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Chuan-Liang Kao

Publications and source records attributed to Chuan-Liang Kao.

At least 19 recordsLinked to original sources
PubMed2007

Differences in replication capacity between enterovirus 71 isolates obtained from patients with encephalitis and those obtained from patients with herpangina in Taiwan.

The cellular-tropism and biological characteristics of enterovirus 71 (EV71) isolates in Taiwan (TW) were studied. Growth curve experiments were conducted using cell lines that were possibly exhibited pathogenesis, and RT-PCR and sequencing tests were undertaken to amplify the 5' non-coding region (5'-NCR). The encephalitis isolate EV71 TW98NTU2078 was PBMC-tropic, temperature-resistant (Tr) at 40 degrees C, and easier to replicate in HTB-14 (astrocytoma) than the herpangina isolate EV71 TW98NTU1186 (The viral yields were 100-fold higher than those of the herpangina isolate EV71 TW98NTU1186 at 96 hr post infection.). The herpangina isolate EV71 TW98NTU1186 was non-PBMC-tropic, and temperature-sensitive (Ts) at 40 degrees C. The replication of EV71 TW98NTU1186 in HTB-14 was lower. No EV71 isolate infected HTB-37 (human colon adenocarcinoma cells). The encephalitis EV71 isolate exhibited better replication and transmission in PBMCs and astrocytes than did the EV71 isolate without CNS involvement.

Animals↗
PubMed2006

Evolution of EV71 genogroup in Taiwan from 1998 to 2005: an emerging of subgenogroup C4 of EV71.

In Taiwan, enterovirus 71 (EV71) has played an important role in severe enterovirus-related cases every year since the devastating outbreak in 1998. Three genogroups A, B, C occur worldwide; with the B and C genogroups being subdivided into B1-B4 and C1-C4 subgenogroups respectively. To understand the mutation of the EV71 genogroup in Taiwan before and after 1998, a total of 54 worldwide strains were studied including 41 Taiwanese strains obtained in 1986 and 1998-2004. A fragment of 207 bp of the VP4 region was amplified and sequenced. Genetic analysis was performed using MEGA software (version 3.0) for the nucleotide sequence alignment and phylogenetic analysis. In Taiwan, the subgenogroup B1 was predominant before 1998 while subgenogroup C2 was the major etiologic group in 1998 outbreak. A minor etiologic group outbreak in 1998, subgenogroup B4, became predominant during the period from 1999 to 2003. In this study, subgenogroup C4 emerged and became predominant in 2004 in Taiwan. The nucleotide differences between B1 and C2, C2 and B4, B4 and C4 were 20%-26%, 19%-27%, 18%-22%, respectively. Nucleotide sequence alignment revealed 67 substitutions. Most of the substitutions (62/67) were silent mutations. This is the first report about the emergence of EV71 subgenogroup C4 in Taiwan.

Base Sequence↗
PubMed2006

Molecular epidemiology of HIV type 1 subtypes in Taiwan: outbreak of HIV type 1 CRF07_BC infection in intravenous drug users.

In Taiwan, sexual transmission is responsible for most HIV-1 infections with two dominant subtypes, subtype B and CRF01_AE, distributing among homosexual and heterosexual groups, respectively. Recently, intravenous drug use has become an emerging route of HIV-1 transmission and contributed to a significant increase of HIV-1 infection. To characterize the HIV isolates responsible for the outbreak among intravenous drug users (IDUs), phylogenetic analysis was performed to analyze the protease/RT sequences amplified from HIV-1-infected IDUs at National Taiwan University Hospital and Taipei City STD Control Center. CRF07_BC, which is circulating in northern China, was demonstrated to account for the majority of HIV-1 infection in IDUs in the past 2 years. Although these Taiwanese CRF07_BC sequences shared the same breakpoint positions as those described in the CRF07_BC reference sequences, they formed a unique cluster in the phylogenetic tree, suggesting they originated from a founder virus. This finding was further supported by the relative low genetic diversity and unique sequence features. Our results demonstrated the emergence of CRF07_BC and its association with the HIV-1 outbreak among IDUs between 2004 and 2005 in Taiwan. This finding not only helps us to have a better understanding of the HIV evolution in Asia, but also has important implications for vaccine design in the future.

