Biomedical subjects

T Chung

Publications and source records attributed to T Chung.

At least 19 recordsLinked to original sources

PubMed2007

Effects of testosterone and nandrolone on cardiac function: a randomized, placebo-controlled study.

BACKGROUND: Androgens have striking effects on skeletal muscle, but the effects on human cardiac muscle function are not well defined, neither has the role of metabolic activation (aromatization, 5alpha reduction) of testosterone on cardiac muscle been directly studied. OBJECTIVE: To assess the effects of testosterone and nandrolone, a non-amplifiable and non-aromatizable pure androgen, on cardiac muscle function in healthy young men. DESIGN: Double-blind, randomized, placebo-controlled, three-arm parallel group clinical trial. SETTING: Ambulatory care research centre. PARTICIPANTS: Healthy young men randomized into three groups of 10 men. INTERVENTION: Weekly intramuscular injections of testosterone (200 mg mixed esters), nandrolone (200 mg nandrolone decanoate) or matching (2 ml arachis oil vehicle) placebo for 4 weeks. MAIN OUTCOME MEASURES: Comprehensive measures of cardiac muscle function involving transthoracic cardiac echocardiography measuring myocardial tissue velocity, peak systolic strain and strain rates, and bioimpedance measurement of cardiac output and systematic vascular resistance. RESULTS: Left ventricular (LV) function (LV ejection fraction, LV modified TEI index), right ventricular (RV) function (ejection area, tricuspid annular systolic planar motion, RV modified TEI index) as well as cardiac afterload (mean arterial pressure, systemic vascular resistance) and overall cardiac contractility (stroke volume, cardiac output) were within age- and gender-specific reference ranges and were not significantly (P < 0.05) altered by either androgen or placebo over 4 weeks of treatment. Minor changes remaining within normal range were observed solely within the testosterone group for: increased LV end-systolic diameter (30 +/- 7 vs. 33 +/- 5 mm, P = 0.04) and RV end-systolic area (12.8 +/- 1.3 vs. 14.6 +/- 3.3 cm(2), P = 0.04), reduced LV diastolic septal velocity (Em, 9.5 +/- 2.6 vs. 8.7 +/- 2.0 cm/s, P = 0.006), increased LV filling pressure (E/Em ratio, 7.1 +/- 1.6 vs. 8.3 +/- 1.8, P = 0.02) and shortened PR interval on the electrocardiogram (167 +/- 13 vs. 154 +/- 12, P = 0.03). CONCLUSION: Four weeks of treatment with testosterone or nandrolone had no beneficial or adverse effects compared with placebo on cardiac function in healthy young men.

Adult↗

PubMed2006

Axial oblique MR imaging of the intrinsic ligaments of the wrist: initial experience.

OBJECTIVE: To evaluate two separate MR sequences acquired in the axial oblique plane, parallel to the long axis of the scapholunate (SL) and lunotriquetral (LT) ligaments, to determine whether the addition of these sequences to the standard MR wrist examination improves visualization of the intrinsic ligaments, and the evaluation of their integrity. To our knowledge, this plane has not been described in the literature previously. DESIGN AND PATIENTS: In total we evaluated 26 patients with chronic wrist pain or instability, referred for MR imaging following assessment by an orthopedic surgeon or physiatrist. All patients underwent initial conventional tri-compartment wrist arthrography, which served as the reference standard. This was immediately followed by MR arthrography, in the standard coronal and true axial planes, as well as in the axial oblique plane. The SL and LT ligaments were initially assessed for the presence or absence of tear, using the standard coronal and true axial sequences, and subsequently re-evaluated with the addition of the axial oblique planes. RESULTS: A total of ten intrinsic ligament tears were identified with conventional arthrography: six SL and four LT tears. Five of the six SL tears were identified on the standard sequences. All six were diagnosed with the addition of the oblique sequences. There were three false-positive SL tears identified using standard MR imaging, and two false-positives with the addition of the oblique sequences. No LT tear was identified on standard sequences, whereas all four were confidently seen with the addition of oblique images. No false-positives of the LT ligament were recorded with either standard or axial oblique sequences. CONCLUSION: The study suggests that the addition of axial oblique MR sequences helps identify tears to the intrinsic ligaments of the wrist, particularly the LT ligament. In addition, the axial oblique images assist in localization of the tear.

