Postoperative hypoxaemia in children undergoing elective palatoplasty.
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Adolescent↗
Biomedical subjects
G An
Publications and source records attributed to G An.
Enhanced recovery of a secreted mammalian protein from suspension culture of genetically modified tobacco cells.
Increasing the level of recovery of mammalian proteins secreted by a genetically modified Nicotiana tabacum was explored in suspension culture. As a model protein system, a mouse monoclonal antibody heavy chain gamma (MAb HC) with an antigen specificity for p-azophenylarsonate was used. Consistent with findings for other plant cell suspension culture systems expressing proteins with mammalian leader sequences, the synthesized mouse MAb HC was secreted through the plasma membrane. In addition, the majority of the MAb HC was also secreted through the cell wall into the growth medium. However, efficient recovery of the protein was only possible when the protein stabilizing agent, polyvinylpyrrolidone (PVP) was present in the plant cell growth medium. The presence of PVP increased the recovered concentration of secreted protein 35-fold from 0.010 to 0.36 micrograms protein/ml culture medium. Biological activity of the approximately 50-kDa MAb HC polypeptide was demonstrated by arsonate affinity matrix binding as determined by Western blot analysis. In addition to antigen binding activity, the secreted protein also exhibited reactivity to protein G, a protein which specifically binds mouse IgG. These findings are important because they demonstrate that culture conditions can significantly influence the concentration of a biologically active foreign protein secreted from plant cells into the media of suspension cultures. The ability to increase the efficiency of mammalian protein production in plant suspension culture systems should provide significant advantage over protein production in intact transgenic plants which require cultivation, harvesting, and expensive extraction procedures to obtain nonsecreted foreign proteins.
Animals↗
Promoter elements controlling developmental and environmental regulation of a tobacco ribosomal protein gene L34.
The rpL34 gene, which encodes a cytoplasmic ribosomal protein with a high homology to the rat 60S r-protein L34, was isolated from a genomic library of tobacco (Nicotiana tabacum L. cv. Xanthi-nc). A 1500 bp upstream promoter fragment was fused to the chloramphenicol acetyltransferase (CAT) reporter gene or beta-glucuronidase (GUS) reporter gene and transferred into tobacco plants by the Agrobhacterium-mediated leaf disk transformation method. Analysis of CAT activity in leaf tissues showed that mechanical wounding increased the rpL34 promoter activity about 5 times as compared to untreated controls and that the promoter activity was further enhanced by plant growth regulators, 2,4-dichlorophenoxyacetic acid and benzyladenine. Histochemical GUS staining patterns of the transgenic plants showed that the rpL34 promoter activity is high in actively growing tissues, including various meristems, floral organs, and developing fruits. A series of 5' deletion analyses of the rpL34 promoter indicated that a 50 bp region located between -179 and -129 is essential for wound, auxin and cytokinin responses. Deletion of this region reduced the promoter activity to an undetectable level. Insertion of the 50 nucleotide sequence into a minimal promoter restored the promoter activity and the promoter strength was proportional to the copy number of the upstream sequence. The role of TATA and CAAT box regions was studied by a series of 3' deletion analyses. A 3' deletion up to -28 did not significantly affect the promoter strength. However deletion of the promoter up to 70 bp, which deleted the TATA box region, significantly reduced promoter activity. Further deletion of the promoter up to - 104. eliminating the CAAT box region, abolished the promoter activity. These results suggest that the TATA box and CAAT box regions are also important for the rpL34 promoter activity in addition to the 50 bp upstream region.
Base Sequence↗
Regulated expression of a calmodulin isoform alters growth and development in potato.
A transgene approach was taken to study the consequences of altered expression of a calmodulin isoform on plant growth and development. Eight genomic clones of potato calmodulin (PCM1 to 8) have been isolated and characterized (Takezawa et al., 1995). Among the potato calmodulin isoforms studied, PCM1 differs from the other isoforms because of its unique amino acid substitutions. Transgenic potato plants were produced carrying sense construct of PCM1 fused to the CaMV 35S promoter. Transgenic plants showing a moderate increase in PCM1 mRNA exhibited strong apical dominance, produced elongated tubers, and were taller than the controls. Interestingly, the plants expressing the highest level of PCM1 mRNA did not form underground tubers. Instead, these transgenic plants produced aerial tubers when allowed to grow for longer periods. The expression of different calmodulin isoforms (PCM1, 5, 6, and 8) was studied in transgenic plants. Among the four potato calmodulin isoforms, only the expression of PCM1 mRNA was altered in transgenic plants, while the expression of other isoforms was not significantly altered. Western analysis revealed increased PCM1 protein in transgenic plants, indicating that the expression of both mRNA and protein are altered in transgenic plants. These results suggest that increasing the expression of PCM1 alters growth and development in potato plants.
