Molecular mechanism for the activation of the potent hepatotoxin acetylhydrazine: Identification of the initial N-centered radical and the secondary C-centered radical intermediates.

Acetylhydrazine (AcHZ), a major human metabolite of the widely-used anti-tuberculosis drug isoniazid (INH), was considered to be responsible for its serious hepatotoxicity and potentially fatal liver injury. It has been proposed that reactive radical species produced from further metabolic activation of AcHZ might be responsible for its hepatotoxicity. However, the exact nature of such radical species remains not clear. Through complementary applications of ESR spin-trapping and HPLC/MS methods, here we show that the initial N-centered radical intermediate can be detected and identified from AcHZ activated by transition metal ions (Mn(III)Acetate and Mn(III) pyrophosphate) and myeloperoxidase. The exact location of the radical was found to be at the distal-nitrogen of the hydrazine group by 15N-isotope-labeling techniques via using 15N-labeled AcHZ we synthesized. Additionally, the secondary C-centered radical was identified unequivocally as the reactive acetyl radical by complementary applications of ESR spin-trapping and persistent radical TEMPO trapping coupled with HPLC/MS analysis. This study represents the first detection and unequivocal identification of the initial N-centered radical and its exact location, as well as the reactive secondary acetyl radical. These findings should provide new perspectives on the molecular mechanism of AcHZ activation, which may have potential biomedical and toxicological significance for future research on the mechanism of INH-induced hepatotoxicity.

Identification of thrombotic biomarkers in orthopedic surgery patients by plasma proteomics.

BACKGROUND: Due to the poor specificity of D-dimer, more accurate thrombus biomarkers are clinically needed to improve the diagnostic power of VTE. METHODS: The plasma samples were classified into low-risk group (n = 6) and high-risk group (n = 6) according to the Caprini Thrombosis Risk Assessment Scale score. Data-independent acquisition mass spectrometry (DIA-MS) was performed to identify the proteins in the 12 plasma samples. Bioinformatics analysis including volcano plot, heatmap, KEGG pathways and chord diagram analysis were drawn to analyze the significantly differentially expressed proteins (DEPs) between the two groups. Then, another 26 plasma samples were collected to verify the key proteins as potential biomarkers of VTE in orthopedic surgery patients. RESULTS: A total of 371 proteins were identified by DIA-MS in 12 plasma samples. Volcano plotting showed that there were 30 DEPs. KEGG pathway enrichment analysis revealed that the DEPs were majorly involved in the blood coagulation pathway. The chord diagram analysis demonstrated that proteins SAA1, VWF, FLNA, ACTB, VINC, F13B, F13A and IPSP in the DEPs were significantly related to blood coagulation. VWF and F13B were selected for validation experiments. ELISA test showed that, as compared with those in the low-risk group, the level of VWF in the high-risk sera was significantly increased. CONCLUSIONS: The level of VWF in the high-risk group of thrombosis after orthopedic surgery was significantly higher than that in the low-risk group of preoperative thrombosis, suggesting that VWF may be used as a potential thrombus biomarker in orthopedic surgery patients.

[Risk factors for metabolic bone disease of prematurity in very/extremely low birth weight infants: a multicenter investigation in China].

OBJECTIVE: To investigate the incidence rate and risk factors for metabolic bone disease of prematurity (MBDP) in very low birth weight/extremely low birth weight (VLBW/ELBW) infants. METHODS: The medical data of 61 786 neonates from multiple centers of China between September 1, 2013 and August 31, 2016 were retrospectively investigated, including 504 VLBW/ELBW preterm infants who met the inclusion criteria. Among the 504 infants, 108 infants diagnosed with MBDP were enrolled as the MBDP group and the remaining 396 infants were enrolled as the non-MBDP group. The two groups were compared in terms of general information of mothers and preterm infants, major diseases during hospitalization, nutritional support strategies, and other treatment conditions. The multivariate logistic regression analysis was used to investigate the risk factors for MBDP. RESULTS: The incidence rate of MBDP was 19.4% (88/452) in VLBW preterm infants and 38.5% (20/52) in ELBW preterm infants. The incidence rate of MBDP was 21.7% in preterm infants with a gestational age of < 32 weeks and 45.5% in those with a gestational age of < 28 weeks. The univariate analysis showed that compared with the non-MBDP group, the MBDP group had significantly lower gestational age and birth weight, a significantly longer length of hospital stay, and a significantly higher incidence rate of extrauterine growth retardation (P < 0.05). Compared with the non-MBDP group, the MBDP group had significantly higher incidence rates of neonatal sepsis, anemia, hypocalcemia, and retinopathy of prematurity (P < 0.05). The MBDP group had a significantly lower mean feeding speed, a significantly higher age when reaching total enteral feeding, and a significantly longer duration of parenteral nutrition (P < 0.05). The use rate of caffeine citrate in the MBDP group was significantly higher, but the use rate of erythropoietin was significantly lower than that in the non-MBDP group (P < 0.05). The multivariate logistic regression analysis showed that gestational age < 32 weeks, hypocalcemia, extrauterine growth retardation at discharge, and neonatal sepsis were risk factors for MBDP (P < 0.05). CONCLUSIONS: A lower gestational age, hypocalcemia, extrauterine growth retardation at discharge, and neonatal sepsis may be associated an increased risk of MBDP in VLBW/ELBW preterm infants. It is necessary to strengthen perinatal healthcare, avoid premature delivery, improve the awareness of the prevention and treatment of MBDP among neonatal pediatricians, and adopt positive and reasonable nutrition strategies and comprehensive management measures for preterm infants.

