Biomedical subjects

Li Cao

Publications and source records attributed to Li Cao.

At least 55 records · Page 3Linked to original sources

PubMed2005

[Molecular basic of interaction between disease resistance gene and avirulence gene].

Plant-pathogen interaction is the more important phytopathological subjects. Landmark progress in the past 10 years have resulted in the identification of functional R genes from the host and Avr genes from the pathogen,additionally interaction between their encoded productions. This paper reviewed the two models of R-Avr interaction, namely "receptor-ligand model" and "guard model", and discussed how to utilize the R gene during crop breeding and commercial production.

Fungal Proteins↗

PubMed2005

[Construction of the eukaryotic expression vector of MJD1 and its expression in SH-SY5Y cells].

OBJECTIVE: To construct the eukaryotic expression vector of MJD1 with normal copies of CAG trinucleotide repetition and MJD1 with CAG trinucleotide repetition expansion mutation respectively, and to determine whether the polyglutamine expansion in ataxin-3 could lead to the formation of intranuclear aggregation. METHODS: The coding sequence of wild-type MJD1 and mutant MJD1 was amplified by PCR from pAS2-1-MJD20Q and pAS2-1-MJD68Q respectively. After being digested with BamH I and Hind III, the PCR products were inserted into pcDNA3. 1-Myc-His(-) B. The recombinant plasmids pcDNA3.1-Myc-His(-) B-MJD20Q and pcDNA3.1-Myc-His(-) B-MJD68Q were identified by enzyme digestion analysis and DNA sequencing. The recombinant plasmid was transfected into SH-SYSY cells and the expression of MJD1 in the transfected cells was analyzed by Western blot. The immunofluorescence of the transfected cells was examined using a confocal microscope to observe the formation of intranuclear aggregation. RESULTS: Enzyme digestion analysis and DNA sequencing showed that the target gene was cloned into pcDNA3. 1-Myc-His(-) B. The expression of MJD1 in the transfected cells was confirmed by Western blot; The SH-SY5Y cells transfected with pcDNA3. 1-Myc-His(-) B-MJD68Q showed the formation of intranuclear aggregation, but the cells transfected with pcDNA3.1-Myc-His(-) B-MJD20Q did not show such phenomenon. CONCLUSION: The eukaryotic expression vectors of MJD1 has been successfully constructed; The polyglutamine expansion in ataxin-3 could lead to the formation of intranuclear aggregation.

Ataxin-1↗

PubMed2004

Active site engineering of the epoxide hydrolase from Agrobacterium radiobacter AD1 to enhance aerobic mineralization of cis-1,2-dichloroethylene in cells expressing an evolved toluene ortho-monooxygenase.

Chlorinated ethenes are the most prevalent ground-water pollutants, and the toxic epoxides generated during their aerobic biodegradation limit the extent of transformation. Hydrolysis of the toxic epoxide by epoxide hydrolases represents the major biological detoxification strategy; however, chlorinated epoxyethanes are not accepted by known bacterial epoxide hydrolases. Here, the epoxide hydrolase from Agrobacterium radiobacter AD1 (EchA), which enables growth on epichlorohydrin, was tuned to accept cis-1,2-dichloroepoxyethane as a substrate by accumulating beneficial mutations from three rounds of saturation mutagenesis at three selected active site residues, Phe-108, Ile-219, and Cys-248 (no beneficial mutations were found at position Ile-111). The EchA F108L/I219L/C248I variant coexpressed with a DNA-shuffled toluene ortho-monooxygenase, which initiates attack on the chlorinated ethene, enhanced the degradation of cis-dichloroethylene (cis-DCE) an infinite extent compared with wild-type EchA at low concentrations (6.8 microm) and up to 10-fold at high concentrations (540 microm). EchA variants with single mutations (F108L, I219F, or C248I) enhanced cis-DCE mineralization 2.5-fold (540 microm), and EchA variants with double mutations, I219L/C248I and F108L/C248I, increased cis-DCE mineralization 4- and 7-fold, respectively (540 microm). For complete degradation of cis-DCE to chloride ions, the apparent Vmax/Km for the Escherichia coli strain expressing recombinant the EchA F108L/I219L/C248I variant was increased over 5-fold as a result of the evolution of EchA. The EchA F108L/I219L/C248I variant also had enhanced activity for 1,2-epoxyhexane (2-fold) and the natural substrate epichlorohydrin (6-fold).

