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Biomedical subjects

G An

Publications and source records attributed to G An.

At least 19 recordsLinked to original sources
PubMed2001

Characterization of MADS box genes from hot pepper.

The cDNA clone, CanMADS1, was isolated from young flower buds of the hot pepper (Capsicum annuum L.) by screening a cDNA library using the OsMADS1 rice MADS-box gene as a probe. We used a yeast two-hybrid screening method to investigate interaction partners of the protein product of CanMADS1. A MADS-box gene, CanMADS6, was isolated from young flower buds using the region containing the K domain and 15 amino acid residues of the C-terminal region of CanMADS1 as a bait. CanMADS1 and CanMADS6 showed high amino acid sequence similarities to members of the AGL2 subfamily and the SQUA subfamily, respectively. CanMADS1 transcript was expressed in flower buds and fruits, and the transcription signal was the strongest in the stage of the fruit set (2 d after anthesis). CanMADS6 showed the same expression pattern as CanMADS1. CanMADS1 and CanMADS6 were not expressed in leaves. These results suggest that a regulatory role for flower and fruit development of the hot pepper may be accomplished through an interaction of the protein products of the two MADS-box genes, CanMADS1 and CanMADS6.

Amino Acid Sequence↗
PubMed2001

Standardization, analytical validation, and quality control of intermediate endpoint biomarkers.

Standardized processes should be used in the identification and development of intermediate endpoint biomarkers (IEB) for the prediction of patient-specific disease outcomes. Using our own experiences, we outline some of our standardized processes. Using computer-assisted image analysis, we developed a new biomarker of genetic instability, termed quantitative nuclear grade (QNG). The QNG biomarker is derived using nuclear images analyzed from the tumor areas of Feulgen-stained 5-microm biopsy or radical prostatectomy tissue sections. From the variances of 41 to 60 different nuclear size, shape, and chromatin organization features, a QNG solution is computed using either logistic regression or artificial neural networks. QNG can then be used as an input for models that solve for a patient-specific probability to accurately predict disease outcomes. Preoperatively, QNG predicted both the pathologic stage and progression of prostate cancer using biopsies (P <0.0001). Postoperatively, QNG proved extremely valuable in the prediction of biochemical progression using radical prostatectomy specimens with more than 10 years of follow-up (P <0.0001). We also demonstrate the identification of novel, differentially expressed, prostate cancer genes using RNA fingerprinting methods and the clinical utility of testing for these genes in both blood and tissue samples. Also illustrated is the improvement of serum biomarker performance by combining molecular forms of PSA with new biomarkers. In conclusion, the development of new IEBs requires planning based upon an understanding of the molecular pathogenesis of disease. IEB selection and clinical evaluation should employ standardized methods of testing and validation, followed by publication. QNG is 1 example of a new, highly predictive, IEB for prostate cancer that has been developed using these processes.

Analysis of Variance↗
PubMed2001

Gene tagging in rice: a high throughput system for functional genomics.

Rice, with its small genome size and well-characterized molecular information, is an ideal model plant for cereal genomics research. Sequence of the rice (Oryza sativa) genome will be determined by the International Rice Genome Sequencing Project (IRGSP) in the near future. Therefore, a large population of mutant plants should be required for adequately assigning function to the abundant sequence information. Here we summarize strategies as well as the progress that has been made in producing gene tags that may be invaluable for understanding the functional genomics of rice.

Journal Article↗
PubMed2001

Agent-based computer simulation and sirs: building a bridge between basic science and clinical trials.

The management of Systemic Inflammatory Response Syndrome (SIRS)/Multiple Organ Failure (MOF) remains the greatest challenge in the field of critical care. There has been uniform difficulty in translating the results of basic science research into effective therapeutic regimes. We propose that this is due in part to a failure to account for the complex, nonlinear nature of the inflammatory process of which SIRS/MOF represents a disordered state. Attempts to manipulate this process without an understanding of the dynamics of the system may potentially produce unintended consequences. Agent-Based Computer Simulation (ABCS) provides a means to synthesize the information acquired from the linear analysis of basic science into a model that preserves the complexity of the inflammatory system. We have constructed an abstracted version of the inflammatory process using an ABCS that is based at the cellular level. Despite its abstraction, the simulation produces non-linear behavior and reproduces the dynamic structure of the inflammatory response. Furthermore, adjustment of the simulation to model one of the unsuccessful initial anti-inflammatory trials of the 1990's demonstrates the adverse outcome that was observed in those clinical trials. It must be emphasized that the current model is extremely abstract and simplified. However, it is hoped that future ABCSs of sufficient sophistication eventually may provide an important bridging tool to translate basic science discoveries into clinical applications. Creating these simulations will require a large collaborative effort, and it is hoped that this paper will stimulate interest in this form of analysis.