Endothelium-derived Cdk5 deficit aggravates air pollution-induced peripheral vasoconstriction through AT1R upregulation.

PM2.5 infiltrates into circulation and increases the risk of systemic vascular dysfunction. As the first-line barrier against external stimuli, the molecular mechanism of the biological response of vascular endothelial cells to PM2.5 exposure remains unclear. In this study, 4-week-old mice were exposed to Hangzhou 'real' airborne PM2.5 for 2 months and were found to display bronchial and alveolar damage. Importantly, in the present study, we have demonstrated that Cdk5 deficit induced peripheral vasoconstriction through angiotensin II type 1 receptor under angiotensin II stimulation in Cdh5-cre;Cdk5f/n mice. In the brain, Cdk5 deficit increased the myogenic activity in the medullary arterioles under external pressure. On the other hand, no changes in cerebral blood flow and behavior patterns were observed in the Cdh5-cre;Cdk5f/n mice exposed to PM2.5. Therefore, our current findings indicate that CDK5 plays an important role in endothelium cell growth, migration, and molecular transduction, which is also a sensor for the response of vascular endothelial cells to PM2.5.

Analysis of In-hospital Neonatal Death in the Tertiary Neonatal Intensive Care Unit in China: A Multicenter Retrospective Study.

BACKGROUND: Globally, the proportion of child deaths that occur in the neonatal period remains a high level of 37-41%. Differences of cause in neonate death exist in different regions as well as in different economic development countries. The specific aim of this study was to investigate the causes, characteristics, and differences of death in neonates during hospitalization in the tertiary Neonatal Intensive Care Unit (NICU) of China. METHODS: All the dead neonates admitted to 26 NICUs were included between January l, 2011, and December 31, 2011. All the data were collected retrospectively from clinical records by a designed questionnaire. Data collected from each NICU were delivered to the leading institution where the results were analyzed. RESULTS: A total of 744 newborns died during the 1-year survey, accounting for 1.2% of all the neonates admitted to 26 NICUs and 37.6% of all the deaths in children under 5 years of age in these hospitals. Preterm neonate death accounted for 59.3% of all the death. The leading causes of death in preterm and term infants were pulmonary disease and infection, respectively. In early neonate period, pulmonary diseases (56.5%) occupied the largest proportion of preterm deaths while infection (27%) and neurologic diseases (22%) were the two main causes of term deaths. In late neonate period, infection was the leading cause of both preterm and term neonate deaths. About two-thirds of neonate death occurred after medical care withdrawal. Of the cases who might survive if receiving continuing treatment, parents' concern about the long-term outcomes was the main reason of medical care withdrawal. CONCLUSIONS: Neonate death still accounts for a high proportion of all the deaths in children under 5 years of age. Our study showed the majority of neonate death occurred in preterm infants. Cause of death varied with the age of death and gestational age. Accurate and prompt evaluation of the long-term outcomes should be carried out to guide the critical decision.

Mortality and Morbidity of Extremely Low Birth Weight Infants in the Mainland of China: A Multi-center Study.

