Biomedical subjects

J Cao

Publications and source records attributed to J Cao.

At least 73 records · Page 4Linked to original sources

PubMed2001

Nicotinic agonists stimulate acetylcholine release from mouse interpeduncular nucleus: a function mediated by a different nAChR than dopamine release from striatum.

Acetylcholine release stimulated by nicotinic agonists was measured as radioactivity released from perfused synaptosomes prepared from mouse interpeduncular nucleus (IPN) that had been loaded with [(3)H]choline. Agonist-stimulated release was dependent upon external calcium and over 90% of released radioactivity was acetylcholine. The release process was characterized by dose response curves for 13 agonists and inhibition curves for six antagonists. alpha-Conotoxin MII did not inhibit this release, while alpha-conotoxin AuIB inhibited 50% of agonist-stimulated release. Comparison of this process with [(3)H]dopamine release from mouse striatal synaptosomes indicated that different forms of nicotinic acetylcholine receptors (nAChRs) may mediate these processes. This was confirmed by assays using mice homozygous for the beta 2 subunit null mutation. The deletion of the beta 2 subunit had no effect on agonist-stimulated acetylcholine release, but abolished agonist-stimulated release of dopamine from striatal synaptosomes. Mice heterozygous for the beta 2 subunit null mutation showed decreased dopamine release evoked by L-nicotine with no apparent change in EC(50) value, as well as similar decreases in both transient and persistent phases of release with no changes in desensitization rates.

Acetylcholine↗

PubMed2001

Differential regulation of hepatic bile salt and organic anion transporters in pregnant and postpartum rats and the role of prolactin.

We characterized expression and activity of the bile salt transporters Na(+)/taurocholate (TC) cotransporting polypeptide (Ntcp), and bile salt export pump (Bsep), and the expression of organic anion transporting polypeptides 1 and 2 (Oatp1 and 2) and multidrug resistance associated protein-2 (Mrp2) in pregnancy and throughout lactation in rats. The V(max) for Na(+)/TC cotransport in basolateral liver plasma membrane was increased 1.7-fold in 2 days postpartum relative to control and pregnant rats. This correlated well with an increase in Ntcp messenger RNA (mRNA) and a 2-fold increase in Ntcp protein. Ntcp mRNA remained significantly elevated until 14 days postpartum but had begun to decline by 21 days postpartum. The maximal secretory rate (nmol/min/g liver) for TC in the single pass isolated perfused liver was also increased by 10%, 31%, and 24% at 2, 14, and 21 days postpartum and correlated with increased expression of Ntcp and Bsep mRNA and protein. Infusion of ovine prolactin (oPRL) to ovariectomized rats increased expression of both Ntcp and Bsep mRNA and protein. These data indicate a coordinate increased expression of bile salt transporters postpartum and by PRL. Mrp2 mRNA was stable in pregnancy and postpartum, whereas Mrp2 protein expression decreased significantly in pregnancy, but returned to control levels postpartum. Organic anion transporting polypeptide 2 (Oatp2) mRNA was decreased in pregnancy and increased postpartum, but changes in Oatp2 protein were not significant. Oatp1 mRNA and protein were unchanged in pregnancy and postpartum.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2001

The use of psychoactive substances among adolescent students in an area in the south-west of China.

