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.

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.

[Epidemiology of dental caries and periodontal diseases in middle school students in Suzhou City]

OBJECTIVE

To assess the prevalence of dental caries and periodontal diseases in middle school students at the ages of 11 to 13 and 15 to 17.

METHODS

Dental caries and periodontal diseases were assessed strictly by "national survey table of dental caries and periodontal diseases for school students".

RESULTS

The study group consisted of 20 581 students. The percentage of dental caries, DMFT and DMFS in students 11 to 13 years of age were 23.6%,0.40 and 0.54, respectively. The corresponding results were 29.76%, 0.64 and 0.87 for students 15 to 17 years of age, respectively. The percentage of gingivitis and dental calculus in students 11 to 13 years were 75.33% and 35.86%, respectively. The corresponding values in students 15 to 17 years of age were 73.1% and 44.91%, respectively. Female students have significantly few gingivitis and dental calculus than male students in both groups.

CONCLUSION

Compared with the students at the same ages in other cities, students in Suzhou city have low percentage of dental caries and periodontal diseases.

[Effect of propofol and etomidate for anesthesia induction on plasma total cortisol concentration]

OBJECTIVE

To investigate the effect of propofol and etomidate for anesthesia induction on adrenocortical function.

METHODS

The plasma total cortisol concentration was determined in 20 patients who were treated with propofol or etomidate.

RESULTS

After propofol induction, the plasma total cortisol level decreased from (308.7 +/- 27.4) nmol/L to (267.7 +/- 31.2) nmol/L at post-medication 2 hours, increased to (400.2 +/- 26.9) nmol/L at postmedication 5 hours and restored to premedication level at postmedication 24 hours [(306.4 +/- 35.4) nmol/L]. After etomidate induction, the plasma total cortisol level decreased from (309.1 +/- 36.6) nmol/L to (115.9 +/- 29.7) nmol/L at postmedication 2 hours, maintained (171.1 +/- 34.7) nmol/L at postmedication 5 hours and restored to premedication level at postmedication 24 hours [(311.8 +/- 46.2) nmol/L].

CONCLUSIONS

Propofol induction has little effect on adrenocortical function whereas etomidate induction inhibits adrenocortical function.

[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.

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.

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.

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.

[The summarization of clinical experience of difficult tracheal intubation]

OBJECTIVE

To summarize our experiences and lessons of difficult tracheal intubation for clinical anesthesia reference.

METHODS

We had done a retrospective analysis of clinical data on difficult tracheal intubation in 2,825 patients undergoing elective plastic surgery with anesthesia. The main causes of difficult tracheal intubation were the limitations of neck extension (n = 1,169), mouth opening (n = 889), both neck extension and mouth opening (n = 698), and micromaxillary deformity (n = 69). By the Cormack's classification, all the patients had the laryngeal exposure of grade II or more. The tracheal intubations were done under neuroleptanalgesia combined with topical spray of local anesthetic in 439 patients, intravenous anesthesia of sedative drugs and nondepolarizing relaxants of subnormal doses in 629 subjects, and total intravenous or inhaled anesthesia in 1,757 cases, respectively.

RESULTS

The difficult tracheal intubations were completed using blind nasal intubations in 142 patients, blind oral intubations with direct laryngoscope in 2,377 patients, oral intubations with fiberoptic stylet rigid laryngoscope in 186 patients, and oral or nasal intubations with flexible fiberoptic bronchoscope in 72 patients. The incidence of successful intubation was 99.7%. The common complication of intubation was airway trauma and its incidence was 19.3% in all the patients. Anesthetic techniques could affect significantly the intubation time and the incidences of complications in the patients with difficult intubation.

CONCLUSIONS

By the improvement of anesthetic methods and common intubation techniques, the intubation time and the incidence of complications in the patients with difficult intubations were reduced.

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.

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.

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.