Capillaries↗
PubMed2001

[Influences of age and gender on dose-response and recovery time-course of atracurium].

OBJECTIVES: To evaluate the influences of age and sex on dose-response and recovery time course of atracurium. METHODS: Seventy-two patients (38 men and 34 women), ASA grade I, aged 15-59 years, scheduled for elective surgery were included in the study. All patients were divided into three groups according to their ages: Group 1, 32 patients aged 15-29 years; Group 2, 21 patients aged 30-40 years, and Group 3, 19 patients aged 41-59 years. General anesthesia was maintained with 60% nitrous oxide in oxygen, thiopentone and fentanyl. Neuromuscular function was assessed by train-of-four(TOF) stimulation of accelerometry and the percentage depression of the first response (T1) of the TOF stimulus was used as the study parameter. The dose-response relations of atracurium were determined by the cumulative dose-response technique. RESULTS: As compared to older and female patients, dose-response curves of atracurium in young and male patients were shifted in a parallel fashion to the left. The dose-response relation of atracurium correlated closely with patients' ages and sexes by multiple linear regression analysis. There were significant differences of ED50, ED90 and ED95, and clinical duration and total duration of action following administration of atracurium of same doses between the three age groups as well as men and women. CONCLUSIONS: Age and gender could significantly affect the pharmacodynamics of atracurium.

Adolescent↗
PubMed2000

Cloning and characterization of UROC28, a novel gene overexpressed in prostate, breast, and bladder cancers.

A novel gene, designated UROC28, was identified by an agarose gel-based differential display technique, and it was found to be up-regulated in prostate, breast, and bladder cancer. Expression of UROC28 was also up-regulated in prostate cancer cells in the presence of androgens as demonstrated by relative quantitative reverse transcription-PCR. The elevated expression of this gene was observed to increase in surgically removed tissues concomitantly with rising Gleason grade and was most elevated in metastatic tissue. UROC28 protein was detected in serum by Western slot blot analyses, and a significant higher UROC28 protein level was found in sera of prostate cancer individuals compared with normal individuals and individuals with nonmalignant prostatic hyperplasia. Northern analyses in normal tissues showed that the UROC28 cDNA hybridizes to two mRNAs at about 2.1 and 2.5 kb. Nucleic acid sequence analyses indicated that these two alternatively spliced mRNA variants differ only at the 3' untranslated region. These two mRNAs encode the same protein with 135 amino acids. Bioinformation analyses suggest that there is a possible transmembrane domain from amino acid aa34 to aa50, three protein kinase-C phosphorylation sites at aa62 (SQK), aa89 (TMK), and aa94 (SMK), and one myristylation site at aa118 (GLECCL). Genomic Southern hybridization and chromosomal mapping demonstrated that UROC28 is encoded by a single copy of gene at chromosome 6q23-24. In situ hybridization and immunohistochemistry experiments further confirmed up-regulation of this gene in prostate and breast cancers with the expression localizing to the glandular epithelium. This gene did not demonstrate increased expression in lung and colon cancer tissues.

3' Untranslated Regions↗
PubMed2000

Analysis of expressed sequence tags of Porphyra yezoensis.

Single direct partial sequencing of anonymous cDNA clones was performed to obtain genetic information on red algae Porphyra yezoensis of which genetic information is not available. This expressed sequence tags (EST) analysis revealed 81 clones (42%) had significant homologies to known genes in GenBank. Of these clones, eight are related to known algal genes, whereas above 90% of the EST clones were newly identified in algae. Putative functional categories of these clones showed that the most abundant genes were involved in stress and defense mechanisms and that the next abundant genes were associated with protein synthetic pathways.

DNA, Complementary↗
PubMed2000

Developmentally regulated expression of two MADS-box genes, MdMADS3 and MdMADS4, in the morphogenesis of flower buds and fruits in apple.