Agrobacterium tumefaciens↗

PubMed2004

The effects of ciliary neurotrophic factor on neurological function and glial activity following contusive spinal cord injury in the rats.

Ciliary neurotrophic factor (CNTF) has been implicated in the pathophysiology of injury to the central nervous system. The rapid increase in CNTF production following spinal cord injury (SCI) in rats is thought to serve a role in the neuronal survival and functional recovery. In this study, 40 SD rats were divided into four groups: sham-operated group, saline-treated group, 5- and 10-microg CNTF group. Saline and CNTF were given through lumbar intrathecal catheter for 10 days after T10 segment of spinal cord were injured by modified Allen contusion method. Animals were behaviorally tested for 6 weeks using the Basso, Beattie, Bresnahan locomotor rating scale and inclined plane test. At the end of 6 week, rubrospinal neurons of five rats in each group were labeled by retrograde transport of the horseradish peroxidase (HRP) from the lesion site, and then the labeled red nucleus neuron (RN) numbers were counted. Additional rats were histologically assessed for tissue sparing and neuronal loss and reactive gliosis at the injury site and adjacent areas. Rats treated with CNTF regained greater improvements in hindlimb function than controls. The amount of spared tissue was significantly higher in CNTF-treated animals than in controls. After CNTF treatment, the number of HRP-labeled RN neurons were significantly increased. Astrocytes and microglia reactivity was more pronounced in CNTF-treated animals than in controls. These results indicate that intrathecal infusion of exogenous CNTF following SCI may significantly reduce tissue damage and protect the rubrospinal descending tracks and enhances functional recovery, and may also induce more gliosis.

Animals↗

PubMed2004

Interferon alpha-inducible protein 27 (IFI27) is upregulated in psoriatic skin and certain epithelial cancers.

IFI27 is an interferon alpha-inducible protein found to be upregulated in lesional and non-lesional psoriatic skin in a gene array study. To further characterize its function, we studied by in situ hybridization whether IFI27 is expressed in psoriasis, other inflammatory skin diseases, and wound repair in vivo. We also examined its regulation by different growth factors and anti-psoriatic agents using quantitative RT-PCR (TaqMan). IFI27 mRNA expression was highly upregulated in lesional psoriatic epidermis and also detected in non-lesional keratinocytes. It was also expressed in lichen planus, chronic eczema, cutaneous squamous cell cancers, and during normal wound repair when IFI27 was found in the proliferating subpopulation of keratinocytes. A 3-17-fold upregulation of IFI27 mRNA expression was observed when keratinocytes were stimulated with IFN-gamma, TNF-alpha, or TGF-beta1 while retinoids and vitamin D downregulated its expression. Our results suggest that IFI27 is a novel marker of epithelial proliferation and cancer.

Cells, Cultured↗

PubMed2004

[Clinical characteristics of bronchiolitis caused by human metapneumovirus in infants].

OBJECTIVE: The fact that the acute lower respiratory infections (ALRI) are associated with a newly discovered virus, human metapneumovirus (hMPV), has been shown in several studies. The authors conducted this study to understand the etiological and clinical characteristics of bronchiolitis, one of the most common ALRI in infants, caused by hMPV. METHODS: Nasopharyngeal aspirate specimens from 54 out of 126 infants with bronchiolitis admitted to the Children's Hospital Affiliated to Capital Institute of Pediatrics, Beijing from November 2002 to February 2003 were examined for hMPV gene fragments by reverse transcription-polymerase chain reaction (RT-PCR). Prior to the detection, the specimens were confirmed as negative for the common respiratory pathogens including RSV, influenza A and B, parainfluenza I, II, III, adenovirus, Mycoplasma pneumoniae by indirect immunofluorescence test, virus isolation and ELISA test. The clinical data of the patients diagnosed etiologically as hMPV infection analyzed included the infants' age, sex, the degree of fever, the severity of wheezing and clinical Lowell score, the findings of chest examination and chest X-ray, the white blood cell count and blood gas analysis, the course of the disease, the major treatments and the outcome of the disease. RESULTS: Twenty-one specimens showed the predicted 213 bp PCR products in agarose gel and the positive rate was 16.7% of all patients (21/126) and 39% of the patients with negative results for common respiratory pathogens detections (21/54). The range of patients' age was 2 - 15 months and the young infants with hMPV bronchiolitis (1 - 6 month of age) accounted for 62% and the male:female ratio was 3.2:1. The patients presented a low-medium grade fever (T < 39 degrees C) accounted for 86%; 81.0% of patients had a white blood cell count lower than 10.0 x 10(9)/L. The radiological findings were patchey opacity in both lungs (68%) and(or) hyperinflation (62%). Assessed by the Lowell score system, 5 out of 21 cases were considered as severe cases. The major clinical findings of hMPV bronchiolitis had no significant difference compared with that of subgroup A hRSV bronchiolitis, and showed longer course of disease than that of subgroup B hRSV bronchiolitis (P < 0.01). CONCLUSIONS: Of the infants with bronchiolitis hospitalized in our hospital from November of 2002 through February of 2003, 16.7% were caused by hMPV infection. These data showed that the major clinical characteristics and the outcome of treatment of hMPV bronchiolitis had no statistically significant difference compared to the cases with either subgroup A or subgroup B hRSV infection.