Ectopic expression of tobacco MADS genes modulates flowering time and plant architecture

MADS genes encode regulatory factors that are involved in various developmental steps of the plant life cycle. During flower development, they regulate the early step of specifying floral meristem identity as well as the later step of determining the fate of floral organ primordia. Here, we report the isolation of two cDNA clones, NsMADS2 and NsMADS3, from a long-day tobacco species, Nicotiana sylvestris, which encode MADS domain-containing proteins. The NsMADS2 amino acid sequence showed 66% identity to SQUA and 64% to AP1. NsMADS3 showed a high degree of amino acid identity with FBP2 (98%), DEFH 72 (89%), DEFH 200 (88%), and AGL9 (76%). RNA blot analyses of NsMADS2 and NsMADS3 revealed that both transcripts were present in floral organs, but not in vegetative organs such as the leaf, root, stem, and 10 d old seedlings. The NsMADS2 transcript was localized in all four whorls and the NsMADS3 transcript was restricted in the three inner whorls of floral organs. The ectopic expression of NsMADS2 using the CaMV 35S promoter caused early flowering and lengthened internode length in transgenic tobacco plants. The ectopic expression of NsMADS3 also caused early flowering phenotype in transgenic tobacco plants, but the plants exhibited reduced apical dominance. Possible implications of these results in relation to the functions of NsMADS2 and NsMADS3 are discussed.

Human prostate-specific transglutaminase gene: promoter cloning, tissue-specific expression, and down-regulation in metastatic prostate cancer

OBJECTIVES

To investigate the tissue-specific and differential expression of the human prostate-specific transglutaminase (pTGase) gene in metastatic prostate cancer (CaP) and to study how this gene is regulated in the prostate.

METHODS

Northern blot hybridization and polymerase chain reaction (PCR) were performed using RNA from a variety of organs to confirm prostate-specific expression of the gene. Relative quantitative reverse transcriptase-PCR (RT-PCR) was performed to investigate the differential expression of the gene among normal prostates and prostates with CaP and metastatic CaP. The pTGase gene promoter was cloned using genomic library screening and sequencing. Transfection experiments and chloramphenicol acetyltransferase (CAT) assays were performed to study the regulation of the gene.

RESULTS

Northern hybridization and RT-PCR confirmed that the gene is only expressed in the prostate. Relative quantitative RT-PCR demonstrated a loss of expression of the pTGase gene among men with CaP and higher Gleason grades. In metastatic CaP tissue from various sites, 86% of the samples lost expression of the gene. We cloned and sequenced a 1.4-kilobase promoter region of the pTGase gene. Transfection and CAT assay results supported the theory that certain elements in the -1 to -520 region are sufficient to direct prostate-specific expression of the gene. Additional elements in the -520 to -1400 region may also contribute to its prostate-specific expression.

CONCLUSIONS

The results of our study demonstrate that the human pTGase gene is only expressed in prostate tissue and that its expression is inhibited in most metastatic CaP. Prostate-specific expression of the gene is controlled by elements in the promoter region. The observed preferential loss of pTGase gene expression in metastatic CaP may be important to the pathogenesis and progression of this disease.

Cloning and molecular analyses of a gibberellin 20-oxidase gene expressed specifically in developing seeds of watermelon

To understand the biosynthesis and functional role of gibberellins (GAs) in developing seeds, we isolated Cv20ox, a cDNA clone from watermelon (Citrullus lanatus) that shows significant amino acid homology with GA 20-oxidases. The complementary DNA clone was expressed in Escherichia coli as a fusion protein, which oxidized GA(12) at C-20 to the C(19) compound GA(9), a precursor of bioactive GAs. RNA-blot analysis showed that the Cv20ox gene was expressed specifically in developing seeds. The gene was strongly expressed in the integument tissues, and it was also expressed weakly in inner seed tissues. In parthenocarpic fruits induced by 1-(2-chloro-4-pyridyl)-3-phenylurea treatment, the expression pattern of Cv20ox did not change, indicating that the GA 20-oxidase gene is expressed primarily in the maternal cells of developing seeds. The promoter of Cv20ox was isolated and fused to the beta-glucuronidase (GUS) gene. In a transient expression system, beta-glucuronidase staining was detectable only in the integument tissues of developing watermelon seeds.

Evisceration after abdominal stab wounds: is laparotomy required?