Adolescent↗

PubMed2004

The relationship between COLI A1 polymorphisms (Sp 1) and COLI A2 polymorphisms (Eco R1 and Puv II) with bone mineral density in Chinese men and women.

Polymerase chain reaction was used to amplify across variable restriction sites of the COLI A1 and COLI A2 genes that encode the alpha 1 and 2 subunits of type I collagen. The relationship between these polymorphisms and bone mineral density (BMD) was studied in 683 Chinese men and women. In 100 men and women, COLI A1 Sp1 polymorphism was not found, which was consistent with other previous studies in Asian populations. However a statistically significant relationship was observed between COLI A2 Eco R1 and Puv II genotypes among the Chinese men studied. The mean BMD was consistently lower in men of the EE and PP genotype (P < 0.05 by analysis of variance [ANOVA]) than in men of the ee and pp genotypes. However, no association between BMD and the Eco R1 or Puv II genotypes was observed in Chinese women (P > 0.05 by ANOVA). We conclude that the COLI Al Sp1 binding site is absent in Hong Kong Chinese, whereas the COLI A2 Eco R1 and Puv II genetic polymorphisms may be associated with the BMD of elderly Chinese men.

Age Factors↗

PubMed2004

The Randomized Nitric Oxide Tocolysis Trial (RNOTT) for the treatment of preterm labor.

OBJECTIVE: This study was undertaken to assess the effectiveness of glyceryl trinitrate (GTN) patches in comparison with beta2 sympathomimetics (beta2) for the treatment of preterm labor. STUDY DESIGN: A multicenter, multinational, randomized controlled trial was conducted in tertiary referral teaching hospitals. Women in threatened preterm labor with positive fetal fibronectin or ruptured membranes between 24 and 35 weeks' gestation were recruited and randomly assigned to either beta2 or GTN with rescue beta2 tocolysis if moderate-to-strong contractions persisted at 2 hours. Obstetric and neonatal outcomes were assessed. RESULTS: Two hundred thirty-eight women were recruited and randomly assigned, 117 to beta2 and 121 to GTN. On a strict intention-to-treat basis, there was no significant difference in the time to delivery using Kaplan-Meier curves (P = .451). At 2 hours, 27% of women receiving beta2 had moderate or stronger contractions compared with 53% in the GTN group (P < .001). This led to 35% of women in the GTN group receiving rescue treatment. If delivery or requirement for beta2 rescue are regarded as treatment failure, then a significant difference was observed between the 2 arms (P = .0032). There were no significant differences in neonatal outcomes. CONCLUSION: GTN is a less efficacious tocolytic compared with ss2 sympathomimetics.

Adrenergic beta-2 Receptor Agonists↗

PubMed2001

Concomitant infusional paclitaxel and fluorouracil, oral hydroxyurea, and hyperfractionated radiation for locally advanced squamous head and neck cancer.

PURPOSE: To improve local disease control and survival with organ preservation, we conducted a phase II multi-institutional trial with a concomitant taxane-based chemotherapy and hyperfractionated radiation regimen. PATIENTS AND METHODS: Sixty-four patients with locally advanced squamous cancers (stage IV, 98%; N2/3, 81%) were treated on an intensive regimen consisting of 5-day (120-hour) infusions of paclitaxel (20 mg/m(2)/d) and fluorouracil (600 mg/m(2)/d), oral hydroxyurea 500 mg every 12 hours for 11 doses, and radiation 1.5 Gy bid (T-FH2X). Chemoradiation was administered concomitantly on days 1 to 5 of each 14-day cycle. A full treatment course consisted of five cycles during a 10-week period to a total radiation dose of 72 to 75 Gy. RESULTS: The median follow-up for the group is 34 months. At 3 years, progression-free survival is 63%, locoregional control is 86%, and systemic control is 79%; overall survival is 60%. Seventeen patients died of recurrent cancer, two died of second primary cancers, and four died of other causes. Side effects observed include anemia (22% required transfusion), leucopenia (34%, grade 3 to 4), and mucositis (84%, grade 3 to 4). Organ preservation principles were maintained. At 1 year posttreatment, 61% of patients had severe xerostomia and 47% had compromised swallowing. There was little disturbance of speech quality in 97% of patients at the same follow-up point. CONCLUSION: T-FH2X is a highly active and tolerable concomitant chemotherapy and hyperfractionated radiation regimen that induces sustained local tumor control and holds promise for improved survival with organ preservation in high-risk patients. Identification of less toxic therapy and improved distant disease control are needed. T-FH2X should be tested in a randomized trial and compared with a less intensive concomitant regimen that uses once-daily radiation fractionation.

