[Clinical characteristics and risk factors for bronchoscopic airway mucus hypersecretion in childhood pneumonia infected by different pathogens]

Objective: To investigate the risk factors for airway mucus hypersecretion in childhood pneumonia infected by different pathogens. Method: A retrospective cohort included 968 children who were hospitalized for Mycoplasma pneumoniae pneumonia (MPP), respiratory syncytial virus (RSV) pneumonia, adenovirus pneumonia and underwent bronchoscopy in Respiratory Department of Children's Hospital of Chongqing Medical University from January 2019 to December 2021 was conducted. The children were divided into two groups distinguished by airway mucus secretion according to the airway mucus hypersecretion score which were scored according to the mucus secretion under the bronchoscope. The demographic characteristics, clinical characteristics, laboratory tests and disease severity of the two groups were compared. And the risk factors for the development of airway mucus hypersecretion in two groups were analyzed. Chi square test, Mann-Whithey U test and Fisher exact test were used to analyze the differences between the two groups, and multivariate Logistic regression was used to analyze the influencing factors. Result: There were 559 males and 409 females in the 968 children, with an age of 4.0 (1.4, 6.0) years. Among the 642 children with MPP, 185 cases were in the hypersecretion group and 457 cases were in the non-hypersecretion group. There were 41 cases in the hypersecretion group and 160 cases in the non-hypersecretion group of 201 children with RSV pneumonia. In the 125 children with adenovirus pneumonia, there were 39 cases in the hypersecretion group and 86 cases in the non-hypersecretion group. In these children, the age of children in the hypersecretion group was older than that in the non-hypersecretion group (6.0 (4.0, 7.0) vs. 5.0 (3.0, 7.0) years old, 1.5 (0.5, 3.6) vs. 0.8 (0.4, 1.6) years old, 2.0 (1.2, 4.5) vs. 1.3 (0.8, 2.0) years old, U=35 295.00, 2 492.00, 1 101.00, all P<0.05). Through multivariate Logistic regression analysis it found that increased risk of airway mucus hypersecretion was present in childhood MPP with increase in peripheral blood white blood cell count (OR=3.30, 95%CI 1.51-7.93, P=0.004) or increase in neutrophil ratio (OR=2.24, 95%CI 1.16-4.33, P=0.016) or decrease in lymphocyte count (OR=3.22, 95%CI 1.66-6.31, P<0.001) or decrease in serum albumin (OR=2.00, 95%CI 1.01-3.98, P=0.047). The risk of airway mucus hypersecretion was increased in children with RSV pneumonia combined with elevated peripheral blood eosinophils (OR=3.04, 95%CI 1.02-8.93, P=0.043). Meanwhile, airway mucus hypersecretion was associated with severe pneumonia (OR=2.46, 95%CI 1.03-6.15, P=0.047) in children with RSV pneumonia. Older age was associated with increased risk of airway mucus hypersecretion in children with adenovirus pneumonia (OR=1.02, 95%CI 1.00-1.04, P=0.026). In these children with occurrence of pulmonary rales, wheezes or sputum sounds (OR=3.65, 95%CI 1.22-12.64, P=0.028) had an increased risk of airway mucus hypersecretion. Neutrophils in bronchoalveolar lavage fluid (BALF) demonstrated higher ratio in hypersecretion group from children with MPP (0.65 (0.43, 0.81) vs. 0.59 (0.34, 0.76), U=24 507.00, P<0.01), while the proportion of macrophages in BALF was lower (0.10 (0.05, 0.20) vs. 0.12 (0.06, 0.24), U=33 043.00, P<0.05). Nucleated cell count and neutrophil ratio in BALF were higher in hypersecretion group of children with RSV pneumonia (1 210 (442, 2 100)×10⁶ vs. 490 (210, 1 510)×10⁶/L, 0.43 (0.26, 0.62) vs. 0.30 (0.13, 0.52), U=2 043.00, 2 064.00, all P<0.05). Conclusions: The increase in peripheral blood white blood cell count, neutrophil ratio and decrease in lymphocyte count, serum albumin in children with MPP is related to the development of airway mucus hypersecretion. In children with RSV pneumonia, the abnormal increase of eosinophils in peripheral blood has relationship with hypersecretion. The appearance of lung rale, wheezing, and sputum rale are associated with airway mucus hypersecretion in children with adenovirus pneumonia. In addition, local neutrophil infiltration in the respiratory tract is closely related to the occurrence of airway mucus hypersecretion caused by Mycoplasma pneumoniae and RSV infection.