Two MADS-box genes, MdMADS3 and MdMADS4, were isolated from the apple (Malus x domestica Borkh.) cultivar Fuji, and their spatial and temporal expression patterns were studied during morphological differentiation of the flower buds and the fruits. Both MdMADS3 and MdMADS4 showed high sequence similarities to FBP2 from petunia, TM5 from tomato, and AGL2, AGL4 from Arabidopsis. Although MdMADS3 was expressed in the inner three whorls of the floral primordium, its expression was hardly detectable in developing fruit. The second gene, MdMADS4, was ubiquitously expressed in the inflorescence meristem, floral meristem, all four floral organs, and fruit. Moreover, MdMADS4 expression was high in the vascular bundles assigned to the floral tube and the carpellary vascular bundles in fruit at early developmental stages. The MdMADS4 transcript also accumulated in embryos of the developing seeds. These results suggest that MdMADS3 and MdMADS4 are involved in different functions, and that MdMADS4 may function in the important events controlling flower and fruit development.

Amino Acid Sequence↗
PubMed2000

Two rice MADS domain proteins interact with OsMADS1.

OsMADS1 is a MADS box gene controlling flower development in rice. In order to learn more about the function of OsMADS1, we searched for cellular proteins interacting with OsMADS1 employing the yeast two-hybrid system. Two novel proteins with MADS domains, which were named OsMADS14 and OsMADS15, were isolated from a rice cDNA library. OsMADS14 and -15 are highly homologous to the maize MADS box gene ZAP1 which is an orthologue of the floral homeotic gene APETALA1 (AP1). Interactions among the three MADS domain proteins were confirmed by in vitro experiments using GST-fused OsMADS1 expressed in Escherichia coli and in vitro translated proteins of OsMADS14 and -15. We determined which domains in OsMADS1, -14, and -15 were required for protein-protein interaction employing the two-hybrid system and pull-down experiments. While the K domain was essential for protein-protein interaction, a region preceded by the K domain augmented this interaction. Interestingly, the C-terminal region of OsMADS1 functioned as a transcriptional activation domain in yeast and mammalian cells, while, on the other hand, the C domains of OsMADS14 and -15 exhibited only very weak transcriptional activator functionality, if any at all.

Amino Acid Sequence↗
PubMed2000

Influence of acute normovolaemic haemodilution on the dose-response and time-course of action of atracurium.

BACKGROUND: Acute normovolaemic haemodilution is a common method to save and avoid homologous blood transfusion during surgery. The aim of this study was to evaluate the influence of acute isovolaemic haemodilution on the dose-response and time-course of action of atracurium. METHODS: We studied 25 patients undergoing acute isovolaemic haemodilution during surgery and 25 patients not receiving haemodilution as a control group. All patients were ASA grade I and aged 18-54 yr. The haemodilution patients underwent major elective plastic surgery with an anticipated surgical blood loss of more than 600 ml, and the control patients underwent elective superficial plastic surgery with an anticipated surgical blood loss of less than 200 ml. Anaesthesia was induced with thiopental 4-6 mg/kg and fentanyl 2-4 microg/kg i.v., and maintained with 60% nitrous oxide in oxygen. After stabilization of anaesthesia, acute isovolaemic haemodilution in the haemodilution group was achieved by drainage of venous blood and an i.v. infusion of lactated Ringer's solution, and 6% dextran, during which haematocrit and haemoglobin decreased from 45.1% to 25.8% and from 147.2 g/l to 91.2 g/l, respectively. When anaesthesia was stable in the control group and haemodilution was completed in the haemodilution group, neuromuscular function was assessed by measuring with accelerography the response of the adductor pollicis muscle to supramaximal train-of-four (TOF) stimuli every 12 s to the ulnar nerve at the wrist via surface electrodes. The dose-response relationships of atracurium in the two groups were determined by the cumulative dose-response technique. RESULTS: The results showed that during haemodilution, the dose-response curve of atracurium was shifted to the left in a parallel fashion and the potency of atracurium was increased. In patients undergoing haemodilution, ED50, ED90 and ED95 of atracurium were decreased by 25-33%, and duration of action was increased by 21-48% following administration of the same dose (mg/kg), as compared with patients not undergoing haemodilution. CONCLUSION: We concluded that the patients undergoing acute isovolaemic haemodilution were about 30% more sensitive to neuromuscular blockade of atracurium and had a longer duration after administration of the same dose (microg/kg) than the control patients. Care must be taken with this problem when atracurium is used as a muscle relaxant during acute haemodilution.

Adolescent↗
PubMed2000

T-DNA insertional mutagenesis for functional genomics in rice.

