[Study on the related factors of intestinal obstruction after cesarean section].

Objective: To analyze the related factors of intestinal obstruction after cesarean section. Methods: From April 2009 to April 2019, 500 patients with cesarean section and postoperative intestinal obstruction in Beijing Maternity Hospital Affiliated to Capital Medical University were taken as the case group, and 500 patients without postoperative intestinal obstruction who underwent cesarean section on the same day as the case group were taken as the control group. The data of patients' general characteristics, pregnancy complications, blood routine and biochemical indexes, and operation related factors were collected to compare the differences between patients with intestinal obstruction and patients without intestinal obstruction. Multivariate logistic regression model was used to analyze the related factors of intestinal obstruction after cesarean section. Results: The age of 500 patients with intestinal obstruction after cesarean section was (33.3±4.2) years, and the age of 500 patients without intestinal obstruction after cesarean section was (31.6±3.9) years. The incidence of pregnancy complications in patients with intestinal obstruction was higher than that in patients without intestinal obstruction (all P<0.05). Multivariate analysis showed that preoperative anemia [OR(95%CI) of 5.318(1.522-18.580), P=0.009], postoperative low protein [OR(95%CI) of 0.376(0.143-0.993), P=0.048], intraoperative bleeding ≥500 ml [OR(95%CI) of 3.085(1.551-6.136), P=0.001],intraoperative adhesion [OR(95%CI) of 2.856(1.285-6.347), P=0.010] were the risk factor of intestinal obstruction after cesarean section. The intraoperative application of antiadhesion drugs [OR(95%CI) of 0.322(0.158-0.654), P=0.002] was the protective factor of intestinal obstruction after cesarean section. Conclusions: Patients with anemia and low protein have an increased risk of intestinal obstruction after cesarean section.

[Effect of induction on maternal and neonatal outcomes of vaginal birth after cesarean].

Objective: To investigate the effect of induction on maternal and neonatal outcomes of vaginal birth after cesarean section (VBAC). Methods: Retrospective cohort study. A total of 452 pregnant women who underwent trail of labor after cesarean section (TOLAC) from January 2015 to March 2019 of Beijing Obstetrics and Gynecology Hospital, Capital Medical University were enrolled. According to the mode of the onset of labor, those 331 women who underwent VBAC were divided into spontaneous labor group (n=280) and induction group(n=51). According to induction methods, the pregnant women in the induction group was divided into the low-dose oxytocin subgroup (n=35) and other method subgroup (n=16, 9 cases with cervical ripening by balloon and 7 cases combined with oxytocin). The effect of induction on labor duration and maternal and neonatal outcome in VBAC were analyzed. Results: No maternal and neonatal death occurred. There were 23.0% (76/331) with forceps, 15.1% (50/331) of postpartum hemorrhage, and 24.5% (81/331) of fetal distress. The gravidity, birth weight and the gestational weeks of delivery in the induction group were significantly higher than those in the spontaneous onset group [2.0 (2.0-3.0) vs 2.0(1.0-2.0) times, 39.0(38.0-40.0) vs 38.0(37.0-39.0) weeks, (3 467±372) vs (3 168±538) g, Z=-3.548,-3.892,-3.813, all P<0.01]. The duration of the second stage of labor was significantly longer than that of the spontaneous onset group [43(26-60) vs 30(17-49) min, Z=-2.145,P<0.05], but the duration of the first stage, the total duration of labor, the rate of forceps, the incidence of postpartum hemorrhage, the rate of perineal incision and the incidence of fetal distress were not obvious different (all P>0.05). The duration of the first stage and total duration in oxytocin group were significantly shorter than those other method group [260(210-435) vs 325(250-490) min, 450(355-620) vs 523(370-668) min, Z=-2.001,-1.913, all P<0.05]. There were not significantly different in the duration of second stage, mode of delivery, perineal injury, the rate of postpartum hemorrhage, and fetal distress in the two groups (all P>0.05). Conclusion: Pregnant women who have undergone TOLAC after caesarean section can be induced after fully evaluation. Although induction prolongs the labor duration, it does not affect the maternal and neonatal complication rate.

[The influence of the intrapartum inventions on the maternal and neonatal outcomes of vaginal birth after cesarean].