[Impact of Streptococcus pneumoniae colonization in upper airway on the clinical manifestations of children with respiratory syncytial virus infection]

Objective: To investigate the effects of Streptococcus pneumoniae (Spn) colonization and the change of upper airway microbiome on the clinical manifestations in children with respiratory syncytial virus (RSV) infection. Methods: A retrospective cohort included 508 RSV-infected children with pneumonia and hospitalized in Respiratory Department of Children's Hospital of Chongqing Medical University from July 2009 to July 2018. A total of 508 cases of RSV-infected children (RSV non-sequencing group) were divided into 2 groups: children with Spn airway colonization (RSV+Spn group) and children without with Spn airway colonization (RSV group) according to the detection for virus and bacteria in nasopharyngeal aspirate, and these 2 groups were compared in terms of clinical manifestations by chi-square test in different age groups. In addition, in RSV pandemic season from November 2018 to February 2020, nasopharyngeal aspirates were collected from 20 children hospitalized in Respiratory Department of Children's Hospital of Chongqing Medical University and infected with RSV but without any positive detection of bacteria (RSV 16 S-sequencing group) and from children undergoing surgery without any sign of respiratory infection (control group). The difference of microbiome detected by 16 S RNA sequencing was compared using rank sum test between RSV 16 S-sequencing group and control group, and also between children with severe and mild pneumonia in RSV 16 S-sequencing group. Results: A total of 508 RSV non-sequencing group included 346 males and 162 females, and the visiting age was 6 (2, 12)  months. RSV group included 443 cases and RSV+Spn group included 65 cases. In the study 244 cases were aged <6 months and 264 cases were aged ≥6 months. In children aged ≥6 months of RSV non-sequencing group, the proportion of cases presenting fever over 38 ℃ and cases with severe pneumonia in RSV+Spn group were higher than those in RSV group (53.2% (25/47) vs. 34.6% (72/217), 38.3% (18/47) vs. 21.2% (46/217), χ²=5.70,6.15, both P<0.05). RSV 16 S-sequencing group included 16 males and 4 females and the visiting age was 3.0 (1.9, 8.0) months. Airway microbiome diversity in RSV 16 S-sequencing group was lower than that in control group (alpha index: 0.93 (0.42, 2.51) vs. 3.05 (2.88, 3.61), U=60.00, P=0.001). Conclusions: RSV infection is associated with the changes of the upper airway microbiome. When the balance of airway microbiome is broken and the presence of the dominant colonization of Spn follows, it may aggravate the severity of RSV infection in children aged ≥6 months.

The Impact of Weather and Air Pollution on Viral Infection and Disease Outcome Among Pediatric Pneumonia Patients in Chongqing, China, from 2009 to 2018: A Prospective Observational Study

BACKGROUND

For pediatric pneumonia, the meteorological and air pollution indicators have been frequently investigated for their association with viral circulation but not for their impact on disease severity.

METHODS

We performed a 10-year prospective, observational study in 1 hospital in Chongqing, China, to recruit children with pneumonia. Eight commonly seen respiratory viruses were tested. Autoregressive distributed lag (ADL) and random forest (RF) models were used to fit monthly detection rates of each virus at the population level and to predict the possibility of severe pneumonia at the individual level, respectively.

RESULTS

Between 2009 and 2018, 6611 pediatric pneumonia patients were included, and 4846 (73.3%) tested positive for at least 1 respiratory virus. The patient median age was 9 months (interquartile range, 4‒20). ADL models demonstrated a decent fitting of detection rates of R2 > 0.7 for respiratory syncytial virus, human rhinovirus, parainfluenza virus, and human metapneumovirus. Based on the RF models, the area under the curve for host-related factors alone was 0.88 (95% confidence interval [CI], .87‒.89) and 0.86 (95% CI, .85‒.88) for meteorological and air pollution indicators alone and 0.62 (95% CI, .60‒.63) for viral infections alone. The final model indicated that 9 weather and air pollution indicators were important determinants of severe pneumonia, with a relative contribution of 62.53%, which is significantly higher than respiratory viral infections (7.36%).

CONCLUSIONS

Meteorological and air pollution predictors contributed more to severe pneumonia in children than did respiratory viruses. These meteorological data could help predict times when children would be at increased risk for severe pneumonia and when interventions, such as reducing outdoor activities, may be warranted.

[Current status of antibiotic therapy for Staphylococcus aureus sepsis in children]

OBJECTIVE

To investigate the current status of empirical antibiotic therapy for children with Staphylococcus aureus sepsis and the effect of therapeutic paradigm on prognosis based on a retrospective analysis.

METHODS

A total of 78 children with Staphylococcus aureus sepsis who were admitted from January 2014 to August 2017 were enrolled. According to the preferred empirical antibiotics before the detection of Staphylococcus aureus by blood culture, these children were divided into a carbapenem group with 16 children, a β-lactam group with 37 children, a vancomycin group with 15 children and a vancomycin+β-lactam group with 10 children. A retrospective analysis was performed for related clinical data including general status, underlying diseases, Acute Physiology and Chronic Health Evaluation II (APACHE II) score, history of use of immunosuppressant, drug resistance to methicillin and prognosis. A logistic regression analysis was used to investigate the effect of empirical antibiotic therapy on the clinical outcome and prognosis of children with Staphylococcus aureus sepsis.

