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Biomedical subjects

S Jiang

Publications and source records attributed to S Jiang.

At least 19 recordsLinked to original sources
PubMed2007

Prognostic indicators in metastatic spinal cord compression: using functional independence measure and Tokuhashi scale to optimize rehabilitation planning.

STUDY DESIGN: Retrospective, descriptive study. OBJECTIVE: To determine if patients with metastatic spinal cord compression (MSCC) make significant functional gains through rehabilitation. To study survival and predictors of survival in MSCC. To explore predictive factors for high or low functional gains in MSCC. SETTING: Inpatient neuro-oncology rehabilitation ward, Henderson General Hospital, Hamilton, Canada. METHODS: Clinical records were examined for 63 inpatients with MSCC. Demographics, treatment of MSCC, length of rehabilitation, admission, and discharge Functional Independence Measure (FIM) scores, Tokuhashi score and survival data were collected. Statistical analyses included nonparametric comparisons, Kaplan-Meier analyses, Cox regression, and exploratory logistic regression. RESULTS: FIM score improved from 83 to 102 (P<0.0001). Estimated median survival from time of rehabilitation was 10.0 months. Kaplan-Meier analysis showed longer survival in patients with high Tokuhashi scores (9-15) compared to low scores (0-8) (P<0.005); and high FIM change (>13) compared to low FIM change (< or =13) (P<0.02). Cox regression revealed that high FIM gain and high Tokuhashi score were prognostic factors. Logistic regression showed Tokuhashi score (odds ratio (OR)=1.30, 95% confidence interval (CI)=1.04-1.62) and length of rehabilitation (OR=1.04, 95% confidence interval (CI)=1.01-1.07) were associated with high FIM gain. CONCLUSIONS: Rehabilitation improves functional outcomes in MSCC. Patients who had a high Tokuhashi score and achieved high functional gains after rehabilitation had longer survival. Tokuhashi score and length of rehabilitation were associated with high FIM gain. The Tokuhashi score can help identify patients with good prognosis and potential for improvement during rehabilitation.

Activities of Daily Living↗
PubMed2006

20 W single-mode Yb3+ -doped phosphate fiber laser.

We report the demonstration of the first, to our knowledge, cladding-pumped continuous-wave Yb(3+)-doped phosphate-glass fiber laser. Phosphate hosts are of interest because they can be much more heavily doped than silica, and because of the possibility that they may have a higher photodarkening threshold. In an 84.6 cm double-clad fiber doped with 12 wt. % of Yb(2)O(3) and laser-diode pumped at 940 nm, nearly 20 W of single-mode 1.07 microm output power was generated with 60.2 W of absorbed pump power. The measured dependence of the output power on pump power is in excellent agreement with simulations.

Journal Article↗
PubMed2006

Fusion-induced apoptosis contributes to thymocyte depletion by a pathogenic human immunodeficiency virus type 1 envelope in the human thymus.

The mechanisms of CD4(+) T-cell depletion during human immunodeficiency virus type 1 (HIV-1) infection remain incompletely characterized. Of particular importance is how CD4(+) T cells are depleted within the lymphoid organs, including the lymph nodes and thymus. Herein we characterize the pathogenic mechanisms of an envelope from a rapid progressor (R3A Env) in the NL4-3 backbone (NL4-R3A) which is able to efficiently replicate and deplete CD4(+) thymocytes in the human fetal-thymus organ culture (HF-TOC). We demonstrate that uninterrupted replication is required for continual thymocyte depletion. During depletion, NL4-R3A induces an increase in thymocytes which uptake 7AAD, a marker of cell death, and which express active caspase-3, a marker of apoptosis. While 7AAD uptake is observed predominantly in uninfected thymocytes (p24(-)), active caspase-3 is expressed in both infected (p24(+)) and uninfected thymocytes (p24(-)). When added to HF-TOC with ongoing infection, the protease inhibitor saquinavir efficiently suppresses NL4-R3A replication. In contrast, the fusion inhibitors T20 and C34 allow for sustained HIV-1 production. Interestingly, T20 and C34 effectively prevent thymocyte depletion in spite of this sustained replication. Apoptosis of both p24(-) and p24(+) thymocytes appears to be envelope fusion dependent, as T20, but not saquinavir, is capable of reducing thymocyte apoptosis. Together, our data support a model whereby pathogenic envelope-dependent fusion contributes to thymocyte depletion in HIV-1-infected thymus, correlated with induction of apoptosis in both p24(+) and p24(-) thymocytes.

