Predictive factors for poor prognosis of neonates with early-onset sepsis / 中国当代儿科杂志

OBJECTIVE@#To study the predictive factors for poor prognosis of neonates with early-onset sepsis (EOS).@*METHODS@#The clinical data of 371 neonates with EOS were collected. According to prognosis, they were divided into a good prognosis group with 264 neonates and a poor prognosis group with 107 neonates. The two groups were compared in terms of perinatal conditions, clinical manifestations, laboratory markers, comorbidities, and treatment process. Multivariate logistic regression analysis was used to investigate the predictive factors for poor prognosis of EOS.@*RESULTS@#The poor prognosis group had significantly lower birth weight and gestational age than the good prognosis group (P<0.05). Compared with the good prognosis group, the poor prognosis group had significantly higher proportions of preterm neonates, low birth weight neonates, very low birth weight neonates and twins (P<0.05), as well as a significantly higher proportion of mothers who used hormone or antibiotics before delivery (P<0.05). Compared with the good prognosis group, the poor prognosis group had significantly higher incidence rates of poor response and respiratory hypofunction (P<0.05) and a significantly lower incidence rate of jaundice (P<0.05). Compared with the good prognosis group, the poor prognosis group had significantly higher incidence rates of white blood cell count <5×10/L, platelet count <100×10/L, anemia, coagulation disorder, renal dysfunction, liver impairment, hypoproteinemia, and hypoglycemia (P<0.05). The poor prognosis group had significantly higher incidence rates of neonatal respiratory distress syndrome, pulmonary hemorrhage, necrotizing enterocolitis, intraventricular hemorrhage, brain injury, pulmonary hypertension, and shock than the good prognosis group (P<0.05). Compared with the good prognosis group, the poor prognosis group had significantly longer length of hospital stay and course of treatment with antibiotics (P<0.05) and a significantly higher proportion of neonates receiving mechanical ventilation or vasoactive agents (P<0.05). The multivariate logistic regression analysis showed that very low birth weight (OR=41.734), necrotizing enterocolitis (OR=12.669), brain injury (OR=8.372), shock (OR=5.889), mechanical ventilation (OR=5.456), and liver impairment (OR=4.075) were independent predictive factors for poor prognosis of neonates with EOS (P<0.05).@*CONCLUSIONS@#Very low birth weight, mechanical ventilation, necrotizing enterocolitis, brain injury, shock, and liver impairment have a certain value in predicting the poor prognosis of neonates with EOS.

Accurate use of antibiotics for preterm infants with early-onset sepsis should be taken seriously / 中国当代儿科杂志

At present, non-standard use of antibiotics remains a common phenomenon in the treatment of preterm infants with early-onset sepsis (EOS) in China. The expert panel of neonatologists in Hunan Province formulated a consensus on the diagnosis and use of antibiotics for EOS in preterm infant [Chin J Contemp Pediatr, 2020, 22(1): 1-6], which has a positive effect on the rational use of antibiotics. Based on this consensus, this article points out that in order to use antibiotics accurately, it is necessary to accurately identify EOS in preterm infants, accurately understand their clinical manifestations and medical history, and accurately evaluate the laboratory test results. Also, this article offers suggestions for the use of antibiotics in preterm infants with EOS.

Cut-off value of white blood cell count in the diagnosis of early-onset sepsis in neonates / 中国当代儿科杂志

OBJECTIVE@#To study the clinical significance and cut-off value of white blood cell (WBC) count in the diagnosis of early-onset sepsis (EOS) in neonates.@*METHODS@#A retrospective analysis was performed on 306 neonates with EOS who were admitted from January 2019 to March 2020. A total of 580 children without infection who were admitted during the same period of time were enrolled as the control group. General status and WBC count were compared between the two groups. The diagnostic value of WBC count was analyzed based on the diagnostic and therapeutic protocol of neonatal sepsis in 2003 (referred to as the 2003 diagnostic and therapeutic protocol) and the expert consensus on the diagnosis and treatment of neonatal sepsis (2019 edition) (referred to as the 2019 expert consensus).@*RESULTS@#According to the two different diagnosis and treatment protocols, the statistical analysis showed that WBC count had a relatively positive rate (51.3% and 32.0% respectively) but a relatively high specificity (93.3% and 98.6% respectively). The receiver operating characteristic (ROC) curve analysis showed that the area under the ROC curve of WBC count in the 2003 diagnostic and therapeutic protocol was larger than that in the 2019 expert consensus (P<0.05).@*CONCLUSIONS@#The cut-off value of WBC ≥25×10

Clinical value of blood lactate in predicting the prognosis of neonatal sepsis / 中国当代儿科杂志

OBJECTIVE@#To explore the clinical value of arterial blood lactate level in predicting the prognosis of neonatal sepsis.@*METHODS@#The clinical data of 301 cases of neonatal sepsis were collected, which mainly included biochemical indicators such as blood lactate on admission, C-reactive protein, and procalcitonin. ROC curves were plotted to evaluate the value of lactate level on admission in predicting the prognosis of neonatal sepsis.@*RESULTS@#The mortality rate was significantly higher for full-term infants in the severely-elevated lactate group than in the mildly-elevated lactate group and the normal lactate group (26.1% vs 3.1% and 0%; P<0.017). The poor prognosis group had a significantly increased lactate level on admission compared with the good prognosis group (6.5±5.1 mmol/L vs 3.6±1.7 mmol/L; P<0.05). The sensitivity and specificity of blood lactate level on admission (cutoff value: 6.15 mmol/L) were 0.545 and 0.919 respectively, in predicting the prognosis of neonatal sepsis.@*CONCLUSIONS@#Early blood lactate level can be used as a biochemical parameter to predict the prognosis of neonatal sepsis as it has a high specificity but a low sensitivity.

