Recent research on machine learning in the diagnosis and treatment of necrotizing enterocolitis in neonates / 中国当代儿科杂志

Necrotizing enterocolitis (NEC), with the main manifestations of bloody stool, abdominal distension, and vomiting, is one of the leading causes of death in neonates, and early identification and diagnosis are crucial for the prognosis of NEC. The emergence and development of machine learning has provided the potential for early, rapid, and accurate identification of this disease. This article summarizes the algorithms of machine learning recently used in NEC, analyzes the high-risk predictive factors revealed by these algorithms, evaluates the ability and characteristics of machine learning in the etiology, definition, and diagnosis of NEC, and discusses the challenges and prospects for the future application of machine learning in NEC.

Influence of enteral feeding initiation time on intestinal flora and metabolites in very low birth weight infants: a prospective study / 中国当代儿科杂志

OBJECTIVES@#To study the influence of enteral feeding initiation time on intestinal flora and metabolites in very low birth weight (VLBW) infants.@*METHODS@#A total of 29 VLBW infants who were admitted to the Department of Neonatology, Children's Hospital of Chongqing Medical University, from June to December, 2020, were enrolled as subjects. According to the enteral feeding initiation time after birth, the infants were divided into two groups: <24 hours (n=15) and 24-72 hours (n=14). Fecal samples were collected at weeks 2 and 4 of hospitalization, and 16S rDNA high-throughput sequencing and gas chromatography-mass spectrometry were used to analyze the microflora and short-chain fatty acids (SCFAs) respectively in fecal samples.@*RESULTS@#The analysis of microflora showed that there was no significant difference between the two groups in Chao index (reflecting the abundance of microflora) and Shannon index (reflecting the diversity of microflora) at weeks 2 and 4 after birth (P>0.05). The analysis of flora composition showed that there was no significant difference in the main microflora at the phylum and genus levels between the two groups at weeks 2 and 4 after birth (P>0.05). The comparison of SCFAs between the two groups showed that the <24 hours group had a significantly higher level of propionic acid than the 24-72 hours group at week 4 (P<0.05), while there was no significant difference in the total amount of SCFAs and the content of the other SCFAs between the two groups (P>0.05).@*CONCLUSIONS@#Early enteral feeding has no influence on the diversity and abundance of intestinal flora in VLBW infants, but enteral feeding within 24 hours can increase the level of propionic acid, a metabolite of intestinal flora.

Long-term effect of active parenteral nutrition support regimen in preterm infants with a gestational age of <34 weeks / 中国当代儿科杂志

OBJECTIVES@#To study the long-term effect of active parenteral nutrition support regimen in preterm infants with a gestational age of <34 weeks.@*METHODS@#According to the different doses of fat emulsion and amino acids used in the early stage, the preterm infants with a gestational age of <34 weeks, who were admitted to the hospital within 24 hours after birth from May to December 2019, were divided into an active parenteral nutrition group and a conventional parenteral nutrition group (@*RESULTS@#At the age of 6 months, the active parenteral nutrition group (@*CONCLUSIONS@#For preterm infants with a gestational age of <34 weeks, an active parenteral nutrition support strategy with high doses of fat emulsion and amino acids within 24 hours after birth can improve their long-term neurodevelopment.

Effect of the course of treatment with broad-spectrum antibiotics on intestinal flora and short-chain fatty acids in feces of very low birth weight infants: a prospective study / 中国当代儿科杂志

OBJECTIVES@#To study the effect of the course of treatment with broad-spectrum antibiotics on intestinal flora and short-chain fatty acids (SCFAs) in feces of very low birth weight (VLBW) infants.@*METHODS@#A total of 29 VLBW infants who were admitted to the Neonatal Diagnosis and Treatment Center of Children's Hospital Affiliated to Chongqing Medical University from June to December 2020 were enrolled as subjects for this prospective study. According to the course of treatment with broad-spectrum antibiotics, they were divided into two groups: ≤7 days (@*RESULTS@#There was a significant reduction in Chao index of the intestinal flora in the ≤7 days group and the >7 days group from week 2 to week 4 (@*CONCLUSIONS@#The course of treatment with broad-spectrum antibiotics can affect the abundance, colonization, and evolution of intestinal flora and the content of their metabolites SCFAs in VLBW infants. The indication and treatment course for broad-spectrum antibiotics should be strictly controlled in clinical practice.

Risk factors for concurrent sepsis in neonates with necrotizing enterocolitis / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the risk factors for concurrent sepsis in neonates with necrotizing enterocolitis (NEC).</p><p><b>METHODS</b>A retrospective analysis was performed for the clinical data of 273 neonates with NEC. The risk factors for concurrent sepsis were analyzed from the aspects of perinatal factors and treatment regimen before the diagnosis of NEC.</p><p><b>RESULTS</b>The incidence rate of concurrent sepsis in NEC was 32.2% (88/273). The neonates with stage III NEC had a significantly higher incidence rate of concurrent sepsis than those with stage II NEC (69.0% vs 15.9%; P<0.05). Of all neonates with sepsis, 62.5% experienced sepsis within 3 days after the diagnosis of NEC, and 37.5% experienced sepsis more than 3 days after the diagnosis. Compared with those without concurrent sepsis, the neonates with concurrent sepsis had significantly lower gestational age and birth weight (P<0.05). The neonates who had scleredema, had stage III NEC, needed gastrointestinal decompression after the diagnosis of NEC, and experienced a long time of gastrointestinal decompression tended to develop sepsis more easily (P<0.05). Scleredema (OR=9.75, 95%CI: 2.84-33.52, P<0.001), stage III NEC (OR=12.94, 95%CI : 6.82-24.55, P<0.001), and gastrointestinal decompression (OR=2.27, 95%CI: 1.14-4.5, P=0.02) were independent risk factors for concurrent sepsis in NEC.</p><p><b>CONCLUSIONS</b>Scleredema, stage III NEC, and gastrointestinal decompression are independent risk factors for concurrent sepsis in neonates with NEC.</p>

Relationship between viral burden in urine and hearing loss in neonates with cytomegalovirus infection / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To determine the relationship between viral burden in urine and hearing loss in neonates with cytomegalovirus (CMV) infection.</p><p><b>METHODS</b>Twenty-two neonates with CMV infection between April 2006 and January 2010 were enrolled. Their viral burden in urine and hearing loss information were studied. The receiver operating characteristic curve (ROC) was constructed and the cutoff was determined based on their medical information. The hearing levels were evaluated by brain stem auditory evoked potential (BAEP) during the age of 3 to 6 months in 20 patients.</p><p><b>RESULTS</b>The viral burden in urine in neonates with abnormal BAEP was higher than that in neonates with normal BAEP (5.06 ± 1.50 vs 3.73 ± 0.86, P<0.05). Hearing loss was predicted with a sensitivity of 0.545 and a specificity of 1.0 by using ROC at the cutoff point of 5.1 which were defined after logarithmic conversion at 1.27×10(5) copies/mL of CMV burden in urine. The incidence of hearing loss during the age of 3 to 6 months was strikingly higher in high viral burden group than that in low viral load group (P<0.05).</p><p><b>CONCLUSIONS</b>The viral burden in urine can predict the possibility of hearing loss in neonates with CMV infection. Hearing loss is likely to be developed when viral burden in urine ≥1.27×10(5) copies/mL in neonates with CMV infection.</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>

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>

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>