Anti-HIV Agents↗
PubMed2006

Transcatheter closure of patent ductus arteriosus with severe pulmonary arterial hypertension in adults.

BACKGROUND: Surgical closure of patent ductus arteriosus (PDA) with severe pulmonary arterial hypertension in adults carries higher risk than in children. OBJECTIVES: To investigate the application of self-expandable occluders for transcatheter closure of PDA associated with severe pulmonary arterial hypertension in adults, and the assessment of immediate and short-term results. METHODS: 29 adult patients (6 men, 23 women) underwent attempted transcatheter closure of PDA at a mean (standard deviation (SD)) age of 31.1 (11.4) years (range 18-58 years) and a mean (SD) weight of 54.1 (7.1) kg (range 42-71 kg). On the basis of haemodynamic and clinical data obtained before and after trial occlusion, the final duct occlusion was determined and carried out. Radiographs of the chest, electrocardiograms and echocardiograms were used for follow-up evaluation of the treatment within 1 day, 1 month and 3-6 months after successful closure. RESULTS: 20 of the 29 patients had successful occlusion (group 1), and 9 patients failed (named group 2). In group 1, in which occlusion was successful, mean (SD) pulmonary arterial pressures decreased markedly after trial occlusion: 78 (19.3) mm Hg (range 50-125 mm Hg) before occlusion and 41 (13.8) mm Hg (range 23-77 mm Hg) after occlusion. Systemic arterial oxygen saturation was found to be >90% in 19 patients and <90% in the remaining patient before inhalation of oxygen, and >95% during inhalation of oxygen or after occlusion in all 20 patients. In group 2, the occlusion was not successful, because in two patients the device was not available; another two patients showed worsening of symptoms. The other five patients showed increased pulmonary arterial pressures after trial closure; their mean (SD) pulmonary arterial pressures increased by 10.3 (6) mm Hg (4-16 mm Hg) after trial occlusion, and systemic arterial oxygen saturation was 85.5% (2.6%) (range 82.6-88%) before inhalation of oxygen and 94.7% (1.7%) (range 90.7-99.1%) during inhalation of oxygen. In group 1, the dimensions of the left atrium, left ventricle and pulmonary artery increased considerably in 3-6-months of follow-up compared with those of preocclusion. CONCLUSIONS: Transcatheter closure is an effective treatment for adults with PDA associated with reversible severe pulmonary arterial hypertension. Further research is needed for the evaluation of long-term results.

Adolescent↗
PubMed2006

Reduction of organ motion effects in IMRT and conformal 3D radiation delivery by using gating and tracking techniques.

Respiration-gated radiotherapy offers a significant potential for improvement in the irradiation of tumour sites affected by respiratory motion such as lung, breast and liver tumours. An increased conformality of irradiation fields leading to decreased complications rates of organs at risk (lung, heart) is expected. Four main strategies are used to reduce respiratory motion effects: integration of respiratory movements into treatment planning, breath-hold techniques, respiratory gating techniques, and tracking techniques. Measurements of respiratory movements can be performed either in a representative sample of the general population, or directly on the patient before irradiation. The measured amplitude could be applied to a geometrical margin or integrated into dosimetry. However, these strategies remain limited for very mobile tumours, in which this approach results in larger irradiated volumes. Reduction of breathing motion can be achieved by using either breath-hold techniques or respiration synchronized gating techniques. Breath-hold can be achieved with active techniques, in which a valve temporarily blocks airflow of the patient, or passive techniques, in which the patient voluntarily breath-holds. Synchronized gating techniques use external devices to predict the phase of the respiration cycle while the patient breaths freely. Another category is tumour tracking, which consists of two major aspects: real-time localization of, and real-time beam adaptation to, a constantly moving tumour. These techniques are presently being investigated in several medical centres worldwide. Although promising, the first results obtained in lung and liver cancer patients require confirmation. This paper describes the most frequently used gating and tracking techniques and the main published clinical reports.

Artifacts↗
PubMed2006

Cesium dimer spectroscopy on helium droplets.