Disease Outbreaks↗
PubMed2006

Molecular epidemiology of G9 rotaviruses in Taiwan between 2000 and 2002.

Since the mid-1990s, novel G9 rotaviruses have been detected in many countries, suggesting that G9 is a globally important serotype. The molecular epidemiology of G9 rotaviruses in Taiwan from 2000 to 2002 was investigated in this study. G9 rotavirus first appeared in 2000 with 4 cases and constituted 33.8% and 54.8% of the rotavirus-positive samples in 2001 and 2002, respectively. These G9 strains belonged to P[8]G9, subgroup II, and long electropherotype, except one belonged to P[4]G9, subgroup II, and short electropherotype. Nucleotide sequencing and phylogenetic analysis of 52 Taiwanese G9 rotaviruses showed that the VP7 genes shared a high degree of identity to overseas G9 rotaviruses detected after 1993 and that the VP8* portions of the VP4 genes were more closely related to those of local rotaviruses of other G types. The two P[8]G9 strains with high nucleotide identities in the VP7 and the partial VP4 genes, 01TW591 of Taiwan from 2001 and 95H115 of Japan from 1995, varied in four genes, genes 2, 3, 7, and 8, which was revealed by RNA-RNA hybridization. Representative strains for different RNA patterns were also analyzed in the partial VP2 and VP3 genes; the nucleotide identities were high between Taiwanese G9 strains and local G3 or G2 strains. These results suggested that Taiwanese G9 rotaviruses possibly had evolved through reassortment between overseas G9 strains and circulating rotaviruses of other G types.

Antigens, Viral↗
PubMed2006

Modeling the early events of severe acute respiratory syndrome coronavirus infection in vitro.

The clinical picture of severe acute respiratory syndrome (SARS) is characterized by pulmonary inflammation and respiratory failure, resembling that of acute respiratory distress syndrome. However, the events that lead to the recruitment of leukocytes are poorly understood. To study the cellular response in the acute phase of SARS coronavirus (SARS-CoV)-host cell interaction, we investigated the induction of chemokines, adhesion molecules, and DC-SIGN (dendritic cell-specific ICAM-3-grabbing nonintegrin) by SARS-CoV. Immunohistochemistry revealed neutrophil, macrophage, and CD8 T-cell infiltration in the lung autopsy of a SARS patient who died during the acute phase of illness. Additionally, pneumocytes and macrophages in the patient's lung expressed P-selectin and DC-SIGN. In in vitro study, we showed that the A549 and THP-1 cell lines were susceptible to SARS-CoV. A549 cells produced CCL2/monocyte chemoattractant protein 1 (MCP-1) and CXCL8/interleukin-8 (IL-8) after interaction with SARS-CoV and expressed P-selectin and VCAM-1. Moreover, SARS-CoV induced THP-1 cells to express CCL2/MCP-1, CXCL8/IL-8, CCL3/MIP-1alpha, CXCL10/IP-10, CCL4/MIP-1beta, and CCL5/RANTES, which attracted neutrophils, monocytes, and activated T cells in a chemotaxis assay. We also demonstrated that DC-SIGN was inducible in THP-1 as well as A549 cells after SARS-CoV infection. Our in vitro experiments modeling infection in humans together with the study of a lung biopsy of a patient who died during the early phase of infection demonstrated that SARS-CoV, through a dynamic interaction with lung epithelial cells and monocytic cells, creates an environment conducive for immune cell migration and accumulation that eventually leads to lung injury.

Acute Disease↗
PubMed2005

Lack of association between infection with a novel human coronavirus (HCoV), HCoV-NH, and Kawasaki disease in Taiwan.