OBJECTIVES

To determine the incidence of intra-abdominal injury requiring laparotomy after an abdominal stab wound with evisceration. To identify clinical signs that increase the likelihood of an intra-abdominal injury in the presence of such a wound.

METHODS

Information was collected prospectively over an 8-year period on all patients who presented to our urban level I trauma center with an abdominal stab wound and evisceration. This information included which organ eviscerated, presence of other indications for laparotomy, organs injured, and postoperative complications. All comparisons used the Fisher's exact chi2.

RESULTS

A total of 81 patients were admitted with evisceration after an abdominal stab wound. Sixty-one patients (75%) had eviscerated omentum, 18 patients (22%) had eviscerated small bowel, and 2 patients (2%) had eviscerated colon. Sixty-two patients (76%) had evisceration as the sole indication for laparotomy, the remaining 19 patients (24%) had another indication such as hypotension or peritonitis. Overall, 63 patients (78%) had an intra-abdominal injury that required repair. This was true regardless of organ eviscerated (omentum = 77% vs. viscus = 80%, not significant) or clinical presentation (no other indication = 76% vs. another indication = 84%, not significant).

CONCLUSION

The majority of patients who present with an evisceration after a stab wound to the abdomen require a laparotomy. This is true regardless of what has eviscerated or the presence of other clinical indications to operate. Evisceration should continue to prompt operative intervention.

Influences of age and gender on dose response and time course of effect of atracurium in anesthetized adult patients

STUDY OBJECTIVE

To determine the influences of age and gender on the dose response and the time course of effect of atracurium.

DESIGN

Prospective, nonrandomized, clinical comparison.

SETTING

Operating room, Plastic Surgery Hospital of the Chinese Academy of Medical Sciences and Peking Union Medical College.

PATIENTS

72 adult ASA physical status I patients (38 male and 34 female), aged 15 to 59 years, scheduled for elective plastic surgery.

INTERVENTIONS

Patients were divided into the three groups on the basis of age: Group 1, patients aged 15-29 years (n = 32); Group 2, patients aged 30-40 years (n = 21); and Group 3, patients aged 41-59 years (n = 19). Anesthesia was maintained with 60% nitrous oxide in oxygen, thiopental, and incremental doses of fentanyl as required. The dose-response relationship of atracurium was determined by a cumulative dose-response technique.

MEASUREMENTS AND MAIN RESULTS

Neuromuscular function was assessed mechanomyographically with train-of-four stimulation at the wrist every 12 seconds and the percentage depression of first twitch (T1) response was used as the study variable. Age and gender significantly affected the dose-response relationship and time course of recovery of atracurium. Advancing age was associated with a reduced effective doses (ED50, ED90, and ED95) of atracurium and a longer duration of action. The effective doses of atracurium were greater, and its duration of action was shorter in men than in women. There were significant differences in the 50%, 90%, and 95% effective dose (ED50, ED90, and ED95) of atracurium, and clinical duration and total duration following administration of atracurium 400 micrograms/kg among the three age groups, and between men and women.

CONCLUSIONS

Age and gender have significant effects on the dose response and time course of effect of atracurium. Older patients and women are more sensitive to atracurium-induced neuromuscular block than are young patients and men.

Characterization of MdMADS2, a member of the SQUAMOSA subfamily of genes, in apple

A MADS-box gene, MdMADS2, was isolated from the apple (Malus x domestica Borkh.) var Fuji and its developmental expression pattern was studied during flower development. MdMADS2 shares a high degree of amino acid sequence identity with the SQUAMOSA subfamily of genes. RNA blot analysis showed that MdMADS2 is transcribed through all stages of flower development, and its transcription was seen in the four floral organs. RNA in situ hybridization revealed that the MdMADS2 mRNA is expressed both in the inflorescence meristem and in the floral meristem. The MdMADS2 transcript was detected at all stages of flower development. Protein localization analysis showed that MdMADS2 protein was excluded from the stamen and carpel primordia, in which a considerable MdMADS2 mRNA signal was detected. This indicates that posttanscriptional regulation may be involved in the MdMADS2-mediated control of flower development. Transgenic tobacco expressing the MdMADS2 gene from the cauliflower mosaic virus 35S promoter showed early flowering and shorter bolts, but did not show any homeotic changes in the floral organs. These results suggest that MdMADS2 plays an important role during early stages of flower development.