AIM: To survey drug/psychoactive substance use among adolescent students in a south-west province of China. DESIGN: A cluster sample was drawn from this province of nine districts or cities. Each district/city provided two schools from grade 11 senior high school, A total of 18 schools were selected randomly. FINDINGS: A total of 2649 students completed this self-report questionnaire, mean age 17.1 +/- 0.9 years. The response rate was 92.7-95.6% for each of the specific substances or drugs. The 'life-time prevalences of regular substance use' (at least 15 times during in any one month) were, in rank order of prevalence: tobacco 6.3%, non-steroid anti-inflammatory drugs (NSAID) 2.9%, alcohol 2.9%, solvent 0.3%, sedative/hypnotic 0.2% and cannabis 0.04%. The life-time prevalences of at least some use were: alcohol 66.1%, NSAID 59.3%, tobacco 27.4%, sedative/hypnotic 5.2%, heroin 3.1%, solvents 2.8%, amphetamine-type stimulants (ATS) 0.7% and cannabis 0.3%. The 'prevalences of current regular use' (at least 15 times in the past month) were: tobacco 4.2%, alcohol 1.6%, NSAID 0.8%, sedative/hypnotic 0.1%, solvents 0.1% and cannabis 0.1%. The 'prevalences of current use at any level' were: alcohol 15.2%, NSAID 9.6%, tobacco 7.1%, sedative/hypnotic 0.5%, solvents 0.4%, cannabis 0.1%, heroin 0.1%, and ATS 0.04%. The median age at onset substance use was between 10.7 and 13.4 9.6%. CONCLUSIONS: Drug misuse has appeared among teenage students in this area. The most widely used substances were alcohol and cigarettes. The rates of solvent, tobacco and alcohol use among males were substantially higher than in females.

Adolescent↗

PubMed2001

QSAR modeling of bioconcentration factors in fish based on fragment constants and structural correction factors.

The quantitative structure-activity relationship between the BCF and fragment constant of organic chemicals was studied using a database containing 337 experimental BCF values. The database covered a large variety of chemicals ranging from the very hydrophobic to the very hydrophilic with logKow values between 0.39 and 8.60. The structural features affecting the BCFs were identified and evaluated during a preliminary modeling. A final linear multivariate regression model was derived that was able to account for as much as 98.0% of the variation in the experimental BCF values. The mean absolute error for the final model was 0.315 log-units. In addition, the predictability and robustness of the model was also evaluated.

Animals↗

PubMed2001

Expression of multidrug resistance-associated protein 2 in small intestine from pregnant and postpartum rats.

We analyzed the expression of multidrug resistance-associated protein 2 (mrp2) in the small intestine of control female rats and in rats during late pregnancy (19-20 days of pregnancy) and lactation (2-4, 10-14, and 21 days after delivery). Western blot analysis was performed on brush-border membranes prepared from different regions of the small intestine. Expression of mrp2 was maximal in the proximal segments for all experimental groups, was preserved in pregnant rats, and increased by 100% in postpartum rats by late lactation with respect to control animals. Northern blot analysis of mrp2 mRNA revealed a positive correlation with protein levels. Transport of S-glutathione-dinitrophenol (DNP-SG) from the intestinal cell to the lumen was analyzed in the everted intestinal sac model. Secretion of DNP-SG was not altered in pregnant rats but increased in lactating animals by late lactation. Intestinal mrp2 mRNA, protein, and transport activity are increased in lactating rats, suggesting that this may represent an adaptive mechanism to minimize the toxicity of dietary xenobiotics in response to increased postpartum food consumption.

ATP Binding Cassette Transporter, Subfamily B↗

PubMed2001

PRL, placental lactogen, and GH induce NA(+)/taurocholate-cotransporting polypeptide gene expression by activating signal transducer and activator of transcription-5 in liver cells.