Visible absorption spectra of cesium-doped helium nanodroplets between 14,500 and 17,600 cm(-1) were probed by laser-induced fluorescence. A strong absorption band peaking around 16,700 cm(-1) is identified as Cs2 1(a) 3Sigmau+-3 3Sigmag+ transition. A broad unstructured band near 17,520 cm(-1) is assigned as the Cs2 1(X) 1Sigmag+-2 1Sigmau+ transition. Explanations of the observations are discussed on the basis of ab initio potential curves calculated by Spies and Meyer [(unpublished)]. All spectra have been modeled using narrow Frank-Condon windows around the equilibrium internuclear distance of the lowest singlet and triplet states. Many observed absorption peaks of smaller intensities could be identified, some of which may be due to transitions of cesium trimers formed on the droplets.

Journal Article↗
PubMed2006

Dysregulated expression of P1 and P2 promoter-driven hepatocyte nuclear factor-4alpha in the pathogenesis of human cancer.

Hepatocyte nuclear factor-4alpha (HNF4alpha) exists in multiple isoforms that are generated by alternative promoter (P1 and P2) usage and splicing. Here we establish monoclonal antibodies (mAbs) for detecting P1 and P2 promoter-driven HNF4alpha, and evaluate their expression in normal adult human tissues and surgically resected carcinomas of different origins. Using immunohistochemical analysis, we demonstrate that, while P1 promoter-driven HNF4alpha is expressed in hepatocytes, small intestine, colon, kidney and epididymis, P2 promoter-driven HNF4alpha is expressed in bile duct, pancreas, stomach, small intestine, colon and epididymis. Altered expression patterns of P1 and P2 promoter-driven HNF4alpha were observed in gastric, hepatocellular and colorectal carcinomas. HNF4alpha was expressed in lung metastases from renal cell, hepatocellular and colorectal carcinoma but was not observed in lung tumours. The P1 and P2 promoter-driven HNF4alpha expression pattern of tumour metastases correlated with the primary site of origin. P1 promoter-driven HNF4alpha was also found in intestinal metaplasia of the stomach. These data provide evidence for the tissue distribution of P1 and P2 promoter-driven HNF4alpha at the protein level and suggest that HNF4alpha may be a novel diagnostic marker for metastases of unknown primary. We propose that the dysregulation of alternative promoter usage of HNF4alpha is associated with the pathogenesis of certain cancers.

Animals↗
PubMed2006

Expression of elevated levels of pro-inflammatory cytokines in SARS-CoV-infected ACE2+ cells in SARS patients: relation to the acute lung injury and pathogenesis of SARS.

The authors have previously shown that acute lung injury (ALI) produces a wide spectrum of pathological processes in patients who die of severe acute respiratory syndrome (SARS) and that the SARS coronavirus (SARS-CoV) nucleoprotein is detectable in the lungs, and other organs and tissues, in these patients. In the present study, immunohistochemistry (IHC) and in situ hybridization (ISH) assays were used to analyse the expression of angiotensin-converting enzyme 2 (ACE2), SARS-CoV spike (S) protein, and some pro-inflammatory cytokines (PICs) including MCP-1, TGF-beta1, TNF-alpha, IL-1beta, and IL-6 in autopsy tissues from four patients who died of SARS. SARS-CoV S protein and its RNA were only detected in ACE2+ cells in the lungs and other organs, indicating that ACE2-expressing cells are the primary targets for SARS-CoV infection in vivo in humans. High levels of PICs were expressed in the SARS-CoV-infected ACE2+ cells, but not in the uninfected cells. These results suggest that cells infected by SARS-CoV produce elevated levels of PICs which may cause immuno-mediated damage to the lungs and other organs, resulting in ALI and, subsequently, multi-organ dysfunction. Therefore application of PIC antagonists may reduce the severity and mortality of SARS.

Acute Disease↗
PubMed2006

Adoptive cell therapy using in vitro generated human CD4+ CD25+ regulatory t cells with indirect allospecificity to promote donor-specific transplantation tolerance.