BACKGROUND: With the progress of perinatal medicine and neonatal technology, more and more extremely low birth weight (ELBW) survived all over the world. This study was designed to investigate the short-term outcomes of ELBW infants during their Neonatal Intensive Care Unit (NICU) stay in the mainland of China. METHODS: All infants admitted to 26 NICUs with a birth weight (BW) < l000 g were included between January l, 2011 and December 31, 2011. All the data were collected retrospectively from clinical records by a prospectively designed questionnaire. The data collected from each NICU transmitted to the main institution where the results were aggregated and analyzed. Categorical variables were performed with Pearson Chi-square test. Binary Logistic regression analysis was used to detect risk factors. RESULTS: A total of 258 ELBW infants were admitted to 26 NICUs, of whom the mean gestational age (GA) was 28.1 ± 2.2 weeks, and the mean BW was 868 ± 97 g. The overall survival rate at discharge was 50.0%. Despite aggressive treatment 60 infants (23.3%) died and another 69 infants (26.7%) died after medical care withdrawal. Furthermore, the survival rate was significantly higher in coastal areas than inland areas (53.6% vs. 35.3%, P = 0.019). BW < 750 g and GA < 28 weeks were the largest risk factors, and being small for gestational age was a protective factor related to mortality. Respiratory distress syndrome was the most common complication. The incidence of patent ductus arteriosus, intraventricular hemorrhage, periventricular leukomalacia, bronchopulmonary dysplasia, retinopathy of prematurity was 26.2%, 33.7%, 6.7%, 48.1%, and 41.4%, respectively. Ventilator associated pneumonia was the most common hospital acquired infection during hospitalization. CONCLUSIONS: Our study was the first survey that revealed the present status of ELBW infants in the mainland of China. The mortality and morbidity of ELBW infants remained high as compared to other developed countries.

[Epidemiology of neonatal purulent meningitis in Hebei Province, China: a multicenter study].

OBJECTIVE: To investigate the clinical characteristics, diagnosis and main pathogenic bacteria, and outcomes of neonatal purulent meningitis. METHODS: A prospective epidemiological study was conducted in neonates with purulent meningitis admitted to 23 cooperating hospitals between 2013 and 2014. Clinical data were collected and clinical characteristics and outcomes were analyzed. RESULTS: A total of 301 neonates with purulent meningitis from the 23 cooperating hospitals were included. Neonatal pneumonia was the most common primary disease (167 cases, 55.5%). Fever was the most common manifestation (214 cases, 71.1%). Blood culture findings were positive in 72 patients (23.9%), with Escherichia coli, Klebsiella pneumoniae and Staphylococcus epidermidis as the most common bacteria. Positive cerebrospinal fluid (CSF) culture was found in 36 patients (36/264, 13.6%) , with Escherichia coli and Staphylococcus epidermidis as the most common bacteria. The median of CSF WBC counts was 80/mm(3) (range: 0-9 2500/mm(3)), and 11 cases (3.7%) had CSF WBC counts of <20/mm(3) and 154 cases (51.2%) had CSF WBC counts of >100/mm(3). There were 258 patients (85.7%) who were cured or improved at discharge and 15 deaths (15/298, 5.0%). CONCLUSIONS: The most common primary disease of neonatal purulent meningitis is neonatal pneumonia in this area. The patients with neonatal purulent meningitis most often present with fever. Escherichia coli is the leading pathogenic bacteria causing neonatal purulent meningitis. A normal CSF WBC count can barely be used to exclude the possibility of this diosorder.

[Investigation of risk factors for hearing impairment in premature infants].

OBJECTIVE: To investigate the risk factors for hearing impairment in premature infants. METHODS: A total of 895 premature infants who were admitted to the neonatal intensive care unit from January to December 2010 were evaluated using distortion product otoacoustic emission to detect hearing impairment. The failure rates in initial screening and secondary screening were recorded. The risk factors for failure to pass hearing screenings were elucidate using multivariate logistic regression analysis. RESULTS: The failure rate in initial screening was 38.4%, and the failure rate in secondary screening was 18.3%. In the auditory brainstem response test conducted at three months after birth, the failure rate was 22.2%. In premature infants with a gestational age of 28-29(+6) weeks, 60.5% did not pass the initial screening; 48.1% of the premature infants with a birth weight of 1 001-1 499 g failed the initial screening; 70.0% of the premature infants with a birth weight of ≤1 000 g failed the initial screening; 53.8% of the premature infants who had severe asphyxia failed the initial screening; 45.0% of the premature infants who used invasive ventilation failed the initial screening; 47.9% of the premature infants with a total bilirubin of ≥340 µmol/L failed the initial screening; 54.6% of the premature infants with septicemia failed the initial screenings. The multivariate logistic regression analysis revealed the following independent risk factors for failing the initial and secondary hearing screenings: gestational age, birth weight, hyperbilirubinemia and septicemia. CONCLUSIONS: Premature infants are susceptible to hearing impairment because they have immature organs and tissues and incomplete blood-brain barrier function and are sensitive to such factors as hyperbilirubinemia and infection. Early hearing screening and follow-up are necessary for premature infants to ensure timely interventions.