We investigated whether infection with a novel human coronavirus (HCoV), called "New Haven coronavirus" (HCoV-NH)--which is similar to and likely represents the same species as another novel HCoV, HCoV-NL63--is associated with Kawasaki disease (KD) in Taiwan. Fifty-three patients with KD were enrolled in our study. Serum, peripheral-blood mononuclear cells, nasopharyngeal aspirates, throat swabs, and rectal swabs from these patients were assayed for HCoV-NL63 by real-time reverse-transcriptase (RT) polymerase chain reaction (PCR), and the throat swabs, nasopharyngeal aspirates, and rectal swabs were also assayed for HCoV-NH by RT-PCR. All PCR results were negative for both HCoV-NL63 and HCoV-NH; therefore, we did not find any association between HCoV-NH infection and KD in Taiwan.

Child, Preschool↗
PubMed2005

Development of immunoglobulin G enzyme-linked immunosorbent assay for the serodiagnosis of severe acute respiratory syndrome.

Severe acute respiratory syndrome (SARS) is an emerging infectious disease caused by a novel SARS-associated coronavirus (SARS-CoV). The clinical characteristics are high fever, rapidly progressive diffuse pneumonitis and respiratory distress. It is highly infectious through intimate contact or direct contact with infectious body fluids. Outbreaks within communities and hospitals have been reported. Development of rapid and reliable diagnostic tools is urgently needed. We developed an immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA), using whole virus antigen of SARS-CoV. Eighty-six serum samples collected from patients who were hospitalized for other causes were examined to determine the cut-off O.D. value. The cut-off O.D. value was defined as 0.175 by calculating the mean O.D. value of the 86 sera plus 3 standard deviations. To determine the sensitivity and specificity of the ELISA, 56 positive sera and 204 negative sera were tested. The sensitivity was 96.4% and the specificity was 100%. The results suggest that the IgG ELISA using whole virus antigen of SARS-CoV has a high sensitivity and specificity in detecting SARS IgG antibodies. This IgG ELISA is a powerful tool for serodiagnosis of SARS.

Antigens, Viral↗
PubMed2005

Surface ultrastructure of SARS coronavirus revealed by atomic force microscopy.

Atomic force microscopy has been used to probe the surface nanostructures of severe acute respiratory syndrome coronavirus (SARS-CoV). Single crown-like virion was directly visualized and quantitative measurements of the dimensions for the structural proteins were provided. A corona of large, distinctive spikes in the envelope was measured after treatment with hydroxyoctanoic acid. High-resolution images revealed that the surface of each single SARS-CoV was surrounded with at least 15 spherical spikes having a diameter of 7.29 +/- 0.73 nm, which is in close agreement with that of S glycoproteins earlier predicted through the genomes of SARS-CoV. This study represents the first direct characterization of the surface ultrastructures of SARS-CoV particles at the nanometre scale and offers new prospects for mapping viral surface properties.

Hemagglutinins, Viral↗
PubMed2005

Laboratory-based surveillance and molecular epidemiology of influenza virus in Taiwan.

A laboratory-based surveillance network of 11 clinical virological laboratories for influenza viruses was established in Taiwan under the coordination of the Center for Disease Control and Prevention (CDC), Taiwan. From October 2000 to March 2004, 3,244 influenza viruses were isolated, including 1,969 influenza A and 1,275 influenza B viruses. The influenza infections usually occurred frequently in winter in the northern hemisphere. However, the influenza seasonality in Taiwan was not clear during the four seasons under investigation. For example, the influenza A viruses peaked during the winters of 2001, 2002, and 2003. However, some isolated peaks were also found in the summer and fall (June to November) of 2001 and 2002. An unusual peak of influenza B also occurred in the summer of 2002 (June to August). Phylogenetic analysis shows that influenza A isolates from the same year were often grouped together. However, influenza B isolates from the year 2002 clustered into different groups, and the data indicate that both B/Victoria/2/87-like and B/Yamagata/16/88-like lineages of influenza B viruses were cocirculating. Sequence comparison of epidemic strains versus vaccine strains shows that many vaccine-like Taiwanese strains were circulating at least 2 years before the vaccine strains were introduced. No clear seasonality of influenza reports in Taiwan occurred in contrast to other more continental regions.

