Advances on molecular typing methods and evolution of human parainfluenza virus / 中华预防医学杂志

Human parainfluenza viruses (HPIVs) is one of the main causes of acute respiratory tract infections in children. HPIVs have been grouped into four serotypes (HPIV1~HPIV4) according to serological and genetic variation. Different serotypes of HPIVs have diverse clinical disease spectrum, epidemic characteristics and disease burden. Based on the nucleotide variation in structural protein genes, HPIVs can be further divided into distinct genotypes and subtypes with diverse temporal and spatial distribution features. The standard molecular typing methods are helpful to clarify the gene evolution and transmission patterns of HPIVs in the process of population transmission. However, the development of molecular epidemiology of HPIVs has been hindered by the lack of a standardized molecular typing method worldwide. Therefore, this study reviewed the viral characteristics, genome structure, existing genotyping methods and evolution of HPIVs, and screened the reference strains for molecular typing, so as to improve the understanding of gene characteristics and molecular typing of HPIVs, and provide an important scientific basis for the monitoring and research of molecular epidemiology of HPIVs in China.

Seasonality and etiology of croup in pediatric patients hospitalized with lower respiratory tract infections: A long-term study between 2009 and 2017

PURPOSE: Croup is a common respiratory disease in children. The aim of this study was to analyze the epidemiology, etiology, and seasonal variations of respiratory virus infections in children with croup. METHODS: From October 2009 to September 2017, children admitted with croup to Gachon University Gil Medical Center under the age of 18 years were enrolled in this study. We retrospectively reviewed patients' medical records. RESULTS: A total of 1,053 of 27,330 patients (3.9%) infected with lower respiratory infections were diagnosed as having croup. In the age distribution, croup was most common (50.0%) in children aged 1 to <2 years. There were 2 peaks, the major in summer (July to August) and the minor in spring (March to May). Parainfluenza virus type 1 (15.8%) was most prevalent and coincided with the summer peaks of croup. Influenza virus type B and parainfluenza virus type 3 were the most frequent etiologic agents in a spring peak of croup. Although parainfluenza virus type 1 was predominant of all ages, human coronavirus was a significant cause of croup in children younger than 1 year, whereas influenza virus played an important role in children above the age of 3 years. CONCLUSION: Seasonality and epidemiology of croup varied with age and regions. Two peaks of seasonal fluctuation were in summer and spring, which were related to the seasonality of respiratory viruses in croup. These results may be helpful in planning clinical and research needs.

Comparison of etiology and clinical presentation between children with laryngotracheobronchopneumonitis and croup

PURPOSE: Croup, a common childhood respiratory illness with various severities, has many unanswered questions. Laryngotracheobronchopneumonitis (LTBP) is a disease entity considered to be an extension of croup to the lower respiratory tract. The object of this study was to compare epidemiology, clinical characteristics, and viral etiologic spectrum between croup and LTBP. METHODS: Patients hospitalized with croup at Gachon University Gil Hospital from January 2010 to April 2016 were recruited. LTBP was defined as pneumonia confirmed on radiographs of patients with croup. Clinical findings and demographic data were reviewed of patients whose nasopharyngeal swabs were done for viral analysis. RESULTS: A total of 371 patients with only croup and 63 patients with LTBP were included. Croup was found to be significantly associated with parainfluenza virus type 1 (P=0.006). LTBP was related to parainfluenza virus type 3, respiratory syncytial virus, and human bocavirus (P=0.001, P=0.030, and P=0.019, respectively). The duration of fever was longer in patients with LTBP than in those with croup (3.87±1.85 days vs. 2.86±1.80 days, P<0.001). CONCLUSION: Specific etiologic viruses might be associated with the progression from croup to LTBP. Pronged fever is also associated with progression from croup to LTBP.