[Effect of pulmonary surfactant on Th1/Th2 balance in neonates with respiratory distress syndrome].

OBJECTIVE: To investigate the effect of pulmonary surfactant (PS) on the Th1/Th2 balance and serum levels of interleukin-4 (IL-4), interferon-γ (IFN-γ) and IgE in neonates with respiratory distress syndrome (RDS). METHODS: A total of 58 neonates with RDS were divided into control (n=20) and PS treatment groups (n=38). The control group underwent mechanical ventilation and other conventional treatment, while the PS treatment group received with bovine PS treatment within 1 hour of being admitted to the hospital together with mechanical ventilation and other conventional treatment. Enzyme-linked immunosorbent assay was used to measure serum levels of IL-4, IFN-γ and IgE before treatment and 24, 48 and 72 hours after treatment. Simultaneously, arterial blood gas, respiratory system compliance, and other ventilator parameters were recorded. RESULTS: Compared with the control group, the PS treatment group showed significantly shorter duration of mechanical ventilation and oxygen exposure time (P<0.05), significantly better respiratory system compliance and significantly lower oxygenation index 24, 48 and 72 hours after treatment (P<0.05). At 48 and 72 hours after treatment, serum levels of IFN-γ were significantly lower in the PS treatment group than in the control group (120±46 ng/L vs 229±59 ng/L, P<0.05; 141±40 ng/L vs 282±44 ng/L, P<0.05), and serum levels of IL-4 were significantly higher in the PS treatment group than in the control group (263±48 pg/mL vs 152±45 pg/mL, P<0.05; 417±49 pg/mL vs 201±46 pg/mL, P<0.05). At 72 hours after treatment, serum level of IgE was significantly lower in the PS treatment group than in the control group (115±44 pg/mL vs 199±43 ng/mL; P<0.05). CONCLUSIONS: PS treatment can shorten the duration of mechanical ventilation and oxygen exposure time, regulate serum levels of IFN-γ, IL-4 and IgE, and influence Th1/Th2 balance in neonates with RDS, thus inhibiting lung inflammatory response and reducing lung injury.

[Prospective study on in-hospital mortality and its risk factors in very low birth weight infants requring mechanical ventilation].

OBJECTIVE: To describe the clinical features, treatments and prognosis of very low birth weight infants (VLBWIs) requring mechanical ventilation, to assess the risk factors associated with the mortality of VLBWIs, and to evaluate the significance of the scoring system based on clinical risk index for babies (CRIB) and the score for neonatal acute physiology-perinatal extension II (SNAPPE-II) for predicting mortality risk for premature infants in China. METHODS: Perinatal data were collected from 127 VLBWIs requring mechanical ventilation who were admitted to the neonatal intensive care unit (NICU) from January 2010 to October 2011. RESULTS: The enrolled infants had a mean gestational age of 31±2 weeks, a mean birth weight of 1290±170 g, a male/female ratio of 1.23∶1, and extremely low birth weight infant accounting for 6.3%. Of the 127 cases, 48.0% were administered with pulmonary surfactant (PS), and 49.6% received endotracheal intubation ventilation. The overall in-hospital mortality was 41.7%. Multivariate logistic regression revealed the following independent risk factors for mortality: low birth weight, multiple birth, cesarean section, and low PaO2/FiO2 ratio (OR = 1.611, 7.572, 4.062, and 0.133 respectively; P<0.05). SNAPPE-II and CRIB showed good performance in predicting prognosis, with areas under the ROC curve of 0.806 and 0.777 respectively. CONCLUSIONS: The overall mortality rate of VLBWIs is still relatively high. The high-risk factors for VLBWI mortality include low birth weight, multiple birth, cesarean section, and low PaO2/FiO2 ratio. The neonatal illness severity scoring system (using SNAPPE-II and CRIB) can be used to quantify illness severity in premature infants.

[Randomized controlled study of targeted tidal volume ventilation for treatment of severe neonatal respiratory distress syndrome].