Objective: To investigate the maternal and neonatal outcomes after different intrapartum interventions for vaginal birth after cesarean (Vaginal Birth After Cesarean-section, VBAC). Methods: One hundred and forty three cases in Beijing Obstetrics & Gynecology Hospital, Capital Medical University from January 2015 to November 2016 were selected retrospectively.The relationship between the intrapartum inventions such as induction style, oxytocin usage and spinal analgesia and the maternal and neonatal outcomes such as delivery way, labor time, postpartum hemorrhage and fetal distress were analyzed in pregnant women underwent VBAC. Results: (1) Maternal and neonatal outcomes: No maternal and newborn deaths occurred in the 143 cases of VBAC.One hundred and thirteen cases underwent vaginal delivery (79.0%) and 30 cases underwent operative vaginal delivery (21.0%). Twenty-four cases (16.8%) occurred postpartum hemorrhage, 32 cases (24.3%) fetal distress, and 2 (1.4%) asphyxia.(2) Intrapartum inventions: 123 cases (86.0%) were spontaneous onset of labor and 20 cases (14.0%) induction of labor.41 cases (30.6%) used oxytocin during labor to strengthen contractions, 37 cases (25.9%) underwent spinal analgesia.The operative vaginal delivery rate in the induction labor group was significantly higher than that in natural labor group (P<0.05). The duration of the first stage, second stage and total labor in the group using oxytocin were significantly longer than those in the group not using oxytocin (P<0.05). The rate of operative vaginal delivery in the group using oxytocin was significantly higher than that in the group not using oxytocin (P<0.05). The duration of the first stage, second stage and total labor in analgesia group were significantly longer than those in the group not using analgesia (P<0.05). The incidence of postpartum hemorrhage and operative vaginal delivery in analgesia group was significantly higher than those in the group not using analgesia (P<0.05). Conclusion: Oxytocin may increase the rate of vaginal delivery in VBAC.Spinal analgesia and oxytocin may prolong the labor time and increase the incidence of postpartum hemorrhage in VBAC.

[Clinic characteristics of women with advanced maternal age and perinatal outcomes].

Objective: To explore the association between maternal age and perinatal outcomes. Methods: Totally, 3 151 women with advanced maternal age and 6 098 women younger than 35 years old who delivered in Beijing Obstetrics and Gynecology Hospital in 2016 were recruited. Their clinic characteristics and perinatal outcomes were collected to divide into 3 groups based on delivery age, Group 1 (aged 35-39 years, 2 683 cases), Group 2 (aged ≥40 years, 366 cases) and the control group (aged<35 years, 6 098 cases). The association between maternal age and adverse perinatal outcomes were analyzed, including hypertensive disorder complicating pregnancy, gestational diabetes mellitus (GDM), preterm birth and postpartum hemorrhage. Results: The rate of cesarean section history (27.39%, 33.61%, 5.53%) or previous myomectomy history (2.80%, 5.46%, 0.72%) were compared between the advanced maternal age groups and the control group, and the differences were statistically significant (P<0.05). The percentage of prepregnancy overweight and obesity (29.67%, 27.05%, 18.47%), complicated with myoma (14.83%,19.95%, 5.64%) were compared among the three groups, and the differences were statistically significant (P<0.05). The percentage of pregnancy through assisted reproductive technology (9.84%, 15.03%, 3.12%) also had statistically significant differences (P<0.05). The incidence of fetal chromosomal abnormalities (1.23%, 3.01%, 0.36%) and fetal malformations (1.94%, 4.37%, 0.48%) increased with the maternal age, with statistically significant differences (P<0.01). The mobidity of hypertensive disorders (9.84%, 13.11%, 9.23%), pregestational diabetes mellitus (1.83%, 2.19%, 0.72%), gestational diabetes mellitus (22.70%, 28.42%, 14.87%), premature rupture of membranes (25.57%, 19.40%, 31.42%), placenta previa (2.05%, 2.46%, 0.92%), preterm birth(8.35%, 11.20%, 5.51%), postpartum hemorrhage (25.11%, 18.31%, 20.27%) and forceps delivery (5.42%, 2.33%, 5.71%) were compared, and the differences were statistically significant (P<0.05). The cesarean section rate in primipara (45.42%, 75.74%, 21.33%) and multipara (51.46%, 61.54%, 30.95%) had statistically significant difference (P<0.05). The proportion of macrosomia (10.80%, 8.85%, 7.96%) and neonates transferred into neonatal ICU (9.63%, 11.48%, 5.21%) in term neonates had statistically significant difference (P<0.05). Conclusions: Women with advanced maternal age increase after new family planning policy put into effect, so do the risk of adverse perinatal outcomes. Attention and interventions should be made to cope with the occurrence of adverse perinatal outcomes.

