Biomedical subjects

Fei Yu

Publications and source records attributed to Fei Yu.

68 records · Page 4Linked to original sources

PubMed2002

Galectin-3 translocates to the perinuclear membranes and inhibits cytochrome c release from the mitochondria. A role for synexin in galectin-3 translocation.

Galectin-3 is a multifunctional oncogenic protein found in the nucleus and cytoplasm and also the extracellular milieu. Although recent studies demonstrated an anti-apoptotic activity of galectin-3, neither the functional site nor the mechanism of how galectin-3 regulates apoptosis is known. In this study, we examined the subcellular localization of galectin-3 during apoptosis and investigated its anti-apoptotic actions. We report that galectin-3 translocates to the perinuclear membrane following a variety of apoptotic stimuli. Confocal microscopy and biochemical analysis revealed that galectin-3 is enriched in the mitochondria and prevents mitochondrial damage and cytochrome c release. Using a yeast two-hybrid system, we screened for galectin-3-interacting proteins that regulate galectin-3 localization and anti-apoptotic activity. Synexin, a Ca(2+)- and phospholipid-binding protein, was one of the proteins identified. We confirmed direct interaction between galectin-3 and synexin by glutathione S-transferase pull-down assay in vitro. We showed that galectin-3 failed to translocate to the perinuclear membranes when expression of synexin was down-regulated using an oligodeoxyribonucleotide complementary to the synexin mRNA, suggesting a role for synexin in galectin-3 trafficking. Furthermore, synexin down-regulation abolished anti-apoptotic activity of galectin-3. Taken together, these results suggest that synexin mediates galectin-3 translocation to the perinuclear mitochondrial membranes, where it regulates mitochondrial integrity critical for apoptosis regulation.

Annexin A7↗

PubMed2002

Ambient air pollution and risk of birth defects in Southern California.

The authors evaluated the effect of air pollution on the occurrence of birth defects ascertained by the California Birth Defects Monitoring Program in neonates and fetuses delivered in southern California in 1987-1993. By using measurements from ambient monitoring stations of carbon monoxide (CO), nitrogen dioxide, ozone, and particulate matter <10 microm in aerodynamic diameter, they calculated average monthly exposure estimates for each pregnancy. Conventional, polytomous, and hierarchical logistic regression was used to estimate odds ratios for subgroups of cardiac and orofacial defects. Odds ratios for cardiac ventricular septal defects increased in a dose-response fashion with increasing second-month CO exposure (odds ratio (OR)(2nd quartile) CO = 1.62, 95% confidence interval (CI): 1.05, 2.48; OR(3rd quartile) CO = 2.09, 95% CI: 1.19, 3.67; OR(4th quartile) CO = 2.95, 95% CI: 1.44, 6.05). Similarly, risks for aortic artery and valve defects, pulmonary artery and valve anomalies, and conotruncal defects increased with second-month ozone exposure. The study was inconclusive for other air pollutants. The authors' results are supported by the specificity of the timing of the effect and some evidence from animal data; however, this is the first known study to link ambient air pollution during a vulnerable window of development to human malformations. Confirmation by further studies is needed.

Air Pollutants↗

PubMed2002

The effect of long-term intermittent trimethoprim/sulfamethoxazole treatment on recurrences of toxoplasmic retinochoroiditis.

PURPOSE: To determine the effect of long-term intermittent trimethoprim/sulfamethoxazole treatment on recurrences of toxoplasmic retinochoroiditis. DESIGN: Prospective randomized open-labeled interventional clinical trial. METHODS: A total of 124 patients with a history of recurrent toxoplasmic retinochoroiditis were randomized to treatment with one tablet of trimethoprim (160 mg)/sulfamethoxazole (800 mg) (Bactrim F; Roche Pharmaceuticals, Rio de Janeiro, Brazil) every 3 days (61 patients) or to observation without treatment (63 patients) and were followed monthly for up to 20 consecutive months for clinical signs of disease recurrence. A recurrence was defined as a new focus of necrotizing retinochoroiditis with active inflammation either adjacent to or remote from preexisting retinochoroidal scars. RESULTS: Recurrences developed in four (6.6%) treated patients and in 15 (23.8%) controls (P =.01). Treatment was discontinued prematurely in four patients because of mild drug reactions. CONCLUSION: Long-term intermittent treatment with trimethoprim/sulfamethoxazole can reduce the rate of recurrent toxoplasmic retinochoroiditis.

Adolescent↗

PubMed2002

Depression in patients with glaucoma as measured by self-report surveys.