OBJECTIVE: To evaluate the efficacy of targeted tidal volume ventilation in the treatment of severe neonatal respiratory distress syndrome (RDS). METHODS: Eighty-four neonates with severe RDS between June 2008 and January 2010 were randomly assigned to 3 groups according to the ventilation mode: synchronized intermittent positive pressure ventilation plus volume guarantee (SIPPV+VG; n=31), high frequency oscillation ventilation (HFOV; n=23) and intermittent mandatory ventilation (IMV; n=30). The oxygenation status, the durations of oxygen exposure and ventilation and the incidence of complications were observed. RESULTS: The oxygenation status (P/F and a/APO2) in the SIPPV+VG and the HFOV groups was improved significantly 12 hrs after ventilation (P<0.05). While in the IMV group, the oxygenation status was not improved until 24 hrs after ventilation. The durations of oxygen exposure and ventilation in the SIPPV+VG and the HFOV groups were shorter than in the IMV group (P<0.05). The incidences of air leak syndrome and ventilation-associated pneumonia (VAP) were lower in the SIPPV+VG and the HFOV groups than in the IMV group (P<0.05). The incidence of severe intracranial hemorrhage in the HFOV group was higher than in the other two groups (P<0.05). CONCLUSIONS: Compared with IMV, SIPPV+VG and HFOV can improve the oxygenation status more quickly, shorten the ventilation duration and decrease the incidences of air leak syndrome and VAP in neonates with severe RDS.

[Treatment of newborns with severe injured brain with transplantation of human neural precursor cells].

OBJECTIVE: To analyze the therapeutic effect of human neural precursor cells transplantation in treatment of neonates with severe brain injury. METHOD: The transplantation was performed on 6 newborns, one of them was diagnosed as extremely severe carbon monoxide poisoning at 5(th) day after birth; one of them was diagnosed as severe hypoglycemia; the others had asphyxia at birth with Apgar scores from 1 to 3 and were diagnosed as severe neonatal asphyxia, severe hypoxic ischemic encephalopathy according to images, electroencephalogram, biochemical examination and clinical manifestation. With the approval of hospital ethics committee and informed consent of the family members, the newborns received human neural precursor cells transplantation at the 4(th) to 20(th) day after birth. With the agreement of a pregnant woman, forebrain cells were obtained from the forebrain of her 12-week old fetus after spontaneous abortion. The cells from the fetal brain were amplified into human neural precursor cells in vitro and were injected into the cerebral ventricle of the patients. RESULT: On the 2(nd) day after transplantation, sucking and swallowing reflexes gradually appeared in all the patients, muscular tension was also improved, and convulsion stopped. NBNA scoring in 3 of the patients reached normal level on the 28(th) day after birth. The 6 patients were followed up for 12 months. Four patients were normal in psychomotor development and scores of each scale reached normal level. Two patients have cerebral palsy. CONCLUSION: hNPCs transplantation is safe and effective in treatment of severe neonatal brain injury. More clinical trials and further observation are needed.

Effects of inhaled nitric oxide in neonatal hypoxemic respiratory failure from a multicenter controlled trial.

BACKGROUND: Hypoxemic respiratory failure (HRF) is one of the most common causes for neonatal infants requiring aggressive respiratory support. Inhaled nitric oxide (iNO) has been established routinely as an adjunct to conventional respiratory support in developed countries. The aim of this study was to investigate effects of iNO in neonates with HRF in resource limited condition with no or limited use of surfactant, high frequency oscillatory ventilation (HFOV) and extracorporeal membrane oxygenation. METHODS: A non-randomized, open, controlled study of efficacy of iNO was conducted over 18 months. Eligible term and near-term neonates from 28 hospitals with HRF (oxygenation index > 15) were enrolled prospectively into two groups as either iNO or control. Oxygenation improvement and mortality as primary endpoint were determined in relation with dosing and timing of iNO, severity of underlying diseases, complications and burden. Intention-to-treat principle was adopted for outcome assessment. Response to iNO at 10 or 20 parts per million (ppm) was determined by oxygenation in reference to the control (between-group) and the baseline (within-group). RESULTS: Compared to 93 controls, initial dose of iNO at 10 ppm in 107 treated infants significantly improved oxygenation from first hour (P = 0.046), with more partial- and non-responders improved oxygenation with subsequent 20 ppm NO (P = 0.018). This effect persisted on days 1 and 3, and resulted in relatively lower mortalities (11.2% vs. 15%) whereas fewer were treated with surfactant (10% vs. 27%), HFOV (< 5%) or postnatal corticosteroids (< 10%) in both groups. The overall outcomes at 28 days of postnatal life in the iNO-treated was not related to perinatal asphyxia, underlying diseases, severity of hypoxemia, or complications, but to the early use of iNO. The cost of hospital stay was not significantly different in both groups. CONCLUSIONS: With relatively limited use of surfactant and/or HFOV in neonatal HRF, significantly more responders were found in the iNO-treated patients as reflected by improved oxygenation in the first three days over the baseline level. It warrants a randomized, controlled trial for assessment of appropriate timing and long-term outcome of iNO.

