Epidemiological study on nasal carriage in hospitalized children infected with Staphylococcus aureus / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the relationship between nasal carriage and Staphylococcus aureus (S. aureus) infection in hospitalized children.</p><p><b>METHODS</b>Fifty-six hospitalized children infected with S. aureus were recruited in this study. Nasal swabs were collected and cultured, and the nasal carriage rate of S. aureus was examined. PVL virulence gene and mecA resistance gene were both detected in clinical strains and nasal carriage strains by PCR.</p><p><b>RESULTS</b>Twenty-two (39%) of the 56 children had nasal carriage of S. aureus, and most of them (18 cases) were younger than one year. Among these 22 children, 11 (50%) had previous hospitalization over the past year. In the infected strains, the rate of methicillin-resistant S. aureus (MRSA) was 29% (16/56), while it was 32% (7/22) in carriage strains. The mecA positive results in clinical strains were consistent with the results in nasal carriage strains. Among 5 PVL-positive nasal carriage strains, 4 (90%) could be matched with their clinical strains, all of which were MRSA.</p><p><b>CONCLUSIONS</b>Nasal carriage is a potential risk factor for S. aureus infection. Nosocomial transmission may lead to nasal carriage, which can cause S. aureus infection. The isolation rate of MRSA is high in hospitalized children infected with S. aureus, which implies that more attention is needed for this situation. The isolates from noses may be clonally identical to the isolates from clinical secretions, and the homology between them needs to be confirmed by multi-locus sequence typing.</p>

Factors influencing short-term prognosis of tuberculous meningitis in children / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the factors influencing short-term prognosis of tuberculous meningitis (TBM) in children.</p><p><b>METHODS</b>The clinical data of 137 hospitalized children with TBM between January 2007 and February 2011 were retrospectively reviewed. A total of 30 potential factors influencing short-term prognosis of TBM were evaluated by univariate analysis and multivariate logistic regression analysis.</p><p><b>RESULTS</b>Clinical staging showed that of the 137 children 21 cases (15.3%) were in the early stage, 67 cases (48.9%) in the medium stage and 49 cases (35.8%) in the late stage of TBM. The univariate analysis revealed 8 factors associated with a poor short-term prognosis: clinical stage of TBM (late), coma, positive Babinski signs, cranial nerve involvements, paralysis, seizures, obvious abnormalities in brain computed tomography (CT) or magnetic resonance imaging (MRI) and elevated protein concentrations in cerebrospinal fluid (CSF). Factors associated with a favourable short-term prognosis for TBM included glucocorticoid steroids therapy, positive reaction of PPD skin test and an increased length of stay in hospital. Multivariate logistic analysis revealed two independent risk factors for a poor short-term prognosis: clinical stage of TBM (late) (OR: 11.168, 95%CI: 3.521-35.426) and positive signs of meningeal irritation (OR: 4.275, 95%CI: 1.043-17.521). An increased length of stay in hospital was shown as a favorable factor (OR: 0.893, 95%CI: 0.825-0.968).</p><p><b>CONCLUSIONS</b>Late-stage TBM and positive signs of meningeal irritation suggest a poor prognosis, while an appropriately longer length of stay in hospital may contribute to a favorable short-term prognosis for children with TBM.</p>

Nasal carriage of community-acquired methicillin-resistant Staphylococcus aureus in healthy children from Chengdu / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To evaluate the prevalence of nasal carriage of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) in healthy children from Chengdu.</p><p><b>METHODS</b>Strains of Staphylococcus aureus were isolated from nasal swabs of healthy children from five kindergartens in Chengdu from September, 2005 to December, 2005 and questionnaires were obtained. Antibiotic susceptibility test was performed with agar disk diffusion and Bauer-Kirby on Mueller-Hinton medium method to determine CA-MRSA. mecA and PVL genes were detected with PCR in all of the CA-MRSA isolates.</p><p><b>RESULTS</b>A total of 801 children were enrolled. Overall 147 children (18.4%) were carried with Staphylococcus aureus and 9 (1.1%) were carried with CA-MRSA. All CA-MRSA isolates were positive for mecA gene, and 5 CA-MRSA isolates were positive for PVL gene. Of the 9 CA-MRSA isolates, 6 were multiresistant.</p><p><b>CONCLUSIONS</b>CA-MRSA nasal colonization is present among Chengdu healthy children. The CA-MRSA isolates are multiresistant and parts of CA-MRSA isolates carry PVL gene. The nasal carriage of CA-MRSA in healthy children should be a concerned issue.</p>