We investigated the transcriptional regulation of the Na(+)/taurocholate cotransporting polypeptide gene by PRL, placental lactogen, and GH. In primary hepatocytes, ovine PRL induced a dose-dependent phosphorylation and nuclear translocation of signal transducers and activators of transcription-5a and -5b, but not -1 or -3, whereas mouse placental lactogen I and rat GH activated -5a, -5b, and -1. In EMSAs, ovine PRL, mouse placental lactogen I, and rat GH increased the specific DNA binding of nuclear signal transducer and activator of transcription-5 to its consensus element in both transfected HepG2 cells and primary hepatocytes. PRL, placental lactogen I, and GH also increased Na(+)/taurocholate cotransporting polypeptide mRNA expression in hepatocytes from control and pregnant (mouse placental lactogen I) rats. Genistein, a phosphotyrosine kinase inhibitor, inhibited PRL-induced signal transducer and activator of transcription-5 activation and Na(+)/taurocholate-cotransporting polypeptide mRNA. In HepG2 cells transiently cotransfected with either the long form of the rat PRL receptor or rat GH receptor, signal transducer and activator of transcription-5a and a -5-responsive luciferase expression vector containing the Na(+)/taurocholate-cotransporting polypeptide promoter, mouse placental lactogen I, like ovine PRL, activated -5a via the long form of the rat PRL receptor; whereas rat GH activated -5a via rat GH receptor, leading to transactivation of the Na(+)/taurocholate-cotransporting polypeptide promoter. These data establish that PRL and placental lactogen I induce Na(+)/taurocholate-cotransporting polypeptide gene expression via signal transducer and activator of transcription-5 proteins in liver, and indicate that these hormones play an important role in regulating liver metabolic function.

Animals↗

PubMed2001

Ruscogenin glycoside (Lm-3) isolated from Liriope muscari improves liver injury by dysfunctioning liver-infiltrating lymphocytes.

The effects of ruscogenin 1-O-[beta-D-glucopyranosyl(1 --> 2)] [beta-D-xylopyranosyl(1 --> 3)]-beta-D-fucopyranoside (Lm-3) and its aglycone, ruscogenin, on liver injury induced in mice by delayed-type hypersensitivity to picryl chloride have been investigated. Lm-3 and ruscogenin significantly decreased liver injury when given during the effector phase of the delayed-type hypersensitivity reaction. The pretreatment of nonparenchymal cells, but not hepatocytes, with Lm-3 or ruscogenin in-vitro caused a concentration- and time-dependent inhibition against the damage. Lm-3 showed a stronger inhibition against the damage than ruscogenin (IC50: Lm-3 6.3 x 10(-10) M, ruscogenin 3.9 x 10(-7) M). However, neither Lm-3 nor ruscogenin blocked the hepatotoxic potential of CCl4, when used to pretreat hepatocytes. Moreover, Lm-3 and ruscogenin inhibited concanavalin A-induced lymphocyte proliferation only at high concentrations. These results suggested that Lm-3 and ruscogenin improved the immunological liver injury by selectively causing dysfunction of the liver-infiltrating cells rather than by protecting hepatocyte membranes. Such characteristics would be significant for treating immunologically related liver diseases as well as for developing new drugs.

Animals↗

PubMed2001

Effect of long-term exposure to fluoride in drinking water on risks of bone fractures.

Findings on the risk of bone fractures associated with long-term fluoride exposure from drinking water have been contradictory. The purpose of this study was to determine the prevalence of bone fracture, including hip fracture, in six Chinese populations with water fluoride concentrations ranging from 0.25 to 7.97 parts per million (ppm). A total of 8266 male and female subjects > or =50 years of age were enrolled. Parameters evaluated included fluoride exposure, prevalence of bone fractures, demographics, medical history, physical activity, cigarette smoking, and alcohol consumption. The results confirmed that drinking water was the only major source of fluoride exposure in the study populations. A U-shaped pattern was detected for the relationship between the prevalence of bone fracture and water fluoride level. The prevalence of overall bone fracture was lowest in the population of 1.00-1.06 ppm fluoride in drinking water, which was significantly lower (p < 0.05) than that of the groups exposed to water fluoride levels > or =4.32 and < or =0.34 ppm. The prevalence of hip fractures was highest in the group with the highest water fluoride (4.32-7.97 ppm). The value is significantly higher than the population with 1.00-1.06 ppm water fluoride, which had the lowest prevalence rate. It is concluded that long-term fluoride exposure from drinking water containing > or =4.32 ppm increases the risk of overall fractures as well as hip fractures. Water fluoride levels at 1.00-1.06 ppm decrease the risk of overall fractures relative to negligible fluoride in water; however, there does not appear to be similar protective benefits for the risk of hip fractures.