Parainfluenza virus as a cause of acute respiratory infection in hospitalized childrens

Background: Human parainfluenza viruses account for a significant proportion of lower respiratory tract infections in children.Objective: To assess the prevalence of Human parainfluenza viruses as a cause of acute respiratory infection and to compare clinical data for this infection against those of the human respiratory syncytial virus.Methods: A prospective study in children younger than five years with acute respiratory infection was conducted. Detection of respiratory viruses in nasopharyngeal aspirate samples was performed using the indirect immunofluorescence reaction. Length of hospital stay, age, clinical history and physical exam, clinical diagnoses, and evolution (admission to Intensive Care Unit or general ward, discharge or death) were assessed. Past personal (premature birth and cardiopathy) as well as family (smoking and atopy) medical factors were also assessed.Results: A total of 585 patients were included with a median age of 7.9 months and median hospital stay of six days. No difference between the HRSV+ and HPIV+ groups was found in terms of age, gender or length of hospital stay. The HRSV+ group had more fever and cough. Need for admission to the Intensive Care Unit was similar for both groups but more deaths were recorded in the HPIV+ group. The occurrence of parainfluenza peaked during the autumn in the first two years of the study.Conclusion: Parainfluenza was responsible for significant morbidity, proving to be the second-most prevalent viral agent in this population after respiratory syncytial virus. No difference in clinical presentation was found between the two groups, but mortality was higher in the HPIV+ group.

Parainfluenza Virus Types 1, 2, and 3 in Pediatric Patients with Acute Respiratory Infections in Beijing During 2004 to 2012 / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Although human parainfluenza virus (HPIV) has been determined as an important viral cause of acute respiratory infections (ARIs) in infants and young children, data on long-term investigation are still lacking to disclose the infection pattern of HPIV in China.</p><p><b>METHODS</b>Nasopharyngeal aspirates were collected from 25,773 hospitalized pediatric patients with ARIs from January 2004 through December 2012 for respiratory virus screen by direct immuno-fluorescence assay.</p><p><b>RESULTS</b>Out of these specimens, 1675 (6.50%, 1675/25,773) showed HPIV positive, including 261 (1.01%, 261/25,773) for HPIV1, 28 (0.11%, 28/25,773) for HPIV2, and 1388 (5.39%, 1388/25,773) for HPIV3, 2 of the samples were positive for both HPIV1 and HPIV3, and 36 were co-detected with other viruses. The positive rates of HPIVs were higher in those younger than 3 years old. HPIV3 was detected from all age groups, predominantly from patients under 3 years of age, and the highest frequency was found in those 6 months to 1-year old (352/4077, 8.63%). HPIV3 was the dominant type in each of the years detected between May and July. HPIV1 showed a peak in every odd year, mainly in August or September. HPIV was detected most frequently from patients with upper respiratory infection (12.49%, 157/1257), followed by bronchitis (11.13%, 176/2479), asthma (9.31%, 43/462), bronchiolitis (5.91%, 150/2536), pneumonia (6.06%, 1034/17,068), and those with underlying diseases (1.0%, 15/1506). HPIV3 is the dominant type in these six disease groups referred above, especially in the asthma group.</p><p><b>CONCLUSIONS</b>HPIV is one of the important viral causes of ARIs in infants and young children in Beijing based on the data from the hospitalized children covering a 9-year term. HPIV3 is the predominant type in all these years and in most of the disease groups. HPIVs with different types show different seasonality.</p>

Recombinant human interferon alpha 2b broad-spectrum anti-respiratory viruses pharmacodynamics study in vitro / 药学学报

This study is to investigate the effect of recombinant human interferon alpha 2b against broad-spectrum respiratory viruses in vitro. At the cellular level, the effect of the recombinant human interferon alpha 2b on influenza A virus was detected using real-time fluorescence quantitative RT-PCR. The effects of the recombinant human interferon alpha 2b on influenza B virus, parainfluenza virus, respiratory syncytial virus (RSV) and coronavirus were detected using cytopathic effect (CPE) method. In this study, the therapeutic index of recombinant human interferon alpha 2b anti-HPIV was 1476.63, the therapeutic index of recombinant human interferon alpha 2b anti-RSV was 141.37, the therapeutic index of recombinant human interferon alpha 2b anti-coronavirus was more than 2820.76, and the antiviral effect of recombinant human interferon alpha 2b was better than ribavirin (RBV). Recombinant human interferon alpha 2b has a stronger inhibitory effect on different influenza A virus RNA than drug control. The therapeutic index of recombinant human interferon alpha 2b anti-influenza B virus was 2.74, with modest effect. Recombinant human interferon alpha 2b in vitro has broad spectrum antiviral activities, low toxicity and high therapeutic index. Recombinant human interferon alpha 2b is expected to become the efficient medicine in clinical against respiratory viruses, as well as provide better services for prevention and treatment of respiratory viruses' infections.