Agrobacterium tumefaciens↗
Study of the safe threshold of apneic period in children during anesthesia induction.
STUDY OBJECTIVES: (1) To investigate changes in arterial oxygen saturation via pulse oximeter (SpO2) during apnea and after reinstitution of manual ventilation at SpO2 of 95% or 90% following rapid sequence induction of anesthesia in children after 2-minute preoxygenation; (2) to determine whether the setting of a safe threshold of apneic period to an SpO2 of 95% is appropriate in children during anesthetic induction; and (3) to evaluate the influences of age, body weight, and height on the time from the start of apnea to SpO2 of 95%. DESIGN: A clinical study of random design and comparison among groups. SETTING: Operating room of a plastic surgery hospital of the Chinese Academy of Medical Sciences and Peking Union Medical College. PATIENTS: 152 infants and children, ASA physical status 1, aged 3 months to 12 years, scheduled for elective plastic surgery. INTERVENTIONS: Patients were divided into three age groups: Group 1-infants 3 months to 1 year (n = 39); Group 2 children 1 to 3 years (n = 41); and Group 3-children 3 to 12 years (n = 72). Patients in each age group were randomly allocated again to Subgroups A and B. After a 2-minute preoxygenation, anesthesia was induced with thiopental 5 mg/kg, fentanyl 5 micrograms/kg and suxamethonium 1.5 mg/kg. Patients were manually ventilated when SpO2 decreased to 90% in Subgroups A and 95% in Subgroups B, respectively, during apnea. MEASUREMENTS AND MAIN RESULTS: SpO2 was measured continuously with a Datex pulse oximeter applied to the right index finger. During apnea, the times for SpO2 to decrease to 09% (T99) and 95% (T99) in all children, and 90% (T90) in Subgroups A were recorded. The time for SpO2 to decrease from 95% to 90% (T95-90) in Subgroups A was also measured. After reinstitution of manual ventilation, the time when SpO2 continued to decrease (T1) and the time from the end of apnea to recovery of SpO2 baseline (T2) were determined. In addition, the lowest value of SpO2 after apnea was also recorded. The results showed that younger children were more susceptible than older children to the risk of hypoxemia during apnea. There were significant differences in T99, T95, T90, and T95-90 between the three age groups T1 and T2 were significantly longer in Group 3 than in Groups 1 and 2. There were significant differences in the lowest values of SpO2 following apnea among the three Subgroups A and between Subgroups A and B of each age group. During apnea, heart rate decreased gradually as SpO2 decreased, showing a significant decrease at SpO2 of 95%. Bradycardia was found in three children in Subgroups A. The apnea time to SpO2 of 95% correlated well with age, weight, and height by linear regression analysis. CONCLUSIONS: The safe threshold of an apneic period setting to an SpO2 of 95% was appropriate in children during anesthesia induction. Despite the same duration of preoxygenation, younger children were more susceptible than elder ones to the risk of hypoxemia during apnea. The apnea time to SpO2 of 95% correlated with age, body weight, and height using linear regression analysis.
Age Factors↗
A comparative study of early postoperative hypoxemia in infants, children, and adults undergoing elective plastic surgery.