Current status of neonatal acute respiratory disorders: a one-year prospective survey from a Chinese neonatal network.

BACKGROUND: We conducted a prospective, multicenter investigation of incidence, management and outcome of neonatal acute respiratory disorders (NARD), and evaluated related perinatal risk factors and efficacy of respiratory therapies in neonatal intensive care units (NICUs) in a Chinese neonatal network. METHODS: Data were prospectively collected in 2004 - 2005 from infants with NARD defined as presence of respiratory distress and oxygen requirement during the first 3 days of life. RESULTS: A total of 2677 NARD was classified (20.5% of NICU admissions). There were 711 (5.44%) with respiratory distress syndrome (RDS), 589 (4.51%) pulmonary infection, 409 (3.13%) meconium aspiration syndrome, 658 (5.03%) aspiration of amniotic fluid and 239 (1.83%) transient tachypnoea. Meconium aspiration syndrome had the highest rate with fetal distress, transient tachypnoea from cesarean section, and RDS with maternal disorders. Assisted mechanical ventilation was applied in 53.4% of NARD, and in above five disorders with 84.7%, 52.3%, 39.8%, 24.5%, and 53.6%, respectively. Corresponding mortality in these disorders was 31.4%, 13.6%, 17.8%, 4.1% and 5.0%, respectively. Surfactant was provided to 33.9% of RDS. In all RDS infants, the survival rate was 78.8% if receiving surfactant, and 63.4% if not (P < 0.001). CONCLUSIONS: This study provided NICU admission-based incidence and mortality of NARD, reflecting efficiency of advanced respiratory therapies, which should be a reference for current development of respiratory support in NICU at provincial and sub-provincial levels, justifying efforts in upgrading standard of care in emerging regions through a collaborative manner.

A 12-month prospective survey of perinatal outcome of liveborn neonates in Julu County, China.

BACKGROUND: Population based epidemiologic study on the main diseases and birth status of liveborn neonates remains scarce in China, especially in rural areas where a large number of neonates are born. The aim of this study was to establish an epidemiological basis of live births in Julu County, a representative of the northern and mid-western parts of China in terms of demography, disease pattern and women and children's health care infrastructure. METHODS: The perinatal data of all live births were prospectively collected in three participating county-level hospitals from September 1, 2007 to August 30, 2008. RESULTS: There were 5822 live births in these hospitals. Among all live births, 53.7% were male and 4.5% were born prematurely. Mean (SD) birth weight (BW) was (3348 ± 503) g. The low (< 2500 g) and very low BW (< 1500 g) infants accounted for 3.8% and 0.5% of the total births, with 6.5% as small for gestational age and 2.8% as multi-births. Cesarean section rate was 30.2%, of which 68.6% were elective. There were 745 infants (12.8% of the live births) admitted to local neonatal wards within 7 days of postnatal life, in which 48.3% and 19.3% were due to perinatal asphyxia and prematurity, respectively. The incidences of perinatal aspiration syndrome, transient tachypnea and respiratory distress syndrome were 4.9%, 0.6% and 0.5%, respectively. Neonatal mortality was 7.6‰ (44/5822), with 16 in delivery room and 28 in neonatal ward before discharge. CONCLUSIONS: This study provided a population-based perinatal data of live births and neonatal mortality in a northern China county with limited resources. Neonatal disorders related to perinatal asphyxia remain a serious clinical problem, which calls for sustained education of advanced neonatal resuscitation and improvement in the quality of perinatal-neonatal care.

[Effects of selective head cooling with mild hypothermia on serum levels of caspase-3 and IL-18 in neonates with hypoxic-ischemic encephalopathy].

OBJECTIVE: The study examined the changes of serum caspase-3 and IL-8 levels following selective head cooling with mild hypothermia (SHC) treatment in neonates with hypoxic-ischemic encephalopathy (HIE) in order to explore the mechanism of neuroprotection of SHC against HIE. METHODS: Thirty-three neonates with moderate or severe HIE were randomly assigned to two groups: SHC treatment (n=16) and conventional treatment (n=17). Serum levels of caspase-3 and IL-18 were measured using ELISA before treatment and 24 hrs, 48 hrs, 72 hrs and 5 days after treatment. RESULTS: Serum caspase-3 levels in the SHC group decreased 24 and 48 hrs after treatment (3.8±1.9 and 2.6±1.2 ng/mL, respectively) compared with 6.1±2.3 ng/mL at 24 hrs and 7.2±3.1 ng/mL at 48 hrs in the conventional treatment group (P<0.05). Serum IL-18 levels in the SHC group decreased 24 hrs, 48 hrs and 72 hrs after treatment (119±30, 76±33 and 71±40 ng/mL, respectively) compared with those in the conventional treatment group (138±28 ng/mL at 24 hrs, 156±60 ng/mL at 48 hrs and 182±54 ng/mL at 72 hrs; P<0.01). CONCLUSIONS: SHC treatment can inhibit the release of caspase-3 and the expression of IL-18 in neonates with moderate or severe HIE. This may contribute to the neuroprotection of SHC against HIE.

