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C J Jiang

Publications and source records attributed to C J Jiang.

16 recordsLinked to original sources
PubMed1998

In vitro characterization of rice importin beta1: molecular interaction with nuclear transport factors and mediation of nuclear protein import.

We recently isolated two cDNAs encoding importin 3 homologues (rice importin beta1 and beta2), the first such homologues identified in plants. To address the function of rice importin beta1 in the process of nuclear import of proteins, we carried out in vitro binding and nuclear import assays. Recombinant protein of rice importin beta1 assembled a complex (PTAC) with rice importin alpha1 and NLS protein, and also bound to the nuclear envelope of tobacco BY-2 cells. Ran-GTP, but not Ran-GDP, interacted with rice importin beta1 and dissociated the heterodimer formed between rice importin alpha1 and rice importin beta1. An in vitro nuclear import assay using digitonin-permeabilized HeLa cells revealed that rice importin beta1 can mediate nuclear envelope docking of NLS proteins and their subsequent translocation into the nucleus. These data strongly suggest that rice importin beta1 functions as a component of the NLS receptor in plant cells.

Cell Nucleus↗
PubMed1998

Functional characterization of a plant importin alpha homologue. Nuclear localization signal (NLS)-selective binding and mediation of nuclear import of nls proteins in vitro.

Nuclear import of most nuclear proteins is initiated by recognition of the nuclear localization signal (NLS) by importin alpha. We recently isolated an importin alpha homologue from rice (rice importin alpha1) and demonstrated that transcription of the gene is down-regulated by light in rice leaves. To address the function of rice importin alpha1 in the process of nuclear import of proteins, we performed in vitro binding and nuclear import assays. The rice importin alpha1 showed specific binding to fusion proteins containing either monopartite or bipartite NLSs, but not to a fusion protein containing a Matalpha-2-type NLS, suggesting that there exists selective binding of rice importin alpha1 to different plant NLSs. The rice importin alpha1 is also capable of forming a complex with mouse importin beta and NLS protein in vitro. An in vitro nuclear import assay using permeabilized HeLa cells revealed that rice importin alpha1, in conjunction with other vertebrate transport factors, mediates the nuclear envelope docking of NLS proteins and their subsequent translocation into the nucleus. These data provide strong, direct evidence suggesting that rice importin alpha1 functions as a component of the NLS receptor in plant cells.

Animals↗
PubMed1998

Ser6 in the maize actin-depolymerizing factor, ZmADF3, is phosphorylated by a calcium-stimulated protein kinase and is essential for the control of functional activity.

Maize actin-depolymerizing factor, ZmADF, binds both G- and F-actin and enhances in vitro actin dynamics. Evidence from studies on vertebrate ADF/cofilin supports the view that this class of protein responds to intracellular and extracellular signals and causes actin reorganization. As a test to determine whether such signal-responsive pathways existed in plants, this study addressed the ability of maize ADF to be phosphorylated and the likely effects of such phosphorylation on its capacity to modulate actin dynamics. It is shown that maize ADF3 (ZmADF3) can be phosphorylated by a calcium-stimulated protein kinase present in a 40-70% ammonium sulphate fraction of a plant cell extract. Phosphorylation is shown to be on Ser6, which is only one of nine amino acids that are fully conserved among the ADF/cofilin proteins across distantly related species. In addition, an analogue of phosphorylated ZmADF3 created by mutating Ser6 to Asp6 (zmadf3-4) does not bind G- or F-actin and has little effect on the enhancement of actin dynamics. These results are discussed in context of the previously observed actin reorganization in root hair cells.

Actin Depolymerizing Factors↗
PubMed1998

Isolation and characterization of two importin-beta genes from rice.

The nuclear transport of proteins is mediated by the complex of importin-alpha and importin-beta. We isolated two cDNAs encoding importin-beta from rice. A rice importin-beta was demonstrated to interact with rice GST-importin-alpha fusion proteins. The presence of two importin-beta genes was shown for the first time among a variety of eukaryotes.

Amino Acid Sequence↗
PubMed1997

F-actin and G-actin binding are uncoupled by mutation of conserved tyrosine residues in maize actin depolymerizing factor (ZmADF).