To determine the influence of age on postoperative hypoxemia, we studied postoperative hypoxemia in 1152 patients, from infants to adults, ASA physical status I, undergoing elective plastic surgery. Subjects were divided into four groups on the basis of age: Group 1, infants aged 1 yr or less (n = 108); Group 2, children aged 1-3 yr (n = 240); Group 3, children aged 3-14 yr (n = 482); and Group 4, adults aged 14-58 yr (n = 322). Arterial oxygen saturation (Spo2) levels were recorded while patients were breathing room air in the postanesthesia recovery room shortly after arrival (0 min), and 5, 10, 15, 20, 30, 40, 50, 60, 120, and 180 min thereafter. Younger patients showed lower Spo2 levels and a higher incidence of hypoxemia during the early postoperative period. The incidences of hypoxemia (Spo2 = 86%-90%) and severe hypoxemia (Spo2 < or = 85%) in the recovery room were 30.6% and 16.7%, respectively, in Group 1, 20.0% and 10.0% in Group 2, 14.1% and 3.3% in Group 3, and 7.8% and 0.6% in Group 4. Hypoxemia occurred most commonly within 1 h after anesthesia, particularly during the first 40 min in infants and during the first 15 min in older children and adults. A significant correlation was found by linear regression analysis between low Spo2 levels on admission to the recovery room and children's age. Thereafter, Spo2 levels and the incidence of hypoxemia during the early postoperative period were related only to infants' recovery scores.
Adolescent↗
Effect of epidural block on the lag time of pulse oximeter response.
Thirty-six healthy patients, ASA 1, aged 16-41 years, scheduled for elective plastic surgery were studied to determine if thoracocervical or lumbar epidural blocks affected the lag time of the pulse oximeter response. Patients were allocated to receive thoracocervical epidural block (n = 20) (group 1) (lignocaine 1%) or lumbar epidural block (n = 16) (group 2) (lignocaine 1.5%). Epidural block was performed with a 17-gauge Tuohy needle inserted in the midline between C7-T2 vertebrae in group 1 and between L1-S1 in group 2 and an epidural catheter was introduced. Arterial oxygen saturation (SpO2) was measured continuously using a Datex pulse oximeter. The lag time of the pulse oximeter response was measured while breathing oxygen (100%) after breath-holding. Values were obtained 10 min before and 5, 10, 15, 20, 30, and 40 min after epidural injection of a test dose. There was a progressive decrease in the lag time of the pulse oximeter response so that by 30 min after epidural injection the mean (SD) value had decreased from 29 (6.1) to 14 (3.4) in Group 1 and 41 (12.8) to 23 (7.9) s in group 2 (p < 0.01).
Adolescent↗
Isolation and characterization of nucleolin gene as one of the vitamin A-responsive genes in airway epithelium by a palindromic primer-based mRNA differential display method.
A palindromic primer-based mRNA differential display method has been used to isolate various vitamin A-responsive genes from primary cultures of monkey tracheobronchial epithelial cells. This method, as compared with the original mRNA differential display (mDD) method described by Liang and Pardee, used only one arbitrarily designed primer instead of two in the polymerase chain reaction. The single-primer mDD method has several advantages over the two-primer mDD system, especially in the reamplification and the selection of 5'-end cDNA clone. To verify the usefulness of this approach, one of these differential display bands, M34, was initially chosen for further amplification and cloning. The clone derived from the M34 band has a DNA sequence with > 90% homology to the human nucleolin gene. Furthermore, DNA sequencing confirms that both 5' and 3' ends of the insert of M34 contain the invertly repetitive nucleotide sequence that was used to direct this cloning. Nucleolin is a multifunctional phosphoprotein that plays an important role in ribosome biogenesis and mRNA stability. Northern blot analysis demonstrated that in addition to the elevation by vitamin A, the level of nucleolin message is significantly higher in fetal than in adult tracheobronchial epithelial cultures. Furthermore, in situ hybridization demonstrated that the amount of nucleolin message is significantly higher in both basal and ciliated cell types than in mucous and intermediary cell types. These results support the feasibility that the single-primer mDD technique can be used to isolate vitamin A-responsive genes with a palindromic nature.
Animals↗
Sensitive, nonradioactive differential display method using chemiluminescent detection.
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Animals↗
Two nuclear proteins in tracheal epithelial cells are recognized by antibodies specific to a squamous differentiation marker, sprI.