PURPOSE: This study aimed to determine whether patients with glaucoma have more depressive symptoms than patients without glaucoma. DESIGN: Prospective case-control study. PARTICIPANTS: The study population was recruited from two university-based glaucoma clinical practices and a university-based general ophthalmology clinic and consisted of 121 patients with open-angle glaucoma, 42 with diagnoses of suspected glaucoma, and 135 with no chronic ocular conditions except cataract. INTERVENTION: The Center for Epidemiologic Studies Depression Scale (CES-D) and Composite International Diagnostic Interview, Short Form (CIDI-SF) questionnaires were administered to all subjects. Demographic information, medical history, and responses to the questionnaires were elicited by an interviewer. Medical record review was performed to obtain clinical examination data and to substantiate the medical and demographic data obtained by the interviewer. MAIN OUTCOME MEASURES: The questionnaire scores by diagnostic group, demographic characteristics, and medical history were examined. Secondary outcome measures were questionnaire scores in patients with glaucoma by visual impairment and glaucoma medication use. RESULTS: Depression scores for patients with glaucoma did not differ significantly from scores of control patients. Having past or present mental illness was the only consistent predictor for depression in both questionnaires. Among glaucoma patients, visual acuity level, visual field severity, and use of topical beta-blockers were not predictors for depression. CONCLUSIONS: Patients with glaucoma do not report being more depressed than patients without glaucoma as measured by the CES-D and the CIDI-SF questionnaires.

Adult↗

PubMed2002

Trends in glaucoma surgery incidence and reimbursement for physician services in the Medicare population from 1995 to 1998.

OBJECTIVE: To better understand the relationship between glaucoma management and economic incentives, we examined the volume and the reimbursement of argon laser trabeculoplasty (ALT) and trabeculectomy in a 5% random sample of the Medicare population from 1995 to 1998. DESIGN: Retrospective cohort study. PARTICIPANTS: Subjects in a 5% random sample of the Medicare population who had ALT and trabeculectomy from 1995 to 1998. METHODS: Using the Health Care Financing Administration (HCFA) Physician/Supplier Part-B files for a 5% random sample of the Medicare population, we identified all subjects who had ALT and trabeculectomy from 1995 to 1998. Descriptive summaries (the number of surgeries and the mean and the standard deviation of reimbursement per surgery) were calculated for each year. Analysis of variance was used to test for differences in reimbursement per surgery across years. Chi-square tests were used to assess any associations between the changing numbers of ALTs and trabeculectomies over the study period and both age and race. MAIN OUTCOME MEASURES: We assessed the number of ALTs and trabeculectomies and the allowed charges for each surgery in the 5% random sample of the Medicare population from 1995 to 1998. RESULTS: The volume of both ALTs and trabeculectomies declined during the study period. Reimbursement per surgery for both ALT and trabeculectomy varied significantly across years (P < 0.001). Significant associations were found between the changing number of ALTs and both age and race. CONCLUSIONS: Changing numbers of ALT and trabeculectomy seem unrelated to reimbursement rates. Rather, these changes are more likely driven by new developments in the clinical management of glaucoma, among other factors.

Aged↗

PubMed2002

Second Prize: The effectiveness of physical modalities among patients with low back pain randomized to chiropractic care: findings from the UCLA low back pain study.

BACKGROUND: Although chiropractors often use physical modalities with spinal manipulation, evidence that modalities yield additional benefits over spinal manipulation alone is lacking. OBJECTIVE: The purpose of the study was to estimate the net effect of physical modalities on low back pain (LBP) outcomes among chiropractic patients in a managed-care setting. METHODS: Fifty percent of the 681 patients participating in a clinical trial of LBP treatment strategies were randomized to chiropractic care with physical modalities (n = 172) or without physical modalities (n = 169). Subjects were followed for 6 months with assessments at 2, 4, and 6 weeks and at 6 months. The primary outcome variables were average and most severe LBP intensity in the past week, assessed with numerical rating scales (0-10), and low back-related disability, assessed with the 24-item Roland-Morris Disability Questionnaire. RESULTS: Almost 60% of the subjects had baseline LBP episodes of more than 3 months' duration. The 6-month follow-up was 96%. The adjusted mean differences between groups in improvements in average and most severe pain and disability were clinically insignificant at all follow-up assessments. Clinically relevant improvements in average pain and disability were more likely in the modalities group at 2 and 6 weeks, but this apparent advantage disappeared at 6 months. Perceived treatment effectiveness was greater in the modalities group. CONCLUSIONS: Physical modalities used by chiropractors in this managed-care organization did not appear to be effective in the treatment of patients with LBP, although a small short-term benefit for some patients cannot be ruled out.

Adult↗

PubMed2002

Comparing the satisfaction of low back pain patients randomized to receive medical or chiropractic care: results from the UCLA low-back pain study.

