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Biomedical subjects

Ping Fang

Publications and source records attributed to Ping Fang.

At least 19 recordsLinked to original sources
PubMed2006

DNA sequence analysis of GJB2, encoding connexin 26: observations from a population of hearing impaired cases and variable carrier rates, complex genotypes, and ethnic stratification of alleles among controls.

Mutations in GJB2 are associated with hereditary hearing loss. DNA sequencing of GJB2 in a cohort of hearing impaired patients and a multi-ethnic control group is reported. Among 610 hearing impaired cases, 43 DNA sequence variations were identified in the coding region of GJB2 including 24 mutations, 8 polymorphisms, 3 unclassified variants (G4D, R127C, M163V), 1 controversial variant (V37I), and 7 novel variants (G12C, N14D, V63A, T86M, L132V, D159, 592_600delinsCAGTGTTCATGACATTC). Sixteen non-coding sequence variations were also identified among cases including the IVS1+1A>G mutation, 2 polymorphisms, and 13 novel variants. A diagnosis of GJB2-associated hearing loss was confirmed for 63 cases (10.3%). Heterozygous mutations were found in 39 cases (6.4%). Eleven cases carrying novel or unclassified variants (1.8 %) and 18 cases carrying the controversial V37I variant were identified (3%). In addition, 294 control subjects from 4 ethnic groups were sequenced for GJB2. Thirteen sequence variations in the coding region of GJB2 were identified among controls including 2 mutations, 6 polymorphisms, 2 unclassified variants (G4D, T123N), 1 controversial variant (V37I), and 2 novel variants (R127L, V207L). Nine sequence variations were identified among controls in the non-coding regions in and around GJB2 exon 2. Of particular interest among controls were the variability in carrier rates and ethnic stratification of alleles, and the complex genotypes among Asians, 47% of whom carried two to four sequence variations in the coding region of GJB2. These data provide new information about carrier rates for GJB2-based hearing loss in various ethnic groups and contribute to evaluation of the pathogenicity of the controversial V37I variant.

Alleles↗
PubMed2006

Inhibition of respiratory syncytial virus in cultured cells by nucleocapsid gene targeted deoxyribozyme (DNAzyme).

Respiratory syncytial virus (RSV), which presents the primary cause of bronchiolitis and pneumonia among infants and causes significant morbidity and mortality in immunodeficient patients, remains a health problem worldwide. Unfortunately, an effective vaccine is currently unavailable and pharmacologic treatment needs further optimization for RSV disease. Because RSV is a non-segmented negative-strand RNA virus, it may be sensitive to the genome RNA cleaving by DNAzyme, an artificial nucleic acids molecule with high catalytic capability of cleaving complementary RNA molecules. Thus, RSV-targeted DNAzymes potentially present as a therapeutic candidate of RSV diseases. In this study, DNAzymes targeting the RSV genomic RNA or mRNA were designed and synthesized, one of which (DZn1133) did cleave RSV RNA in vitro, inhibit the transcription and expression of F viral gene, reduce the RSV yield by about 7 logs and protect more than 90% RSV-infected Hep-2 cells from a cytopathic effect at 8 microM. Moreover, 10 wild RSV strains isolated from clinic patients including both subgroups A and B were all suppressed by DZn1133 with greater anti-RSV activity than antisense DNA or ribavirin.

Base Sequence↗
PubMed2006

Increased MECP2 gene copy number as the result of genomic duplication in neurodevelopmentally delayed males.

PURPOSE: Mutations in the MECP2 gene are associated with Rett syndrome, an X-linked mental retardation disorder in females. Mutations also cause variable neurodevelopmental phenotypes in rare affected males. Recent clinical testing for MECP2 gene rearrangements revealed that entire MECP2 gene duplication occurs in some males manifesting a progressive neurodevelopmental syndrome. METHODS: Clinical testing through quantitative DNA methods and chromosomal microarray analysis in our laboratories identified seven male patients with increased MECP2 gene copy number. RESULTS: Duplication of the entire MECP2 gene was found in six patients, and MECP2 triplication was found in one patient with the most severe phenotype. The Xq28 duplications observed in these males are unique and vary in size from approximately 200 kb to 2.2 Mb. Three of the mothers who were tested were asymptomatic duplication carriers with skewed X-inactivation. In silico analysis of the Xq28 flanking region showed numerous low-copy repeats with potential roles in recombination. CONCLUSIONS: These collective data suggest that increased MECP2 gene copy number is mainly responsible for the neurodevelopmental phenotypes in these males. These findings underscore the allelic and phenotypic heterogeneity associated with the MECP2 gene and highlight the value of molecular analysis for patient diagnosis, family members at risk, and genetic counseling.