Viral etiology of acute respiratory tract infection among pediatric inpatients and outpatients from 2010 to 2012 in Beijing, China / 中华儿科杂志

<p><b>OBJECTIVE</b>Acute respiratory tract infections (ARI) are the leading cause of pediatric morbidity and mortality worldwide, particularly in developing countries. Viruses are the main pathogens of ARI in children. The purpose of the present study was to determine the epidemiologic features of respiratory viruses, including novel viruses, in outpatient and hospitalized children with ARI.</p><p><b>METHOD</b>From March 2010 to February 2012, 2066 children with ARI, including 1050 outpatients and 1016 inpatients, were involved in this study. One nasopharyngeal aspirate or throat swab specimen was collected from each patient. Reverse transcription (RT) PCRs were performed to detect common respiratory tract viruses including respiratory syncytial virus (RSV), human rhinovirus (HRV), influenza virus (IFV), parainfluenza virus (PIV) type 1-4, adenovirus (ADV), enterovirus (EV), human coronavirus (HCOV), human metapneumonia virus (HMPV) and human bocavirus (HBOV).</p><p><b>RESULT</b>At least one viral pathogen was identified in each of 1274 out of 2066 patients and the overall positive rate was 61.7%. The positive rate in inpatient (69.7%) was higher than that in outpatient (53.9%). The frequencies of detection of various viruses among in- and outpatients were different. RSV was the most prevalent virus detected among hospitalized children, followed by HRV and PIV, whereas IFV was the most frequently identified virus in the outpatient group, followed by ADV and PIV. Simultaneous detection of two or more viruses was found in 377 cases. Coinfection was more frequent in inpatients than in outpatients (30.1% vs. 6.8%, P < 0.001).</p><p><b>CONCLUSION</b>Respiratory viruses play an important role in children with ARI, especially in young children. RSV was the most prevalent virus detected among hospitalized children, whereas IFV was the most frequently identified virus in the outpatient group. Viral coinfections are frequently identified, particularly in hospitalized patients. Further studies are required to better understand the impact of coinfections in children with ARI.</p>

Viral agents causing acute lower respiratory tract infections in hospitalized children at a tertiary care center in Saudi Arabia

To determine the load and importance of respiratory viruses in hospitalized Saudi children with acute lower respiratory tract infections [ALRIs]. A retrospective study was performed in the Departments of Pediatrics, Pathology/Microbiology, King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia from January 2005 to December 2010. Nasopharyngeal aspirates were collected from 643 children with ALRI. Viruses were detected by direct immunofluorescence, respiratory syncytial virus [RSV], adenovirus [ADV], type 1 to 3 parainfluenza viruses [PIV], and type A and B influenza virus [flu]. Of the 643 children with ALRI, viruses were detected in 309 [48.1%] specimens. The viruses that were identified included RSV [n=295, 95.5%], PIV [n=8, 1.2%], ADV [n=2, 0.3%], flu A [n=2, 0.3%], and flu B [n=2, 0.3%]. The RSV was predominated in 231 [75%] children less than one year of age. Only younger age and male gender were associated with severe illness. The peak frequency of the viruses detected was in the winter. Of the 309 virus positive samples, bronchiolitis was detected in 81.2% [n=251], and pneumonia in 14.2% [n=44] [p<0.0001]. Viruses are an important cause of ALRIs in Saudi children constituting approximately 48.1% of the total cases. The RSV is the most common pathogen [95.5%] causing ALRIs. Most of the children were younger than one year of age, and were more likely to present with bronchiolitis than pneumonia