In cell-free translations of RNA from primary cultures of pig trachea surface epithelial cells we observed that a mRNA encoding a 20 kDa proline-rich protein (sPRP) was dramatically induced during culturing (Tesfaigzi et al., 1990, Biochem. Biophys. Res. Commun., 172:M1304-1309). This mRNA was not detected in tracheal tissue or in epithelial cells prior to culturing. Antisera were raised to synthetic peptide sequences corresponding to 23 amino acids on the C-terminus (C23-antiserum) and 29 amino acids on the N-terminus (N29 antiserum) of sPRP. On Western blot analysis, C23 antiserum reacted with a 20 kDa protein in cytosolic extracts from pig tracheal cells maintained in culture for 4 days. The reaction with the 20 kDa protein was inhibited by adding C23 peptide. Two nuclear proteins (66 and 70 kDa) obtained by micrococcal nuclease treatment of tracheal cell nuclei were detected on Western blots with C23 antiserum. These proteins were present in cells both before and after culturing. Sucrose gradient fractionation indicated that these nuclear proteins are associated with chromatin. Small amounts of the 66 and 70 kDa proteins were obtained from nuclear matrix fractions. These nuclear proteins also reacted with N29 antiserum. Since these proteins share similar epitopes with the N- and C-termini of sPRP, it is likely that the 20 kDa protein (sPRP) is part of these proteins. However, purification of the nuclear proteins followed by an amino acid sequence analysis is necessary to clarify whether sPRP is part of these proteins.
Amino Acid Sequence↗
Phenotypic alterations of petal and sepal by ectopic expression of a rice MADS box gene in tobacco.
Floral organ development is controlled by a group of regulatory factors containing the MADS domain. In this study, we have isolated and characterized a cDNA clone from rice, OsMADS3, which encodes a MADS-domain containing protein. The OsMADS3 amino acid sequence shows over 60% identity to AG of Arabidopsis, PLE of Antirrhinum majus, and AG/PLE homologues of petunia, tobacco, tomato, Brassica napus, and maize. Homology in the MADS box region is most conserved. RNA blot analysis indicated that the rice MADS gene was preferentially expressed in reproductive organs, especially in stamen and carpel. In situ localization studies showed that the transcript was present primarily in stamen and carpel. The function of the rice OsMADS3 was elucidated by ectopic expression of the gene under the control of the CaMV 35S promoter in a heterologous tobacco plant system. Transgenic plants exhibited an altered morphology and coloration of the perianth organs. Sepals were pale green and elongated. Limbs of the corolla were split into sections which in some plants became antheroid structures attached to tubes that resembled filaments. The phenotypes mimic the results of ectopic expression of dicot AG gene or AG homologues. These results indicate that the OsMADS3 gene is possibly an AG homologue and that the AG genes appear to be structurally and functionally conserved between dicot and monocot.
Amino Acid Sequence↗
Calmodulin gene family in potato: developmental and touch-induced expression of the mRNA encoding a novel isoform.
Eight genomic clones of potato calmodulin (PCM1 to 8) were isolated and characterized. Sequence comparisons of different genes revealed that the deduced amino acid sequence of PCM1 had several unique substitutions, especially in the fourth Ca(2+)-binding area. The expression patterns of different genes were studied by northern analysis using the 3'-untranslated regions as probes. The expression of PCM1, 5, and 8 was highest in the stolon tip and it decreased during tuber development. The expression of PCM6 did not vary much in the tissues tested, except in the leaves, where the expression was lower; whereas, the expression of PCM4 was very low in all the tissues. The expression of PCM2 and PCM3 was not detected in any of the tissues tested. Among these genes, only PCM1 showed increased expression following touch stimulation. To study the regulation of PCM1, transgenic potato plants carrying the PCM1 promoter fused to the beta-glucuronidase (GUS) reporter gene were produced. GUS expression was found to be developmentally regulated and touch-responsive, indicating a positive correlation between the expression of PCM1 and GUS mRNAs. These results suggest that the 5'-flanking region of PCM1 controls developmental and touch-induced expression. X-Gluc staining patterns revealed that GUS localization is high in meristematic tissues such as the stem apex, stolon tip, and vascular regions.
Amino Acid Sequence↗
Study of the optimal duration of preoxygenation in children.