Animals↗
PubMed2005

Laboratory diagnosis of dengue virus infection: current and future perspectives in clinical diagnosis and public health.

Since no protective vaccine or specific treatments are available for dengue fever/dengue hemorrhagic fever (DHF), accurate diagnosis is critical for the early initiation of specific preventive health measures to curtail epidemic spread and reduce economic losses. Commonly used diagnosis methods for confirming dengue infection involve virus isolation, detection of virus antigen or RNA in plasma or serum or tissues, and the presence of dengue virus-specific antibodies in serum and other body fluids. Recently, several techniques have been developed for rapid laboratory diagnosis of dengue virus, including centrifugation amplification to enhance virus isolation rate, the flow cytometry method for early detection of cultured virus, detecting viral nucleic acid e.g., by nested reverse transcriptase-polymerase chain reaction (RT-PCR), quantitative RT-PCR, nucleic acid sequence-based amplification, and real-time PCR, detecting free viral non-structure antigens, anti-dengue virus immunoglobulin M (IgM) or IgG antibodies by enzyme-linked immunosorbent assay, and differentiation of primary versus secondary dengue virus infection. Newly established methods must be standardized to maintain high quality laboratory performance. Laboratory diagnostics must be tailored to a specific laboratory environment, the objectives of clinical needs and the availability of clinical specimens. Speed and accuracy of diagnosis must be balanced against test cost and availability. Future challenges in the study of dengue and DHF include the application of modern techniques, such as nucleic acid chips, protein chips and new biomarkers to avoid cross-reactivity among different serotypes of dengue viruses and other flaviviruses, plus development of internationally standardized guidelines to improve quality assurance of these advanced laboratory tests.

Antibodies, Viral↗
PubMed2005

Clinical features and factors of unfavorable outcomes for non-polio enterovirus infection of the central nervous system in northern Taiwan, 1994-2003.

This study investigated the clinical manifestations and outcomes of central nervous system (CNS) infection by enteroviruses. Cases with CNS involvement among all enterovirus-culture-positive cases from January 1995 to June 2003 were retrospectively reviewed. Among 1028 enterovirus-culture-positive cases, there were 333 cases involving the CNS. Of these, the ratio of male to female subjects was 1.78, and the mean (+/- standard deviation) age was 6.83 +/- 5.9 years; 21 were premature neonates, and 10 failed to thrive. Disease entities included 282 cases of aseptic meningitis (84.7%), 44 cases of encephalitis (13.2%), and 7 cases of encephalomyelitis/polio-like syndrome (2.1%). Of these cases, 97.9% (326/333) had fever with peak body temperature at 38.9 degrees C, 85% had headache and vomiting, 70% had meningeal signs, 64% had neck stiffness, 16.6% (55/333) had change of consciousness, 5.4% (18/333) had seizures and 5.2% (17/333) had myoclonic jerks. Mannitol was administered in 77.2% of patients (257/333), along with intravenous immunoglobulin in 6.6% (22/333). Twelve cases received ventilator support. One patient died of hand-foot-and-mouth disease, encephalitis plus cardiopulmonary failure, and 2 premature neonates died of hepatic failure, disseminated intravascular coagulation, sepsis-like syndrome and myocarditis. Eighteen had neurologic sequelae, including 7 with limb weakness, 5 with epilepsy, 2 with sixth cranial nerve palsy, 3 with cerebral palsy, 4 with psychomotor retardation, 2 with spasticity, and 1 with hearing loss. Factors associated with unfavorable outcomes (death or sequelae) included younger age (p=0.0003), higher peak white blood cell count (WBC) [p=0.0009] and skin rash (p=0.005). Younger age and higher peak WBC were poor prognostic factors of severe enterovirus CNS infection. Death was related to neonatal enterovirus infection and enterovirus 71 infection in young children.

Adolescent↗
PubMed2004

Temporal relationship of viral load, ribavirin, interleukin (IL)-6, IL-8, and clinical progression in patients with severe acute respiratory syndrome.