Bronchiolitis↗

PubMed2004

Analysis of prosthetic replacement in treatment of femoral neck fracture on the hemiplegia side in the elderly.

OBJECTIVE: To study the effect of prosthetic replacement in treatment of femoral neck fractures on the hemiplegia side in the elderly. METHODS: From May 1990 to May 2000, 189 elderly patients with femoral neck fractures were treated with prosthetic replacement in my hospital. Twenty-nine hemiplegia patients, who suffered from stroke previously, had Garden type III and type IV femoral neck fractures on the hemiplegia side. Thirty non-hemiplegia patients were chosen randomly. The two groups were followed-up for 27-98 months (average: 59 months). The age, hospitalization days, operating time, blood loss, blood transfusion, complications during perioperative period and long-term complications were compared between the two groups and the results of femoral head replacement and total hip replacement in the hemiplegia group were also compared. RESULTS: All the patients of the two groups survived the perioperative period. No significant difference was found in the age, hospitalization days, operation time, blood loss and blood transfusion and long-term complications between the two groups (P>0.05). However there was significant difference in complications during perioperative period between the two groups (P<0.05). Five patients died in the hemiplegia group with the mortality of 17.2% and two died in the non-hemiplegia group with the mortality of 6.7% 11 months to 5 years after operation. There was significant difference in long-term complications between the femoral head replacement and the total hip replacement in the hemiplegia group (P<0.05). The result of the total hip replacement was better than that of the femoral head replacement. CONCLUSIONS: Prosthetic replacement is a reliable method in treatment of Garden type III and type IV femoral neck fractures on the hemiplegia side in the elderly, and patients are safe during perioperative period. More complications during perioperative period occur in the hemiplegia group, and long-term complications are insignificantly different between the two groups. The mortality rate is higher in the hemiplegia group than in the non-hemiplegia group within 5 years after operation. Since the result of the total hip replacement is better than that of the femoral head replacement, total hip replacement should be chosen firstly to treat Garden type III and type IV femoral neck fractures on the hemiplegia side in the elderly if the muscular strength of the hip is beyond IV degree.

Aged↗

PubMed2004

[Effect of total glucosides of Centella asiatica on antagonizing liver fibrosis induced by dimethylnitrosamine in rats].

OBJECTIVE: To investigate the anti-liver fibrosis effect of total glucosides of Centella asiatica (GCA) in experimental rats. METHODS: Rat liver fibrosis model was induced by injecting dimethylnitrosamine (DMN) intraperitoneally for 6 weeks. Rats were randomly divided into 6 groups, the normal group, the model group, the positive control group treated by colchicine, and the three GCA groups treated by high, moderate and low dosage of GCA through gastrogavage started simultaneously with the modeling. At the end of the experiment, levels of serum total protein (TP), albumin (ALB), alanine transaminase (ALT), aspartate aminotransferase (AST), hyaluronic acid (HA), laminin (LN) were measured, and the pathology of liver tissue was observed. RESULTS: The liver function in the GCA groups was improved, the levels of serum ALT, AST, HA were significantly lower than those in the model group (P < 0.05). Histopathological observation showed that GCA has significant anti-liver fibrosis effect. CONCLUSION: GCA has significant preventive and therapeutic effect on DMN induced liver fibrosis in rats.