Protective effect of sodium butyrate on the neonatal mouse model of necrotizing enterocolitis / 解放军医学杂志

Objective To investigate the protective effect of sodium butyrate on the neonatal mouse model of necrotizing enterocolitis and analyze its possible mechanism.Methods Sixty c57BL/6 neonatal mice were randomly divided into two groups (n=30):PBS group and butyric acid group.At the third day after birth,mice in both groups were respectively given PBS and sodium butyrate solution by gavage once a day for 7 days,and neonatal necrotizing enterocolitis (NEC) model was established by hypoxia,cold stimulation and artificial feeding.The newborn mice were sacrificed overnight after modeling.HE staining and double-blind pathological score were performed to observe the pathological changes of ileocecal intestinal tissue.The mRNA expressions of IL-6,IL-10,TGF-β1 and TNF-a were tested by quantitative real-time PCR.The levels of IL-10 and TGF-β1 in intestine tissues were evaluated using ELISA.Flow cytometry was used to analyze the ratio of regulatory T cells (Treg) on CD4+ T cells in both groups.Results When mice were sacrificed overnight after NEC modeling,the body weight was significantly higher in butyric acid group (4.50 ± 0.42g) than in PBS group (4.16 ± 0.60g,P＜0.05);No significant difference (P＞0.05) existed in survival rate of butyric acid group (76.34％) and PBS group (67.95％).The pathological damage score of intestinal tissue showed that the median score of intestinal injury was significantly lower in butyric acid group [1.33(1.33-1.67)] than in PBS group [2.00(1.67-2.25),P＜0.05].qPCR demonstrated that the expressions of IL-6 and TNF-α mRNA were obviously lower in butyric acid group than in PBS group (0.85 ± 0.30 vs.1.77 ± 0.49 and 0.41 ± 0.25 vs.0.96 ± 0.56,respectively,P＜0.05);and the expressions of IL-10 and TGF-β1 mRNA were markedly higher in butyric acid group than in PBS group (1.91 ± 0.82 vs.0.94 ± 0.43 and 1.46 ± 0.57 vs.0.88 ± 0.29,respectively,P＜0.05);Intestinal tissue ELISA results showed that the expressions of IL-10 and TGF-β1 were higher in butyric acid group than in PBS group (68.60 ± 15.06 vs.37.25 ± 5.81 and 424.93 ± 19.34 vs.127.31 ± 60.83,respectively,P＜0.05);Flow cytometry revealed that the proportion of regulatory T cells (Treg) of CD4+ T cells was higher in butyric acid group than in PBS group (12.68％ ± 6.79％ vs.3.57％ ± 0.88％,P＜0.05).Conclusions Butyric acid plays a protective effect in the intestinal injury of neonatal mouse model of necrotizing enterocolitis.The possible mechanism is that butyrate can down-regulate the expressions of cytokines IL-6 and TNF-o,up-regulate the expressions of cytokines IL-10 and TGF-β1,and promote the differentiation of T cells into Treg cells.

Imaging assessment of neonatal necrotizing enterocolitis / 中华儿科杂志

<p><b>OBJECTIVE</b>To improve the understanding of recognizing and diagnosis of neonatal necrotizing enterocolitis (NEC), imaging assessment of neonates with NEC was analyzed retrospectively.</p><p><b>METHOD</b>Data of 211 cases of NEC were retrospectively collected from the Department of Neonatology, Children's Hospital of Chongqing Medical University between Jan.1(st) 2006-Dec.31(st) 2011.</p><p><b>RESULT</b>Analysis of abdominal X-ray of 211 cases showed that there were 40 cases (19.0%) who had no changes on each X-ray, 47 cases (22.3%) had improvement and 23 cases (10.9%) became worse. In the group of no changes, positive rate with good prognosis was 97.5% and with poor prognosis, it was 2.5%. In the group of improvement, positive rate with good prognosis was 97.9%, and the contrary was 2.1%. Positive rate with good prognosis was 56.5%, and the contrary was 43.5% in worse group. Chi-square analysis of the three groups showed χ(2) = 31.742, P < 0.01. Comparison of detection rate of pneumoperitoneum on abdominal X-ray (16.0%, 12/75) and Doppler US (1.3%, 1/75), χ(2) = 10.191, P < 0.05, portal pneumatosis on abdominal X-ray(1.3%, 1/75) versus Doppler US (12.0%,9/75), χ(2) = 6.857, P < 0.05. Surgical timing mostly corresponded to pneumoperitoneum (OR = 19.543) and intestinal obstruction (OR = 19.527) of abdominal X-ray. The logistic regression equation is y = -2.915-1.588x1+2.972x4+2.973x7 + 1.711x9 (χ(2) = 101.705, P < 0.01).</p><p><b>CONCLUSION</b>Abdominal X-ray is the most important method of diagnosis of NEC, the group of deterioration of abdominal X-ray has obvious bad prognosis differ from no change group and better group. Comparison with abdominal X-ray and Doppler US, the former in pneumoperitoneum positive rate was higher than the latter, at the same time, portal pneumatosis on Doppler US is more sensitive to abdominal X-ray, the value of two imaging assessments both supplement each other. Surgical timing mostly corresponds to pneumoperitoneum and intestinal obstruction.</p>