Adolescent↗
PubMed2006

Replication and inheritance of Nocardia plasmid pC1.

Nocardia sp. C-14-1, isolated from acrylic fiber wastewater, can degrade long-chain alkanes and succinonitrile efficiently. Here we report the characterization of an indigenous plasmid pC1. The overall nucleotide sequence of pC1 consisted of 5841 bp. The five ORFs, encoding a DNA recombinase, replication protein (Rep(pC1)) and three proteins of unknown function, were predicted on pC1. The Rep(pC1) displayed its homology with the Rep of Rhodococcus large plasmid p33701, suggesting a theta type of replication. An Escherichia coli plasmid (containing the single rep(pC1) gene) propagated autonomously in low copy number in Nocardia or Rhodococcus, suggesting that rep(pC1) was an essential gene for plasmid replication. The plasmid (containing the single rep(pC1) gene) presented as inheritance unstable hints that other pC1 loci were required for the stable inheritance of plasmids. By comparison of the plasmid-borne Rep proteins, we classify Rhodococcus or Nocardia plasmids into four groups.

DNA Replication↗
PubMed2006

Diversity of telomere palindromic sequences and replication genes among Streptomyces linear plasmids.

Streptomyces sp. linear plasmids and linear chromosomes usually contain conserved terminal palindromic sequences bound by the conserved telomeric proteins Tap and Tp, encoded by the tap and tpg genes, respectively, as well as plasmid loci required for DNA replication in circular mode when the telomeres are deleted. These consist of iterons and an adjacent rep gene. By using PCR, we found that 8 of 17 newly detected linear plasmids in Streptomyces strains lack typical telomeric tap and tpg sequences. Instead, two novel telomeres in plasmids pRL1 and pRL2 from the eight strains and one conserved telomere in pFRL1 from the other strains were identified, while multiple short palindromes were also found in the plasmids. The complete nucleotide sequence of pRL2 revealed a gene encoding a protein containing two domains, resembling Tap of Streptomyces and a helicase of Thiobacillus, and an adjacent gene encoding a protein similar to Tpg of Streptomyces and a portion of the telomere terminal protein pTP of adenoviruses. No typical iterons-rep loci were found in the three plasmids. These results indicate an unexpected diversity of telomere palindromic sequences and replication genes among Streptomyces linear plasmids.

Amino Acid Sequence↗
PubMed2006

[A retrospective study of one case of human infection by the highly pathogenic avian influenza A (H5N1)].

OBJECTIVE: To describe the clinical features of the infection caused by the highly pathogenic avian influenza A (H(5)N(1)). METHODS: A previously healthy 24 year old woman presented to our hospital on November 7, 2005. She was confirmed to be an H(5)N(1) infected case after death. The clinical, radiological and epidemiological data were analyzed. RESULTS: The patient had a history of direct contact with diseased and dead poultry (chicken and duck). The disease course was 10 days from onset of illness to death, and fever preceded dyspnea by 5 days. On admission, the striking characteristics were acute community-acquired pneumonia (CAP) and acute respiratory distress syndrome (ARDS), and the major radiographic abnormalities included extensive infiltration bilaterally, focal consolidation and air bronchograms. The radiographic and clinical deterioration was rapid, and the patient died in less than 3 days after hospitalization. The diagnosis of influenza A (H(5)N(1)) was confirmed by means of reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time PCR on specimens of the lower respiratory tract, performed by Chinese Center for Disease Control. The postmortem examination showed bronchial hyperemia, extensive consolidation, serous cavity effusions, disseminated intravascular coagulation (DIC) and multiple organ failure (MOF). CONCLUSIONS: Human infection by the highly pathogenic avian influenza A (H(5)N(1)) is a fatal communicable disease. Information of avian influenza A (H(5)N(1)) virus, more attention to the epidemiologic data, and early intervention are critical in reducing the mortality.