Although viral replication and overwhelming immune responses are believed to contribute to the progression of severe acute respiratory syndrome (SARS), little is known about the temporal relationship between viral load, ribavirin, proinflammatory cytokines, and clinical progression. We report that ribavirin was not effective in reducing the SARS coronavirus load in 3 of 8 probable cases studied and that elevated levels of interleukin (IL)-6 and IL-8 subsequent to the peak viral load were found in 8 and 6 cases, respectively. The nadir lymphocyte count during lymphopenia, the peak level of lactate dehydrogenase, and the peak density of pulmonary infiltrates lag further behind the peak viral load by a median of 4, 5, and 3.5 days, respectively. These findings provide important information for therapeutic strategies to treat SARS.

Adult↗
PubMed2004

Disease-specific B Cell epitopes for serum antibodies from patients with severe acute respiratory syndrome (SARS) and serologic detection of SARS antibodies by epitope-based peptide antigens.

Severe acute respiratory syndrome (SARS) has emerged as a highly contagious, sometimes fatal disease. To find disease-specific B cell epitopes, phage-displayed random peptide libraries were panned on serum immunoglobulin (Ig) G antibodies from patients with SARS. Forty-nine immunopositive phage clones that bound specifically to serum from patients with SARS were selected. These phageborne peptides had 4 consensus motifs, of which 2 corresponded to amino acid sequences reported for SARS-associated coronavirus (SARS-CoV). Synthetic peptide binding and competitive-inhibition assays further confirmed that patients with SARS generated antibodies against SARS-CoV. Immunopositive phage clones and epitope-based peptide antigens demonstrated clinical diagnostic potential by reacting with serum from patients with SARS. Antibody-response kinetics were evaluated in 4 patients with SARS, and production of IgM, IgG, and IgA were documented as part of the immune response. In conclusion, B cell epitopes of SARS corresponded to novel coronavirus. Our epitope-based serologic test may be useful in laboratory detection of the virus and in further study of the pathogenesis of SARS.

Amino Acid Motifs↗
PubMed2004

Characterization of severe acute respiratory syndrome coronavirus genomes in Taiwan: molecular epidemiology and genome evolution.

Since early March 2003, the severe acute respiratory syndrome (SARS) coronavirus (CoV) infection has claimed 346 cases and 37 deaths in Taiwan. The epidemic occurred in two stages. The first stage caused limited familial or hospital infections and lasted from early March to mid-April. All cases had clear contact histories, primarily from Guangdong or Hong Kong. The second stage resulted in a large outbreak in a municipal hospital, and quickly spread to northern and southern Taiwan from late April to mid-June. During this stage, there were some sporadic cases with untraceable contact histories. To investigate the origin and transmission route of SARS-CoV in Taiwan's epidemic, we conducted a systematic viral lineage study by sequencing the entire viral genome from ten SARS patients. SARS-CoV viruses isolated from Taiwan were found closely related to those from Guangdong and Hong Kong. In addition, all cases from the second stage belonged to the same lineage after the municipal hospital outbreak, including the patients without an apparent contact history. Analyses of these full-length sequences showed a positive selection occurring during SARS-CoV virus evolution. The mismatch distribution indicated that SARS viral genomes did not reach equilibrium and suggested a recent introduction of the viruses into human populations. The estimated genome mutation rate was approximately 0.1 per genome, demonstrating possibly one of the lowest rates among known RNA viruses.

Base Pairing↗
PubMed2004

Childhood severe acute respiratory syndrome in Taiwan and how to differentiate it from childhood influenza infection.