Recent progress in the diagnosis of neonatal septicemia / 中国当代儿科杂志

Neonatal septicemia is one of the major causes of morbidity and mortality worldwide during the neonatal period. It can be classified into two subtypes: early-onset sepsis (EOS) and late-onset sepsis (LOS) depending upon the time of onset. In the western developed countries, group B Streptococcal and Escherichia coli are leading pathogens for EOS, while the most frequent microorganism involved in LOS is coagulase negative Staphylococci, which are different from the domestic data. Clinical manifestations of neonatal septicemia are not specific, so that it is often misdiagnosed. This review describes the progress in diagnostic methods for neonatal septicemia, including blood culture, blood cell counts, cytokine profiles and umbilical cord blood examinations. It provides useful information for early diagnosis and treatment of neonatal septicemia.

Diversity analysis of biofilm bacteria on tracheal tubes removed from intubated neonates / 中华儿科杂志

<p><b>OBJECTIVE</b>The catheter-related infections caused by mechanical ventilation have become a intractable clinical problem, and it is related to the formation of bacterial biofilm (BF) on the surface of the implanted material. The majority of natural biofilms are formed by multiple bacterial species. However, there always only one or limited species were detected on tracheal tubes removed from intubated neonates by using traditional methods including bacterium culture and antigen detection. The aims of this study were to observe the bacterial communities diversity of BF on endotracheal tube (ETT), and discuss the difference between traditional bacterium culture methods and the use of molecular biology techniques on the basis of denatured gradient gel electrophoresis (DGGE), to provide new ideas for clinical prevention, diagnosis and treatment of bacterial infections.</p><p><b>METHOD</b>Thirty-five ETTs were obtained from 26 neonates on mechanical ventilator (from October 2012 to March 2013) in Department of Neonatology of Children's Hospital. Among the patients, 18 were boys and 8 girls, and 19 patients were < 37 weeks gestational age and 7 patients ≥ 37 weeks. DGGE profiling of 16S rDNA gene amplicons was used to assess the diversity of the bacterial population by using the software of quantity one. TA Cloning Kit and sequencing were used to investigate the distribution of bacteria and common dominant bacteria in ETT-BF.</p><p><b>RESULT</b>The mean bands of 35 ETTs cases were 13.8 ± 5.4 from 16S rDNA PCR-DGGE, and the mean Shanon-Wiener indexes was 2.42 ± 0.38. The 16 ETTs were collected in different stages of diseases from the 7 patients. The indwelling days of 6/7 patients' ETTs increased, the Shanon-siener indexes were decreased. Among the 6 cases from different basic illnesses, and there were different Shanon-siener indexes. The result of molecular cloning and sequencing for 24 dominant bands showed that 35 cases (100%) contained Klebsiella SP·, 28 cases (80%) had Pseudomonas SP·, 27 cases (77%) had Streptococcus SP·, and 32 cases (91%) had Uncultured bacterium, while more than 2 bacterial species were found in 34 cases (97%). 28/35 (80%) Klebsiella SP· and 22/27(82%) Streptococcus SP· were accompanied by Pseudomonas SP·. There were 22 positive results of sputum culture from 26 newborns, including 10 strains (45%) of Klebsiella pneumoniae, 2 strains (9%) of Acinetobacter baumannii, Enterobacter cloacae and non-cultured bacterium in each patient (5%), but only one bacterium isolated from every sputum. Eight sputum samples had normal flora only, corresponding to the ETTs on which Klebsiella and other bacterial genuses were found.</p><p><b>CONCLUSION</b>The diversity of microbiota in BF on ETT was confirmed. 16S rDNA PCR-DGGE could produce a more complete picture of bacterial community than traditional bacterium culture method. Klebsiella, Pseudomonas and Streptococcus were common dominant bacteria in ETT-BF, and there might be interactions among them in the formation of BF.</p>

Changes in perinatal care and predictors of in-hospital mortality for very low birth weight preterm infants

Mortality of very low birth weight premature infants is of great public health concern. To better guide local intervention program, it is essential that current and reliable statistics be collected to understand the factors associated with mortality of these infants. Data of very low birth weight premature infants admitted to a neonatal unit during 2002-2009 was retrospectively collected. Changes in perinatal care between two halves of the study period [2002-2005 and 2006-2009] were identified. Factors associated with in-hospital mortality were found by logistic regression and a predictive score model was established. A total of 475 cases were enrolled. In-hospital mortality decreased from 29.8% in 2002-2005 to 28.1% in 2006-2009 [P>0.05]. More infants born<28 gestational weeks survived to discharge in the latter epoch [38.1% vs. 8.3%, P<0.05]. Persistent pulmonary hypertension of newborn, pulmonary hemorrhage, birth weight <1000 grams, gestational age <33 weeks, feeding before 3 postnatal days and enteral feeding were found predictors of in-hospital mortality by logistic regression. The discriminating ability of the predictive model was 82.4% and the cutoff point was -0.56. Survival of very low birth weight premature neonates was not significantly improved in 2006-2009 than 2002-2005. Infants with a score higher than -0.56 were assessed to be at high risk of in-hospital mortality. Multi-center studies of planned follow-up are needed to develop a comprehensive and applicable score system

Clinical manifestations and treatment of early-onset neonatal sepsis: a Chinese-French comparison / 中华儿科杂志