Adult↗
PubMed2005

Interruptions in the expanded ATTCT repeat of spinocerebellar ataxia type 10: repeat purity as a disease modifier?

Spinocerebellar ataxia type 10 (SCA10) is one of numerous genetic disorders that result from simple repeat expansions. SCA10 is caused by expansion of an intronic ATTCT pentanucleotide repeat tract. It is clinically characterized by progressive ataxia, seizures, and anticipation, which can vary within and between families. We report two SCA10 families showing distinct frequencies of seizures and correlations of repeat length with age at onset. One family displayed uninterrupted ATTCT expansions, whereas the other showed multiple interruptions of the repeat by nonconsensus repeat units, which differed both in the length and/or sequence of the repeat unit. Disease-causing microsatellite expansions have been assumed to be composed of uninterrupted pure repeats. Our findings for SCA10 challenge this convention and suggest that the purity of the expanded repeat element may be a disease modifier.

Age of Onset↗
PubMed2005

Relationship between entero-hepatic bile acid circulation and interdigestive migrating myoelectrical activity in rats.

AIM: To investigate the effects of entero-hepatic bile acid circulation on the inter-digestive migrating myoelectrical complex (MMC) in rats. METHODS: Thirty-two rats were divided into four groups. Three pairs of bipolar silver electrodes were chronically implanted in the antrum, duodenum and jejunum. Three groups of them were ligated around the upper part of common bile duct (CBD). The experiments were performed in conscious and fasting state. The gastrointestinal myoelectrical activity was recorded. Ursodeoxycholic acid (UDCA) and saline were then perfused into stomachs of two groups with CBD obstruction and the effects of them on the MMC were observed. RESULTS: A typical pattern of MMC was observed in normal fasting rats. MMC of antral and duodenal origin disappeared temporarily in earlier stage of CBD obstruction. While MMC of jejunum origin appeared. increased MMC cycle duration was seen after 4 d in rats with CBD obstruction. The MMC after CBD obstruction was characterized by an increased duration of phase II-like activity and decreased duration of phase I and III activity. Perfusion into stomachs with UDCA resulted in a shorter MMC cycle duration and a longer duration of phase III of duodenal origin compared to the normal group. CONCLUSION: Entero-hepatic bile acid circulation initiates inter-digestive MMC of duodenal origin.

Animals↗
PubMed2005

Perceptions of ADHD in China and the United States: a preliminary study.

College students (n = 226) and teachers (n = 328) in the United States and China completed a 55-item questionnaire examining perceptions of attention deficit/hyperactivity disorder (ADHD) in the two countries. Although a factor analysis yielded somewhat similar structures for the construct of ADHD, many differences emerged as well, with Chinese participants somewhat more attuned to hyperactivity than inattention. Furthermore, presented with a list of potential perceptions of ADHD, there were significant differences by culture in agreement with most of those statements. Thus, it appears that the concept of ADHD may be similar between the cultures, but the many differences warrant further exploration before ADHD is considered to be equivalent in the two countries.

Attention Deficit Disorder with Hyperactivity↗
PubMed2005

[Construction and effect of the recombinant pshRNA plasmid against respiratory syncystial virus M2-1 gene].

OBJECTIVE: Respiratory syncystial virus (RSV) is the most common cause of lower respiratory infections in infants worldwide. There is no reliable vaccine or antiviral drug against RSV at present. RNA interference (RNAi) technology is a potent method to degrade expression of the cognate mRNA. In order to inhibit the replication of RSV at gene level, the effects of specific RNAi against M2-1 gene of RSV on inhibition of viral replication in cell culture system was observed in this study. METHODS: RSV M2-1 gene, which plays a key role in RSV transcription, was chosen in this study and was used as target gene and recombinant plasmid pshRNA7816 targeting the mRNA of RSV M2-1 gene coding sequence was constructed. The pshRNA7816 was transfected into Hep2 cells. The effects of the pshRNA7816 on changes of cytopathogenic effect (CPE) of Hep2 cell induced by RSV infection were observed microscopically. Viral plaque forming assay and MTT assay were used to detect the viral titer change and protective function of the pshRNA7816 on RSV infected Hep2 cell. RESULTS: The recombinant RNAi plasmid pshRNA7816 which targets the mRNA of RSV M2-1 gene was successfully constructed. The pshRNA7816 significantly reduced CPE of RSV infected Hep2 cells, reduced the viral titer of RSV in the cells (P < 0.001). The pshRNA7816 raised the survival rate of RSV infected Hep2 cells (P < 0.001). Non-specific pshRNA plasmid did not show anti-RSV effects (P > 0.05). CONCLUSION: The recombinant pshRNA7816 plasmid which targeted the mRNA of RSV M2-1 gene showed a significant and specific anti-RSV effect.