OBJECTIVE: To investigate clinical features and outcomes of children in Taiwan with laboratory-confirmed severe acute respiratory syndrome (SARS) vs those of children with influenza to differentiate the 2 diseases. DESIGN, SETTING, AND PARTICIPANTS: Patients 20 years or younger with clinical, epidemiological, and laboratory evidence of SARS from March to July 2003 vs children with virus culture-confirmed influenza in a 1:1 age- and sex-matched control group. MAIN OUTCOME MEASURES: Rates of symptoms, abnormal laboratory data, and outcomes of recovery, sequelae, or death. RESULTS: The 15 SARS patients (9 girls and 6 boys) had a median age of 17 years (age range, 4-20 years). Nine patients (60%) were infected through household contact, 4 (27%) nosocomially, 1 (7%) through contact with a neighbor, and 1 (7%) after returning from Hong Kong. All 15 patients had fever, 3 (20%) had chills, and 11 (73%) had cough. Only 1 patient (7%) had sputum production; 1 (7%) had rhinorrhea. At presentation, 5 patients (33%) had leukopenia, 6 (40%) had lymphopenia, and 5 (33%) had monocytopenia. All children recovered without sequelae. Children with SARS had significantly lower incidences of rhinorrhea (odds ratio [OR], 0.01; 95% confidence interval [CI], 0.00-0.09), sputum production (OR, 0.10; 95% CI, 0.02-0.63), and sore throat (OR, 0.17; 95% CI, 0.03-0.85) than children with influenza. Both groups had similar incidences of leukopenia or lymphopenia, but SARS patients had a significantly higher incidence of monocytopenia (33% vs 0%, P = .04). CONCLUSIONS: Childhood SARS is usually not fatal. The absence of rhinorrhea and presence of monocytopenia in SARS may distinguish it from influenza.

Adolescent↗
PubMed2004

Lymphocyte activation and hepatic cellular infiltration in immunocompetent mice infected by dengue virus.

Activation and expansion of dengue virus-specific T cells and abnormal liver functions in dengue patients have been documented. However, it remains to be determined whether T cells are involved in the pathogenic mechanism of dengue virus infection. In this study, immunocompetent C57BL/6 mice were employed to study dengue virus-induced T cell activation. Mice were inoculated with 10(8) PFU dengue virus serotype 2 strain 16681 by the intravenous route. Dengue viral core RNA was detected by RT-PCR in mouse serum, liver, spleen, and brain at different time points after infection. Splenic T cells were activated as evidenced by their expression of CD69 and O-glycosylated CD43 at as early as day 3 after infection. Splenic T cell expression of O-glycosylated CD43 and IFN-gamma production coordinately peaked at day 5. Coincided with the peak of splenic T cell activation was hepatic lymphocyte infiltration and elevation of liver enzymes. Flow cytometric analysis revealed the infiltrating CD8(+) T cell to CD4(+) T cell ratio was 5/3. After a second inoculation of dengue virus, hepatic T cell infiltration and liver enzyme levels increased sharply. The infiltrating hepatic CD8(+) T cell to CD4(+) T cell ratio increased to 5.8/1. A strong correlation was found between T cell activation and hepatic cellular infiltration in immunocompetent mice infected with dengue virus. The kinetics of liver enzyme elevation also correlated with that of T cell activation. These data suggest a relationship between T cell infiltration and elevation of liver enzymes.

Alanine Transaminase↗
PubMed2004

Lateral nasal wall mucoperiosteal flap: a versatile new reconstruction of the inner defect of translocated facial bone segments.

From July 1998 to December 2002, 42 patients (including 29 patients who had undergone radiation therapy) underwent a newly designed lateral nasal wall mucoperiosteal flap pedicled anteriorly on the lateral nasal artery of the angular artery to resurface a translocated facial bone segment during a facial translocation approach to the skull base to prevent its avascular necrosis. Of the 42 patients studied, 1 patient had full-thickness flap loss that resulted in bone graft necrosis. Another patient had marginal necrosis. The average length, width, and surface area of the flap was 30 mm, 45 mm, and 1350 mm measured on 5 patients. The mucoperiosteal flap tolerated radiation therapy well. The lateral nasal wall mucoperiosteal flap is a simple, reliable flap that provides ample vascularized tissue to resurface the nude translocated facial bone segment during a facial translocation approach to the skull base. It thus prevents its avascular necrosis even after radiation therapy.

Facial Bones↗