<p><b>OBJECTIVE</b>To realize the difference between China and France in the clinical manifestations, diagnosis and treatment of early-onset neonatal sepsis (EONS) and to provide basis to improve the level of our hospital in diagnosing and treating this disease.</p><p><b>METHOD</b>Data of 146 cases of EONS were retrospectively analyzed. All data were collected from our hospital and a French hospital. Bacterial spectrum, clinical manifestations, use of antibacterial drugs, occurrence of recording and screening of perinatal risk factors were compared between the two hospitals.</p><p><b>RESULT</b>The most common pathogenic bacteria in our hospital were coagulase-negative staphylococcus (69.2%) and Escherichia coli (15.4%) while in the French Hospital, group B streptococcus (33.3%) and Escherichia coli (33.3%). The most common pathogenic bacteria in gastric liquid and peripheral swabs of the French hospital were Escherichia coli (33.3%) and group B streptococcus (21.2%). Total days of antibacterial use 11.4 ± 7.2 (d), mean sorts of antibacterial drugs for single patient (3.1 ± 0.9) and proportion of patients who had antibacterial drug changes (70.2%) were greater than the French hospital 6.2 ± 2.5 (d), 2.2 ± 0.8(d), (9.9%). Both hospitals were inclined to combine 2 antibacterial drugs for the first dose (second-generation cephalosporins + semi-synthetic penicillin in our hospital vs. amoxicillin + amikacin in the French hospital). The common second and third line antibacterial drugs in our hospital are carbapenems and vancomycin vs. third-generation cephalosporins and vancomycin in the French hospital. The rates of occurrence of recording and screening perinatal risk factors (chorioamnionitis, maternal fever, prolonged rupture of membranes, screening results of vaginal swabs or urinary infection, amniotic fluid contamination, prenatal antibacterial prophylaxis, anamnesis of EONS) in our hospital was all lower than those of the French hospital. There was no significant difference in positive rate of perinatal risk factors between the two hospitals. For newborns hospitalized for immediate abnormalities after birth, the most common symptom was respiratory distress (96.5% vs. 88.2%). For those admitted after a period of time after birth, the proportion of abnormalities was different: in our hospital, the most common reasons were respiratory distress (44.4%) and lethargy (22.2%) while in the French hospital there were rise of C reactive proteins (78.2%) and fever (5.5%). The false negative rate of C reactive proteins in diagnosing EONS was not significantly different between the two hospitals.</p><p><b>CONCLUSION</b>There was significant difference in diagnosing and treating EONS in the two hospitals. Emphasis on screening and recording perinatal risk factors, as well as strengthened surveillance on neonates in obstetric department could improve the accuracy of early diagnosis of EONS of our hospital. Positive attitude to gastric liquid and peripheral swabs culture, with drug susceptibility test may help pediatricians better select antibacterial drugs and reduce unnecessary changes and the total time of antibiotic use.</p>

Economic evaluation on diagnosis of congenital cytomegalovirus infection by fluorescent quantitative polymerase chain reaction in neonates / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To explore the cost-effectiveness of the diagnosis of congenital cytomegalovirus (CMV) infection by fluorescent quantitative polymerase chain reaction (FQ-PCR) in neonates.</p><p><b>METHODS</b>Serum CMV immunoglobulin M (CMV-IgM) and CMV-IgG were detected using ELISA in 610 neonates aged less than 14 days. CMV DNA content was detected by FQ-PCR. The cost-effectiveness analysis was then performed.</p><p><b>RESULTS</b>The positive rate of FQ-PCR in neonates with positive CMV-IgM was 42.9% (15/35), while, 2.9% (16/547) in neonates with positive CMV-IgG. The mean logarithm values of CMV DNA in neonates with positive CMV-IgM were higher than those in neonates with positive CMV-IgG (5.79±1.24 vs 4.11±0.87; P<0.01). The costs of the diagnosis of CMV infection by FQ-PCR were 256 RMB/case in neonates with positive CMV-IgM, and 3 760 RMB/case in neonates with positive CMV-IgG.</p><p><b>CONCLUSIONS</b>The CMV DNA content in neonates with positive CMV-IgM is higher than that in neonates with positive CMV-IgG. Diagnosis of congenital CMV infection by FQ-PCR in neonates with positive CMV-IgG is not suitable for large scale epidemiological survey because of high cost-effectiveness ratio.</p>

Protective effects of curcumin on neonatal rats with necrotizing enterocolitis / 中国当代儿科杂志

<p><b>OBJECTIVE</b>This study examined the effects of curcumin on intestinal histopathological changes, cyclooxygenase-2 (COX-2) expression, and tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) concentrations in neonatal rats with necrotizing enterocolitis (NEC), in order to investigate the effects of curcumin against NEC.</p><p><b>METHODS</b>Forty neonatal rats were randomly divided into four groups (n=10 each): normal control, solvent control, NEC model, and curcumin intervention. The general situations of rats were observed for 3 consecutive days, and the rats were then sacrificed on the 4th day. Intestinal tissues were obtained for examining the histopathological changes, COX-2 expression, and TNF-alpha and IL-10 concentrations.</p><p><b>RESULTS</b>Curcumin treatment ameliorated the general situations and histopathological signs in rats with NEC. TNF-alpha and IL-10 concentrations in the NEC model and the curcumin intervention groups increased significantly compared with those in the normal and solvent control groups (p<0.05). The concentration of TNF-alpha decreased (p<0.05), while the concentration of IL-10 increased significantly in the curcumin intervention group in comparison with the NEC model group (p<0.05). Immunohistochemistry results indicated that the positive expression of COX-2 in the curcumin intervention group was significantly lower than that in the NEC model group.</p><p><b>CONCLUSIONS</b>Curcumin has protective effects against NEC in neonatal rats, possibly through inhibiting COX-2 expression, reducing TNF-alpha content, and increasing IL-10 content.</p>