Animals↗

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↗

PubMed2003

Olfactory ensheathing cells genetically modified to secrete GDNF to promote spinal cord repair.

Olfactory ensheathing cell (OEC) transplantation has emerged as a very promising therapy for spinal cord repair. In this study, we tested the ability of genetically modified OECs to secrete high levels of glial cell line-derived neurotrophic factor (GDNF) to promote spinal cord repair. The GDNF gene was transduced into OECs using a retroviral-based system. The engineered OECs were first characterized by their ability to express and secrete biologically active GDNF in vitro. After implantation into the spinal cord of adult rats with complete spinal cord transection, OEC survival and GDNF production were examined. The locomotor functions of animals were assessed and axon regeneration was evaluated at the morphological level. To our knowledge, we report for the first time that the genetically modified OECs are capable of producing GDNF in vivo to significantly improve recovery after spinal cord injury (SCI). This work combined the outgrowth-promoting property of OECs with the neuroprotective effects of the additionally overexpressed neurotrophic factors and opens new avenues for the treatment of SCI.

Animals↗

PubMed2003

A putative RUNX1 binding site variant between SLC9A3R1 and NAT9 is associated with susceptibility to psoriasis.

Psoriasis (OMIM 177900) is a chronic inflammatory skin disorder of unknown pathogenesis affecting approximately 2% of the Western population. It occurs more frequently in individuals with human immunodeficiency virus, and 20-30% of individuals with psoriasis have psoriatic arthritis. Psoriasis is associated with HLA class I alleles, and previous linkage analysis by our group identified a second psoriasis locus at 17q24-q25 (PSORS2; ref. 7). Linkage to this locus was confirmed with independent family sets. Additional loci have also been proposed to be associated with psoriasis. Here we describe two peaks of strong association with psoriasis on chromosome 17q25 separated by 6 Mb. Associated single-nucleotide polymorphisms (SNPs) in the proximal peak lie in or near SLC9A3R1 (also called EBP50 and NHERF1) and NAT9, a new member of the N-acetyltransferase family. SLC9A3R1 is a PDZ domain-containing phosphoprotein that associates with members of the ezrin-radixin-moesin family and is implicated in diverse aspects of epithelial membrane biology and immune synapse formation in T cells. The distal peak of association is in RAPTOR (p150 target of rapamycin (TOR)-scaffold protein containing WD-repeats). Expression of SLC9A3R1 is highest in the uppermost stratum Malpighi of psoriatic and normal skin and in inactive versus active T cells. A disease-associated SNP lying between SLC9A3R1 and NAT9 leads to loss of RUNX1 binding. This is the second example of loss of a RUNX1 binding site associated with susceptibility to an autoimmune disease. It also suggests defective regulation of SLC9A3R1 or NAT9 by RUNX1 as a susceptibility factor for psoriasis.

Arylamine N-Acetyltransferase↗

PubMed2003

T cell survival/proliferation reconstitution by trifluoperazine in human immunodeficiency virus-1 infection.

Recent findings support an indirect relationship between T cell depletion in HIV-1 infection and the rate of virus replication with implications for treatment strategies. We have initiated a new approach to recover immune function through the use of novel chemical agents. A cationic amphiphilic drug that binds to Ca(2+)-calmodulin at high concentrations, [10-[3-(4-methyl-1-piperazinyl)-propyl]-2- (trifluoromethyl)-(10)H-phenothiazine dihydrochloride] [denoted trifluroperazine dihydrochloride (Tfp); molecular weight 480.43] TFP was found at low concentrations (10(-6) to 10(-10) M) to help T cells from AIDS patients to restore proliferation in vitro. Here we show that the Tfp molecule can restore the cell survival of T lymphocytes from PBMCs derived from HIV-1-infected patients in vitro. Tfp enhances T cell proliferation and Th-cell responses by selectively inhibiting cell mortality and apoptosis. The restored antigen-specific response is associated with the synthesis of IL-2 and gamma-interferon. Even though this drug does not possess any detectable antiviral effect, it might be considered as a potential therapeutic agent in HIV-infected patients, to correct immune defects. Besides antiviral compounds, these data may facilitate immune reconstitution in patients with HIV infection and other immunosuppressive diseases.

