried mutation R208X in the CLN(2) gene showed that all fetuses were carriers. In NCL2 families who carried either mutation IVS5-1C or/and IVS5-1A two normal pregnancies were detected. Our studies indicate that DNA testing, which may provide definitive prenatal diagnosis for NCL, may be used in combination with lysosomal enzyme activity analyses.

Alleles↗
PubMed2005

[The role of biomarkers CK7, Vim and P53 in the development of subtypes of endometrial carcinoma].

OBJECTIVE: Analyzing the protein expression of biomarkers CK7, Vim, and P53 to investigate their possible pathogenic roles in the development of variant subtypes of endometrial carcinoma. METHODS: Biomarkers CK7, Vim, and P53 were immunohistochemistry-stained among 131 endometrial carcinoma specimens including 93 endometroid, 8 adenoacanthoma, and 32 rare subtypes of adenosquamas carcinoma, clean cell carcinoma, and papillary carcinoma, which had been confirmed clinically and pathologically, and studied statistically with Fisher test and Cochran-Mantel-Haenszel (CMH) Test. RESULTS: Positive correlation was demonstrated among CK7, Vim, and P53 expression levels. The CK7 protein expression is increased, while the Vim and P53 are decreased in the subtype of endometrioid carcinoma. The clinical staging of endometriroid carcinoma is positively correlated with the expression of Vim. The positive rate of Vim and P53 is correlated with cytological differentiation of the carcinoma cells. CONCLUSION: Biomarkers CK7, Vim, and P53 are playing pathogenic roles, assuming as a mutual transcriptional modulator, and Vim but not P53 is likely the favorable prognostic factor, in the development of variant subtypes of endometrial carcinoma in addition to a evaluating the treatment.

Adult↗
PubMed2005

[Laminopathies--one gene, multiple diseases].

Laminopathies are genetic diseases that encompass a wide spectrum of phenotypes with diverse tissue pathologies and result mainly from mutations in the LMNA gene encoding nuclear lamin A/C. To date, at least 9 different human diseases, which superficially seem to share little with one another, result from LMNA mutations. The position of the mutation within LMNA appears to be associated with the phenotypes. This review gives an overview of genotype-phenotype relationship and describes recent advances in animal models and pathogenic mechanisms.

Animals↗
PubMed2005

[Molecular genetics of Charcot-Marie-Tooth disease].

Charcot-Marie-Tooth disease (CMT) affects the peripheral nervous system. It is generally inherited in an autosomal dominant pattern, but also is inherited in recessive or an X-linked pattern. The degree of severity can vary greatly from patient to patient, even within the same family. Traditionally, the different classes of CMT have been divided into demyelinating forms and axonal forms. Until 10 years ago, the genetic basis of CMT disease was largely unknown. An intrachromosomal duplication on chromosome 17 was found in 1991, and a point mutation in the peripheral myelin protein-22 gene was discovered in 1992. The work starts a new stage of the molecular basis of this large group of peripheral neuropathies. In this review, we will summarize what is known today about the genetics of CMT, and what we have learned about the underlying disease mechanisms.

Animals↗
PubMed2005

[The application of RNAi to the medical genetics].

Experimental RNA interference (RNAi) leading to the selective knockdown of gene function is induced by introducing into cells either double stranded RNA (dsRNA), or short interfering RNA (siRNA) fragments into which dsRNA is cut. The siRNA triggers degradation of homologous messenger RNA (mRNA). Widely used as a research tool in the genetic model organisms Caenorhabditis elegans, Drosophila melanogaster and mouse to investigate the function of individual genes, RNAi has also been deployed in genome-wide, specific gene-knockdown screens. Recent rapid progress in the application of RNAi to mammalian cells, including neurons and muscle cells, offers new approaches to drug target identification and validation. Advances in targeted delivery of RNAi-inducing molecules have raised the possibility of using RNAi directly as a therapy for a variety of human genetic and other neural and neuromuscular disorders. Here, we review examples of the application of RNAi to worm, fly and mouse models of such diseases aimed at understanding their pathophysiology.

Gene Silencing↗