Expression of high mobility group protein-B1 in mice with hyperoxia-induced bronchopulmonary dysplasia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the effect of hyperoxia exposure on high mobility group protein-B1 (HMGB1) expression in neonatal mice and the role of HMGB1 in the pathogenesis of bronchopulmonary dysplasia (BPD).</p><p><b>METHODS</b>C57BL/6 mice were randomly exposed to 60% O2 or air 1 day after birth. BPD was induced by 60% O2 exposure. The pulmonary tissue samples were harvested 3, 7 and 14 days after exposure. The pathologic changes of pulmonary tissues were observed by hematoxylin and eosin staining, Masson staining and radical alveolar count. The expression of HMGB1 protein in lungs was detected by immunofluorescence. The expression of HMGB1 mRNA was detected by real-time fluorescent quantitative PCR.</p><p><b>RESULTS</b>In the BPD group, the lungs developed decreased alceolar septation, swollen alveolar epithelium, stroma edema, interstitial fibrosis and developmental lag when compared with the control group. These changes became more obvious with more prolonged hyperoxia exposure. The expression of HMGB1 protein and mRNA 7 and 14 days after exposure increased significantly in the BPD group compared with that in the control group.</p><p><b>CONCLUSIONS</b>Hyperoxia exposure results in an increase in lung HMGB1 expression. The increased HMGB1 expression may be associated with the development of BPD.</p>

A new hypoxic brain damage model in the neonatal rat / 中国当代儿科杂志

<p><b>OBJECTIVE</b>This study aimed to prepare a hypoxic brain damage model in the neonatal rat using a new approach, 0% oxygen exposure, and to explore the reliability and advantages of the new model.</p><p><b>METHODS</b>Seven-day-old Wistar rats were randomly exposed to either 7 minutes of 0% oxygen, to the conventional Rice-Vannucci method (ischemia + 2 hrs hypoxia exposure), or to left common carotid artery ligation (ischemia). Rat pups which were not subjected to any hypoxia-ischemia treatment were used as the control group. Brain water content and neuronal apoptosis were measured. Neurofunctional assessment was performed. Brain pathological changes were observed using hematoxylin and eosin staining.</p><p><b>RESULTS</b>The water content (88.96+/-0.29%) and apoptosis of neurons (31.52+/-5.45%) of the left brain in the 0% oxygen group were significantly higher than those of the ischemic and the control groups (P<0.01), and similar to those in the Rice-Vannucci group. The water content (88.68+/-0.24%) and apoptosis of neurons (30.85+/-5.38%) of the right brain in the 0% oxygen group were significantly higher than those of the Rice-Vannucci, the ischemic and the control groups (P<0.01). Both side brains of the 0% oxygen group showed pathological injuries, but only left brain of the Rice-Vannucci group had pathological changes. No pathological abnormalities were seen in the ischemic and the control groups. Significant neurofunctional impairments were found in the 0% oxygen and the Rice-Vannucci groups.</p><p><b>CONCLUSIONS</b>A hypoxic brain damage model of neonatal rat was successfully prepared using 7 minutes 0% oxygen exposure. The new approach appears to be simple and reliable.</p>

Clinical value and multiple risk factors analysis of sputum culture for fungus in neonates / 中华儿科杂志

<p><b>OBJECTIVE</b>In recent years, the incidence of fungal infection in neonates has been risen year by year, but there are no widely accepted criteria to identify the clinical significance of the culture results of secretion from lower respiratory tract at present. The aim of the present study was to understand the clinical value and risk factors of fungal infections as suggested by sputum culture in neonates, which may help clinicians to diagnose and treat the neonates with fungal infection of respiratory tract.</p><p><b>METHODS</b>One hundred and forty nine neonates with positive sputum culture results and suffered from pneumonia hospitalized from October, 2002 to May, 2005 in Children's Hospital of Chongqing Medical University were analyzed. The cases were divided into three groups according to the results of sputum culture. Forty cases who were only fungus positive were enrolled into the fungal group, 30 cases who were positive for both fungus and bacteria were classified into the mixed group, and the remaining 79 cases who were positive for bacteria only were recruited into bacterial group. Several clinical characteristics of neonates from the three groups were compared retrospectively. t test, chi-square test and Logistic regression analysis were used for statistical analyses.</p><p><b>RESULTS</b>Seventy of the 149 patients (47.0%) had fungal infections. Candida was the main genus cultured from sputum. Rate of resistance to fluconazole was 25.7% (9/35). Candida albicans was the most common strain, which was found in 56.9% of cases whose sputum culture was positive for fungi. In fungal group (n = 40), mixed group (n = 30) and bacterial group (n = 79), white blood cell count were (10.3 +/- 3.5) x 10(9)/L (11.7 +/- 5.2) x 10(9)/L and (14.4 +/- 10.5) x 10(9)/L, respectively, F = 3.78, P = 0.03, with neutrophil count (5.1 +/- 3.3) x 10(9)/L, (7.4 +/- 4.7) x 10(9)/L and (9.0 +/- 7.4) x 10(9)/L, respectively, F = 5.50, P = 0.01. Ratios of risk factors were as follows:for preterm infant, 32.5% (13/40), 20% (6/30) and 12.7% (10/79), chi(2) = 6.68, P = 0.04; for antepartum glucocorticoid used, 10.0% (4/40), 6.7% (2/30) and 0% (0/79), P = 0.01; for trilogy of antibiotics used, 10.0% (4/40), 16.7% (5/30) and 2.5% (2/79), P = 0.02; for therapy with carbapenems (Carbenin or Tienam), 32.5% (13/40), 63.3% (19/30) and 17.7% (14/79), chi(2) = 21.26, P = 0.00. There was significant difference among the three groups in the above factors respectively. Using the sputum culture results with or without fungus as the dependent variable, multivariate logistic regression showed that preterm infant (X(1)) and the therapy with carbapenems (X(2)) suited the best regression equation: Logistic (SCF) = beta(0) (0.12) + 1.63X(1) + 1.20X(2) (chi(2) = 43.04, P < 0.05).</p><p><b>CONCLUSION</b>Fungal growth in sputum culture in the neonates with pneumonia was common, Candida was the main genus, and Candida albicans was the most common one. Prematurity and the therapy with carbapenems were the most important independent risk factors associated with fungal growth in culture of sputum specimen from neonates.</p>