We have produced 22 090 primary transgenic rice plants that carry a T-DNA insertion, which has resulted in 18 358 fertile lines. Genomic DNA gel-blot and PCR analyses have shown that approximately 65% of the population contains more than one copy of the inserted T-DNA. Hygromycin resistance tests revealed that transgenic plants contain an average of 1.4 loci of T-DNA inserts. Therefore, it can be estimated that approximately 25 700 taggings have been generated. The binary vector used in the insertion contained the promoterless beta-glucuronidase (GUS) reporter gene with an intron and multiple splicing donors and acceptors immediately next to the right border. Therefore, this gene trap vector is able to detect a gene fusion between GUS and an endogenous gene, which is tagged by T-DNA. Histochemical GUS assays were carried out in the leaves and roots from 5353 lines, mature flowers from 7026 lines, and developing seeds from 1948 lines. The data revealed that 1.6-2.1% of tested organs were GUS-positive in the tested organs, and that their GUS expression patterns were organ- or tissue-specific or ubiquitous in all parts of the plant. The large population of T-DNA-tagged lines will be useful for identifying insertional mutants in various genes and for discovering new genes in rice.

Base Sequence↗
PubMed2000

Mutagenicity of recombinant antihemophilic factor (GC-gamma AHF).

This study was carried out to evaluate the mutagenic potential of recombinant antihemophilic factor VIII (GC-gamma AHF). Salmonella typhimurium (S. typhimurium) reversion assay with/without histidine moiety, chromosomal aberration assay on Chinese hamster lung (CHL) fibroblast cells and in vivo micronucleus assay using mouse bone marrow cells and supravital micronucleus assay using peripheral blood were performed. GC-gamma AHF containing histidine did show inconsistent and irregular mutagenic effects on S. typhimurium TA98, TA100, TA1535 and TA1537 both in the absence and presence of the metabolic activation system, however, GC-gamma AHF without histidine showed no mutagenic effects regardless of the metabolic activation system, thus suggesting that the histidine moiety in GC-gamma AHF might cause inconsistent mutagenic effect. Also GC-gamma AHF did not increase the number of cells having structural or numerical chromosome aberration in the cytogenetic test. In classical and supravital micronucleus assay, no significant increases were observed in the occurrence of micronucleated polychromatic erythrocytes and micronucleated peripheral lymphocytes in male ICR mice. These results strongly indicate that GC-gamma AHF has no genetic toxicity under these experimental conditions.

Animals↗
PubMed2000

Transgenic rice plants expressing a Bacillus subtilis protoporphyrinogen oxidase gene are resistant to diphenyl ether herbicide oxyfluorfen.

Protoporphyrinogen oxidase (Protox), the penultimate step enzyme of the branch point for the biosynthetic pathway of Chl and hemes, is the target site of action of diphenyl ether (DPE) herbicides. However, Bacillus subtilis Protox is known to be resistant to the herbicides. In order to develop the herbicide-resistant plants, the transgenic rice plants were generated via expression of B. subtilis Protox gene under ubiquitin promoter targeted to the cytoplasm or to the plastid using Agrobacterium-mediated gene transformation. The integration and expression of the transgene were investigated at T0 generation by DNA and RNA blots. Most transgenic rice plants revealed one copy transgene insertion into the rice genome, but some with 3 copies. The expression levels of B. subtilis Protox mRNA appeared to correlate with the copy number. Furthermore, the plastidal transgenic lines exhibited much higher expression of the Protox mRNA than the cytoplasmic transgenic lines. The transgenic plants expressing the B. subtilis Protox gene at T0 generation were found to be resistant to oxyfluorfen when judged by cellular damage with respect to cellular leakage, Chl loss, and lipid peroxidation. The transgenic rice plants targeted to the plastid exhibited higher resistance to the herbicide than the transgenic plants targeted to the cytoplasm. In addition, possible resistance mechanisms in the transgenic plants to DPE herbicides are discussed.

Agrobacterium tumefaciens↗
PubMed2000

Tissue-preferential expression of a rice alpha-tubulin gene, OsTubA1, mediated by the first intron.

The genomic clone encoding an alpha-tubulin, OsTubA1, has been isolated from rice (Oryza sativa L.). The gene consists of four exons and three introns. RNA-blot analysis showed that the gene is strongly expressed in actively dividing tissues, including root tips, young leaves, and young flowers. Analysis of chimeric fusions between OsTubA1 and beta-glucuronidase (GUS) revealed that the intron 1 was required for high-level GUS expression in actively dividing tissues, corresponding with normal expression pattern of OsTubA1. Fusion constructs lacking the intron 1 showed more GUS staining in mature tissues rather than young tissues. When the intron 1 was placed at the distal region from 5'-upstream region or at the 3'-untranslated region, no enhancement of GUS expression was observed. Sequential deletions of the OsTubA1 intron 1 brought about a gradual reduction of GUS activity in calli. These results suggest that tissue-preferential expression of the OsTubA1 gene is mediated by the intron 1 and that it may be involved in a mechanism for an efficient RNA splicing that is position dependent.