Simultaneous detection of human parainfluenza viruses 1, 2, 3 by multiplex real-time reverse transcription-polymerase chain reaction with LNA probes / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>Human parainfluenza virus (HPIV) types 1, 2 and 3 are major viral pathogens responsible for upper and lower respiratory tract infections. In this study, a real-time RT-PCR was developed using multiplex primers-probe (HPIV-1, 2, 3) for the simultaneous detection of both HPIV1, HPIV2 and HPIV3 genomes.</p><p><b>METHODS</b>Optimal primers and probes were designed using specialized software. The conditions for multiplex real-time RT-PCR had been optimized. The synthesis of RNA standards of HPIV1, 2, 3 were used a T7 RNA polymerase. Check the specificity sensitivities and stability of one step RT-PCR assay.</p><p><b>RESULTS</b>Obtained in a 10-fold dilution series assay demonstrate a high sensitivity of the assay with a lowest detection limit of 10 copies for HPIV1, 100 copies for HPIV2 and 100 copies for HPIV3.</p><p><b>CONCLUSION</b>The assays demonstrates an improved sensitivity and scope of detecting HPIV1, 2, 3 viruses relative to routine antigen detection assays while the quantitative utility may facilitate investigation of the pre-diagnosis and respiratory virus pathogenesis.</p>

Epidemiologic Features of Parainfluenza Virus Type 1, 2 and 3 Infection in Seoul and a Neighboring Area, 2008-2011 / 대한임상미생물학회지

BACKGROUND: Parainfluenza virus (PIV) is a significant cause of acute respiratory infections. Epidemiological information on PIV infection could be very helpful for patient management. The aim of this study was to investigate the epidemiology of PIV infection in Seoul and a neighboring area with regard to PIV type. METHODS: The diagnosis of PIV infection was made by virus isolation. The R-mix Too cell system (Diagnostic Hybrids, Inc., Athens, OH, USA) and D3 Ultra DFA Respiratory Virus Screening & ID kits (Diagnostic Hybrids, Inc.) were used for virus culture and identification. The medical records of patients with positive virus cultures were reviewed retrospectively. RESULTS: Seven hundred and ten PIV viruses (5.6%) were isolated from 12,723 specimens. The number of subjects with PIV type III, I and II was 357, 304 and 49, respectively. PIV infection showed a peak incidence in the first year of life regardless of subtypes. The most common diagnosis among all PIV subtypes was pneumonia. Lower respiratory tract infections constituted the majority (76.3%) of PIV infections. The most common diagnosis of PIV type I and II was croup and that of PIV type III was pneumonia. A difference in seasonal variation between subtypes was observed. PIV I (62.2%) was mainly isolated from July to September while PIV type III (86.8%) was isolated from April to July. CONCLUSION: Lower respiratory infection was most commonly found in hospitalized patients with PIV infection. Clinical features of PIV infection were similar those seen in Western PIV reports, with the exception of the seasonal outbreak pattern.

Three years surveillance of viral etiology of acute lower respiratory tract infection in children from 2007 to 2010 / 中华儿科杂志

<p><b>OBJECTIVE</b>Viruses are common pathogens of acute lower respiratory tract infection (ALRTI) in children. There are few studies on consecutive monitoring of viral pathogens of ALRTI in a larger cohort during the past several years. The aim of this study was to investigate the viral pathogens of ALRTI in children of different age groups and to outline the epidemic feature of different viruses.</p><p><b>METHOD</b>(1) Totally 1914 (1281 male and 709 female) children with clinical diagnosis of ALRTI during the period of March 2007 to March 2010 were recruited into this study. These patients were hospitalized patients in department of internal medicine or outpatients in emergency department in Beijing Children's Hospital. The patients were divided into four groups, including 1072 patients < 1 year old, 326 patients 1- < 3 years old, 158 patients 3- < 6 years old, 358 patients ≥ 6 years old. One nasopharyngeal aspirate specimen was collected from each patient. Reverse transcription (RT) PCR methods were applied to detect common respiratory viruses including respiratory syncytial virus (RSV), human rhinovirus (HRV), influenza virus type A, B and C (IFA, IFB, IFC), parainfluenza virus (PIV) type 1-4, adenovirus (ADV), enterovirus (EV), human coronavirus (HCOV), human metapneumovirus (HMPV) and human bocavirus (HBOV).</p><p><b>RESULT</b>(1) The total positive rate of viruses was 70.3%. The positive rate was 83.0% (890/1072) in the group of < 1 year old, and 80.1% (261/326) in group of 1- < 3 years old, 60.8% (96/158) in group of 3- < 6 years old and 27.7% (99/358) in group of ≥ 6 years old, respectively. There was a significant difference in the positive rate among different age groups (χ² = 2213.5, P = 0.000). The top three viruses were RSV, HRV and PIV; and the positive rates were 50.9%, 36.2% and 12.0% respectively in group of < 1 year old. (2) The epidemic seasons of RSV and HRV were winter and spring, and PIV infection was epidemic in spring and summer. (3) The detection rates of 2 or more viruses were 38.2%, 36.4%, 30.2% and 15.2% in groups of < 1 year old, 1- < 3 years old, 3- < 6 years old and ≥ 6 years old, respectively. There was a significant difference in the mixed infection rate among different age groups (χ² = 1346.00, P = 0.000).</p><p><b>CONCLUSION</b>RSV, HRV and PIV were the most predominant pathogens in younger children with ALRTI. Different viral infections had different seasonal features. Mixed infections with two or more viruses were detected in substantial proportion of patients with ALRTI, but further studies are needed to explore the clinical significance of mixed infection with viruses in patients with ALRTI.</p>