Electron microscopic analysis of biofilm on tracheal tubes removed from intubated neonates and the relationship between bilofilm and lower respiratory infection / 中华儿科杂志

<p><b>OBJECTIVE</b>Mechanical ventilation support is a very important method for the salvage of serious patients. However, it can result in the formation of an adherent matrix of bacteria on the surfaces of implanted materials which is termed "biofilm". Biofilm is dense bacterial communities attached to a solid surface and surrounded by an exopolysaccharide matrix. One of the most important features of bacterial biofilm is their resistance to antimicrobial agents and host immune system components. As a consequence, diseases involving biofilm are generally chronic and difficult to treat. The present study was conducted to explore the relationship between ETT-biofilm and the lower respiratory infection by observing microbial colonization and associated biofilm accumulation on the surface of endotracheal tubes (ETTs) removed from neonates treated with intubated mechanical ventilation.</p><p><b>METHODS</b>Twenty neonates undergoing mechanical ventilation (from January to June in 2005) were recruited into this study. Clinical data about lower respiratory infection for each case were collected. ETTs were collected at the first time of extubation. A sterile control tube was also processed. For each ETT, a 1-cm-long cross-sectional segment was divided into two portions for both scanning electron microscopy (SEM) and aerobic/anaerobic cultures. The presence of biofilm on the surface of ETTs were examined by SEM, meanwhile, bacteria harvested from the surface of ETTs and the secretions of lower respiratory tract were isolated, identified and assessed on antimicrobial susceptibility, respectively.</p><p><b>RESULTS</b>The diagnosis on admission of the twenty cases included: neonatal respiratory distress syndrome (10), meconium aspirate syndrome (2), severe asphyxia (2), pneumatothorax (2), severe pneumonia (1), scleredema neonatorum (1), inborn pulmonary hypoplasia (1) and recurrent apnea (1). Thirteen cases did not present symptoms and signs of lower respiratory infection before mechanical ventilation. However, during the mechanical ventilation process, symptoms and signs of lower respiratory infection presented and lasted until extubation. Nine of the above mentioned thirteen cases (70%) had the same duration of tube use as mechanical ventilation duration (mean: 3.6 days). Observation by SEM showed that colonization was time dependent and the incidence of microbial colonization increased when the duration of tube use exceeded one days (12/20). There were no obvious bacterial colonies except that some amorphous material was noted in 5 of 20 ETTs as early as one day of tube use. Up to 2 days of tube use (4/20), attached bacterial colonization was seen embedded in amorphous material (3/4). Up to 3 days (7/20), a layer of biofilm formation presented on ETTs (5/7). Furthermore, biofilm architecture became more mature and complex if the duration exceeded 3 days. Neither bacteria nor biofilm formation was seen on the control ETT. The results of aerobic/anaerobic cultures showed that there were 14 cultures from ETTs (normal flora grew in 4) and 7 pathogens were isolated; 13 cultures from the secretions of lower respiratory tract (normal flora grew in 1) and 10 pathogens were isolated. Seven samples had the same pathogen both on the surface of ETTs and in the secretions of lower respiratory tract, which accounted for 50% of the positive cultures from ETTs, including Xanthomonas maltophilia (2), Klebsiella pneumoniae (2), Acinetobacter lwoffii (1), Acinetobacter baumannii (1) and normal flora (1). The gram-negative bacteria isolated from the surface of ETTs and the secretions of lower respiratory tract presented multi-resistance to antibiotics.</p><p><b>CONCLUSIONS</b>The ETT-biofilm develops into mature and complex form with the duration of tube use increase. This study provides evidence that there is correlation between microbial colonization, biofilm formation on the surface of ETTs and the lower respiratory infection in neonates who were intubated and ventilated for a prolonged period. ETT-Biofilm could also be a possible source of the recurrent infection. Increased attention must be paid to modification of the ETT to prevent or substantially reduce biofilm formation.</p>

Genotyping of major outer membrane protein gene of Chlamydia trachomatis by cleavase fragment length polymorphism analysis / 中华儿科杂志