[The effect of short-term exposure to ambient NO(2) on lung function and fractional exhaled nitric oxide in 33 chronic obstructive pulmonary disease patients].

Objectives: To investigate the effect of short-term exposure to ambient NO(2) has influence on lung function and fractional exhaled nitric oxide (FeNO) in chronic obstructive pulmonary disease (COPD) patients. Methods: A panel of doctor-diagnosed stable COPD patients (n=33) were recruited and repeatedly measured for lung function and FeNO from December 2013 to October 2014. The patients who lived in Beijing for more than one year and aged between 60 and 85 years old were included in the study. We excluded patients with asthma, bronchial tensor, lung cancer and other respiratory disorders other than chronic obstructive pulmonary disease and occupational exposure and chest trauma surgery patients. Because the frequency of each subject visiting to the hospital was different, a total of 170 times of lung function measurements and 215 times of FeNO measurements were conducted. At the same time, the atmospheric NO(2) data of Beijing environmental monitoring station near the residence of each patient during the study period were collected from 1 day to 7 days lag before the measurement. Effects of short-term NO(2) exposure on lung function and FeNO in COPD patients were estimated by linear mixed-effects models. Results: The subjects' forced vital capacity (FVC), forced expiratory volume in one second (FEV(1)), peak expiratory flow (PEF), and exhaled NO of subjects were (3.26±0.83) L, (1.66±0.61) L, (4.13±1.77) L/s, and (48.99±14.30) µg/m(3), respectively. The concentration of NO(2) was (70.3±34.2) µg/m(3) and the interquartile range (IQR) was 39.0 µg/m(3). Short-term exposure to NO(2) resulted in a significant decrease in FVC among COPD patients' which was most obvious in 2 days lag. Every quartile range increased in NO(2) (39 µg/m(3), 2 day) would cause a 1.84% (95%CI: -3.20%- -0.48%) reduction in FVC. The effects of exposure to higher concentration of NO(2) (≥58.0 µg/m(3)) on FVC estimate was -2.32% (95%CI: -4.15%- -0.48%)(P=0.02). No significant relevance of FeNO and NO(2) was observed in this study. Conclusions: Short term exposure to ambient NO(2) may bring down pulmonary function in COPD patients.

[Analysis of factors affecting vaginal birth after cesarean].

OBJECTIVE: To investigate the factors affecting the vaginal birth after cesarean (VBAC). METHODS: Totaly 298 women who underwent trial of labor after cesarean section (TOLAC) from Jan 2015 to Dec 2015 were recruited from Beijing Obstetrics and Gynecology Hospital, FuXing Hospital, Tongzhou Maternal and Child Health Hospital of Beijing, the Second Affiliated Hospital of Chongqing Medical University and the People's Hospital of Chengyang District of Qingdao. The maternal age, the interval from the last cesarean section, the body mass index (BMI) before pregnancy, the weight gain during pregnancy, the way into labor, the Bishop score before labor, the gestational age and the birth weight of the neonate were recorded in a self-made form. The factors affecting VBAC were analyzed by univariate analysis and multivariable logistic regression. RESULTS: (1)The incidence of VBAC, uterine rupture, postpartum hemorrhage and neonatal asphyxia were 70.5% (210/298), 2.7% (8/298), 9.4% (28/298) and 1.3% (4/298), respectively. No maternal death and perinatal death occurred. (2)The univariate analysis suggested that the maternal age, the BMI before pregnancy, the Bishop score before labor, the labor induction, the gestational age at delivery and the neonatal weight were factors affecting VBAC. The maternal age and the Bishop score before labor were significantly higher in the VBAC group than in the unsuccessful TOLAC group(P<0.05). While the BMI before pregnancy, the induction rate, the gestational weeks at delivery and the birth weight of the neonate were significantly lower in the VBAC group than in the unsuccessful TOLAC group (P<0.05). Multivariable logistic regression analysis showed that successful VBAC was affected by the maternal age, the BMI before pregnancy, the Bishop score before labor and the birth weight of the neonates(P<0.05). CONCLUSION: The maternal age, the BMI before pregnancy, the Bishop score before labor and the birth weight of neonate are the main factors affecting VBAC.