The holy grail in clinical transplantation is the establishment of long-term donor-specific transplantation tolerance with the minimum use of immunosuppressive agents. CD4+ CD25+ regulatory T cells (Tregs) play a crucial role in the prevention of autoimmunity, and appear to mediate transplantation tolerance. Harnessing Tregs for potential adoptive cell therapy to promote donor-specific transplantation tolerance is promising. Here we show that human CD4+ CD25+ Tregs with indirect allospecificity for an HLA-A2 (103-120) peptide can be generated from purified peripheral blood CD4+ CD25+ by priming with HLA-DR0101+ A2- autologous dendritic cells (DCs) pulsed with the A2 peptide in vitro. The antigen specificity for the A2 peptide was demonstrated in functional assays and flow cytometric analysis using a fluorescent tetramer composed of HLA-DR0101 and the A2 peptide. The CD4+ CD25+ Tregs with indirect allospecificity for the A2 peptide showed potent suppression of an indirect alloresponse by effector CD4+ CD25- T-helper cells. Importantly, the selected CD4+ CD25+ Tregs can be expanded substantially to meet a therapeutic end after T-cell receptor (TCR) stimulation by CD3/CD28 antibody-coated beads in the presence of high doses of interleukin-2 (IL-2). The expanded CD4+ CD25+ Tregs highly expressed Foxp3, and retained their suppressive properties and maintained expression of lymphoid homing receptor CD62L. Taken together, these data pave the way for clinical studies using in vitro generated and expanded human CD4+ CD25+ Tregs with indirect allospecificity as therapeutic reagents to promote donor-specific transplantation tolerance.

Adoptive Transfer↗
PubMed2006

Immunocapture UPPCR combined with DGGE for rapid detection of Shigella species.

AIMS: To develop an immunocapture universal primer PCR (iUPPCR) combined with denaturing gradient gel electrophoresis (DGGE) and evaluate it as a method permitting rapid detection of Shigella species and their serotypes. METHODS AND RESULTS: This method amplifying the conserved regions of bacterial 16S rRNA genes of different species or serotypes of Shigella dysentery bacilli captured and enriched by polyvalent antibodies can detect and distinguish causative pathogens rapidly. Four serotypes from three Shigella species including Shigella dysenteriae serotype 1, Shigella boydii serotype 1, Shigella flexneri serotypes 1a and 3a were examined. CONCLUSION: Our approach could be adopted for not only axenic bacterial population but also mixed communities and achieve rapid detection of various bacteria from the same genus or species in one sample. SIGNIFICANCE AND IMPACT OF THE STUDY: The iUPPCR-DGGE method was shown to be more convenient than serotype-specific-antibody-based method of iUPPCR for Shigella species detection and it could be also applied to the quick detection for other kinds of pathogens with many serotypes.

Electrophoresis, Polyacrylamide Gel↗
PubMed2005

Gender-specific association between pulse pressure and C-reactive protein in a Chinese population.

There is growing evidence that low-grade chronic inflammation, as reflected by the raised serum concentration of C-reactive protein, might be a risk factor for hypertension, in particular in women. We therefore investigated gender-specific associations of systolic and diastolic blood pressure and pulse pressure with serum C-reactive protein concentration in a Chinese population sample. In 463 participants, we measured serum C-reactive protein concentration using a high-sensitivity immunonephelometric latex-enhanced assay. We performed single and multiple linear regression analyses. The 224 male and 239 female subjects were of similar age (51.0 years) and had similar levels of systolic blood pressure (124.7 mmHg) and pulse pressure (47.1 mmHg), but men, compared with women, had higher diastolic blood pressure (79.6 vs 75.8 mmHg; P<0.0001) and body mass index (24.3 vs 23.4 kg/m2; P=0.003). Both before and after adjustment for age, age2, body mass index, current smoking, alcohol intake, and use of antihypertensive drugs, pulse pressure was significantly associated with serum C-reactive protein concentration in women (P< or =0.002) but not in men (P>0.10; P=0.02 for interaction between gender and serum C-reactive protein). In women, with one-fold increase in serum C-reactive protein concentration, pulse pressure was 1.94 mmHg higher. The categorical analyses confirmed our findings. With similar adjustments applied, women in the fourth quartile, compared with those in the lowest quartile, had a 7.6 mmHg higher pulse pressure (95% confidence interval 3.5-11.7 mmHg; P=0.0003). Furthermore, when women were analysed according to menopausal status, the association between pulse pressure and C-reactive protein was only significant in postmenopausal (P< or =0.04), but not in premenopausal, subjects (P> or =0.21). In conclusion, taken together with the previous gender-specific observations on carotid lesions and hypertension, our finding suggests that chronic low-grade inflammation might play a role in the widening of pulse pressure in Chinese women. This cross-sectional observation warrants further investigation in prospective studies.

Biomarkers↗
PubMed2005

Anti-human immunodeficiency virus type 1 microbicide cellulose acetate 1,2-benzenedicarboxylate in a human in vitro model of vaginal inflammation.