<p><b>OBJECTIVE</b>To establish a methed of cleavage fragment length polymorphism (CFLP) analysis with a primer labeled at the 5'-end with digoxigenin for genotyping of Chlamydia trachomatis (Ct). The methods for detection of Ct by major outer membrane protein (MOMP) gene (ompl) with nested polymerase chain reaction (ompl-nPCR) were studied. The incidence of Ct infection in pregnant women, the common genotypes and vertical transmission rate of Ct in Chongqing area during the past one year was also investigated.</p><p><b>METHODS</b>The samples were taken from cervical scrapes of parturient women and nasopharygeal swabs of their neonates from April 2003 to Feb. 2004 in Chongqing Women and Children's Health Care Institute. Totally 300 pairs (605 specimens) were detected by using ompl-nPCR, ompl-PCR (inside pair of primers was used directly) and plasmid-PCR. The results were judged by the modified gold standard (MGS). The ompl-nPCR amplified DNA was purified by recovery of DNA from agarose gel electroelution into dialysis bags. The DNA amplified from ompl-nPCR was sequenced by ABI PRISM 377 DNA sequencer. CFLP assay with a primer labeled at the 5'-end with digoxigenin was created for genotyping of Ct, and was primarily applied.</p><p><b>RESULTS</b>The minimum detectable levels of ompl-nPCR and ompl-PCR corresponded to 2.5 elementary body (EB) and 25 EB, respectively. The sensitivity of ompl-nPCR was 10 times that of ompl-PCR. The positive rate of Ct in the samples from the pregnant women was 11% (33/300). The vertical transmission rate of Ct from mothers to their infants was 24.2% (8/33). The rate of Ct isolated from nasopharyngeal swabs 5 - 10 days after birth was 38.9% (7/18), which was significantly greater than that [3.0% (1/33)] detected within 24 hours after birth (chi(c)(2) = 8.79, P < 0.01). Of the 33 Ct-positive samples from pregnant women, 9 had vaginal delivery and 24 had caesarean section. The vertical transmission rates in vaginal delivery group and caesarean section group were 66.7% (6/9) and 8.3% (2/24), respectively (chi(c)(2) = 9.16, P < 0.01). Incidence of premature rupture of membrane in Ct-positive group was 30.3% (10/33), which was greater than that of Ct-negative groups (13.5%, 36/267, chi(2) = 6.40, P < 0.05). Four different patterns were observed in the 16 Ct-positive samples from 8 pregnant women and 8 matched maternal-infants by using CFLP, which were confirmed by DNA sequencing later. They were type E (3 pairs), type F (2 pairs), type H (2 pairs) and type D (1 pair). Each pair of matched maternal-infantile samples presented identical CFLP pattern.</p><p><b>CONCLUSIONS</b>This study revealed the infection rate of Ct in pregnant women, vertical transmission rate of Ct and the common genotypes of Ct in Chongqing Women and Children's Health Care Institute. The CFLP assay by using a primer labeled at the 5'-end with digoxigenin was first used for genotyping of Ct. The assay showed a good sensitivity and reproducibility, no radioactive contamination, and is simple. Therefore the assay is a potential new method for Ct genotyping.</p>

Multiple-factor analysis of weight gain in very low birth weight infants / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the correlative factors of weight gain in very low birth weight infants (VLBW).</p><p><b>METHODS</b>Fifty-one cases of VLBW from July 1998 to March 2004 were analyzed retrospectively.</p><p><b>RESULTS</b>Twenty two cases were small for gestational age (SGA) and 29 cases were appropriate for gestational age (AGA). The age of first feeding was (2.35 +/- 2.29) d. Caloric intake was (377.61 +/- 121.50) kJ/(kg.d) [(90.25 +/- 29.04) kcal/(kg.d)] and protein intake was (2.18 +/- 0.83) g/(kg.d). The age of birth weight regained was (7.41 +/- 3.57) d and the velocity of weight gain was (16.38 +/- 9.29) g/d or (12.63 +/- 7.15) g/(kg.d). Single factor analysis found that early feeding and caloric supply and protein supply had significant influence on weight gain (P < 0.05). The result of multivariate linear analysis showed that the significant risk factors were associated with supply of calorie and protein. The equation was Y (weight gain) = -6.426 + 0.120X(1) (caloric supply) + 3.737X(2) (protein supply) (P < 0.01). The caloric supply of the cases that achieved the nutritional goal was (468.19 +/- 67.11) kJ/(kg.d), [(111.90 +/- 16.04) kcal/(kg.d)], and that with enteral nutrition and partial parenteral nutrition was [(520.62 +/- 21.59) kJ/(kg.d)], [(124.43 +/- 5.16) kcal/(kg.d), (451.49 +/- 68.41) kJ/(kg.d)], [(107.98 +/- 16.35) kcal/(kg.d)] respectively. There was significant difference between the two groups (P < 0.05). The mean rank of time of birth weight regaining, the time in hospital stay and duration of parenteral nutrition providing at least 75% of the total daily fluid volume was 18.58, 20.24 and 20.11 in the group of early feeding, and it was 33.00, 32.48 and 31.83 in the group of late feeding, respectively. There were significant differences between the two groups (P < 0.05).</p><p><b>CONCLUSION</b>Sufficient supply of calorie and protein should be ensured in VLBW infants, especially in SGA and severely ill infants. It was very important to feed VLBW infants as early as possible, which could improve feeding tolerance and gastrointestinal maturation. VLBW infants should receive parenteral nutrition as supplements to enteral feeding.</p>