An atomic force microscopy study on the images of para influenza virus under different treatment conditions / 生物医学工程学杂志

Using atomic force microscope (AFM), we investigated the images of Pars influenza virus (PIV) under different treatment conditions and observed the different appearances of the virus and its ultra-microstructure from the exterior to the interior. From the 2D images under transmission electron microscope (TEM), we could see that the surfaces of PIV particles exhibited spherical and band-shaped 'tufts'; from the 3D images under AFM, we could further observe the whole spherical virus particles and their detailed surfaces, which exhibited round and band-shaped 'tufts'. Comparing the images under TEM with those under AFM, we found that the latter could reveal the surface topograph and ultramicrostructure of viruses more truly than did the former. The samples of viruses were treated by Tritonx-100, the lipid envelopes of virions were partly or completely resolved, and then most of their capsids were exposed. We could observe the different appearances of the virions under AFM, the lipid envelopes of which were gradually removed. The samples of viruses were also treated by SDS, and the RNA was released from the virions. From the AFM images, we could see the structure of the RNA. It was thus clear that AFM could be used to investigate the different appearances and ultramicrostructure of viruses rapidly and efficiently.

The cytology mechanism of anti-parainfluenza virus infection of total flavone of Scutellaria barbata / 药学学报

In order to research into the cytology mechanism of anti-virus action of total flavone of Scutellaria barbata (TFSB), the effects of TFSB on host cells membrane potential, Na(+)-K(+)-ATPase activity and membrane fluidity after parainfluenza virus type1 (PIV-1) infection were studied. The changes of membrane potential which was fluorescent labeled with DiBAC4(3) and its changes were measured by flow cytometer. Phosphorus determination method and spectrophotometry were used to measure the Na(+)-K(+)-ATPase activity of Hep-2 cells membrane after PIV-1 infection. Hep-2 cells membrane phospholipids were fluorescent labeled with NBD-C6-HPC and membrane fluidity was measured by confocal scanning laser microscope. The result demonstrated that post PIV-1 infection membrane potential decreased significantly and the membrane was in a state of hyperpolarization, Na(+)-K(+)-ATPase activity increased significantly and membrane fluidity decreased significantly. There was no apparent interfere effect of TFSB on the changes of membrane potential and Na(+)-K(+)-ATPase activity after PIV-1 infection, while membrane fluidity improved significantly. It was indicated that the cytology mechanism of PIV-1 infection might be related to membrane hyperpolarization, Na(+)-K(+)-ATPase activity increase and membrane fluidity decrease. TFSB can improve membrane fluidity and prevent the infection by protecting the cell membrane. But it is possible that the anti-PIV-1 mechanisms of TFSB had nothing to do with membrane potential and Na(+)-K(+)-ATPase activity.

Viral pathogens of acute lower respiratory tract infection in China.