Prostanoid TP receptor-mediated impairment of cyclic AMP-dependent vasorelaxation is reversed by phosphodiesterase inhibitors.

Activation of the thromboxane prostanoid (TP) receptor produces potent vasoconstriction, which contributes to the increased vascular tone and blood pressure. The present study was designed to examine the hypothesis that stimulation of prostanoid TP receptors impairs endothelium-independent relaxations to cyclic AMP-elevating agents via increasing the activity of phosphodiesterases (PDEs). Rat carotid arteries without endothelium were isolated and suspended in myograph for the measurement of changes in isometric tension; the tissue content of cyclic AMP was assayed by enzyme immunoassay kit; and prostanoid TP receptor was detected in vascular wall by immunohistochemistry and Western blot. In phenylephrine-contracted rings without endothelium, relaxations induced by isoprenaline (receptor-mediated) and forskolin (receptor-independent) were markedly reduced by the presence of a prostanoid TP receptor agonist, U46619; the attenuated relaxations were prevented by acute treatment with S18886, the selective prostanoid TP receptor antagonist, but not by protein kinase C inhibitors. The reduced relaxations were partially restored by IBMX (non-selective PDE inhibitor), cilostazol (PDE3 inhibitor), rolipram (PDE4 inhibitor) or by Y27632 (Rho kinase inhibitor), but not by T0156 (PDE5 inhibitor). U46619 diminished isoprenaline- or forskolin-stimulated rise in cyclic AMP and this effect was inhibited by cilostazol, rolipram or Y27632. The present results suggest that activation of prostanoid TP receptors impairs cyclic AMP-dependent vasorelaxations partly via PDE- and RhoA/Rho kinase-dependent mechanisms. Inhibitors of PDEs and Rho kinase may be useful in the treatment of cardiovascular complications.

[Interleukin-4 and interleukin-13 concentrations in bronchoalveolar lavage fluid in neonates with respiratory distress syndrome and concurrent ventilator-associated pneumonia].

OBJECTIVE: To study the concentrations of IL-4 and IL-13 in bronchoalveolar lavage fluid (BALF) in neonates with respiratory distress syndrome (RDS) and concurrent ventilator-associated pneumonia (VAP). METHODS: Sixty-eight neonates with RDS undergoing mechanical ventilation for over 48 hrs were enrolled. IL-4 and IL-13 levels in BALF were measured using ELISA 1, 72 and 96 hrs after mechanical ventilation. The results were compared between the neonates with concurrent VAP (n=37) and without (n=31). RESULTS: The levels of BALF IL-4 96 hrs after ventilation in the VAP group (35.34+/-1.78 ng/mL) were significantly higher than those in the non-VAP group (13.69+/-2.47 ng/mL, P<0.05). The levels of BALF IL-13 96 hrs after ventilation in the VAP group (33.74+/-2.74 ng/mL) also increased significantly compared with those in the non-VAP group (13.50+/-3.81 ng/mL) (P<0.05). There were significant differences in BALF IL-4 and IL-13 levels between 1 hr and 96 hrs in the VAP group (P<0.05). CONCLUSIONS: BALF IL-4 and IL-13 levels increase in neonates with RDS and concurrent VAP. IL-4 and IL-13 may involve in the regulation of the inflammatory immune response.

Thromboxane prostanoid receptor activation impairs endothelial nitric oxide-dependent vasorelaxations: the role of Rho kinase.