Aged↗

PubMed2001

Different cross-resistance patterns in the diamondback moth (Lepidoptera: Plutellidae) resistant to Bacillus thuringiensis toxin Cry1C.

Two strains of the diamondback moth, Plutella xylostella (L.), were selected using Cry1C protoxin and transgenic broccoli plants expressing a Cry1C toxin of Bacillus thuringiensis (Bt). Both strains were resistant to Cry1C but had different cross-resistance patterns. We used 12 Bt protoxins for cross-resistance tests, including Cry1Aa, Cry1Ab, Cry1Ac, Cry1Bb, Cry1C, Cry1D, Cry1E, Cry1F, Cry1J, Cry2Ab, Cry9Aa, and Cry9C. Compared with the unselected sister strain (BCS), the resistance ratio (BR) of one strain (BCS-Cry1C-1) to the Cry1C protoxin was 1,090-fold with high level of cross-resistance to Cry1Aa, Cry1Ab, Cry1Ac, Cry1F, and Cry1J (RR > 390-fold). The cross-resistance to Cry1A, Cry1F, and Cry1J in this strain was probably related to the Cry1A resistance gene(s) that came from the initial field population and was caused by intensive sprayings of Bt products containing Cry1A protoxins. The neonates of this strain can survive on transgenic broccoli plants expressing either Cry1Ac or Cry1C toxins. The other strain (BCS-Cry1C-2) was highly resistant to Cry1C but not cross-resistant to other Bt protoxins. The neonates of this strain can survive on transgenic broccoli expressing Cry1C toxin but not Cry1Ac toxin. The gene(s) conferring resistance to Cry1C segregates independently from Cry1Ac resistance in these strains. The toxicity of Cry1E and Cry2Ab protoxins was low to all of the three strains. The overall progress of all work has resulted in a unique model system to test the stacked genes strategy for resistance management of Bt transgenic crops.

Animals↗

PubMed2001

CMT-3, a non-antimicrobial tetracycline (TC), inhibits MT1-MMP activity: relevance to cancer.

Tetracyclines (TCs) and their non-antimicrobial analogs (CMTs) have therapeutic potential to inhibit tissue destructive disease processes, such as cancer invasion and metastasis, by inhibiting certain matrix metalloproteinases. Enhanced matrix metalloproteinase-2 (MMP-2; gelatinase A) activity has been correlated to cancer invasiveness, and membrane type MMP (MT1-MMP) expressed by tumor cells is involved in localizing and activating pro-MMP-2, a pathway believed to mediate cancer induced tissue breakdown. CMT-3 (6-demethyl, 6-deoxy, 4-dedimethylamino TC) has been shown to experimentally suppress prostate cancer, colon adenocarcinoma and melanoma invasiveness in cell culture and to inhibit tumor growth and metastasis in vivo and was used in the current in vitro study. Confluent MT1-MMP transfected COS-1 cells were harvested, washed thoroughly, subjected to N(2) cavitation and cell membrane enriched fractions were isolated by sequential centrifugations. This MT1-MMP preparation exhibited (i) pro-MMP-2 activating activity as shown by molecular weight shift of this gelatinase from 72 kDa to 62 kDa using gelatin zymography, and (ii) the ability to degrade both [(3)H-methyl] gelatin and casein at 37 degrees C. Adding CMT-3 at final concentrations of 5--20microM inhibited MT1-MMP gelatinolytic and caseinolytic activity, blocked MT1-MMP activation of pro-MMP-2, and decreased invasiveness (using the Matrigel system) of HT-1080 fibrosarcoma cells. The inhibition of MT1-MMP by CMT-3 may partially explain the inhibition of cancer cell -mediated tissue breakdown and invasiveness by this non-antimicrobial tetracycline analog.