Apoptosis↗

PubMed2003

[Expression of a new cloned nitroreductase gene NOR1 and purification of expressed product].

BACKGROUND & OBJECTIVE: NOR(1)is a good candidate of tumor suppressor/susceptibility gene associated with nasopharyngeal carcinoma. This study was designed to construct the prokaryotic expression vector and to investigate the expression of nitroreductase gene NOR(1)in Escherichia coli and to purify expressed product. METHODS: Total RNA was subtracted from normal nasopharyngeal carcinoma tissue. The full length of NOR(1)gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and digested with BamHIand XhoI restriction endonucleases. The plasmid pGEX-4T-2 was also digested with BamHI and XhoI,then the NOR(1)gene was inserted into vector pGEX-4T-2. The recombinant expression vector pGEX-4T-2/NOR(1)was identified by sequencing and digested with restriction enzymes. E.coli Jm105 transformed with the recombinant plasmid was induced by IPTG to express GST fusion protein. The result was confirmed by Western blot analysis and the purified targeted protein was obtained by affinity chromatography. RESULTS: The 1.25kb NOR(1)gene was successfully isolated. After induction, a new anticipated protein of 74 kDa appeared on sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). It existed not only in supernatant but also in precipitation of broken bacteria. The result was confirmed by Western blot analysis,and the purified targeted protein was obtained by affinity chromatography. CONCLUSION: The successes in construction of expression vector of NOR(1), expression and purification of GST/NOR(1)fusion protein make it possible to prepare for the polyantibodies for NOR(1).

Cloning, Molecular↗

PubMed2003

[SARS-associated coronavirus gene fragments were detected from a suspected pediatric SARS patient].

UNLABELLED: A Special "Fever and Cough" Clinic was set up at the Children's Hospital Affiliated to Capital Institute of Pediatrics for children with symptoms of fever and cough in late April when the severe acute respiratory syndrome (SARS) epidemic was at its peak in Beijing to separate the children with fever from others during their visit to the Outpatient Department. OBJECTIVE: For patients with fever, normal or low count of white blood cell and with suspected pneumonia suggested by X-ray, it was urgent to determine the etiological agents of the diseases before they were admitted to the hospital. METHODS: Throat swabs or nasopharyngeal aspirate specimens were collected from those patients and common respiratory virus antigens including influenza virus A and B, respiratory syncytial virus, adenovirus, parainfluenza virus types I, II, and III were tested by indirect immunofluorescent assay. The patients with atypical pneumonia diagnosed by X-ray and evidences of common respiratory virus infection were admitted to the regular ward for children with respiratory diseases. Children with pneumonia demonstrated by X-ray and negative for common respiratory viruses were admitted to the isolated ward for suspected SARS patients for the first step and further viral etiological studies were requested. RT-PCR was performed for those patients to detect gene fragments of human metapneumovirus (HMPV), rhinovirus (RhV) and enterovirus (EV) in their specimens. Nested RT-PCR was also developed to detect SARS coronavirus gene fragment from the specimens. Primer sequences for SARS virus detection with the PCR were selected according to the primer sequences published online by WHO on April 18, 2003. All the primers derived from the sequence at the 1b frame of coronavirus replicase gene and products with a size of 368 or 348 bp were expected with 2 different primer pairs. RESULTS: Amplicons with the sizes of 368 bp and 348 bp were obtained from a throat swab specimen collected from a 17 years old girl, who was admitted to the isolated ward because of high fever (39.5 degrees C) for 7 days, cough for 2 days, low WBC count, and pneumonia shown by X-ray when she visited the "Fever and Cough" Clinic, and without known history of contact with probable SARS patient. Antigens for the common respiratory viruses were all negative, RT-PCR for HMPV, RhV and EV were also negative while RT-PCR with different primer pairs for SARS virus were all positive which indicated that SARS coronavirus gene fragments were amplified from the specimen from this girl. The amplified fragment with a size of 368 bp was sequenced and the sequence was compared with those in the GenBank. The sequence shared 100% homology with the sequences from 1b frame of replicase genes from all 17 of SARS coronaviruses published in the GenBank so far, and shared very low homology with 2 reference strains of human coronavirus as well as other animal coronaviruses. The serum collected before her discharge from the hospital (19 days after the onset of the disease) showed SARS specific IgM and IgG antibodies. CONCLUSION: These data indicate that the patient was a confirmed case of SARS. It is of great importance to differentiate SARS patients from those infected with common respiratory viruses during SARS epidemic, especially for pediatric patients, because most of the patients visiting the outpatient department present with the symptoms of fever, cough and normal WBC count. The data mentioned above indicate that antigen and gene detections for those common respiratory viruses are useful methods for the differentiation to avoid the spread of SARS.