Activation of thromboxane prostanoid (TP) receptors causes potent vasoconstriction, which contributes to increased vascular tone and blood pressure. The present study examined the hypothesis that stimulation of TP receptor impaired endothelial nitric oxide-mediated vasorelaxation via a Rho kinase-dependent mechanism. The common carotid arteries of Sprague-Dawley rats were isolated and suspended in myograph for measurement of changes in isometric tension. The production of nitric oxide in primary cultured aortic endothelial cells was assayed with an imaging technique and phosphorylated levels of endothelial NOS were determined by Western blot analysis. 9,11-dideoxy-11alpha,9alpha-epoxy-methanoprostaglandin F(2alpha) (U46619) inhibited isoprenaline-induced relaxations in rings with or without endothelium. Treatment with Rho kinase inhibitors, Y27632 (2 microM) or HA 1077 (10 microM) prevented the effect of U46619 only in rings with endothelium while protein kinase C inhibitors were without effect. Rho kinase inhibitors did not affect isoprenaline-induced relaxations in endothelium-intact rings treated with L-NAME or 1H-[1,2,4]oxadizolo[4,3-a]quinoxalin-1-one (ODQ). Isoprenaline stimulated rises in nitric oxide (NO) production in cultured rat endothelial cells. The increased NO production was inhibited by U46619 (100 nM) and this effect was prevented by treatment with Y27632 but unaffected by the absence of extracellular calcium ions. U46619 attenuated isoprenaline-stimulated phosphorylation of eNOS, which was sensitive to inhibition by Y27632 and HA 1077. U46619-mediated effects were abolished by TP receptor antagonist, S18886 and the TP receptor was present in endothelial cells. The present results demonstrate that Rho kinase activation is likely to be the primary mechanism that underlies the U46619-stimulated TP-receptor-mediated inhibition of endothelial NO production and subsequent endothelium-dependent relaxations to isoprenaline.

[A randomized controlled study on the efficacy of inhaled nitric oxide in treatment of neonates with meconium aspiration syndrome].

OBJECTIVE: Meconium aspiration syndrome (MAS) is a disease of the term and near-term infant that is associated with considerable respiratory morbidity. The purpose of this study was to investigate effects of inhaled nitric oxide (iNO) in oxygenation and outcome of newborns with MAS. METHODS: Eligible patients diagnosed as severe MAS admitted consecutively to the neonatal intensive care unit (NICU) of Hebei Children's Hospital from January 2004 to June 2006 were included in the study. The patients with an oxygenation index (OI) > or = 15 were randomized in a nonblinded manner to receive either iNO (NO group, n = 21) or no NO (control group, n = 25). Patients with an OI > or = 15 after enrollment were treated with iNO at 15 ppm initially. The response to iNO was assessed according to the increase in arterial PaO(2) and oxygen saturation (SpO(2)) after exposure to the starting concentration for 60 minutes. A response of 10 mm Hg (1 mm Hg = 0.133 kPa) increase in PaO(2) and a 10% increase in SpO(2) was assessed responsive to iNO. All patients were treated in the same neonatal unit and received the same standard therapy throughout the study period. Arterial blood gas tensions, pulmonary arterial pressure and systemic arterial blood pressures were recorded at baseline, 1 hour, and 24 hours in all patients. Methemoglobin levels were obtained at 12 - 24 hours after inhaled NO treatment. Parameters of fraction of inspired oxygen (FiO(2)), OI, mortality, ventilation time, and incidence of intraventricular hemorrhage (IVH, grade III-IV) were recorded. Informed consent was obtained from parents before enrollment. The protocol and the informed consent forms were approved by the ethic committee of the hospital before patient enrollment. RESULTS: There was no significant difference in gestational age, birth weight, gender ratio, age at admission in hours, c-section delivery between the two groups, and no significant difference was found in respiratory mechanics parameters between the two groups at baseline. The duration of iNO was 34.90 +/- 16.41 hours. At the beginning of the treatment, no significant differences were detected in the OI and PAP between the two groups. One hour later, OI and PAP of NO group decreased significantly (OI, F = 35.27, P < 0.01, PAP, F = 24.30, P < 0.01), while in control group the difference was not found until 24 hours (OI, F = 20.16, P < 0.01, PAP, F = 101.22, P < 0.01). There were significant differences in PAP at 1, 24 hours between the two groups (1 h, t = 2.41, P < 0.05; 24 h, t = 3.11, P < 0.01). The methemoglobin levels were normal. Compared to the controls, hospital stay (t = 2.86, P < 0.05), duration of the need for oxygen supplement (t = 2.53, P < 0.05) and ventilation time were shorter (t = 2.41, P < 0.05), whereas mortality (chi(2) = 0.21, P > 0.05) and incidence of IVH (chi(2) = 0.00, P > 0.05) were not significantly different between the groups. CONCLUSIONS: iNO could effectively improve the oxygenation and shorten the ventilation time and hospital stay without augmentation of risk of IVH and pneumothorax in these neonatal patients.