Transnasal endoscopic resection of vidian nerve schwannoma accompanied by sphenoid mucopyocele and oculomotor palsy: a case report.

Schwannomas are rare tumours arising from the peripheral nerve sheath. Nearly half of all schwannomas occur in the head and neck region, but the sinonasal tract is rarely involved. We report on an extremely rare case of vidian nerve schwannoma accompanied by mucopyocele with symptoms of oculomotor palsy and CSF leakage. An exclusively endoscopic endonasal approach was performed to excise the tumour and the dural defect was repaired. To our knowledge, this is the first time a vidian nerve schwannoma has been excised in an exclusively endoscopic approach. We first review the literature and then discuss the benefits for patients undergoing this type of operation.

Manipulating nanoscale light fields with the asymmetric bowtie nano-colorsorter.

We present a class of devices called Asymmetric Bowtie nano-Colorsorters. These devices are specifically engineered to not only capture and confine optical fields, but also to spectrally filter and steer them while maintaining nanoscale field distributions. We show that spectral properties and localized spatial mode distributions can be readily tuned by controlled asymmetry. Nano-Colorsorters can control light's spatial and spectral distributions at the nanoscale and thus significantly impact applications ranging from broadband light harvesting to ultrafast wavelength-selective photodetection.

Non-life-threatening leukopenia in a renal transplant recipient with acute overdose of mycophenolate mofetil.

Mycophenolate mofetil (MMF) is increasingly used as an immunosuppressant for organ transplantation and for treatment of autoimmune diseases. As yet, the experience with acute overdose of MMF in humans is limited. Herein we have reported a 40-year-old female kidney recipient with moderate leukopenia and lack of gastrointestinal toxicity following ingestion of 25 g MMF, which was confirmed by serum drug levels. We treated the patient with charcoal decontamination and oral cholestyramine. She recovered completely without sequelae.

Early diagnosis of polyomavirus type BK infection in tailoring immunosuppression for kidney transplant patients: screening with urine qualitative polymerase chain reaction assay.

Polyomavirus type BK (BKV) nephropathy is increasingly a significant cause of graft dysfunction and even failure. Early diagnosis followed by reduction of immunosuppression has been associated with an improved prognosis. We screened 250 patients with the urine qualitative polymerase chain reaction (PCR) for BKV DNA. We followed with blood BKV PCR if the urine screen was positive and then reduced immunosuppression in viremic patients. One hundred ninety-nine patients (80%) had no viuria; 43 (17%) viuria; and 8 (3%) both viuria and viremia. Graft biopsy performed in three patients (1%) with viremia and impaired graft function all revealed BKV nephropathy. After 6 months of follow-up, seven out of eight viremic patients (88%) had negative repeat blood PCR and stabilized graft function. An early diagnosis of BKV infection with reduction of immunosuppression may reverse viremia and retard progression of BKV nephropathy. BKV screening by PCR assays should be considered in kidney transplant recipients, especially those with impaired graft function.

A Salmonella infection complicated with suppurative thyroiditis and ruptured aortic mycotic aneurysm in a renal transplant recipient.

We report a renal transplant recipient who presented with fever and chills for 2 days. The blood and stool cultures revealed the growth of Salmonella enteriditis. A whole-body gallium scan played an important role in the subsequent diagnosis of suppurative thyroiditis. To our knowledge, this is the first report of acute S. enteriditis thyroiditis in a renal transplant recipient. Despite vigorous antibiotic use and a partial thyroidectomy, he experienced recurrent S. enteriditis infection, resulting in a ruptured thoracic mycotic aneurysm 1 month later. Finally the patient was successfully cured with aneurysm resection, in situ reconstruction of the thoracic aorta, and prolonged antibiotics.

Physiological and pathological characterization of capsaicin-induced reversible nerve degeneration and hyperalgesia.