Adolescent↗

PubMed2003

[Human metapneumovirus may associate with acute respiratory infections in hospitalized pediatric patients in Beijing, China].

OBJECTIVE: A new respiratory virus, human metapneumovirus (HMPV) was recently identified by scientists in the Netherlands first and then in a few other countries. To investigate if this newly discovered virus is associated with the acute respiratory infections in pediatric patients in Beijing, tests were developed to detect HPMV gene fragments from nasopharyngeal aspirates collected from infants and young children hospitalized for acute respiratory infections from November 2002 to March 2003. METHODS: The HMPV was screened by reverse transcription-polymerase chain reaction (RT-PCR). RNAs were extracted by Trizol from 247 specimens which had been determined as negative for conventional respiratory viruses including RSV, influenza A and B, parainfluenza I, II, III and adenovirus by indirect immunofluorescence test as well as virus isolation. The HMPV RNAs were detected by reverse transcription tests using random primer and M-MLV reverse transcriptase followed by PCR using the primers designed from the published sequence of the N protein-encoding gene from the first HMPV identified in the Netherlands. PCR products were visualized by 1.2% agarose gel electrophoresis. Selected positive PCR products were sequenced and the sequences of the nucleotides and deduced amino acids were compared with those in the GenBank. RESULTS: Among those 247 specimens negative for common respiratory viruses, 74 (30.0%) showed the predicted 213 bp PCR products in agarose gel. Most of clinical diagnoses for these 58 patients were pneumonia (36, 48.6%), bronchiolitis (21, 28.4%), and bronchitis and asthma in some patients. Nearly 90 percent of positive specimens were from patients under 2 years of age. Ten out of 74 amplicons were randomly selected for sequence analysis. When compared with the sequences in the GenBank, the nucleotide sequences of these 10 amplicons shared high homology only with those of HMPVs. The nucleotide sequence identities of these 10 samples with those from the Netherlands and Canada were 87% - 99%. When compared with the nucleotide sequence from the first reported strain by Van den Hoogen (strain HMPV 00-1), the sequence identities of these 10 fragments ranged from 88.7% to 99.1%. Among the 10 amplicons from the specimens, the nucleotide identities were 87.3% - 100%. One of the 10 amplicons (No. 1816) shared lower identity with others (87.3% - 89.7%), whereas the other 9 shared higher identities (95.8% - 100%) with each other. The comparison of amino acids showed that these 10 amplicons showed high homology (95.8% - 100%). Again, amplicon No.1816 shared lower homology (95.8% - 97.2%) with others, whereas the other 9 shared higher homology (98.6% - 100%). The amino acid homology between No.1816 and HMPV 00-1 was 95.8%, whereas that of the other 9 with HMPV 00-1 was 98.6% - 100%. CONCLUSION: These data suggested that some of acute respiratory infections in pediatric patients in Beijing area are related to the newly identified human metapneumovirus. The HMPV circulating in Beijing may have different genotypes.

Acute Disease↗

PubMed2002

Novel immunoglobulin superfamily gene cluster, mapping to a region of human chromosome 17q25, linked to psoriasis susceptibility.