Administration, Oral↗

PubMed2001

Mesenchymal stem cells are capable of homing to the bone marrow of non-human primates following systemic infusion.

OBJECTIVE: The human bone marrow contains mesenchymal stem cells capable of differentiating along multiple mesenchymal cell lineages. Using a non-human primate model, we sought to determine whether the systemic infusion of baboon-derived mesenchymal stem cells was associated with toxicity and whether these cells were capable of homing to and persisting within the bone marrow. MATERIALS AND METHODS: Five baboons (Papio anubis) were administered lethal irradiation followed by intravenous autologous hematopoietic progenitor cells combined with either autologous (n = 3) or allogeneic (n = 2) mesenchymal stem cells that had been expanded in culture. In four of these baboons, the mesenchymal stem cells were genetically modified with a retroviral vector encoding either the enhanced green fluorescent protein gene (n = 3) or the human placental alkaline phosphatase gene (n = 1) for tracking purposes. A sixth animal received only intravenous gene marked autologous mesenchymal stem cells but no hematopoietic stem cells or conditioning irradiation. RESULTS: Following culture, baboon mesenchymal stem cells appeared morphologically as a homogeneous population of spindle-shaped cells that were identified by the monoclonal antibodies SH-3 and SH-4. These cells did not express the hematopoietic markers CD34 or CD45. Baboon mesenchymal stem cells isolated from primary culture were capable of differentiating along both adipogenic and osteogenic lineages. There was no acute or chronic toxicity associated with the intravenous infusion of mesenchymal stem cells. In all five recipients of gene marked mesenchymal stem cells, transgene was detected in post-transplant bone marrow biopsies. In two animals receiving autologous mesenchymal stem cells, including the one non-conditioned recipient, transgene could be detected over 1 year following infusion. In one recipient of allogeneic gene marked mesenchymal stem cells, transgene was detected in the bone marrow at 76 days following infusion. CONCLUSION: These data demonstrate that baboon mesenchymal stem cells: 1) are not associated with significant toxicity when administered intravenously, 2) are capable of homing to the bone marrow following intravenous infusion, and 3) have the capacity to establish residence within the bone marrow for an extended duration following systemic administration.

Alkaline Phosphatase↗

PubMed2001

Changes in alcoholic patients' coping responses predict 12-month treatment outcomes.

Patient subtypes (Types A and B alcoholism), determinants, and outcomes associated with changes in coping responses of 133 alcoholic patients in the year following admission to treatment were examined. In general, patients' use of avoidance coping declined and use of approach coping increased. Type B patients used more avoidance coping than did Type A patients, but the subtypes did not differ in rate of change in coping. As a determinant of coping, cognitive appraisal of threat showed a trend toward predicting avoidance coping at 6- and 12-month follow-ups. Decreased cognitive avoidance coping (e.g., daydreaming) predicted fewer alcohol, psychological, and interpersonal problems. Increased behavioral approach coping (e.g.. taking action) predicted lower severity of alcohol problems. Further study of changes in the cognitive aspects of coping (i.e., appraisals and cognitive avoidance coping) is needed to determine mechanisms underlying cognitive processes associated with treatment outcomes.

Adaptation, Psychological↗

PubMed2001

Magnetic resonance imaging in a child with primary sternal osteomyelitis.

Primary sternal osteomyelitis (PSO) is rare. In a 9-year-old boy with Staphylococcus aureus bacteremia, magnetic resonance imaging helped to promptly establish the diagnosis of PSO. Eleven previously reported cases are reviewed, emphasiz ing surgical drainage and antimicrobial therapy for optimal outcome. Magnetic resonance imaging may be superior to other imaging studies for the diagnosis of PSO.

Child↗

PubMed2001

A psychiatric epidemiological study of postpartum Chinese women.