RESULTS

There were no significant differences among these groups in general status, underlying diseases, history of use of immunosuppressant, APACHE II score, nosocomial infection and detection rate of methicillin-resistant Staphylococcus aureus (P>0.05). There were significant differences in the incidence rate of septic shock and in-hospital mortality among these four groups (P<0.05). The carbapenem group had the highest incidence rate of septic shock and in-hospital mortality (69% and 50% respectively). The multivariate logistic regression analysis showed that empirical antibiotic therapy with different antibiotics had different risks for septic shock and in-hospital death in children with Staphylococcus aureus sepsis (P<0.05), and that an APACHE II score of ≥15 was an independent risk factor for septic shock in these children (P<0.05). The carbapenem group had significantly higher risks of septic shock and in-hospital death than the vancomycin group (P<0.05).

CONCLUSIONS

Inappropriate empirical use of antibiotics may lead to a poor prognosis in children with Staphylococcus aureus sepsis. Empirical use of carbapenems is not recommended for children suspected of Staphylococcus aureus sepsis.

Epidemiological characteristics of nasopharyngeal Streptococcus pneumoniae strains among children with pneumonia in Chongqing, China

Streptococcus pneumoniae (pneumococcus) is the most common respiratory pathogen worldwide. Nasopharyngeal carriage with S. pneumoniae is the major source of lower respiratory tract infection and horizontal spread among children. Investigating nasopharyngeal S. pneumoniae is crucial for clinicians to control pneumococcus disease. Here, we retrospectively analyzed clinical information of 5,960 hospitalized children, focusing on pneumonia children less than five years with positive nasopharyngeal pneumococcal cultures. Nasopharyngeal aspirates (NPAs) were collected between June 2009 and December 2016, which were outside the pneumococcal conjugate vaccine(PCV) period. NPAs were subjected to common bacterial culture and antibiotic susceptibility tests, and serotypes were identified by both multiplex PCR and DNA sequencing. Results clearly revealed that clinical manifestations of the children whose NPAs were S. pneumoniae culture positive were serious, especially in those less than twelve months old. Fifteen different serotypes of nasopharyngeal S. pneumoniae were detected, the most common ones being 19F (35.2%), 6A/B (23.8%), 19A (11.4%), 15B/C (9.3%) and 23F (7.8%). Eight serotypes, accounting for 85.5% of the isolates, corresponded to the PCV13 serotypes. Approximately one-third of all S. pneumoniae strains were susceptible to penicillin. Overall, we consider nasopharyngeal S. pneumoniae culture is beneficial in assessing the situations of pneumonia children. Moreover, PCV13 could be useful in preventing pneumococcal disease in Chongqing, China.

Evidence of Premating Isolation Between Two Sibling Moths: Ectropis grisescens and Ectropis obliqua (Lepidoptera: Geometridae)

The sex pheromones of Ectropis grisescens Warren and Ectropis obliqua Prout were both reported to contain (Z,Z,Z)-3,6,9-octadecatriene (Z3,Z6,Z9-18:H) and (Z,Z)-3,9-cis-6,7-epoxy-octadecadiene (Z3,epo6,Z9-18:H). To clarify how these two sibling geometrids maintain premating isolation, the female sex pheromones of the two species were reexamined. Gas chromatography-electroantennographic detection (GC-EAD) and gas chromatography-mass spectrometry revealed two GC-EAD-active compounds, Z3,Z6,Z9-18:H and Z3,epo6,Z9-18:H, in E. grisescens female pheromone glands as well as an additional GC-EAD-active compound, (Z,Z)-3,9-cis-6,7-epoxy-nonadecadiene (Z3,epo6,Z9-19:H), in E. obliqua female pheromone glands. Synthesized Z3,Z6,Z9-18:H and Z3,epo6,Z9-18:H elicited dose-dependent electroantennogram (EAG) responses from male antennae of both E. grisescens and E. obliqua. However, Z3,epo6,Z9-19:H only elicited dose-dependent EAG responses from E. obliqua and limited EAG responses from E. grisescens at all doses. In wind-tunnel studies, lures that contained Z3,Z6,Z9-18:H and Z3,epo6,Z9-18:H attracted E. grisescens males and had no effect on E. obliqua males. The addition of Z3,epo6,Z9-19:H to the blend of Z3,Z6,Z9-18:H and Z3,epo6,Z9-18:H strongly attracted E. obliqua males but had a limited attraction for E. grisescens males. Thus, Z3,Z6,Z9-18:H and Z3,epo6,Z9-18:H were sex pheromone components of E. grisescens, whereas Z3,Z6,Z9-18:H, Z3,epo6,Z9-18:H and Z3,epo6,Z9-19:H were sex pheromone components of E. obliqua. The presence or absence of Z3,epo6,Z9-19:H played a central role in the premating isolation of these two sibling species.