Actin depolymerizing factors (ADF) are stimulus responsive actin cytoskeleton modulating proteins. They bind both monomeric actin (G-actin) and filamentous actin (F-actin) and, under certain conditions, F-actin binding is followed by filament severing. In this paper, using mutant maize ADF3 proteins, we demonstrate that the maize ADF3 binding of F-actin can be spatially distinguished from that of G-actin. One mutant, zmadf3-1, in which Tyr-103 and Ala-104 (equivalent to destrin Tyr-117 and Ala-118) have been replaced by phenylalanine and glycine, respectively, binds more weakly to both G-actin and F-actin compared with maize ADF3. A second mutant, zmadf3-2, in which both Tyr-67 and Tyr-70 are replaced by phenylalanine, shows an affinity for G-actin similar to maize ADF3, but F-actin binding is abolished. The two tyrosines, Tyr-67 and Tyr-70, are in the equivalent position to Tyr-82 and Tyr-85 of destrin, respectively. Using the tertiary structure of destrin, yeast cofilin, and Acanthamoeba actophorin, we discuss the implications of removing the aromatic hydroxyls of Tyr-82 and Tyr-85 (i.e., the effect of substituting phenylalanine for tyrosine) and conclude that Tyr-82 plays a critical role in stabilizing the tertiary structure that is essential for F-actin binding. We propose that this tertiary structure is maintained as a result of a hydrogen bond between the hydroxyl of Tyr-82 and the carbonyl of Tyr-117, which is located in the long alpha-helix; amino acid components of this helix (Leu-111 to Phe-128) have been implicated in G-actin and F-actin binding. The structures of human destrin and yeast cofilin indicate a hydrogen distance of 2.61 and 2.77 A, respectively, with corresponding bond angles of 99.5 degrees and 113 degrees, close to the optimum for a strong hydrogen bond.

Actin Depolymerizing Factors↗
PubMed1997

The maize actin-depolymerizing factor, ZmADF3, redistributes to the growing tip of elongating root hairs and can be induced to translocate into the nucleus with actin.

The maize actin depolymerizing factor, ZmADF3, binds G- and F-actin, and increases in vitro actin dynamics. Polyclonal antibodies have been raised against ZmADF3 and these detect a single band of approximately 17 kDa in all maize tissues examined, with the exception of pollen. In the development of root hairs, the distribution of ZmADF3 is related to actin reorganization. In the early stages of hair development, ZmADF3 is distributed throughout the cytoplasm. As the hair emerges and the microfilament bundles redirect to the outgrowth there is a simultaneous redistribution of ZmADF3 which now concentrates at the tip of the emerging hair and remains in this position as elongation proceeds. These observations show that ZmADF3 localizes to a region where actin is being remodelled during tip growth. After cytochalasin D treatment which disrupts actin filaments, short rods of ZmADF3 and actin appear in the nucleus suggesting that ZmADF3 may function by guiding actin to sites of actin polymerization.

Actin Depolymerizing Factors↗
PubMed1996

Pollen specific expression of maize genes encoding actin depolymerizing factor-like proteins.

In pollen development, a dramatic reorganization of the actin cytoskeleton takes place during the passage of the pollen grain into dormancy and on activation of pollen tube growth. A role for actin-binding proteins is implicated and we report here the identification of a small gene family in maize that encodes actin depolymerizing factor (ADF)-like proteins. The ADF group of proteins are believed to control actin polymerization and depolymerization in response to both intracellular and extracellular signals. Two of the maize genes ZmABP1 and ZmABP2 are expressed specifically in pollen and germinating pollen suggesting that the protein products may be involved in pollen actin reorganization. A third gene, ZmABP3, encodes a protein only 56% and 58% identical to ZmABP1 and ZmABP2, respectively, and its expression is suppressed in pollen and germinated pollen. The fundamental biochemical characteristics of the ZmABP proteins has been elucidated using bacterially expressed ZmABP3 protein. This has the ability to bind monomeric actin (G-actin) and filamentous actin (F-actin). Moreover, it decreases the viscosity of polymerized actin solutions consistent with an ability to depolymerize filaments. These biochemical characteristics, taken together with the sequence comparisons, support the inclusion of the ZmABP proteins in the ADF group.