OBJECTIVE: Epidemiological studies in the 1980s have suggested that depression is rare in the Chinese population and there is no postpartum depression among Chinese women. However, subsequent small-scale studies of postpartum depression in China have yielded contradictory and inconsistent findings. Furthermore, after two decades of profound socioeconomic transformation, depression may no longer be rare in the contemporary population. The authors conducted a psychiatric epidemiological study among postpartum Chinese women using rigorous methodology and a representative sample. METHOD: A total of 959 consecutive women were recruited at the antenatal clinic of a university hospital in Hong Kong. At 3 months postpartum, the prevalence and incidence rates of depression were measured with a two-phase design. The participants were first stratified by means of the 12-item General Health Questionnaire. Subsequently, all high scorers and 10% of low scorers were assessed with the nonpatient version of the Structured Clinical Interview for DSM-III-R. The 1-month and 3-month prevalence and incidence rates were estimated by using reverse weighting. RESULTS: The 1-month prevalence rates for major and minor depression were 5.5% and 4.7%, respectively. At 3 months, the corresponding prevalence rates were 6.1% and 5.1%. Together, 13.5% of the participants suffered from one or more forms of psychiatric disorder in the first 3 months postpartum. CONCLUSIONS: Postpartum depression is common among contemporary Chinese women. A universal postpartum depression-screening program would be useful for early detection. Our data suggest that depression may no longer be rare in the Chinese population.

Adult↗

PubMed2001

Assessment of alcohol tolerance in adolescents.

OBJECTIVE: To improve assessment of the DSM-IV alcohol tolerance criterion in adolescents, this study tested the performance of a minimum percentage increase in drinking quantity, and a proxy measure of tolerance (i.e., average heavy-drinking quantity per occasion) in identifying adolescents with alcohol dependence. METHOD: Two adolescent samples were examined. In one sample (N = 415, 58% male, 79% white, 57% clinical), a modified version of the SCID was used to determine DSM-IV alcohol diagnoses, and lifetime drinking history data were collected by interview. In the second sample (N = 470, 60% male, 76% white, 100% clinical), the Adolescent Diagnostic Interview was used to determine DSM-IV alcohol diagnoses and to collect data on initial- and current-drinking quantities needed to become intoxicated. The performance of a percentage increase and average heavy-drinking quantity in identifying those with dependence was evaluated using receiver operating characteristic analysis. RESULTS: The utility of a percentage increase definition was limited by the high degree of variability in initial-drinking quantities. Percentage increase may underassign the tolerance symptom when initial-drinking quantities are high and overassign the symptom when initial-drinking quantities are low. Average heavy-drinking quantity per occasion, combined with a minimum frequency of drinking, demonstrated better performance than any percentage increase definition. CONCLUSIONS: Alternatives to a change-based (e.g., percentage increase) definition of tolerance warrant study due to limits of change-based definitions when initial-drinking quantity shows a high degree of variability. The variability in initial-drinking quantity may reflect individual differences in initial sensitivity that need to be considered in tolerance assessment.

Adolescent↗

PubMed2001

Fast three-point dixon MR imaging using low-resolution images for phase correction: a comparison with chemical shift selective fat suppression for pediatric musculoskeletal imaging.

OBJECTIVE: The purpose of this study is to describe and to implement a new fast three-point Dixon MR imaging sequence with online image reconstruction, and to compare this sequence with conventional chemical shift selective (CHESS) suppression of fat in pediatric musculoskeletal imaging. SUBJECTS AND METHODS: A three-point Dixon technique using a fast spin-echo sequence with a new phase-correction algorithm providing online image reconstruction was implemented on a 1.5-T scanner. Twelve pediatric patients and young adults were imaged with both the new three-point Dixon and conventional CHESS sequences. Three radiologists un-aware of imaging parameters and clinical information independently scored the homogeneity of fat suppression and conspicuity of abnormality using a four-point system. An additional comparison between the two techniques was made using a phantom. RESULTS: The three-point Dixon method showed superior fat suppression and lesion conspicuity (p < 0.001), particularly in the hands and feet, where CHESS is prone to inconsistent fat suppression. The phantom study showed no significant difference in the ratio of suppressed fat signal to background noise and more homogeneous fat suppression using the three-point Dixon method. CONCLUSION: Compared with CHESS, the new fast three-point Dixon sequence with online image reconstruction provides superior fat suppression and lesion conspicuity and can be routinely used in pediatric musculoskeletal imaging.

Adolescent↗

PubMed2001

Fast three-point Dixon MR imaging of the retrobulbar space with low-resolution images for phase correction: comparison with fast spin-echo inversion recovery imaging.