Determination of the motif responsible for interaction between the rice APETALA1/AGAMOUS-LIKE9 family proteins using a yeast two-hybrid system

A MADS family gene, OsMADS6, was isolated from a rice (Oryza sativa L.) young flower cDNA library using OsAMDS1 as a probe. With this clone, various MADS box genes that encode for protein-to-protein interaction partners of the OsMADS6 protein were isolated by the yeast two-hybrid screening method. On the basis of sequence homology, OsMADS6 and the selected partners can be classified in the APETALA1/AGAMOUS-LIKE9 (AP1/AGL9) family. One of the interaction partners, OsMADS14, was selected for further study. Both genes began expression at early stages of flower development, and their expression was extended into the later stages. In mature flowers the OsMADS6 transcript was detectable in lodicules and also weakly in sterile lemmas and carpels, whereas the OsMADS14 transcript was detectable in sterile lemmas, paleas/lemmas, stamens, and carpels. Using the yeast two-hybrid system, we demonstrated that the region containing of the 109th to 137th amino acid residues of OsMADS6 is indispensable in the interaction with OsMADS14. Site-directed mutation analysis revealed that the four periodical leucine residues within the region are essential for this interaction. Furthermore, it was shown that the 14 amino acid residues located immediately downstream of the K domain enhance the interaction, and that the two leucine residues within this region play an important role in that enhancement.

Expression of the Escherichia coli catabolic threonine dehydratase in Corynebacterium glutamicum and its effect on isoleucine production

The catabolic or biodegradative threonine dehydratase (E.C. 4.2.1. 16) of Escherichia coli is an isoleucine feedback-resistant enzyme that catalyzes the degradation of threonine to alpha-ketobutyrate, the first reaction of the isoleucine pathway. We cloned and expressed this enzyme in Corynebacterium glutamicum. We found that while the native threonine dehydratase of C. glutamicum was totally inhibited by 15 mM isoleucine, the heterologous catabolic threonine dehydratase expressed in the same strain was much less sensitive to isoleucine; i.e., it retained 60% of its original activity even in the presence of 200 mM isoleucine. To determine whether expressing the catabolic threonine dehydratase (encoded by the tdcB gene) provided any benefit for isoleucine production compared to the native enzyme (encoded by the ilvA gene), fermentations were performed with the wild-type strain, an ilvA-overexpressing strain, and a tdcB-expressing strain. By expressing the heterologous catabolic threonine dehydratase in C. glutamicum, we were able to increase the production of isoleucine 50-fold, whereas overexpression of the native threonine dehydratase resulted in only a fourfold increase in isoleucine production. Carbon balance data showed that when just one enzyme, the catabolic threonine dehydratase, was overexpressed, 70% of the carbon available for the lysine pathway was redirected into the isoleucine pathway.

Analysis of the C-terminal region of Arabidopsis thaliana APETALA1 as a transcription activation domain

APETALA1 (AP1) of Arabidopsis thaliana is a transcription factor controlling flower development. AP2 is a member of the MADS (MCM1, AGAMOUS, DEFICIENS, SRF) superfamily, which plays important roles in differentiation in plants and animals. MADS domains, which function most importantly in DNA binding, are found in all major eukaryotic kingdoms. In plants, MADS domain-containing proteins also possess a region of moderate sequence similarity named the K domain, which is involved in protein-protein interaction. Little is known about the function of a third, highly variable, domain designated the C domain, as it resides at the C terminus of the MADS proteins of plants. Here we report that the C-terminal domain of Arabidopsis thaliana AP1 and its homologues perform a transcriptional activation function. The C-terminal region of AP1 is composed of at least two separable transcriptional activation domains that function synergistically.