Actin Depolymerizing Factors↗
PubMed1991

Epirubicin and cytosine arabinoside for the induction therapy of childhood acute nonlymphocytic leukemia.

Epirubicin, a new anthracycline, was used in combination with cytosine arabinoside for the induction therapy of de novo acute nonlymphocytic leukemia in childhood. The treatment consisted of epirubicin 20 mg/m2/day for 3 days and cytosine arabinoside 100 mg/m2/day for 7 days. The treatment could be repeated every 3 weeks. Remission induction rate was 80% (20/25). Moreover, in 13 patients, the remissions were obtained after a single course. In general, the side effects of epirubicin and cytosine arabinoside were tolerable. However, the main causes of all the three deaths were infections. Our study suggests that epirubicin is acceptable and effective for the induction therapy for de novo acute nonlymphocytic leukemia in childhood.

Adolescent↗
PubMed1991

Mini-dose intrathecal morphine for post-cesarean section analgesia.

Dose-response relationship of mini-dose intrathecal morphine (0.025-0.125 mg) for analgesia after Cesarean section was studied. Sixty-three patients were randomly divided into six groups by the following intrathecal morphine injection: group 1 (0 mg), group 2 (0.025 mg), group 3 (0.05 mg), group 4 (0.075 mg), group 5 (0.1 mg), and group 6 (0.125 mg). The selected dose of morphine mixed with 2 ml 0.5% hyperbaric bupivacaine (10 mg) was administered intrathecally to induce spinal anesthesia. The mean analgesia duration in each group was 3.6 +/- 2.0, 10.6 +/- 7.1, 17.3 +/- 13.8, 25.6 +/- 7.5, 33.9 +/- 10.1, and 39.5 +/- 11.9 h respectively (mean +/- SD). In morphine groups, duration of analgesia was significantly longer (p less than 0.05) than control group (0 mg), and the first 24 h pain scores were also lower (p less than 0.01). Furthermore, a significant linear dose-response relationship between analgesic duration and the dose of intrathecal morphine was revealed (y = 3.28 + 295.5x, r2 = 0.64, p less than 0.05). Among morphine groups, analgesic quality was significantly better in patients in groups 4-6 than those in group 2 and 3 (p less than 0.05), so as in the proportion of effective analgesia in the first 24 h (p less than 0.01). Neonatal condition was not adversely affected by such mini-dose of intrathecal morphine. The most common maternal adverse effect observed was pruritus, and its incidence was significantly greater in groups 3-6 than in the control group (p less than 0.05). However, no significant difference was observed among all morphine groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Comparison of lower concentrations of lidocaine to suppress bucking before extubation during recovery of general anesthesia.

Thirty females, aged 25-50 years old, scheduled for abdominal total hysterectomy were randomly divided to two groups. For patients in group I, 2 mL 1% lidocaine solution was injected through the catheter on the tube to desensitize the trachea while surgeon started to close the peritoneum. In group II, 2 mL 2% lidocaine was used. The peak cuff pressures generated in the awakening group I patients were 49.0 +/- 2.5 cmH2 O (mean +/- SD) which shows greater than that in group II (27.9 +/- 7.2 cmH2 O), p less than 0.01. Bucking before awakening was also evaluated clinically. One hundred % (15/15) in group I patients bucked compared with 13.3% (2/15) in group II patients (p less than 0.01). Gag reflex was preserved in all patients and none suffered from aspiration postoperatively. Intratracheal administration of two mL 2% lidocaine through the catheter of modified endotracheal tube showed significant effect for suppressing bucking during recovery of general anesthesia.

Adult↗
PubMed1990

The application of pulse oximeter for supraclavicular brachial block.