OBJECTIVES: This study examined the difference in satisfaction between patients assigned to chiropractic vs medical care for treatment of low back pain in a managed care organization. METHODS: Satisfaction scores (on a 10-50 scale) after 4 weeks of follow-up were compared among 672 patients randomized to receive medical or chiropractic care. RESULTS: The mean satisfaction score for chiropractic patients was greater than the score for medical patients (crude difference = 5.5; 95% confidence interval = 4.5, 6.5). Self-care advice and explanation of treatment predicted satisfaction and reduced the estimated difference between chiropractic and medical patients' satisfaction. CONCLUSIONS: Communication of advice and information to patients with low back pain increases their satisfaction with providers and accounts for much of the difference between chiropractic and medical patients' satisfaction.

Adolescent↗

PubMed2002

A randomized trial of chiropractic manipulation and mobilization for patients with neck pain: clinical outcomes from the UCLA neck-pain study.

OBJECTIVES: This study compared the relative effectiveness of cervical spine manipulation and mobilization for neck pain. METHODS: Neck-pain patients were randomized to the following conditions: manipulation with or without heat, manipulation with or without electrical muscle stimulation, mobilization with or without heat, and mobilization with or without electrical muscle stimulation. RESULTS: Of 960 eligible patients, 336 enrolled in the study. Mean reductions in pain and disability were similar in the manipulation and mobilization groups through 6 months. CONCLUSIONS: Cervical spine manipulation and mobilization yield comparable clinical outcomes.

Adult↗

PubMed2002

A preliminary study on the early diagnosis of myelodysplastic syndromes.

OBJECTIVE: To evaluate the four techniques for clonal analysis in the early diagnosis of myelodysplastic syndromes (MDS). METHODS: Four techniques for clonal analysis were performed in bone marrow samples from fifty patients with suspected MDS: (1) Conventional cytogenetics (CC) for clonal chromosomal abnormalities; (2) BrdU-sister chromatid differentiation (BrdU-SCD) for cell cycle analysis; (3) Fluorescence in situ hybridization (FISH) for trisomy 8; (4) PCR-SSCP for N-ras mutation. RESULTS: The diagnosis of forty-five patients was compatible with FAB criteria of MDS, the other five patients didn't fully meet the FAB criteria. They had either only one lineage dyspoiesis or no any obvious dysplastic features and two of them were diagnosed as suspicious refractory anemia (RA), one as anemia with hypercellular bone marrow and two as chronic aplastic anemia. The results of the four techniques performed in them showed that four patients had clonal karyotype abnormalities, two had prolonged cell cycle, three had trisomy 8 of different proportions, and one had N-ras mutation. Thus, they were all diagnosed as RA. CONCLUSION: The untypical MDS patients can be diagnosed early by examination with combining several clonal analysis techniques.

Adolescent↗

PubMed2002

[Analysis of sister chromatid differentiation in myelodysplastic syndrome and its clinical application].

OBJECTIVE: To verify the value of sister chromatid differentiation (SCD) analysis of bone marrow cells in establishing the diagnosis and predicting prognosis of myelodysplastic syndrome (MDS). METHODS: S-bromodeoxyuridine-SCD and karyotyping studies were performed in 50 cases with clinically suspected MDS. RESULTS: Prolonged cell cycle time (CT) was found in 33 of the 50 cases (66.0%). In 13 cases with acute myeloid leukemia (AML), all had prolonged CT. However, only 2 (10.5%) of the 19 cases with nonmalignant hematological disorders had prolonged CT. There were significant differences of CT between the cases with MDS and those with AML, aplastic anemia (AA) and benign hypercellular anemias as well as healthy individuals. However, there were no significant differences between healthy individuals and cases with AA and, with benign hepercellular anemia. CT gradually prolonged during the evolution of MDS. 24 of the 50 patients (48.0%) were found to have clonal chromosomal abnormalities. In seven cases not compatible with MDS according to FAB criteria, six were found to have clonal chromosomal abnormalities. The mortality rates were 11.8 and 50.0% in the groups of normal SCD and of prolonged SCD, respectively (P < 0.05). The rates of leukemia transformation in both the groups were 5.9% and 16.7% (P > 0.05). The median survival of both the groups was 12 months and 8 months (P = 0.051). CONCLUSION: SCD analysis is valuable for establishing the diagnosis and predicting the prognosis of MDS.

Adolescent↗

PubMed2002

[The relationship between glutathione S-transferase M1 genotypes and lipid peroxidation in asbestos workers].