Comparison of the effect of ambroxol and dexamethasone on the expression of pulmonary surfactant proteins in the fetal rat lungs / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the effects of maternally administered dexamethasone and ambroxol on the mRNA levels of surfactant proteins (SP-A, SP-B and SP-C) expression in fetal rat lungs at gestational age day 19.</p><p><b>METHODS</b>A 19-day fetal rat lung model was employed. In situ hybridization was used to detect the expression of SP-B mRNA in alveolar type II cell, and the levels of SP-A, SP-B and SP-C mRNAs were detected by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>(1) SP-B mRNA was detected in situ in alveolar type II cells in fetal rat lung of day 19 gestational age; (2) In the late developmental period of fetal rat lungs, alveolar type II cells were also found around bronchus; (3) Comparing to beta-actin mRNA, the relative values of SP-A, SP-B and SP-C mRNAs were 0.81 +/- 0.26, 0.97 +/- 0.20 and 0.88 +/- 0.11 in fetal lung in the control group. The relative values of mRNAs of SP-A, SP-B and SP-C to beta-actin were 1.04 +/- 0.16, 1.28 +/- 0.29, 1.09 +/- 0.25 in fetal lungs of the ambroxol injected rats, and were 1.08 +/- 0.25, 1.23 +/- 0.35, 1.21 +/- 0.25 in fetal lungs of the dexamethasone injected rats, respectively. Both ambroxol and dexamethasone-treated rats had significantly higher mRNA expression of surfactant proteins compared to the control saline injected animals (P < 0.05). (4) There were no significant differences between ambroxol and dexamethasone in the effects of increasing expressions of surfactant protein mRNAs (P > 0.05).</p><p><b>CONCLUSION</b>Antepartum administration of both ambroxol and dexamethasone can significantly increase fetal lung SP-A, SP-B and SP-C mRNAs expression.</p>

Study on mesenchymal stem cells entering the brain through the blood-brain barrier / 中华儿科杂志

<p><b>OBJECTIVE</b>Neonatal hypoxic-ischemic encephalopathy (HIE) harms the lives and health of newborn infants and children severely. The prognosis is not satisfied, especially of the severe HIE. Mesenchymal stem cells (MSCs) can secrete a series of growth factors and neurotrophic factors. As well they have the potential ability to differentiate to the neural cells in vitro and in vivo. Therefore MSCs transplantation has been employed as a source of progenitor cells for cell therapy in patients with HIE in order to promote recovery of brain function and reduce the sequelae. Studies have shown that MSCs could enter the cerebral parenchyma and differentiate to neural cells through systemic infusion, but most of the researches applied adult stroke animal models. This study used neonatal HIE models to test the hypothesis that MSCs could enter the brain of newborn Wistar rats through the blood-brain barrier (BBB) by intraperitoneal infusion followed by observing the characteristics of the distribution and differentiation of MSCs in brain tissues, and exploring the effects of hypoxic-ischemic brain damage to the penetration and differentiation of MSCs.</p><p><b>METHODS</b>Isolation and purification of MSCs were established from the whole bone marrow of juvenile Wistar rats by removing the nonadherent cells in primary and passage cultures. For cellular identification, MSCs of three to five passages were continuously pre-labeled with 5-bromo-2-deoxyuridine (BrdU) for 72 hours before transplantation. Animal models of HIE were built in 7-day-postnatal Wistar rats according to the method described by Rice. Two hours after hypoxia-ischemia, rats in HIE group (n = 8) were intraperitoneally infused with MSCs (4 x 10(6), 0.5 ml). In control group (n = 8), 7-day-postnatal normal Wistar rats were intraperitoneally infused with the same amount of MSCs. All rats were sacrificed and their cerebra were sectioned by cryomicrotome 14 days after transplantation. Immunohistochemical staining with chromogen diaminobenzidine (DAB) was used to detect and measure the cells derived from MSCs, and study the characteristics of distribution. To determine the differentiation of the BrdU positive cells entering the brains, immunofluorescence double labeling for BrdU and neural cells specific antigens was performed.</p><p><b>RESULTS</b>MSCs were distributed throughout the cerebra in both groups at the 14th day after transplantation. The number of MSCs detected was 2415 +/- 226 in the control group, and 3626 +/- 461 in HIE group, respectively (t = 6.68, P < 0.05). More BrdU reactive cells were observed in the right ischemic hemisphere (1904 +/- 267) than in the contralateral hemisphere (1723 +/- 204), (t = 4.47, P < 0.05). No significant difference was found while comparing both cerebral hemispheres of the control group (t = 0.31, P > 0.05). In the HIE group, MSCs distributed more extensively, and some focal aggregations of MSCs were noticed. A few MSCs expressed Nestin-protein marker of neural progenitor cells, and almost none of the MSCs which expressed proteins characteristic of neuron (e.g. NSE) and astrocyte (e.g. GFAP) was detected at the 14th day after transplantation.</p><p><b>CONCLUSION</b>1. MSCs could enter the cerebral parenchyma through BBB and migrate throughout the brain by intraperitoneal infusion. 2. More MSCs injected intraperitoneally were localized and directed to the sites of hypoxic-ischemic brain damage. 3. Transplanted MSCs could not differentiate to neuron and astrocyte without other interventions during 14 days after transplantation.</p>