Pulmonary C-fiber degeneration downregulates IFN-γ receptor 1 via IFN-α induction to attenuate RSV-induced airway hyperresponsiveness

Respiratory syncytial virus (RSV) is a leading cause of respiratory infection in infants. Unfortunately, no effective vaccine or treatment against RSV is currently available. Pulmonary C-fibers (PCFs) are critical for regulating pulmonary inflammation and airway hyperresponsiveness (AHR). We previously reported that IFN-γ partially mediated RSV-induced airway disorders. In this study, we found that PCF degeneration alleviated RSV-induced airway inflammation, especially AHR by downregulating IFN-γ receptor 1 (IFNGR1), but had no effect on IFN-γ induction. In contrast, PCF degeneration actually increased IFN-α/β levels, as were the levels of STAT1 and phosphorylated STAT1 (pSTAT1). Exogenous IFN-α treatment induced STAT1 activation and downregulated IFNGR1 expression. These results suggest that PCFs affect IFNGR1 expression by inducing IFN-α to regulate IFN-γ-mediated airway inflammation and AHR. Thus, targeting PCFs activation may help control RSV-induced airway disorders, especially AHR, even with the presence of inflammation.

Effect of Trap Color, Height, and Orientation on the Capture of Yellow and Stick Tea Thrips (Thysanoptera: Thripidae) and Nontarget Insects in Tea Gardens

Two thrips species-the yellow tea thrips ( Scirtothrips dorsalis Hood) and the stick tea thrips ( Dendrothrips minowai Priesner)-are serious pests affecting tea plants in southern China. Although the stick tea thrips is primarily restricted to southern China, the yellow tea thrips is gradually proliferating worldwide. Colored sticky card traps may be useful for monitoring and capturing these species, but a systematic analysis has not been conducted to identify the most effective trap color, height, and orientation. We performed indoor experiments using an orthogonal experimental design, as well as field tests in tea gardens, to identify the color most attractive to the two thrips species. Field tests were then conducted using color-optimized traps-lawngreen (RGB: 124, 252, 0) for yellow thrips and lime (RGB: 0, 255, 0) for stick tea thrips-to determine the most effective trap height and orientation. The greatest numbers of both yellow and stick tea thrips were captured on traps positioned 0-20 cm above the tea canopy in an east-west orientation. We also evaluated the performance of the color-optimized sticky card traps compared with commercially available yellow ones. Significantly more yellow and stick tea thrips and fewer natural enemies were captured on the color-optimized traps than on commercial ones. Although additional research is needed to explain the responses of the two different species and to increase trap effectiveness, our findings should assist in the control of these harmful insects.

Association of Pneumococcal Carriage and Expression of Foxp3+ Regulatory T Cells and Th17 Cells in the Adenoids of Children

BACKGROUND

Pneumococcal carriage in the nasopharynx is a primary means of transmission and a necessary prerequisite for pneumococcal disease.

OBJECTIVES

We analyzed the relationship between expressions of Foxp3+ regulatory T (Treg) cells and Th17 cells, and pneumococcal carriage in the adenoids of children who were either positive or negative for pneumococci.

METHODS

We collected adenoidal tissue and nasopharyngeal swab samples from children undergoing an adenoidectomy. Adenoidal mononuclear cells were isolated, cultured and then stimulated with culture concentrated supernatant (CCS) obtained from a D39 bacterial strain.

RESULTS

Foxp3+ Treg cells were upregulated and Th17 cells were downregulated in populations of adenoidal mononuclear cells obtained from the pneumococcus-positive group. Following CCS stimulation, the increment in Foxp3+ Treg cells in the pneumococcus-positive group was significantly greater than that in the pneumococcus-negative group, while the increment in Th17 cells was less as compared to that in the pneumococcus-negative group. These results were consistent with variations in levels of Foxp3 mRNA and retinoic acid receptor-related orphan receptor-γt mRNA in adenoidal mononuclear cells. Levels of IL-17A and IL-6 in adenoid tissue were higher in the pneumococcus-negative group, and the levels of TGF-β in adenoid tissue were lower in the pneumococcus-negative group compared to the pneumococcus-positive group. Pneumococcal carriage in children was closely associated with the expressions of Foxp3+ Treg and Th17 cells in the adenoid.