A new phase-correction algorithm for three-point Dixon (3PD) MR imaging allows on-line image reconstruction of three images per section: pure water, pure fat, and water plus fat. When combined with fast spin-echo acquisition, the sequence is suitable for routine MR imaging of the retrobulbar space. The 3PD pure water images have double the image signal-to-noise ratio of fast spin-echo inversion recovery images. The dramatic contrast-to-noise ratio of the 3PD pure fat images may offer improved lesion detection.

Adolescent↗

PubMed2001

Classification and course of alcohol problems among adolescents in addictions treatment programs.

BACKGROUND: This study tested whether adolescents in addictions treatment programs could be reliably classified into milder and more severe alcohol problem categories using latent class analysis, and examined the relation of latent class structure to DSM-IV alcohol diagnoses. Transition probabilities among the latent classes at 1-year follow-up and their predictors were used to characterize the short-term course of alcohol problems. METHODS: Adolescents recruited from addictions treatment were administered a modified section of the Structured Clinical Interview for the DSM (SCID) alcohol use disorders (AUD) during or shortly after addictions treatment and at 1-year follow-up. DSM-IV lifetime conduct disorder diagnosis was assessed at baseline using a modified version of the Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS). RESULTS: A 3-class solution that represented increasing severity of alcohol problems (i.e., asymptomatic, mild, and severe) provided the best fit to the alcohol symptom data, and was consistent across gender, ethnicity, and presence of conduct disorder. Cross-classification of latent class membership with DSM-IV alcohol diagnosis indicated only a fair level of agreement. There was an overall decrease in alcohol problem severity from baseline to follow-up. Conditional transition probabilities indicated that males and those with conduct disorder, particularly for those in the severe class at baseline, had a lower likelihood of transitioning to the asymptomatic class at 1-year follow-up. CONCLUSIONS: The latent class structure of alcohol problems in an adolescent clinical sample was best represented by a 3-class severity-based model. Cross-classification of latent class membership with DSM-IV alcohol diagnosis suggests the potential utility of re-organizing diagnostic criteria to better distinguish the relative severity of abuse and dependence diagnoses. Transitions between latent classes were fairly common at 1-year follow-up, and characterized by a general reduction in alcohol symptoms.

Adolescent↗

PubMed2000

Atrial conduction disturbance as an indicator of rejection after cardiac transplantation.

BACKGROUND: Abnormalities of the terminal force of the P wave in Lead V1 (ptf-V1) and dispersion of corrected atrial repolarization (Ta-TcD) are believed to represent interatrial conduction defect. METHODS AND RESULTS: To determine whether atrial conduction disturbance correlates with cardiac allograft rejection, we analyzed 249 twelve-lead-electrocardiograms, echocardiograms, hemodynamic parameters, and endomyocardial biopsys from 137 patients with heart transplantation. Both ptf-V1 and Ta-TcD were significantly increased in patients with severe, moderate, and mild rejection. In 22 patients, significant increases of the ptf-V1 and Ta-TcD were observed before positive histological findings, and significantly correlated with severity of rejection during 5- week to 1-year follow-up. Increase of 0.030 mm x sec in ptf-V1 or 0.040 s1/2 in Ta-TcD indicated cardiac rejection > or =1B with sensitivity of 88 and 83%, specificity of 85 and 77%, respectively. CONCLUSION: These results suggest that the ptf-V1 and Ta-TcD might be an adjunct to detect rejection and reduce the number of surveillance EMB.

Atrial Function↗

PubMed2000

3D-shaded surface rendering of gadolinium-enhanced MR angiography in congenital heart disease.

BACKGROUND: Gadolinium-enhanced three-dimensional (3D) MR angiography is a useful imaging technique for patients with congenital heart disease. OBJECTIVE: This study sought to determine the added value of creating 3D shaded surface displays compared to standard maximal intensity projection (MIP) and multiplanar reformatting (MPR) techniques when analyzing 3D MR angiography data. MATERIALS AND METHODS: Seventeen patients (range, 3 months to 51 years old) with a variety of congenital cardiovascular defects underwent gadolinium-enhanced 3D MR angiography of the thorax. Color-coded 3D shaded surface models were rendered from the image data using manual segmentation and computer-based algorithms. Models could be rotated, translocated, or zoomed interactively by the viewer. Information available from the 3D models was compared to analysis based on viewing standard MIP/ MPR displays. RESULTS: Median postprocessing time for the 3D models was 6 h (range, 3-25 h) compared to approximately 20 min for MIP/MPR viewing. No additional diagnostic information was gained from 3D model analysis. All major findings with MIP/MPR postprocessing were also apparent on the 3D models. Qualitatively, the 3D models were more easily interpreted and enabled adjacent vessels to be distinguished more readily. CONCLUSION: Routine use of 3D shaded surface reconstructions for visualization of contrast enhanced MR angiography in congenital heart disease cannot be recommended. 3D surface rendering may be more useful for presenting complex anatomy to an audience unfamiliar with congenital heart disease and as an educational tool.