Animals↗

PubMed2001

Reversal of multidrug resistance by the P-glycoprotein modulator, LY335979, from the bench to the clinic.

Multidrug resistance may be conferred by P-glycoprotein (Pgp, ABCB1) or the multidrug resistance associated protein (MRP). These membrane proteins are members of the ATP binding cassette transporter superfamily and are responsible for the removal from the cell of several anticancer agents including doxorubicin. Modulators can inhibit these transporters. LY335979 is among the most potent modulators of Pgp with a Ki of 59 nM. LY335979 is selective for Pgp, and does not modulate MRP-mediated resistance by MRP1 (ABCC1) and MRP2 (ABCC2). LY335979 significantly enhanced the survival of mice implanted with Pgp-expressing murine leukemia (P388/ADR) when administered in combination with either daunorubicin, doxorubicin or etoposide. Coadministration of LY335979 with paclitaxel compared to paclitaxel alone significantly reduced the tumor mass of the Pgp-expressing UCLA-P3.003VLB lung carcinoma in a xenograph model and delayed the development of tumors in mice implanted with the parental drug-sensitive UCLA-P3 tumor. LY335979 was without significant effect on the pharmacokinetics of these anticancer agents. This may be due impart to its poor inhibition of four major cytochrome P450 isozymes important in metabolizing doxorubicin and other oncolytics. The selectivity and potency of this modulator allows the clinical evaluation of the role of Pgp in multidrug resistance. LY335979 is currently in clinical trials.

ATP Binding Cassette Transporter, Subfamily B↗

PubMed2001

Chemical characteristics and relative bioavailability of supplemental organic copper sources for poultry.

Five commercially available organic Cu products and reagent-grade CuSO4 x 5H2O (Cu Sulf) were evaluated by polarographic analysis and solubility in 0.1 M K2HPO4-KH2PO4 buffer (pH 5), 0.2 M HCl-KCl buffer (pH 2), or deionized water. Fractions from these solubility tests were evaluated by gel filtration chromatography for structural integrity. The organic sources were Cu lysine complex (Cu Lys), Cu amino acid chelate (Cu AA), Cu proteinate A (Cu ProA), Cu proteinate B (Cu ProB), and Cu proteinate C (Cu ProC). Separation of peaks in the chromatograms for the soluble Cu fraction from deionized water indicated that 77, 31, 69, 94, and 16% of the Cu remained chelated for the above sources, respectively. Two experiments were conducted to estimate the relative bioavailability of Cu from the organic Cu supplements for chicks when added at high dietary concentrations to practical corn-soybean meal diets. Liver Cu concentration increased (P < 0.0001) as dietary Cu increased in both experiments. When Cu Sulf was assigned a value of 100% as the standard, linear regression slope ratios of log10 liver Cu concentration regressed on added dietary Cu concentration gave estimated relative bioavailability values of 124 +/- 5.1, 122 +/- 5.3, and 111 +/- 6.0 for Cu Lys, Cu AA, and Cu ProC, respectively, in Exp. 1. The bioavailability estimates for Cu Lys and Cu AA were greater (P < 0.05) than that for Cu Sulf. Values in Exp. 2 were 111 +/- 7.6, 109 +/- 8.4, and 105 +/- 7.5 for Cu Lys, Cu ProA, and Cu ProB, respectively, and all sources were similar in value for chicks. Solubility of Cu in pH 2 buffer provided the best prediction of bioavailability (r2 = 0.924). Other indicators of chelation integrity and solubility had little value as predictors of bioavailability (r2 < or = 0.445).

Animals↗

PubMed2001

Inhibition of TNF-alpha-induced sickle RBC retention in retina by a VLA-4 antagonist.