BACKGROUND: The study aimed to investigate the physiology, psychophysics, pathology and their relationship in reversible nociceptive nerve degeneration, and the physiology of acute hyperalgesia. METHODS: We enrolled 15 normal subjects to investigate intraepidermal nerve fibre (IENF) density, contact heat-evoked potential (CHEP) and thermal thresholds during the capsaicin-induced skin nerve degeneration-regeneration; and CHEP and thermal thresholds at capsaicin-induced acute hyperalgesia. RESULTS: After 2-week capsaicin treatment, IENF density of skin was markedly reduced with reduced amplitude and prolonged latency of CHEP, and increased warm and heat pain thresholds. The time courses of skin nerve regeneration and reversal of physiology and psychophysics were different: IENF density was still lower at 10 weeks after capsaicin treatment than that at baseline, whereas CHEP amplitude and warm threshold became normalized within 3 weeks after capsaicin treatment. Although CHEP amplitude and IENF density were best correlated in a multiple linear regression model, a one-phase exponential association model showed better fit than a simple linear one, that is in the regeneration phase, the slope of the regression line between CHEP amplitude and IENF density was steeper in the subgroup with lower IENF densities than in the one with higher IENF densities. During capsaicin-induced hyperalgesia, recordable rate of CHEP to 43 °C heat stimulation was higher with enhanced CHEP amplitude and pain perception compared to baseline. CONCLUSIONS: There were differential restoration of IENF density, CHEP and thermal thresholds, and changed CHEP-IENF relationships during skin reinnervation. CHEP can be a physiological signature of acute hyperalgesia. SIGNIFICANCE: These observations suggested the relationship between nociceptive nerve terminals and brain responses to thermal stimuli changed during different degree of skin denervation, and CHEP to low-intensity heat stimulus can reflect the physiology of hyperalgesia.

Rate dependent of strength in metallic glasses at different temperatures.

The correlation between the strength at the macroscale and the elastic deformation as well as shear cracking behavior at the microscale of bulk metallic glasses (BMGs) is investigated. The temperatures of 298 K and 77 K as well as the strain rate ranging from 10(-6) s(-1) to 10(-2) s(-1) are applied to the BMGs, in which the mechanical responses of the BMGs are profiled through the compression tests. The yield strength is associated with the activation of the elementary deformation unit, which is insensitive to the strain rate. The maximum compressive strength is linked to the crack propagation during shear fracture process, which is influenced by the strain rate. The cryogenic temperature of 77 K significantly improves the yield strength and the maximum compressive strength of the BMGs.

Mrp--a new auxiliary gene essential for optimal expression of methicillin resistance in Staphylococcus aureus.

Screening of a library of Tn551 insertional mutants selected for reduction in the methicillin resistance level of the parental Staphylococcus aureus strain COL resulted in the isolation of mutant RUSA266 in which the minimal inhibitory concentration (MIC) of the parent was reduced from 1,600 to 1.5 micrograms/mL. Cloning and sequencing of the vicinity of the insertion site omega 726 identified an open reading frame (orf1365) encoding a very large polypeptide of more than 1,365 amino acids. A unique feature of the deduced amino acid sequence was the presence of multiple tandem repeats of 75 amino acids in the polypeptide, reminiscent of the structure of high-molecular-weight cell-surface proteins EF* and Emb identified in some streptococcal strains. Mutant RUSA266 with the inactivated gene, which we shall provisionally refer to as mrp (for multiple repeat polypeptide), produced a peptidoglycan with altered muropeptide composition, and both the reduced antibiotic resistance and the altered cell wall composition were co-transduced in back-crosses into the parental strain COL. Additional sequencing upstream of mrp has revealed that this gene was part of a five-gene cluster occupying a 9.2-kb region of the staphylococcal chromosome and was composed of glmM (directly upstream of mrp), two open reading frames orf310 and orf269 coding for two hypothetical proteins, and the gene encoding the staphylococcal arginase (arg). Transcriptional analysis demonstrated that the five genes in the cluster were transcribed together.

The Staphylococcus aureus transposon Tn551: complete nucleotide sequence and transcriptional analysis of the expression of the erythromycin resistance gene.