STUDY OBJECTIVE: To determine the optimal length of preoxygenation in children. DESIGN: Random design and comparison among groups. SETTING: Operating room of a plastic surgery hospital of the Chinese Academy of Medical Sciences and the Peking Union Medical College. PATIENTS: Forty healthy, ASA status 1 children (age 2 to 7 yrs), undergoing elective plastic surgery. INTERVENTIONS: Children in Group 1 breathed 100% oxygen (O2) for 1 minute. Group 2 children breathed 100% O2 for 2 minutes. Group 3 and Group 4 children breathed 100% O2 for 3 minutes. Anesthesia was induced with midazolam 0.3 mg/kg, fentanyl 5 micrograms/kg. Muscle relaxation was achieved with vecuronium 0.1 mg/kg (Groups 1, 2, and 3) or succinylcholine 1.5 mg/kg (Group 4). MEASUREMENTS AND MAIN RESULTS: Oxygen saturation (SpO2) was measured by pulse oximeter. The oximeter probe was applied to the right big toe. After preoxygenation, the times for SpO2 to decrease to 98% (T98), 95% (T95), and 90% (T90), respectively, were recorded during the apneic period. T98, T95, and T90 were significantly shorter in Group 1 than in Group 2 or Group 3. There was no statistically significant difference among Groups 2, 3, or 4 regarding T98, T95, and T90. The times for SpO2 to decrease from 95% to 90% were similar among the four groups. CONCLUSIONS: 2 minutes of preoxygenation in children can provide the maximum benefit of denitrogenation and achieve 2 minutes of safe apea. 95% and 99% confidence intervals were 69 to 100 and 59 to 100, respectively. Succinylcholine had only a slight effect on the safe apneic period.
Anesthesia↗
Induction of nopaline synthase promoter activity by H2O2 has no direct correlation with salicylic acid.
Transgenic tobacco (Nicotiana tabacum L.) plants carrying a fusion between the nopaline synthase (nos) promoter and chloramphenicol acetyltransferase (CAT) reporter gene (caf) were tested for their response to treatment with H2O2. The nos promoter-driven CAT activity increased significantly by addition of H2O2, reaching the maximum level at 15 mM. Kinetic analysis for CAT activity showed that induction by H2O2 was similar to that of methyl jasmonate (MJ), but was much slower than induction by salicylic acid (SA). Time-course experiments for mRNA level also revealed that the response to H2O2 treatment was similar to that of MJ. The nos promoter displayed a rapid and transient induction of mRNA with SA treatment, with the maximum levels occurring at 3 h, whereas the levels induced by H2O2 or MJ treatment increased continuously during the 11-h experimental period. The antioxidants N-acetyl-L-cysteine and catechol did not alter the SA effect. The responses of the nos promoter to H2O2, MJ, and wounding were significantly reduced by deletions of the CAAT box region and the sequence between -112 and -101. However, these deletions did not significantly alter the SA response. This suggests that H2O2 may have a different mechanism from that of SA for inducing nos promotor activity.
Acetylcysteine↗
Binary Ti plasmid vectors.
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Agriculture↗
[Experimental study of Colles' fracture combined with dorsal radio-carpal subluxation].
By cutting different ligaments and the distal end of radius of 20 fresh specimens with radiophotographic records, the author explored the mechanism of formation and traumatic anatomy of Colles' fracture with dorsal radio-carpal subluxation (DRSA). The results of experimental studies indicate that under normal condition, the change of radiolunate angle has some influence on the displacement of central point of lunate (CPL) but does not lead to DRS. The first is the rupture of the dorsal and palmar ligaments of radiocarpal joint and the second is the fracture of distal end of radius with a reversed palmar tilting angle of articular surface of distal radius. To treat the patients of Colles' fracture with DRS the previous palmar tilting angle should be restored to the full, as well as the anatomic reduction. The fixatiion in neutral or light dorsal extension position should be recommended.
Adult↗
Fixed-node quantum Monte Carlo method for lattice fermions.
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Journal Article↗
Early flowering and reduced apical dominance result from ectopic expression of a rice MADS box gene.
Recent studies with dicot plants reveal that floral organ development is controlled by a group of regulatory factors containing the MADS domain. In this study, we have isolated and characterized a cDNA clone from rice, OsMADS1, which encodes a MADS-domain-containing protein. The OsMADS1 amino acid sequence shows 56.2% identity to AGL2 and 44.4% identity to AP1. The MADS box region was the most homologous to other MADS-domain-containing proteins. Northern blot analysis indicated that the rice MADS gene was preferentially expressed in floral organs. In situ localization studies showed that the transcript was uniformly present in young flower primordia and later became localized in palea, lemma, and ovary. Ectopic expression of OsMAD1 with the CaMV 35S promoter in transgenic tobacco plants dramatically alters development, resulting in short, bushy, early-flowering plants with reduced apical dominance. These results suggest that the OsMADS1 gene is involved in flower induction and that it may be used for genetic manipulation of certain plant species.
Amino Acid Sequence↗