Comparative study of the cytotoxicity induced by chrysotile asbestos, rock wool and substitute fibers in vitro / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the cytotoxicity induced by chrysotile asbestos (CA), rock wool (RW) and wollastonite (WS).</p><p><b>METHODS</b>V79 cells were divided into 4 groups. i.e. CA group, WS group, RW group and control group (200 microl PBS). The exposure concentration of dusts was 100 mg/L, The cell viability was detected by MTT and lactate dehydrogenase (LDH) activity assays. The technique of scanning electron microscopy was used to examine the change of V79 cells.</p><p><b>RESULTS</b>SiO2 was main constituent for 3 kinds of dusts. In MTT assay, the cell viability of RW and WS groups was 64.8% and 65.7%, respectively, which were significantly higher than that (54.5%) of CA group (P < 0.01). In LDH assay, the LDH activity of RW and WS groups [(15.7 +/- 50.9), (12.3 +/- 3.7) U/L, respectively] was significantly lower than that [(20.2 +/- 0.9) U/L] of CA group (P < 0.05). In scanning electron microscopy examination, it was found that the two ends of V79 cells in CA group contained a great deal of fibers remaining bodies, but the V79 cell appearance in RW and WS groups was normal.</p><p><b>CONCLUSION</b>The cytotoxicity induced by RW and WS is significantly lower than that induced by CA for V79 cell.</p>

The preventive and therapeutic effect of advanced airway management on pulmonary infection in patients with inhalation injury after tracheotomy / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the preventive and therapeutic effect of advanced airway management on pulmonary infection in patients with inhalation injury after tracheotomy.</p><p><b>METHODS</b>fourteen burn patients with inhalation injury admitted to our hospital from January 2001 to December 2004 were enrolled as control (C) group, and they were treated with conventional systemic therapy and management of airway. Twenty-seven burn patients with inhalation injury admitted to our hospital from January 2005 to October 2009 were enrolled as advanced (A) group, and they were treated with conventional systemic therapy and advanced airway management, including bedside isolation of airway, fixation of both oxygen supply tube and humidifying tube, humidification in specific body position, thinning of sputum, lavement of airway and procedural sputum elimination, steam inhalation combined with medicine, and suction of sputum with interrupted negative pressure. Result of bacterial culture of sputum (the 7th day after tracheotomy) and chest X-ray (at admission and the 7th day after tracheotomy), pulmonary infection, change in blood gas analysis index and oxygen saturation (SO(2)), (within 7 days after tracheotomy), and the number of patients curd in 2 groups were observed and compared.</p><p><b>RESULTS</b>(1) Positive result of bacterial culture of sputum was observed in 11 (78.6%) patients in C group and 12 (44.4%) patients in A group. The difference between them was statistically significant (chi(2) = 4.36, P < 0.05). The main bacterium detected was Pseudomonas aeruginosa. (2) Pneumonia was suspected in 7 patients (25.9%) in A group by chest X-ray, which was obviously fewer than that in C group (8 Cases, 57.1%, chi(2) = 3.87, P < 0.05). The result was in accordance with the diagnosis of pulmonary infection. (3) No CO(2) retention, SO(2) and PaCO(2) abnormality caused by asphyxia was observed in 2 groups, PaCO(2) value in A group was close to that in C group (t = 0.89, P > 0.05). (4) In C group, 9 (64.3%) patients were cured, 5 patients died of pneumonia, wound sepsis, and MODS. In A group, 25 (92.6%) patients were cured, 2 patients died of MODS. Number of cure was obviously larger in A group than in C group (chi(2)= 5.22, P < 0.05).</p><p><b>CONCLUSIONS</b>The advanced airway management has better effects on isolation and humidification of airway, and thinning, drainage, and elimination of sputum. And it can decrease the probability of blind suction and injury to airway, and it prevents pulmonary infection following tracheotomy.</p>