Adolescent↗

PubMed2000

Small intestinal obstruction by remnants of the omphalomesenteric duct: findings on contrast enema.

OBJECTIVE: We reviewed the contrast enema examinations and medical records of six patients with small intestinal obstruction due to omphalomesenteric duct remnant to evaluate for characteristic imaging findings. RESULTS: In five out of the six patients the point of obstruction was demonstrated on the enema; in three patients, the characteristic "beak" of a volvulus was seen, either in the terminal ileum or cecum. In three patients, there was medial deviation of the cecum. CONCLUSION: The characteristic radiographic features of volvulus at the cecum or terminal ileum and medial deviation of the cecum should suggest persistence of an omphalomesenteric duct remnant as the etiology of obstruction in a child less than 2 years of age. The appearance of omphalomesenteric duct remnant obstruction on enema examination, though not specific, is characteristic and should be familiar to pediatric radiologists.

Contrast Media↗

PubMed2000

The use of oral pentobarbital sodium (Nembutal) versus oral chloral hydrate in infants undergoing CT and MR imaging--a pilot study.

BACKGROUND: Chloral hydrate, a commonly used oral sedative for infants undergoing imaging examinations, has a bitter taste and requires relatively large volume, provoking unpleasant reactions from the infants. Experience with an alternative sedative, oral pentobarbital (Nembutal), has not been reported for infants. OBJECTIVE: To compare patient acceptance of oral Nembutal and oral chloral hydrate for sedation of infants up to 12 months of age. METHODS AND MATERIALS: Fifty-four infants (mean age: 7 months) were prospectively enrolled. Parents chose Nembutal, chloral hydrate, or no preference. Thirty-eight infants received Nembutal (4-6 mg/kg) mixed with cherry syrup and 16 received chloral hydrate (50-100 mg/ kg). We recorded infant's acceptance of sedative, parental impression of infant's acceptance, time to sedation, time to discharge, adverse effects, parental preference of future sedative. RESULTS: Infant acceptance and parental impression were better for Nembutal (P < 0.0001). Fewer parents in the Nembutal group preferred another sedative (P = 0.05). There was a trend toward shorter time to discharge with Nembutal (P = 0.03). There were no adverse effects in either group. One infant failed to sedate with Nembutal. CONCLUSIONS: Compared with chloral hydrate, oral Nembutal has significantly better acceptance by infants and parents, equal effectiveness, and may result in a shorter time to discharge.

Administration, Oral↗

PubMed2000

C-terminal region of the cytosolic subunit p47(phox) is a primary target of conformational change during the activation of leukocyte NADPH oxidase.

The leukocyte NADPH oxidase of neutrophils is a membrane-bound enzyme that catalyzes the production of O(2(-)) from oxygen using NADPH as the electron donor. During activation, the cytosolic oxidase components p47(phox) and p67(phox), each containing two Src homology 3 (SH3) domains, migrate to the plasma membrane, where they associate with cytochrome b(558), a membrane-integrated flavohemoprotein, to assemble the active oxidase. Oxidase activation can be mimicked in a cell-free system using an anionic amphiphile, such as sodium dodecyl sulfate or arachidonic acid and the phosphorylation of p47(phox )with protein kinase C. Activators of the oxidase in vitro cause exposure of p47(phox)-SH3, which has probably been masked by the C-terminal region of this protein in a resting state. We show here that the total protein steady-state intrinsic fluorescence exhibited by the tryptophan residues of p47(phox) substantially decreased when N-terminal truncated p47(phox)-SH3-C was treated with anionic amphiphiles or phosphorylated with protein kinase C. This finding was similar to the results obtained with full-length p47(phox). However, the fluorescence of C-terminal truncated p47(phox)-N-SH3 and both C-terminal and N-terminal truncated p47(phox)-SH3 were not altered by the activators. These results indicate that the C-terminal region of p47(phox) is a primary target of the conformational change during the activation of NADPH oxidase.

Animals↗