PURPOSE: Patients with sickle cell disease have elevated circulating levels of cytokines including tumor necrosis factor (TNF) alpha. TNF-alpha stimulates expression by endothelial cells of adhesion molecules, including vascular cell adhesion molecule (VCAM) 1. Others have demonstrated that VLA-4 (alpha(4)beta(1)), a ligand for VCAM-1 or fibronectin, is present on a fraction of sickle reticulocytes. The intent of this study was to determine, using a rat model, if TNF-alpha increases retention of sickle erythrocytes in retina and if that retention can be inhibited. METHODS: TNF-alpha was given intraperitoneally to rats 5 hours before IV administration of FITC-labeled, density-separated sickle erythrocytes. After 5 minutes, rats were exsanguinated, and retinas were excised and incubated for ADPase activity, permitting the determination of the number and location of retained cells. RESULTS: TNF-alpha caused a three- to fourfold increase in retention of sickle erythrocytes in retinal capillaries (P < 0.05) but not of normal human erythrocytes. Preincubation of sickle erythrocytes with TBC772, a peptide that blocks the binding of alpha(4)beta(1) and alpha(4)beta(7), or a monoclonal antibody against VLA-4 (19H8), significantly inhibited the TNF-alpha-induced retention (P < or = 0.02), whereas a control cyclic peptide and antibody had no effect. IV TBC772 also inhibited sickle erythrocyte retention (P = 0.01). Two intravenously administered anti-fibronectin antibodies inhibited sickle cell retention as well, but an anti-rat VCAM-1 antibody did not inhibit retention. CONCLUSIONS: The authors conclude that TNF-alpha stimulates retention of sickle erythrocytes in the retinal vasculature. This increased retention can be blocked by a VLA-4 antagonist, suggesting that the cells retained after cytokine stimulation are reticulocytes. The counter-receptor for VLA-4 in this rat retina model appears to be fibronectin and not VCAM-1, based on data obtained using antibodies against these molecules.

Anemia, Sickle Cell↗

PubMed2001

Normalization of retinal vascular permeability in experimental diabetes with genistein.

PURPOSE: To study the effects of genistein, a tyrosine kinase inhibitor, on retinal vascular permeability in an experimental diabetic rat model. METHODS: Seventy-two rats were equally divided into four groups: (1) nondiabetic control group, (2) diabetic control group, (3) diabetic rats receiving 150 mg genistein/kg food, and (4) diabetic rats receiving 300 mg genistein/kg food. Diabetes was induced by streptozotocin injection in the three diabetic groups. Rats were fed diets with or without genistein and followed for 6 months. Retinal vascular permeability was assessed by measuring radiolabeled sucrose leakage into the retina and by Western blot analysis for total retinal albumin. Retinal phosphotyrosine levels and proliferating cell nuclear antigen (PCNA) were also evaluated by Western blot analysis. RESULTS: Diabetic control rats had markedly increased retinal vascular leakage of radiolabeled sucrose compared with nondiabetic control rats. Diabetic rats receiving oral genistein had significantly less retinal vascular leakage of radiolabeled sucrose than diabetic control rats in a dose-response fashion. Diabetic control rats had increased levels of phosphotyrosine, retinal albumin, and PCNA by Western blot analysis compared with nondiabetic control rats. Rats receiving 300 mg of genistein had decreased retinal albumin by Western blot analysis. Western blot analysis demonstrated a dose-response decrease in retinal phosphotyrosine levels and PCNA in genistein-treated diabetic rats compared with diabetic control rats. CONCLUSIONS: Long-term oral administration of genistein significantly inhibits retinal vascular leakage in experimentally induced diabetic rats. Tyrosine kinase inhibition may be a useful pharmacological approach for the treatment of diabetic-induced retinal vascular leakage.

Administration, Oral↗

PubMed2001

[Estimation of LC50 of chemicals to rainbow trout by fragment constant method].