The sexual transmission of human immunodeficiency virus type 1 (HIV-1) is facilitated by inflammation and related epithelial barrier perturbation. Microbicides for vaginal applications are currently being developed to reduce the risk of HIV-1 transmission. However, little is known about their interference with epithelial immune function. In recent clinical trials, nonoxynol-9 (N-9), a virucide with a long history of intravaginal use as a contraceptive, failed to protect against HIV-1 possibly due to mucosal inflammatory damage. Cellulose acetate 1,2-benzenedicarboxylate, also named CAP (for "controls AIDS pandemic"), is an anti-HIV-1 microbicide selected from pharmaceutical excipients that are regarded as safe for oral administration but have not been assessed for potential effects on inflammatory factors in the vaginal environment. Here we use a sensitive human cell culture system to evaluate proinflammatory profiles of soluble CAP in reference to N-9 and known epithelial activators such as tumor necrosis factor alpha (TNF-alpha) and bacterial lysates. Within 6 h of exposure, TNF-alpha and N-9 triggered NF-kappaB and AP-1/cFos activation and upregulated interleukins and an array of chemokines by vaginal and polarized cervical epithelial cells. The induced proinflammatory status continued after removal of stimuli and was confirmed by enhanced transepithelial neutrophil migration. While sustaining stability and anti-HIV-1 activity in the epithelial environment, CAP did not increase the production of proinflammatory mediators during or after exposure, nor did it modify the epithelial resistance to leukocyte traffic. CAP attenuated some TNF-alpha-induced responses but did not interfere with epithelial cytokine responsiveness to gonococcal determinants. The described system may be useful for predicting proinflammatory side effects of other microbicide candidates for vaginal application.

Anti-HIV Agents↗
PubMed2004

Abundance, distribution, and diversity of viruses in alkaline, hypersaline Mono Lake, California.

Mono Lake is a large (180 km2), alkaline (pH approximately 10), moderately hypersaline (70-85 g kg(-1)) lake lying at the western edge of the Great Basin. An episode of persistent chemical stratification (meromixis) was initiated in 1995 and has resulted in depletion of oxygen and accumulation of ammonia and sulfide beneath the chemocline. Although previous studies have documented high bacterial abundances and marked seasonal changes in phytoplankton abundance and community composition, there have been no previous reports on the occurrence of viruses in this unique lake. Based on the high concentrations and diversity of microbial life in this lake, we hypothesized that planktonic viruses are also abundant and diverse. To examine the abundance and distribution of viruses and bacteria, water samples were collected from four stations along 5 to 15 vertical depths at each station. Viral abundance ranged from 1 x 10(8) to 1 x 10(9) mL(-1), among the highest observed in any natural aquatic system examined so far. Increases (p < 0.1) in viral densities were observed in the anoxic bottom water at multiple stations. However, regression analysis indicated that viral abundance could not be predicted by any single environmental parameter. Pulsed field gel electrophoresis revealed a diverse viral community in Mono Lake with genome sizes ranging from approximately 14 to >400 kb with most of the DNA in the 30 to 60 kb size range. Cluster analysis grouped the anoxic bottom-water viral community into a unique cluster differentiating it from surface and mid-water viral communities. A hybridization study using an indigenous viral isolate as a probe revealed an episodic pattern of temporal phage distribution with strong niche stratification between oxic and anoxic waters.

Ammonia↗
PubMed2004

Assignment of fourteen microsatellite markers to the chicken linkage map.

A large mapping population, with 874 F2 individuals, was generated by reciprocally intercrossing 2 chicken lines. A genetic map of 2,426.6 cM comprising 25 linkage groups was established based on 145 microsatellite markers. Chromosome locations were assigned for 14 previously unmapped markers. The marker ADL0132 was previously mapped to chromosome 9; however, here close linkage to the MCW0091 marker on chromosome 4 was found. With this exception, the derived linkage map was in excellent agreement with the chicken consensus map. A comparison with the chicken genome assembly (http://genome.ucsc.edu; February 2004) suggested a few minor errors in the assembly. A PCR-RFLP test was used to genotype a single nucleotide polymorphism in the melanocortin receptor 3 (MC3R) gene in the intercross, and pyrosequencing was used to map the genes for Hemopoetic Cell Kinase (HCK) and Bone Morphogenic Protein 7 (BMP7). The HCK and BMP7 genes on linkage group E32 showed significant linkage to MC3R on the distal end of linkage group E47W24, consequently joining the 2 linkage groups. A comparison between the linkage data in the current study and the physical location of markers as revealed in the chicken genome sequence assembly (February 2004) showed a 3-fold higher recombination rate on microchromosomes than on macrochromosomes.