Hep G2 Cells↗
PubMed2005

[Rapid and high-efficient composting process of municipal sewage sludge].

Based on the static composting process of the municipal sewage sludge (MSS), the paper demonstrates the dynamic composting process of the MSS from Shanghai Quyang Municipal Wastewater Treatment Plant. The dynamics of different operational and evaluating indices during the treatment process are discussed, such as water content, temperature, pH, dissolved organic carbon (DOC) and germination index (GI) and so on. It is concluded that the water content of materials, temperature,DOC and GI can be interpreted as the evaluating indices of the maturation of MSS. Under optimized condition, when the water content of initial materials was adjusted to 60 % +/- 2 % with appropriate sawdust and recycled materials, the results indicated that the temperature of composting materials could reach > 55 degrees C rapidly and last 4 days, thus 100% of the pathogens would be killed out. In the end of composting process, the water content of outputs was reduced exactly to about 35%, DOC could be decomposed by about 50%. T heincompact, odorless, and almost mature output could meet the land application control standard of MSS and the class A standard of US EPA.

Bacteria, Aerobic↗
PubMed2004

Effects of motilin and ursodeoxycholic acid on gastrointestinal myoelectric activity of different origins in fasted rats.

AIM: To investigate gastrointestinal migrating myoelectric complex (MMC) and the effects of porcine motilin and ursodeoxycholic acid (UDCA) on MMC of gastrointestinal tract of different origins in fasted rats. METHODS: Three bipolar silver electrodes were chronically implanted on the antrum, duodenum and jejunum. Seven days later 24 experimental rats were divided into 2 groups. One group was injected with porcine motilin via sublingual vein at a dose of 20 microg/kg, the other group was perfused into stomach with UDCA. The gastrointestinal myoelectric activity was recorded 1 h before and 2 h after the test substance infusions into the rats. RESULTS: In all fasted rats a typical pattern of MMC was observed. Among the totally 68 activity fronts recorded in fasted rats under control, 67% started in duodenum, and 33% in antrum. MMC cycle duration and duration of phase III of antral origin were longer than those of duodenal origin. Administration of 20 microg/kg porcine motilin induced a premature antral phase III of antral origin. But perfusion into stomach with UDCA resulted in shorter MMC cycle duration, longer duration of phase III of duodenal origin, which were followed with shorter cycle duration and duration of antral phase III. CONCLUSION: In fasted rats, MMC could originate from antrum and duodenum respectively. The characteristics of MMC of different origins may contribute to the large variations within subjects. The mechanisms of different origins of phase III may be different. Porcine motilin and UDCA could affect MMC of different origins of the gastrointestinal tract in fasted state, respectively.

Animals↗
PubMed2004

Somatic and germline instability of the ATTCT repeat in spinocerebellar ataxia type 10.

Spinocerebellar ataxia type 10 (SCA10) is an autosomal dominant disorder characterized by ataxia, seizures, and anticipation. It is caused by an expanded ATTCT pentanucleotide repeat in intron 9 of a novel gene, designated "SCA10." The ATTCT expansion in SCA10 represents a novel class of microsatellite repeat and is one of the largest found to cause human diseases. The expanded ATTCT repeat is unstably transmitted from generation to generation, and an inverse correlation has been observed between size of repeat and age at onset. In this multifamily study, we investigated the intergenerational instability, somatic and germline mosaicism, and age-dependent repeat-size changes of the expanded ATTCT repeat. Our results showed that (1) the expanded ATTCT repeats are highly unstable when paternally transmitted, whereas maternal transmission resulted in significantly smaller changes in repeat size; (2) blood leukocytes, lymphoblastoid cells, buccal cells, and sperm have a variable degree of mosaicism in ATTCT expansion; (3) the length of the expanded repeat was not observed to change in individuals over a 5-year period; and (4) clinically determined anticipation is sometimes associated with intergenerational contraction rather than expansion of the ATTCT repeat.