CONCLUSION

Upregulation of Foxp3+ Treg cells might downregulate the production of Th17 cells in the adenoid, resulting in decreased scavenging of Streptococcus pneumoniae and chronic pneumococcal carriage.

[Analysis of serum vancomycin concentration after administration of different doses in children with Staphylococcus aureus pneumonia]

OBJECTIVE

To analyze serum vancomycin concentration after administration of different therapeutic doses in children with Staphylococcus aureus pneumonia (SAP) in order to determine the appropriate dose of vancomycin in clinical administration.

METHODS

The clinical data of 35 children who were diagnosed with SAP and treated with vancomycin from January 2008 to December 2013 were retrospectively analyzed.

RESULTS

Among the 35 SAP cases with vancomycin therapy, 22 cases (63%) had serum vancomycin trough concentration monitored. The numbers of cases with vancomycin at 10, 12.5, and 15 mg/(kg·dose) × every 6 hours (q6h) were 11, 4 and 7, respectively. The mean serum trough concentration of vancomycin in the 15 mg/(kg·dose) group was 14.98 mg/L, which was significantly higher than in the 10 mg/(kg·dose) and 12.5 mg/(kg·dose) groups (4.97 and 8.00 mg/L respectively; P<0.05). The percentage of cases that reached the expected trough concentration in the 15 mg/(kg·dose) group (71%) was significantly higher than that in the 10 mg/(kg·dose) group (9%), but there was no significant difference in this percentage between the 15 mg/(kg·dose) and 12.5 mg/(kg·dose) groups (71% vs 25%).

CONCLUSIONS

The reasonable dosage of vancomycin for the treatment of pediatric SAP is 15 mg/(kg·dose) × q6h or 60 mg/(kg·d).

[Clinical features of inhaled and blood-borne Staphylococcus aureus pneumonia and analysis of antibiotic resistance of the pathogen in children]

OBJECTIVE

To compare the clinical manifestations between inhaled and blood-borne Staphylococcus aureus pneumonia (SAP) and the antibiotic resistance between the isolates of inhaled and blood-borne Staphylococcus aureus.

METHODS

The clinical data of 44 pediatric SAP cases in the Children&prime;s Hospital, Chongqing Medical University from January 2008 to December 2013 were retrospectively analyzed. Twenty-four cases were identified as inhaled SAP, and 20 cases as blood-borne SAP.

RESULTS

Inhaled SAP was more common in children younger than 3 years of age, while blood-borne SAP was more prevalent in children older than 6 years of age. Patients with inhaled SAP had significantly higher incidence rates of cough, wheeze, moist rales, dyspnea and empyema than those with blood-borne SAP (P&lt;0.05). The patients with blood-borne SAP were more vulnerable to severe fever, unconsciousness, dysfunction of liver and kidney, pyogenic osteomyelitis, septic arthritis, sepsis, and abscess of skin and soft tissues (P&lt;0.05). Inhaled SAP isolates had significantly higher rates of resistance to amoxicillin/clavulanic acid, oxacillin, and cefoxitin than blood-borne SAP isolates (P&lt;0.05), while the latter had a higher rate of resistance to cotrimoxazole (P&lt;0.05).

CONCLUSIONS

Inhaled SAP often occurs in children younger than 3 years of age, and the respiratory manifestations are commonly seen. Blood-borne SAP often occurs in children older than 6 years of age, with the infectious-toxic symptoms that result in multiple organ infection and dysfunction. The isolates of inhaled and blood-borne SAP have different antibiograms.

[Clinical analysis of 28 cases of bronchiolitis obliterans]

OBJECTIVE

To study the clinical features of bronchiolitis obliterans (BO) in children.

METHODS

The clinical data of 28 children with BO between July 2007 and April 2012 was retrospectively reviewed.

RESULTS

All patients presented with persistent or repeated cough and wheezing. Twenty-three cases were post-infectious bronchiolitis obliterans (PIBO), among whom the etiology were adenovirus (12 cases), measles (2 cases), influenza virus A (2 cases), mycoplasma pneumoniae (1 case), mycoplasma pneumoniae coinfection with adenovirus (1 case), respiratory syncytial virus coinfection with Parainfluenza type 3 virus (1 case) and pulmonary tuberculosis (1 case). The etiology of 3 cases was not associated with infection. The etiology was unknown in 2 cases. Pulmonary HRCT revealed that decreased density in 25 cases, mosaic perfusion in 21 cases, bronchial wall thickening in 15 cases, bronchiectasis in 12 cases and air retention in 6 cases. Lung function test was performed on 21 cases and demonstrated that obstructive ventilation disorder in all 21 cases. Bronchodilation test was performed on 18 cases and 17 cases showed a negative result. All 28 cases received corticosteroid treatment, and 24 cases were orally administered with low doses of azithromycin. One case died during hospitalization. Eighteen cases were followed up for 4 months to 4 years and seven months. Clinical manifestations were improved in 12 cases and one case died.