OBJECTIVES: To document the viral etiology of acute lower respiratory tract infection (ALRIs) in Chinese children. SETTING: Children Hospital, Zhejiang University, China. STUDY DESIGN: Cross-sectional. PARTICIPANTS: 34885 children with ALRI between January 2001 to December 2006. METHODS: Nasopharyngeal aspirates were collected from all subjects. Respiratory syncytial virus (RSV), adenovirus (ADV), type 1 to 3 parainfluenza viruses (PIV), and type A and B influenza virus (Flu) were detected by direct immunofluorescence. RESULTS: Viruses were identified in 32.3% cases, including RSV (23.6%), PIV 3 (4.3%), Flu A (2.0%), ADV (1.7%), PIV I (0.6%), Flu B (0.2%) and PIV 2 (0.1%). RSV and PIV 3 predominated in younger children while Flu A and Flu B predominated in older children (P<0.001, respectively). PIV 1 was more prevalent in children aged 1 to 3 years. The peak frequency of RSV, PIV 3 and Flu A were in early spring, June to August, and August and September, respectively. Flu B had a peak in the winter and spring. Adenovirus infections occurred in all seasons with a relatively constant frequency. CONCLUSIONS: Viruses are an important cause of ALRIs in Chinese children constituting 1/3 of total cases. RSV is the most common pathogen.

Características clínicas y epidemiológicas de la infección por virus parainfluenza en niños hospitalizados / Clinical and epidemiological manifestations of parainfluenza infection in hospitalized children

Los virus parainfluenza del ser humano (VPIh) son patógenos importantes de enfermedad respiratoria en niños; pese a ello, existe escasa información publicada en Sudamérica dirigida a caracterizar esta infección. Objetivo: Describir las manifestaciones clínicas y epidemiológicas específicas de los VPIh en niños hospitalizados. Pacientes y Métodos: Se revisaron todas las hospitalizaciones respiratorias (HR) efectuadas en el Hospital de la Pontificia Universidad Católica, Santiago, Chile, durante el período 2001-2004 y sus respectivos estudios virales obtenidos de secreciones nasofaríngeas en aquellos con sospecha de infección viral. Resultados: Se identificaron 3.043 HR siendo 64 (2,1 por ciento) VPUrh La edad promedio fue 13 meses (rango: 1 m-12 a) siendo 77 por ciento) de edad inferior a dos años. VPIh-2 fue el serotipo prevalente (47 por ciento), observándose una tendencia estacional para los serotipos 2 y 3. Las presentaciones más frecuentes fueron sibilancias asociadas a virus (40 por cientoo) y neumonía (30 por ciento). Todas las bronquiolitis se presentaron asociadas a VPIh serotipos 2 y 3. Sólo 17 por ciento de los hospitalizados por VPIh+ (44 por ciento VPIh-1) desarrollaron laringitis. Conclusión: Virus parainfluenza humano puede ser responsable de HR en niños, mostrando una tendencia estacional VPIh-2 y el serotipo 3. Aunque son poco frecuentes como causa de HR, confirmamos su participación como etiología específica de laringitis, bronquiolitis y neumonía, especialmente en niños pequeños.

Background: Human parainfluenza viruses (hPIV) are a common cause of respiratory illness of children but published data on clinical characteristics of hPIV infection in South America is scarce. Objective: To review the clinical presentation and epidemiological features of hPIV in a series of hospitalized children in Chile. Patients and Methods: Retrospective review of clinical charts from all pediatric admissions with a diagnosis of respiratory disease (between January 2001 to December 2004) at the Catholic University Hospital, Santiago, Chile. Nasopharyngeal secretions were tested for hPIV in children admitted with suspected respiratory viral infections. Results: A total of 3,043 respiratory admissions were recorded during the study period; 64 children (2.1 percent) were hPIV positive. Average age was 13 months (range: lm to 12y) and 77 percent> were younger than 2 years. HPIV-2 was the most common type identified (47 percent). A seasonal trend was noted for serotypes hPIV-2 and 3. Acute wheezing (40 percento) and pneumonia (30 percent) were the most common clinical diagnosis in hPIV positive children and 17 percent> hPIV positive children (44 percent> for hPIV-1) were associated with laryngitis. All hPIV positive bronchiolitis were due to serotypes hPIV-2 and 3. Conclusion: hPIV can cause respiratory disease requiring hospitalization; serotypes hPIV-2 and 3 displayed a seasonal trend. Although hPIV is an uncommon cause of severe respiratory infecion requiring hospitalization in children, it should be considered in the differential diagnosis of laryngitis, bronchiolitis and pneumonia, especially in younger children.