The subclavian artery is the most important landmark of the supraclavicular brachial block. However, it is difficult to locate the artery by palpation in the patients with poor landmark. The present study was aimed to compare two localizing methods of the subclavian artery by a pulse oximeter or by palpation. One hundred patients were divided into three groups. Group A (Slim Group): 6 patients, Group B (Normal Weight Group): 75 and Group C (Obese Group): 19. All patients received both methods to locate the subclavian artery. The first method was by palpating the pulsation of the subclavian artery. The second was by observing the wave depression of the pulse oximeter while pressing supraclavicular area. It was found that the detection rate of the first method was 83.3% in Group A, 52.0% in Group B, 26.3% in Group C and 49.0% in overall patients. However, the detection rate of the second method was 100% in each group. It shows a significant difference between the two methods in Group B, Group C and all patients (P less than 0.001), but no difference in Group A (P = 0.68). There were 13 patients among the 100 patients undergoing surgery of the upper extremity. Seven of them whose pulsation was not clearly palpated but could be located exactly by pulse oximeter. Supraclavicular brachial block was still completed successfully in these 13 patients. No pneumothorax was found. Utilizing pulse oximeter in supraclavicular block provides a high detection rate of the pulsation of the subclavian artery and improves the reliability of the block, especially in the patients with poor landmark.

Adult↗
PubMed1987

Use of the multinomial Dirichlet model for analysis of subdivided genetic populations.

The distribution found by compounding the multinomial distribution with the Dirichlet distribution has been suggested as a basis for the estimation of parameters in subdivided populations, in particular of the "correlation between genotypes" within subpopulations. It is shown that the estimators deriving from these procedures perform poorly when the data are generated by the classical Wright drift model of subdivided populations. This conclusion suggests that the compound distribution estimation approach does not provide a good estimation procedure for real populations which are reasonably described by the Wright model.

Gene Frequency↗
PubMed1984

Pharmacology of radioiodinated hexadecenoic acid--a myocardial imaging agent.

123I- and 131I-labeled hexadecenoic acid (IHDA, radiochemical purity over 92%, dissolved in 6% bovine serum albumin solution) was investigated in vivo. ICR mice were administered IHDA via the tail vein. Maximum myocardial uptake (27.3 +/- 5.1%) was reached about 0.5 min after the injection. The ratio of uptake in the heart to that in the lungs was 2.3, to that in liver 1.5 and to that in other organs 2.4 to 6.4. The dog myocardium was visualized distinctly within 3-5 min with a gamma camera after i.v. 131I-IHDA, and not interfered with by activities in the lungs, liver and other organs. The low blood levels at 20 min had little effect on the quality of the heart images.

Animals↗
PubMedDate not supplied

[A study of insertional length of umbilical artery catheters in newborns].

To correlate the neonatal body measurements that best predict insertional length of the umbilical artery catheter (UAC), we performed this study with two separate parts. In part I, we collected 120 cases with indication for umbilical artery catheterization from Mackay Memorial Hospital during December 1986 to November 1987. They were randomly divided into 4 groups and in each group the internal catheter length of UAC was calculated with formula of: Gr. 1. 3 birth weight (BW) (Kg) + 9 (cm), Gr. 2. suprasternal notch to public symphysis length (SSL) (cm), Gr. 3. 1/3 total body length (TBL) (cm), Gr. 4. shoulder to umbilicus length (SUL) + 2 (cm). The accuracy was 90% in BW group, 90% in TBL group, 70% in SSL group and 70% in SUL group respectively, and there was no statistical difference between any two groups. However, BW and TBL formula were clinically more practical than the other two (SUL and SSL). In part II of our study, out of 120 cases we selected 63 appropriate for gestational age (AGA) cases with catheter tips placed between the 7th and 9th thoracic vertebra. Correlation coefficients (rs) between inserted length of UAC and each of the four parameter (BW, TBL, SSL, and SUL) were shown to have statistically significant correlation. There was no statistical difference among those correlation coefficients. Modified regression equations derived from BW, SSL, TBL and SUL were 1.7BW (kg) + 2 (cm). 2. SSL (cm). 3. 1/3 TBL (cm) + 0.5 (cm). 4. SUL (cm) + 1 (cm). Further study would be necessary for establishing a more widely adaptable equation.

Anthropometry↗