CONCLUSIONS

Low respiratory infection is the most common cause of pediatric BO and adenovirus is a major pathogen. Persistent wheezing and cough were main clinical manifestations. Pulmonary HRCT imaging is important for diagnosis and follow-up of BO. Lung function test can typically show obstructive ventilation disorder. Corticosteroid and methotrexate may be effective for treatment of BO. Prognosis of this disease is unsatisfactory. Early diagnosis and treatment, and avoidance of repeated respiratory tract infection may be helpful to improve the prognosis.

[Etiology of nonspecific chronic cough in children and relationship between TRPV1 gene polymorphisms and nonspecific chronic cough]

OBJECTIVE

To explore the causes of nonspecific chronic cough in children and relationship between transient receptor potential vanilloid 1 (TRPV1) gene polymorphisms and nonspecific chronic cough.

METHODS

A total of 195 children with chronic cough were followed up half a month, one month and three months after their first visit to hospital. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to examine polymorphisms of the TRPV1 gene in the children. A total of 205 healthy or surgical children without chronic cough served as the control group.

RESULTS

The etiologic distribution of the 195 children with chronic cough was as follows: 96 (49.2%) cases of cough variant asthma (CVA), 48 (24.6%) cases of CVA complicated by upper airway cough syndrome (UACS), 34 (17.4%) cases of post-infectious cough, and 17 (8.7%) cases of UACS. Three genotypes were identified in both groups at positions rs222747 (CC, GC and GG), rs222748 (CC, TC and TT) and rs8065080 (CC, TC and TT). The frequencies of genotype and allele at position rs222747 did not accord with the law of Hardy-Weinberg. There was no significant difference in frequencies of genotype and allele at positions rs222748 and rs8065080 between the two groups.

CONCLUSIONS

CVA, UACS and post-infectious cough are common causes of nonspecific chronic cough in children. TRPV1 gene polymorphisms at positions rs222748 and rs8065080 may be unrelated to nonspecific chronic cough in children.

First Report of Bacterial Stem and Root Rot of Sweetpotato Caused by a Dickeya sp. (Erwinia chrysanthemi) in China

Since 2006, stem and root rot of sweetpotato has been observed in fields at a number of sweetpotato-production areas in Huidong, Haifeng, Puning, and Zhanjiang counties and Guangzhou City in Guangdong Province of China. Initially, the leaves turn yellow, and a black, water-soaked rot occurs on the bottom of the stems that gradually extends to the top of the stems. Finally, the entire plant collapses and dies. Bacteria were consistently isolated from stems of diseased seedlings by streaking on nutrient agar. Twelve representative isolates were chosen for further characterization. All strains grew at 37°C, were gram negative, facultatively anaerobic, and rod shaped with peritrichous flagella. The strains were negative for oxidase and positive for catalase and tryptophanase (indole production) They fermented glucose, reduced nitrates to nitrites, degraded pectate, produced phosphatase and lecithinase, and utilized citrate, tartrate, malonate, glucose, sucrose, fructose, and maltose, but not trehalose and lactose. These characteristics were similar to those of Erwinia chrysanthemi (Pectobacterium chrysanthemi) (1). PCR was performed on the 16S rDNA gene from isolate H12 (1,503 bp; GenBank Accession No. GU252371) with primers 27f (5'-GAGAGTTTGATCCTGGCTCAG-3') and reverse primer (5'-GGCTACCTTGTTACGACTTC-3'). Subsequently, PCR products were sequenced. Results of sequence analysis showed the sequence of isolated strain H12 was 99% identical to that of E. chrysanthemi, 99% identical to that of type strain CFBP 1269T of Dickeya dadantii (Accession No. AF520707), and 98% identical to that of type strain CFBP 1200T of D. dianthicola (Accession No. AF520708). Recently, E. chrysanthemi was transferred to Dickeya gen. nov., but it was difficult to identify the species within the genus Dickeya. Seedlings (20 to 30 cm) were planted in 10-cm-diameter plastic pots containing sterilized field soil at room temperature. Four days later, five stem tops of sweetpotato were injected with a bacteria suspension (10⁸ CFU/ml) of approximately 100 μl to fulfill Koch's postulates. Five control plants were inoculated with sterile distilled water. The experiment was conducted three times. All plants were incubated in a chamber at 30°C with high humidity. One to two days after inoculation, symptoms were observed in all inoculated plants and appeared to be identical to those observed in the field. No symptoms were noted on the control plants. The bacterium was reisolated from symptomatic stems of sweetpotato plants. This pathogen was previously reported on sweetpotato in the United States in 1974 (2). To our knowledge, this is the first report of a Dickeya sp. (E. chrysanthemi) causing bacterial stem and root rot of sweetpotato in China. References: (1) D. J. Brenner et al. Page 670 in: Bergey's Manual of Systematic Bacteriology. 2nd ed. Springer, New York, 2005. (2) N. W. Schaad et al. Phytopathology 67:302, 1977.