Blotting, Northern↗
PubMed2000

leafy hull sterile1 is a homeotic mutation in a rice MADS box gene affecting rice flower development.

Rice contains several MADS box genes. It has been demonstrated previously that one of these genes, OsMADS1 (for Oryza sativa MADS box gene1), is expressed preferentially in flowers and causes early flowering when ectopically expressed in tobacco plants. In this study, we demonstrated that ectopic expression of OsMADS1 in rice also results in early flowering. To further investigate the role of OsMADS1 during rice flower development, we generated transgenic rice plants expressing altered OsMADS1 genes that contain missense mutations in the MADS domain. There was no visible alteration in the transgenic plants during the vegetative stage. However, transgenic panicles typically exhibited phenotypic alterations, including spikelets consisting of elongated leafy paleae and lemmas that exhibit a feature of open hull, two pairs of leafy palea-like and lemma-like lodicules, a decrease in stamen number, and an increase in the number of carpels. In addition, some spikelets generated an additional floret from the same rachilla. These characteristics are very similar to those of leafy hull sterile1 (lhs1). The map position of OsMADS1 is closely linked to that of lhs1 on chromosome 3. Examination of lhs1 revealed that it contains two missense mutations in the OsMADS1 MADS domain. A genetic complementation experiment showed that the 11.9-kb genomic DNA fragment containing the wild-type OsMADS1 gene rescued the mutant phenotypes. In addition, ectopic expression of the OsMADS1 gene isolated from the lhs1 line resulted in lhs1-conferred phenotypes. These lines of evidence demonstrate that OsMADS1 is the lhs1 gene.

Amino Acid Sequence↗
PubMed2000

A comparative study of the dose-response and time course of recovery of atracurium and rocuronium.

OBJECTIVE: To compare the characteristics of the dose-response relationship and the time course of action between atracurium and rocuronium in adult patients anesthetized with N2O-O2-fentanyl-thiopene. METHODS: Sixty patients, ASA grade I, aged 18-50 years, scheduled for elective plastic surgery were studied. All patients were randomly divided into either the atracurium or rocuronium group. General anesthesia was maintained with 60% nitrous oxide and 40% oxygen, thiopentone, and fentanyl. Neuromuscular function was assessed using an accelograph with train-of-four (TOF) stimulation at the wrist every 12 seconds. The percentage depression of the first twitch (T1) was used as the study parameter. The dose-response relationship of atracurium and rocuronium was determined by the cumulative dose-response technique. RESULTS: According to the dose-response curves established by a least squares linear regression, the potency ratio of atracurium to rocuronium was 1:1.2. There were significant differences in the ED50, ED90, and ED95 between the two drugs. After the intravenous administration of equipotent doses of both drugs (1.5 x ED95), the duration of peak effect, clinical duration, and total duration were significantly different between the two drugs, but their recovery indexes were similar. CONCLUSIONS: Atracurium and rocuronium are low-potency nondepolarizing relaxants with intermediate duration. As compared to atracurium, the neuromuscular blocking effect of rocuronium was about 20% less potent and its duration of action was shorter.

Adolescent↗
PubMed2000

[Fresh femoral shaft fractures treated with un-reamed intramedullary nail: 203 cases].

OBJECTIVE: To discuss the experience treating fresh femoral shaft fractures with un-reamed intramedullary nail. METHODS: 203 cases of fresh femoral shaft fractures who had been treated with un-reamed intramedullary nail from November. 1995 to January. 1999 were analyzed retrospectively. 18 cases were open, classified as Gustilo I, and. 185 cases were closed. Traction table and image intensifier were used during operation. Closed reduction, un-reamed and free hand distal locking technique were used. Active movements of nearby joints were encouraged and partial weight bearing of 10 - 15 kg were allowed right after operation. RESULTS: All 203 cases of fresh femoral shaft fractures got bone union within 4 - 6 months. No case of delayed union and infection happened. 1 distal locking screw was broken. All patients gained normal extremity functions. CONCLUSION: Un-reamed intramedullary nailing of fresh femoral shaft fracture has less damage to the local soft tissue and blood supply. It has a relative stable fracture fixation, and less interruption to the healing procedure. It is one of the best methods for treating femoral fracture.

Bone Nails↗