Effect of extracted ZG from gardenia on Hep-2 cell membrane post infected with parainfluenza virus type 1 (PIV-1) / 病毒学报

In order to study the anti-viral mechanism of extracted ZG from Gardenia, the effect of extracted ZG on Hep-2 cell membrane potential, Na -K+-ATPase activity and membrane fluidity post infected with parainfluenza virus type 1 (PIV-1) was observed. Acetylcholine which was fluorescent labeled with DiBAC4 (3) was taken as positive control to observe the changes of membrane potential and was measured by flow cytometer. The phosphorus determination method and spectrophotometer were used to measure the Na+-K+-ATPase activity of Hep-2 cell membrane post PIV-1 infection. Hep-2 cell membrane phospholipids was labeled with fluorescent NBD-C6-HPC and membrane fluidity was measured by confocal laser scanning microscope. The results demonstated that after PIV-1 infection the Hep-2 cell membrane potential decreased significantly and the membrane was in the state of hyperpolarization, Na+-K+-ATPase activity increased and membrane fluidity decreased significantly. There was no apparent interferring effect of extracted ZG on the changes of membrane potential and Na+-K+-ATPase activity post PIV-1 infection, while membrane fluidity was improved significantly. Acetylcholine improved the state of hyperpolarization. The changes of membrane potential, Na -K+-ATPase activity and membrane fluidity might be the biomechanism of PIV-1 infectoin. The extracted ZG improved membrane fluidity to prevent from PIV-1 infection by protecting the cell membrane, which was probably the mechanism of anti-PIV-1 activity of the extracted ZG, but ZG probably had nothing to do with membrane potential and Na+-K+-ATPase activity.

Parainfluenza virus infections in pediatric patients with acute respiratory infections in Beijing during 2001 - 2003 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the relationship of parainfluenza virus (PIV) and acute respiratory infections in infants and young children in Beijing, occurred in recent years.</p><p><b>METHODS</b>3141 throat swab/nasopharyngeal aspirate specimens were collected from infants and young children with acute respiratory tract infections in Beijing from Jan 2001 to Dec 2003. All of these 3141 specimens were inoculated into MDCK cells for influenza virus and PIV isolation, since PIV had been isolated in MDCK cells in this laboratory from preliminary studies. Out of 3141 specimens, 702 were inoculated into MDCK as well as Vero cells to compare the sensitivity on virus isolation of these cell lines by micro plate method. Growth of PIV in cell culture were identified by haemoagglutination test and indirect immunofluorescent assay.</p><p><b>RESULTS</b>The PIV positive cases in Vero cells were also positive in MDCK cells, indicating that the sensitivity for PIV isolation in MDCK was equal to Vero cells. Out of these 3141 specimens, 94 (3.0%) were PIV positive, including 35 (35/1191, 2.9%) of PIV1, 11 (11/1191, 0.9%) of PIV3 in upper respiratory tract infections; 15 (15/1634, 0.9%) of PIV1, 24 (24/1634, 1.5%) of PIV3 in lower respiratory tract infections; 3 (3/207, 1.4%) of PIV in asthma; 1 (1/38) of PIV in patients with fever; 5 (5/71) of PIV in others. Data indicated that among upper respiratory tract infections caused by PIV, PIV1 was more commonly seen than PIV3.</p><p><b>CONCLUSION</b>MDCK cells could be used for PIV isolation from clinical samples while PIV was one of the important pathogenic viruses causing acute respiratory tract infections in infants and young children in Beijing for the recente years.</p>

Bronquiolitis / Bronchiolitis

Es una enfermedad aguda de etiología viral, que afecta al aparato respratorio en forma difusa y bilateral y puede determinar en capacidad ventilatoria obstructiva. Si bien para algunos autores puede presentarse en niños de hasta 2 años, la mayoría considera como edad límite de presentación el primer año de vida