[Clinical characteristics of 12 persistently wheezing children with human bocavirus infection]

OBJECTIVE

The impact of human bocavirus (HBoV), a newly identified human parvovirus, on childhood persistent wheezing has not been identified. In this study, the clinical features of infantile persistent wheezing induced by HBoV was analyzed.

METHODS

Tracheal aspirates were collected by bronchofibroscope or nasopharyngeal (NP) aspirates from April, 2006 to January, 2007. HBoV DNA in the tracheal aspirates of 33 children with persistent wheezing and in NP aspirates of 6 children with persistent wheezing, who had at least or more than four weeks wheezing. RSV was identified by virus isolation in Hep-2 cells and antigen detetion by direct immunofluorescence assay (DIFA) which was also used for diagnosis of adenovirus, influenza A and B, parainfluenza 1, 2, 3 infection.

RESULTS

Of the 39 children with persistent wheezing, 12 cases (31%) were positive for HBoV DNA. Age of HBoV-positive patients ranged from 2 month to 1 year. The results of sequencing of PCR products proved that sequences of HBoV DNA from these 12 samples were exactly identical to the those of HBoV stored in GeneBank (accession numbers DQ000495 and DQ000496). Two cases with HBoV infection were found to be co-infected with RSV. Ten of the 12 HBoV-positive samples were collected during the period from winter to spring (1 in November, 4 in December, 2 in January and 3 in April), the other two HBoV-positive samples were collected during the period from summer to autumn (1 in May and the other in July). Seven of the 12 HBoV DNA-positive patients had fever, 5 of them had high fever. Significantly more patients with HBoV infection had fever as compared to patients with RSV infection. All the HBoV positive patients showed abnormal findings on chest X ray such as interstitial infiltrates, lung infiltration and hyperinflation. Abnormal findings on chest X ray were found in higher proportion of HBoV positive patients as compared with RSV positive patients. And other manifestations such as wheezing, cough and respiratory distress had no significant difference between HBoV and RSV infected patients.

CONCLUSIONS

This study further demonstrated that HBoV probably is a common pathogen of lower respiratory infection in children and might particularly be associated with persistent wheezing.

A New Mammaliaform from the Early Jurassic and Evolution of Mammalian Characteristics

A fossil from the Early Jurassic (Sinemurian, approximately 195 million years ago) represents a new lineage of mammaliaforms, the extinct groups more closely related to the living mammals than to nonmammaliaform cynodonts. It has an enlarged cranial cavity, but no postdentary trough on the mandible, indicating separation of the middle ear bones from the mandible. This extends the earliest record of these crucial mammalian features by some 45 million years and suggests that separation of the middle ear bones from the mandible and the expanded brain vault could be correlated. It shows that several key mammalian evolutionary innovations in the ear region, the temporomandibular joint, and the brain vault evolved incrementally through mammaliaform evolution and long before the differentiation of the living mammal groups. With an estimated body weight of only 2 grams, its coexistence with other larger mammaliaforms with similar "triconodont-like" teeth for insectivory within the same fauna suggests a great trophic diversity within the mammaliaform insectivore feeding guild, as inferred from the range of body sizes.

Dual origin of tribosphenic mammals

Marsupials, placentals and their close therian relatives possess complex (tribosphenic) molars that are capable of versatile occlusal functions. This functional complex is widely thought to be a key to the early diversification and evolutionary success of extant therians and their close relatives (tribosphenidans). Long thought to have arisen on northern continents, tribosphenic mammals have recently been reported from southern landmasses. The great age and advanced morphology of these new mammals has led to the alternative suggestion of a Gondwanan origin for the group. Implicit in both biogeographic hypotheses is the assumption that tribosphenic molars evolved only once in mammalian evolutionary history. Phylogenetic and morphometric analyses including these newly discovered taxa suggest a different interpretation: that mammals with tribosphenic molars are not monophyletic. Tribosphenic molars evolved independently in two ancient (holotherian) mammalian groups with different geographic distributions during the Jurassic/Early Cretaceous: an australosphenidan clade endemic to Gondwanan landmasses, survived by extant monotremes; and a boreosphenidan clade of Laurasian continents, including extant marsupials, placentals and their relatives.