Age Distribution↗
PubMed2004

Synthesis and evaluation of N,N-dimethyl-2-(2-amino-5-[18F]fluorophenylthio)benzylamine (5-[18F]-ADAM) as a serotonin transporter imaging agent.

The synthesis and evaluation of a new serotonin transporter (SERT) imaging agent, N,N-dimethyl-2-(2-amino-5-[18F]fluorophenylthio)benzylamine (5-[18F]-ADAM) is reported. Nucleophilic substitution of N,N-dimethyl-2-(2-nitro-5-bromophenylthio)benzylamine with K[18F]/Kryptofix 2.2.2 in DMSO at 125 degrees C followed by reduction with NaBH4-Cu(OAc)2 in EtOH at 78 degrees C and purification with HPLC produces the desired compound with an unoptimized yield of approximately 5-10% in a synthesis time of 150 min from EOB. The biodistribution of 5-[18F]-ADAM in rats showed a high initial uptake and relatively rapid clearance in the brain (3.221+/-0.762, 0.440+/-0.059, 0.160+/-0.035 and 0.028+/-0.003% injected dose/organ at 2, 30, 60 and 120 min after I.V. injection, respectively) with the specific binding peaking at 1 h postinjection (hypothalamus/cerebellum and hippocampus/cerebellum were 2.97 and 3.59, respectively). The initial uptake in blood, lung, kidney and heart were also high, but it cleared rapidly. The radioactivity in the femur increased with time for 5-[18F]-ADAM indicating that in vivo defluorination may occur. Metabolism studies in rats showed that 5-[18F]-ADAM was not metabolized in rat brain, but was metabolized rapidly in the blood. Blocking experiments showed that there were significant decreases in the uptake of 5-[18F]-ADAM in the brain regions (hypothalamus, hippocampus and striatum) where SERT concentrations are high when rats were pretreated with (+)McN 5652 (2 mg/kg, 5 min prior to IV injection of 5-[18F]-ADAM). These results suggest that 5-[18F]-ADAM may be a potential new serotonin transporter PET imaging agent. However, due to its rapid wash-out from the brain, defluorination in vivo and lower uptake in the brain than 4-[18F]-ADAM, 5-[18F]-ADAM may not be as useful as 4-[18F]-ADAM as a SERT imaging agent.

Animals↗
PubMed2004

[Anatomical landmarks of skull base and safety of the skull base surgery].

OBJECTIVE: In order to improve the safety of skull base surgery and to completely resect the skull base tumors, the anatomical landmarks of skull base were studied. METHODS: 29 cases of skull base surgery were performed between 1992 and 2002, and their clinical data were retrospectively analysed. The anatomical landmarks of cranial base, such as comb, pterygoid process, spine of temporal bone, styloid process, and internal caroid artery, were analysed in preoperative diagnosis and operative treatment of various kinds of skull base tumors. RESULTS: In the early stages, because of lacking the knowledge of anatomical landmarks of the skull base, the surgery lasted longer, part of skull base tumors remained and operative blood lose was much more than that in later stage. In the later stage, no operative death and severe complications were found in 26 cases which underwent various kinds of skull base surgery. The survival rates at 3 and 5 years were 72.2% and 35.7% respectively for malignant tumors. CONCLUSIONS: Comb, pterygoid process, spine of temporal bone, styloid process, internal caroid artery and their adjacent structures were important anatomical landmarks for operative treatment of anterior, middle and lateral cranial base tumors. It was important to know the anatomical landmarks to ensure the safety of the skull base surgery.

Adolescent↗
PubMed2004

[Using PCR method to study the EB virus DNA in NPC].