A fragment constant model for prediction of 96 h LC50 of chemicals to rainbow trout was developed based on measured experimental data of 258 chemicals collected from the literature. The accuracy and the robustness of the model were discussed. The coefficient of determination of the model is 0.9495 and the mean residual is 0.42 log-unit. The model is robust for both individual chemical or chemical class.

Animals↗

PubMed2001

Effects of intracellular zinc depletion on metallothionein and ZIP2 transporter expression and apoptosis.

Zinc is critical for the functional and structural integrity of cells. We have used the monocytic cell line THP-1 as a model in which to study both the responsiveness of metallothionein and ZIP2 transporter expression to zinc depletion induced by the intracellular zinc chelator TPEN [N,N,N',N'-tetrakis(2-pyridylmethyl) ethylenediamine] and the extent of concomitant apoptosis. Metallothionein expression increased proportionately with the addition of zinc to the medium and decreased with TPEN treatment. When treated with TPEN, both THP-1 cells and human peripheral blood mononuclear cells exhibited marked decreases in cellular zinc concentrations and increases in ZIP2 mRNA expression. These results suggest that cells attempt to homeostatically adjust to zinc depletion. When THP-1 cells were treated with >5 microM TPEN, cell viability decreased, and cells entered the early stages of apoptosis. These data show that metallothionein and ZIP2 expression are inversely related during zinc depletion and that apoptosis is concurrent with these changes.

Adult↗

PubMed2001

[Effectiveness of short course intermittent regimen on different categories of retreated patients with pulmonary tuberculosis].

OBJECTIVE: To evaluate the efficacy of short course intermittent regimen in the different categories of retreated patients with tuberculosis. METHODS: 303 retreated patients with smear-positive pulmonary tuberculosis were recruited for the study. They were divided into three groups based on the history of tuberculosis and anti-tuberculosis treatment. 87 were in relapse group, 21 in failure group (failure after the initial treatment) and 195 in other retreatment group. Sputum Mycobacterium tuberculosis culture and drug susceptibility test were conducted before treatment. The same retreatment regimen (2-3H3R3Z3E3S3/5-6H3R3E3) was employed for all three groups of patients. Drug resistance and the outcomes of three groups of retreatment tuberculosis were analysed. RESULTS: The drug resistance rates and efficacy of retreatment showed no statistical difference among three groups (P > 0.05). In other retreatment group, the drug resistant rate in patients who received anti-TB drugs for more than 12 months (79.5%) was significantly higher than those for less than 12 months (59.8%, 0.01 < P < 0.05). Meanwhile, the successful rates of treatment were 69.4% vs 90.4% between two subgroups, being significantly different (P < 0.001). The successful treatment rate in susceptible patients (93.3%) was significantly higher than that in drug resistant patients (75.3%, P < 0.01). CONCLUSION: To enhance the efficacy of anti-TB therapy in drug-resistant patients is the key of improving the outcome of retreated patients receiving short course intermittent regimen.

Antitubercular Agents↗

PubMed2001

[Establishment of trans-inactivation system for haloalkane dehalogenase gene in Arabidopsis thaliana].

With haloalkane dehalogenase gene (dhlA) of Xanthobacter autothophicus as a negative selection marker, a novel trans-inactivation system for transgenes in plants was developed. After the Arabidopsis plants were transformed with dhlA, one plant was shown dhlA post-transcriptional silencing by nuclear run-off transcriptional analysis. The Arabidopsis plants containing silencing locus were crossed to those efficiently expressed dhlA, referred as a homologous transgenic locus, and 96% of F1 plants became the homologous dhlA inactivated in trans. When the F1 plants were selfed, and the silencing locus and the homologous locus were separated in some progenies, 42 of the 200 progenies exhibited DhlA activity, and 158 no DhlA activity, and the proportion of the DhlA-expressing plants to the dhlA-silencing ones was 3.76 to 1, which suggested that the silencing locus inactivated in trans the homologous transgenic locus as a Mendelian dominant factor.

Arabidopsis↗