A Chinese triconodont mammal and mosaic evolution of the mammalian skeleton

Here we describe a new triconodont mammal from the Late Jurassic/Early Cretaceous period of Liaoning, China. This new mammal is represented by the best-preserved skeleton known so far for triconodonts which form one of the earliest Mesozoic mammalian groups with high diversity. The postcranial skeleton of this new triconodont shows a mosaic of characters, including a primitive pelvic girdle and hindlimb but a very derived pectoral girdle that is closely comparable to those of derived therians. Given the basal position of this taxon in mammalian phylogeny, its derived pectoral girdle indicates that homoplasies (similarities resulting from independent evolution among unrelated lineages) are as common in the postcranial skeleton as they are in the skull and dentition in the evolution of Mesozoic mammals. Limb structures of the new triconodont indicate that it was probably a ground-dwelling animal.

[Follow-up study of porcine bioprosthetic valve replacement in 15 children]

GD-I porcine bioprosthetic valve replacement were performed in 15 cases from Jul. 1978 to Nov. 1982. Pathology: RHD 11, CHD 4, 13 with MVR, 1 AVR, 1 TVR. One patient died during operation (operative mortality 6.7%). 13 cases were followed up for 3-10 years: in the early years the symptoms and cardiac function were greatly improved and the size reduced. However dysfunction of bioprosthetic valve was detected 2-8 years after operation in 12 patients (19.37%/patient year). The main cause of damage and dysfunction of porcine valve is calcification of the leaflet. As compared with the adult group(dysfunction rate 3.6%/patient year) in this institute, more calcification of the porcine valve in children is considered because of: (1) stronger metabolism of calcium in children, (2) less mobility of the leaflet due to lower cardiac output in children, and (3) stronger immunoreaction to porcine valve in children.

[Surgical treatment of secondary atrial septal defect associated with mitral valve disease]

From March 1965 through August 1991, 703 patients with secondary atrial septal defect were treated surgically in our hospital. Among them, 32 cases (4.6%) were associated with mitral valve disease. The mitral valve lesion was repaired at the same time of closure of the atrial septal defect. The operative mortality was 6.3% and there was no late death. Follow-up study showed that heart function of the patients was improved obviously and most of them have resumed work or study. The clinical features, incidence, etiology, pathology and surgical techniques of secondary atrial septal defect associated with mitral valve disease were discussed.

Removal of tropomyosin overlap modifies cooperative binding of myosin S-1 to reconstituted thin filaments of rabbit striated muscle

Cooperative binding of myosin S-1.ADP to regulated F-actin was previously reported and has been interpreted by a two-state model in which an important source of cooperativity is nearest neighbor interactions between the 7-actin.tropomyosin (TM).troponin units (functional units) (Hill, T.L., Eisenberg, E., and Greene, L. (1980) Proc. Natl. Acad. Sci. U.S.A. 77, 3186-3190). It has been postulated that the head-to-tail overlap between adjacent TM molecules is the structural basis of the nearest neighbor interactions. We tested the hypothesis by examining S-1.ADP binding to reconstituted regulated F-actin containing either intact TM or nonpolymerizable TM from which the COOH-terminal 11 residues were removed. In the absence of Ca2+, substitution of nonpolymerizable TM for TM reduced significantly the slope of the steeply rising phase of the sigmoidal S-1.ADP binding curve. Nevertheless, considerable residual cooperativity remained. Analysis of the data using the two-state model of Hill et al. suggests that removal of TM overlap abolishes nearest neighbor interactions, while the concerted change of the state of 7 actins in a functional unit can account for the residual cooperativity.

Nucleotide sequences of cloned cDNA fragments specific for six Xenopus laevis ribosomal proteins

We have previously constructed and selected six recombinant plasmids containing cDNA sequences specific for different ribosomal proteins of Xenopus laevis (Bozzoni et al., 1981). DNA cloned in these plasmids have been isolated and sequenced. Amino acid sequences of the corresponding portions of the proteins have been derived from DNA sequences; they are arginine- and lysine-rich as expected for ribosomal proteins. One of the cDNA sequences has an open reading frame also on the strand complementary to the one coding for the ribosomal protein; this fragment has inverted repeats twenty nucleotides lone at the two ends. The codon usage for the six sequences appears to be non-random with some differences among the ribosomal proteins analysed.

Xenopus laevis ribosomal protein genes: isolation of recombinant cDNA clones and study of the genomic organization

Poly-A+ mRNA from Xenopus laevis oocytes, partially enriched for r-protein coding capacity has been used as starting material for preparing a cDNA bank in plasmid pBR322. The clones containing sequences specific for r-proteins have been selected by translation of the complementary mRNAs. Clones for six different r-proteins have been identified and utilized as probes for studying their genomic organization. Two gene copies per haploid genome were found for r-proteins L1, L14, S19, and four-five for protein S1, S8 and L32. Moreover a population polymorphism has been observed for the genomic regions containing sequences for r-protein S1, S8 and L14.