Animals↗
PubMed2004

Human VEGF165-myoblasts produce concomitant angiogenesis/myogenesis in the regenerative heart.

Bioengineering the regenerative heart may provide a novel treatment for heart failure. On May 14, 2002, a 55-year-old man suffering from ischemic myocardial infarction received 25 injections carrying 465 million cGMP-produced pure myoblasts into his myocardium after coronary artery bypass grafting. As on August 28, 2002, his EKG was normal and showed no arrhythmia. His ejection fraction increased by 13%. He no longer experienced shortness of breath and angina as he did before the treatment. Three myogenesis mechanisms were elucidated with 17 human/porcine xenografts using cyclosporine as immunosuppressant. Some myoblasts developed to become cardiomyocytes. Others transferred their nuclei into host cardiomyocytes through natural cell fusion. As yet others formed skeletal myofibers with satellite cells. De novo production of contractile filaments augmented the heart contractility. Human myoblasts transduced with VEGF165 gene produced six times more capillaries in porcine myocardium than in placebo. Xenograft rejection was not observed for up to 20 weeks despite cyclosporine discontinuation at 6 weeks. Pros and cons of autografts vs. allografts are compared to guide future development of heart cell therapy.

Animals↗
PubMed2003

The vertical distribution and diversity of marine bacteriophage at a station off Southern California.

Sixty-two bacteriophages were isolated on eight indigenous bacteria from a Pacific Ocean station spanning 887-m vertical depth, on two occasions between 1999 and 2000. On the basis of 16S rRNA sequences, six hosts were tentatively identified to be in the genus Vibrio and the other two were closely related to Altermonas macleodii (W9a) and Pseudoalteromonas spp. (W13a). Restriction fragment length polymorphism (RFLP) analysis of phage genomes using AccI and HapI showed that 16 phages infecting host C4a (Vibrio) displayed 14 unique RFLP patterns. However, identical phages infecting host C4b, C6a, and C6b (all Vibrio) were obtained from both the surface layer and the hypoxic zone at 850 m. Most phage isolates from the second year had a different RFLP pattern but shared genetic similarity to the phages infecting the same host from the previous year based on a hybridization study using phage genome probes. Cluster analysis of RFLP patterns and hybridization results also indicated that phages infecting the same or genetically related hosts, in general, shared higher degrees of homology in spite of the diverse RFLP patterns. Pulsed field gel electrophoresis (PFGE) analysis of native viral genomes indicated a range in genome size from less than 40 to 200 kb, and the dominant band shifted up by about 5-10 kb in the deep samples compared to the shallow ones. Hybridization of phage genome probes with total viral community DNA from various depths suggests these isolates, or at least some of their genes, represent a detectable portion of the natural viral community and were distributed throughout the water column. Thus, the results of this study demonstrated that the genetic diversity of bacteriophage in the ocean is far greater than that of their bacterial hosts. However, host range may have contributed to the evolution of the diverse phage population in the marine environment.

Bacteriophages↗
PubMed2003

Isolation and characterization of an atrazine-degrading bacterium from industrial wastewater in China.

AIMS: To isolate and characterize atrazine-degrading bacteria in order to identify suitable candidates for potential use in bioremediation of atrazine contamination. METHODS AND RESULTS: A high efficiency atrazine-degrading bacterium, strain AD1, which was capable of utilizing atrazine as a sole nitrogen source for growth, was isolated from industrial wastewater. 16S rDNA sequencing identified AD1 as an Arthrobacter sp. The atrazine chlorohydrolase gene (atzA) isolated from strain AD1 differed from that found in the Pseudomonas sp. ADP by only one nucleotide. However, it was found located on the bacterial chromosome rather than on plasmids as previously reported for other bacteria. CONCLUSIONS: Atrazine chlorohydrolase gene, atzA, either encoded by chromosome or plasmid, is highly conserved. SIGNIFICANCE AND IMPACT OF THE STUDY: Comparison analysis of atrazine degradation gene structure and arrangement in this and other bacteria provides insight into our understanding of the ecology and evolution of atrazine-degrading bacteria.

Arthrobacter↗