Chromosome 17q25 harbors a susceptibility locus for psoriasis ( PSORS2). This locus may overlap with loci for atopic dermatitis and rheumatoid arthritis. To further refine the location of PSORS2, we genotyped 242 primarily nuclear families for 15 polymorphic microsatellites mapping to chromosome 17q23-q25. Non-parametric linkage analysis revealed a linkage peak lying close to a novel cluster of genes from the immunoglobulin (Ig) superfamily. This cluster spans >250 kb and harbors five CMRF35-like genes and a sixth inhibitory receptor ( CMRF35H) with three ITIM motifs that is transcribed in the opposite direction from the rest. The Ig domains encoded by these genes are most similar to those of the TREM (triggering receptor expressed selectively in myeloid cells) molecules, NKp44 and the polymeric immunoglobulin receptor. CMRF35-like genes are only expressed in sub-populations of cells of the myeloid lineage. In order to investigate the association of this region with psoriasis, we genotyped the families for 13 novel microsatellites and 19 SNPs from the region of linkage. A maximum NPL of 1.6 ( P=0.05) was obtained within the interval. Two SNP-based haplotypes revealed some evidence for association with psoriasis. One spanned CMRF35H and includes a non-synonymous polymorphism within CMRF35H (R111Q) (TDT P=0.03). The second was a three-locus haplotype lying within the first intron of CMRF35A2 ( TREM5) (TDT P=0.04). The novel markers described here will facilitate additional linkage and association studies between the CMRF35 family and disease.

Adult↗

PubMed2002

Osmoregulation of endothelial nitric-oxide synthase gene expression in inner medullary collecting duct cells. Role in activation of the type A natriuretic peptide receptor.

Previously, we showed that increased extracellular tonicity promotes increased type A natriuretic peptide receptor (NPR-A) expression through a p38 MAPKbeta pathway in inner medullary collecting duct cells. The endothelial and inducible nitric-oxide synthase (eNOS and iNOS respectively) genes are also expressed in this nephron segment and are thought to play a role in regulating urinary sodium concentration. We sought to determine whether changes in tonicity might regulate NOS gene expression, and if so, whether these latter changes might be linked mechanistically to the increase in NPR-A gene expression. Increased extracellular tonicity effected a time-dependent reduction in eNOS and iNOS protein levels, eNOS mRNA levels, and eNOS gene promoter activity over the first 8 h of the incubation. Although levels of the eNOS mRNA and promoter activity had returned to normal after 24 h, eNOS protein levels remained low at 24-36 h, and recovery was not complete even at 48 h. The decrease in eNOS expression was signaled in large part through a p38 MAPK-dependent mechanism. Reduction in eNOS expression together with the concomitant decline in intracellular cyclic GMP levels appears to account for a significant portion of the p38 MAPK-dependent osmotic stimulation of NPR-A gene expression noted previously. Collectively, these findings support the existence of a complex regulatory circuitry in the cells of the inner medullary collecting duct linking two independent cyclic GMP-generating signal transduction systems involved in regulation of urinary sodium concentration.

Animals↗

PubMed2002

[Clinical features and treatment of giant cell arteritis in Chinese, a prospective study].

OBJECTIVE: To investigate the clinical features of giant cell (temporal) arteritis (GCA) in China. METHODS: The clinical manifestations, temporal artery biopsy, response to steroid therapy, and follow-up data of sixteen patients with the diagnosis of GCA from July 1999 to March 2001 were analyzed. The American College of Rheumatology (ACR) criteria for classification of GCA were used as reference. RESULTS: Twenty-one patients who sought medical advice in the Second Hospital Affiliated to Xiangya Medical College were suspected of GCA. A definite diagnosis of GCA was made among sixteen patients. The diagnosis among 13 of them fulfilled the 1990 American College of Rheumatology criteria for the classification of GCA. The mean age at disease onset was 43.13 years (range 28 approximately 60 years) and 81.25% of the patients were under the age of 50 when they came down with the disease. The ratio between male and female cases was 15:1. The commonest initial clinical manifestations included newly occurring headache, temporal artery abnormality, visual symptoms, fever, and raised erythrocyte sedimentation rate. Jaw claudication, fatigue, syncope, and hemiparesis could be found in some patients. All the 16 patients underwent temporal artery biopsy. Light and electron microscopy showed inflammatory cell infiltration in arterial wall in 11 cases, fragmented internal elastica in 16 cases, fibrinoid necrosis in 3 cases, smooth muscle cell changes in 10 cases, and thrombosis in the lumen in 5 cases. The mean time from symptom onset to suspicion of GCA or biopsy was 5.52 months (range 0.25 approximately 24.33 months). The misdiagnosis rate during first visit was 87.50%. CONCLUSION: GCA may not be a rare disorder in China. In comparison with the cases abroad, the Chinese GCA patients come down with disease at the earlier age, and most Chinese GCA patients are male. This disease is not understood by many clinicians in China. Misdiagnosis is common.

Adult↗