The complete nucleotide sequence of Staphylococcus aureus transposon Tn551 was determined. The 5,266-bp sequence encoded five putative proteins. Comparison of the nucleotide sequence of Tn551 with that of the enterococcal transposon Tn917 showed that the two transposons were 99.8% identical and differed only at 11 positions along the entire sequence. The genetic organization of Tn551 was also identical to that of Tn917. Northern analysis of RNA prepared from a staphylococcal strain bearing Tn551 displayed three erm-associated transcripts that were constitutively produced. Mapping of the 5' ends of the transcripts by primer extension suggested that the constitutive transcription of erm was initiated from a nucleotide located 5 bp downstream of ORF1. A second set of three erythromycin-inducible transcripts was also detected and these showed a pattern similar to that described for Tn917. A simple and rapid method is described for the use of the Tn551 sequence information in sequencing transposon-inactivated staphylococcal genes.

Inactivation of the methicillin resistance gene mecA in vancomycin-resistant Staphylococcus aureus.

Acquisition of high-level resistance to vancomycin in the laboratory mutant VM50 (vancomycin MIC increased from 1.5 to 100 microg/ml) was accompanied by the appearance of a heterogeneous phenotype and a virtual loss in methicillin resistance: in most cells of cultures of VM50 the methicillin MIC of the parental strain was reduced from 800 to 1.5 microg/ml with only a subpopulation (10(-5)) retaining methicillin resistance at near the parental level (MIC of 400 microg/ml). Interestingly, the vancomycin MIC of this subpopulation was less (25 microg/ml) than that of VM50 (100 microg/ml). A similar antagonism between methicillin and vancomycin resistance levels was observed upon introduction of an intact mecA into VM50 on a plasmid vector: methicillin resistance of the majority of cells increased from 1.5 to 100 microg/ml while the vancomycin MIC declined from 100 to 12/25 microg/ml. Membrane preparations from mutant VM50 showed no detectable penicillin-binding protein (PBP) 2A by the fluorographic assay. Sequencing of the mecA gene resident in mutant VM50 indicated the presence of a 19-bp duplication between nucleotide residues 280-298, leading to the generation of a stop codon TAA starting at nucleotide position 286.

Molecular cloning and DNA sequencing of the Staphylococcus aureus UDP-N-acetylmuramyl tripeptide synthetase (murE) gene, essential for the optimal expression of methicillin resistance.

The Tn551 insertion in mutant RUSA235 of a highly methicillin resistant Staphylococcus aureus strain results in drastic reduction in the level of methicillin resistance and abnormalities, both in the composition of the peptidoglycan and of the cell wall precursor pool. Cloning and sequencing of the inactivated gene indicates that it is the murE gene of Staphylococcus aureus.

Antibiotic resistance as a stress response: complete sequencing of a large number of chromosomal loci in Staphylococcus aureus strain COL that impact on the expression of resistance to methicillin.

Tn551 inactivation has identified several determinants--fem or auxiliary genes--that, in addition to the mecA gene, are also critical for the expression of high-level and homogeneous resistance to methicillin. Genetic and/or biochemical analysis has shown that of the nearly dozen aux mutations described so far most are in genes involved in cell wall synthesis (murE, pbp2, glmM, glnR, femA/B, llm, etc.) or in complex regulatory functions (sigmaB), suggesting that optimal expression of resistance may involve the cooperative functioning of a number of genes in cell wall metabolism as well as stress response. The exact mechanism of these functions is not known. In an attempt to explore this unusual aspect of methicillin resistance more fully, a Tn551 transposon library, constructed in the background of the highly and homogeneously methicillin-resistant Staphylococcus aureus strain COL, was screened for all independent insertional mutants in which the level of methicillin resistance of the parental strain (MIC, 1,600 microg/ml) was reduced by at least 15-fold and up to 500-fold. We now describe the sequencing of 21 Tn551-inactivated genes and their vicinities in 23 new auxiliary mutants that have been studied before. Using the inverted polymerase chain reaction (IPCR), we amplified fragments corresponding to the right and left junction of the Tn551 insertions, which were then sequenced by primer walking. The two largest groups of these new auxiliary genes encoded either proteins of unknown functions (6 genes) or showed homology with genes encoding proteins involved with putative sensory/regulatory activities (7 genes: protein kinases, ABC transporters, and a catabolite control protein). Sequencing upstream and downstream allowed the identification of a number of additional open reading frames, some of which may also include functions relevant for the expression of antibiotic resistance.