Analysis of the C-terminal region of Arabidopsis thaliana APETALA1 as a transcription activation domain

APETALA1 (AP1) of Arabidopsis thaliana is a transcription factor controlling flower development. AP2 is a member of the MADS (MCM1, AGAMOUS, DEFICIENS, SRF) superfamily, which plays important roles in differentiation in plants and animals. MADS domains, which function most importantly in DNA binding, are found in all major eukaryotic kingdoms. In plants, MADS domain-containing proteins also possess a region of moderate sequence similarity named the K domain, which is involved in protein-protein interaction. Little is known about the function of a third, highly variable, domain designated the C domain, as it resides at the C terminus of the MADS proteins of plants. Here we report that the C-terminal domain of Arabidopsis thaliana AP1 and its homologues perform a transcriptional activation function. The C-terminal region of AP1 is composed of at least two separable transcriptional activation domains that function synergistically.

Identification of a rice APETALA3 homologue by yeast two-hybrid screening

A cDNA clone OsMADS16 was isolated from the rice young inflorescence cDNA expression library by the yeast two-hybrid screening method with OsMADS4 as bait. We have previously shown that the OsMADS4 gene is a member of the PI family and that the MADS-box gene is involved in controlling development of the second and third whorls of rice flowers. The sequence comparison indicated that OsMADS16 belongs to the AP3 family. The OsMADS16 protein contains a PI-derived motif, FAFRVVPSQPNLH, that is a conserved sequence in AP3 family genes at the C-terminal region. In addition, OsMADS16 contains a paleoAP3 motif, YGGNHDLRLG, downstream of the PI-derived motif. The paleoAP3 motif is a consensus sequence in the C-terminal region of the AP3 family genes of lower eudicot and magnolid dicot species. RNA blot analysis showed that the OsMADS16 gene was expressed in the second and third whorls, whereas the OsMADS4 transcripts were present in the second, third, and fourth whorls. These expression patterns of the OsMADS16 and OsMADS4 genes are very similar to those of AP3 and PI, respectively. In the yeast two-hybrid system, OsMADS4 interacted only with OsMADS16 among several rice MADS genes investigated, suggesting that OsMADS4 and OsMADS16 function as a heterodimer in specifying sepal and petal identities. The OsMADS16 protein displayed transcription activation ability in yeast, whereas AP3 did not. It was also shown in yeast that OsMADS16 interacted with PI whereas OsMADS4 did not interact with AP3. These differences between OsMADS16 and AP3 indicate that the functions of the AP3 family genes of monocots and dicots diverged during molecular evolution processes of the B function genes. Deletion analysis showed that the 155-200 amino acid region of the OsMADS16 protein plays an important role in the transcription activation ability.

Observation of the correlation of postanaesthesia recovery scores with early postoperative hypoxaemia in children

To observe the correlation of the postanaesthesia recovery score (PARS) with the incidence, and severity of early postoperative hypoxaemia in children, 1213 infants and children, ASA physical status I, aged three months to 14 years, scheduled for elective plastic surgery were included in this study. Arterial oxygen saturation (Spo2) levels were recorded while children were breathing room air shortly after arrival in the recovery room (0 min), and 5, 10, 15, 20, 30, 40, 50, 60, 120 and 180 min thereafter. The PARS was also determined on all patients when Spo2 levels were recorded in the recovery room. On the basis of different PARS, children were divided into the three groups: Group 1-children having the PARS of < or = 6; Group 2-children having the PARS of 7-9; and Group 3-children having a PARS of 10. The results showed that during the early postoperative period, the incidence and severity of hypoxaemia correlated closely with the PARS. The lower the children's PARS, the higher the incidences of hypoxaemia (Spo2 = 86-90%) and severe hypoxaemia (Spo2 < or = 85%). The incidences of hypoxaemia and severe hypoxaemia were 12.9% and 15.8%, respectively, in Group 1, 20.9% and 2.9% in Group 2, 0.8% and 0% in Group 3. There were significant differences among the three groups. Of the 91 children who required O2 supplementation in the recovery room because of low measured Spo2, 69 had the PARS of < or = 6, and 22 had the PARS of 7-8. It is concluded that if a patient has a PARS of 10, the patient will not need routine oxygen supplement because hypoxaemia will not occur.