OBJECTIVE: To study the EB virus DNA distribution in paraffin-embedded tissue, peripheral blood leukocyte and serum in nasopharyngeal carcinoma patients (NPC). METHOD: PCR method, in paraffin-embedded tissue of 39 patients with NPC (NPC group-1) and 20 patients with chronic nasopharyngitis (control group-1), in peripheral blood leukocyte and serum of 24 patients with NPC (NPC group-2) and 10 patients with other head and neck carcinoma (control group-2) and 10 patients with chronic nasopharyngitis (control group-3) were used to test the presence of Epstein-Barr virus DNA. At the same time, we also measured serum EB virus VCA-IgA antibodies with enzyme-immunoassay in NPC group-2, control group-2 and control group-3. RESULT: The results showed that 28 of 39 nasopharyngeal carcinoma patients (71.8%) (NPC group-1) and 3 of 20 chronic nasopharyngitis (15%) (control group-1) were EB virus DNA positive in paraffin-embedded tissues. The difference between NPC group-1 and control group-1 was statistically significant. Ten of 24 NPC group-2 (41.67%) and 1 of 10 control group-2 (10%) were EB virus DNA positive in peripheral blood leukocyte. Control group-3 EB virus DNA was negative in peripheral blood leukocyte. The difference between NPC group-2 and control group-3 was statistically significant (P < 0.05). All of the patients' EB virus DNA were negative in serum. The difference between NPC group-2 and control group-2; 2 was statistically significant in VCA-IgA titer respectively (Ridit Test P < 0.01). CONCLUSION: EB virus DNA positive in paraffin-embedded tissues is higher than that in peripheral blood leukocyte in nasopharyngeal carcinoma patients. In serum EB virus DNA is negative. The results suggest that EB virus DNA positive from paraffin-embedded tissues to peripheral blood leukocyte to serum is decrease gradually. There must be some relationship between VCA-IgA in serum and EB virus DNA in peripheral blood leukocyte.

Adolescent↗
PubMed2004

[A preliminary investigation on the serological and epidemiological characteristics of severe acute respiratory syndrome in children].

OBJECTIVE: The severe acute respiratory syndrome (SARS) is a highly contagious infection caused by a newly discovered strain of coronavirus (SARS-CoV). During the outbreak of SARS in the first half of 2003, children appeared to be less susceptible to the SARS coronavirus and pediatric patients presented with a less aggressive clinical course than adult patients did, demonstrating the traits which were rarely observed in other viral contagious disease. The present study aimed to preliminarily examine the presence of serum specific antibodies against severe acute respiratory syndrome (SARS)-associated coronavirus virus (SARS-CoV) in pediatric SARS patients and explore the possibility of subclinical infection in children/adults through close association with SARS cases. METHODS: (1) Clinicians and nurses visited families and collected general and epidemiological information about the subjects using a standard questionnaire and took serum specimens. (2) Specific antibodies against SARS-CoV were assayed with two methods, indirect immunofluorescence assay (IFA) for detecting IgG antibodies and enzyme linked immunosorbent assay (ELISA) for mixed antibodies. Serum specimens tested included those from 21 clinically confirmed pediatric SARS cases (aged from 8 months to 14 years, 11 male and 10 female) and their 23 parents who had close contact with the children, 36 adult patients in convalescence stage of SARS, 24 children (aged 1.5 to 14 years) and other 34 adults who had close contact with infected adults. RESULTS: (1) The positive rates of specific IgG and mixed antibodies against SARS-CoV were 38% (8/21) and 33% (7/21) in pediatric cases; whereas the rates were 75% (27/36) and 69% (25/36) in adult patients. (2) The proportion of the patients who had close contact to SARS patients was 7/8 among the antibody-positive group vs. 1/13 for the antibody-negative group (P < 0.05). (3) The IgG antibody emerged in one of 24 children, whose mother, a nurse, had suffered from SARS (4%). (4) Among 23 parents of children with SARS, one was positive for IgG and the mixed antibodies, whose grandson and husband suffered from SARS; The IgG antibody and the mixed antibodies were also positive in another adult who had close contact with adult SARS cases (3%). CONCLUSIONS: (1) SARS-CoV infection was confirmed by serological methods in 38.1% of clinically diagnosed pediatric SARS cases, which leads to the assumption that correct diagnosis of pediatric SARS requires more accurate and efficient ways, for example, screening for antigen or gene of SARS-CoV. (2) The proportion of the patients who had close contact to SARS patients among antibody-positive cases was higher than that in antibody-negative cases. (3) It is possible that subclinical SARS CoV infection exists in children and adults, although the rate of occurrence is low. The data of the present study did not confirm that SARS had subclinical infection among adults who had close contact to pediatric SARS cases.

Adolescent↗