OBJECTIVE: To study the relationship between glutathione S-transferase M1 (GSTM1) genotypes and lipid peroxidation of asbestos workers. METHODS: 94 asbestos workers and 51 controls were selected as subjects. The general information, occupational history and individual habits were collected by questionnaires in all participants. The venous blood was sampled and the plasma was separated for the detection of malondialdehyde (MDA) level and lymphocytes for DNA isolation and GSTM1 genotyping. RESULTS: MDA level was significantly higher in asbestos workers [(0.283 +/- 0.054) nmol/L] than that in controls [(0.163 +/- 0.053) nmol/L, P < 0.01], however, neither duration of exposure nor accumulated asbestos exposure dose was related to MDA levels; MDA levels in control workers with GSTM1 +/- genotype [(0.190 +/- 0.034) nmol/L] were significantly higher than that in control workers with GSTM1 +/+ genotype [(0.138 +/- 0.055) nmol/L, P < 0.01]. Among asbestos workers, the same trend could be found, but the differences was not significant(P > 0.05). When the workers were stratified by duration of exposure or accumulated asbestos exposure dose, MDA levels in individuals with GSTM1 -/- genotype were also higher than those with GSTM1 +/+ genotype, but the differences were also not significant(P > 0.05). CONCLUSION: Both exposure to asbestos and deficiency of GSTM1 genotype were related to lipid peroxidation in workers, but the role of the former may be more important than that of the latter.

Asbestos↗

PubMedDate not supplied

Birdshot chorioretinopathy.

Birdshot chorioretinopathy is a well-known, yet poorly understood, form of posterior uveitis, characterized by multiple, distinctive, hypopigmented choroidal lesions, and strongly associated with human leukocyte antigen (HLA)-A29. We reviewed all English language publications regarding birdshot chorioretinopathy and performed analyses of combined patient data taken from these articles. The mean age at presentation was 53 years, with a slight female predominance (54.1%). At least 95.7% of reported patients have been HLA-A29-positive. Blurring of vision and floaters are the most prevalent presenting complaints, even in patients with visual acuity of 20/20 or better in both eyes. Birdshot chorioretinopathy is a slowly progressive disease with profound dysfunction of vision that may not be reflected in Snellen visual acuity. Two or more lines of Snellen visual acuity were lost in approximately 20% of eyes over a median follow-up of 3.5 years; macular edema was the most common cause of reduced visual acuity. Overall, patients had a slow decline in visual acuity, despite the fact that nearly all were treated with anti-inflammatory therapies. Final visual acuity in the better eye was 20/40 or better in 75.1% of patients and 20/200 or worse in 9.8% of patients. Oral corticosteroids and cyclosporine were the most commonly used medications. Using a regression model, patients in the literature that have been treated with cyclosporine alone had better final visual acuity than patients treated with oral corticosteroids alone. Further study is needed to determine the optimal methods for treating and monitoring patients with birdshot chorioretinopathy.

Chorioretinitis↗

PubMedDate not supplied

The impact of treatment confidence on pain and related disability among patients with low-back pain: results from the University of California, Los Angeles, low-back pain study.

BACKGROUND CONTEXT: Although many researchers and practitioners believe that patients' positive expectations of their treatment favorably influence clinical outcomes, there is little scientific evidence to support this belief. PURPOSE: To describe the level of patients' initial confidence in the success of their assigned treatment, by treatment group and other factors; and to estimate the effects of treatment confidence on subsequent changes in low-back pain and related disability. STUDY DESIGN AND PATIENT SAMPLE: Randomized clinical trial involving 681 patients treated for low-back pain in a managed-care facility in Southern California. OUTCOME MEASURES: Treatment confidence; and changes in three clinical measures of low-back pain: average pain, most severe pain and back-pain-related disability. METHODS: Patients were randomly assigned to one of four treatment groups: medical care with and without physical therapy, and chiropractic care with and without physical modalities. Information was collected by questionnaires at baseline, 2 weeks, 6 weeks and 6 months. Treatment confidence was measured just after randomization on a scale of 0 to 10. RESULTS: Treatment confidence was lowest, on average, for patients assigned to medical care only and highest for patients assigned to medical care plus physical therapy. Other predictors of high treatment confidence were having acute pain and being older, female and nonwhite. Although treatment confidence was only weakly associated with subsequent changes in low-back pain or disability in the total sample, high treatment confidence was associated with greater improvement among patients assigned to medical care plus physical therapy. CONCLUSIONS: Initial confidence in treatment for low-back pain varies by type of care and other factors. Higher confidence may have some beneficial effect on the course of low-back pain in certain patients, but this effect may depend on the type of interaction between client and provider.

Adult↗

PubMedDate not supplied

Immunogenicity and protective efficacy of a targeted fusion DNA construct against dental caries.

Targeting antigens to antigen-presenting cells by fusion to cytotoxic T lymphocyte-associated antigen 4 (CTLA4) has been shown to be a highly efficient method to enhance the efficacy of DNA vaccines. The purpose of this study was to determine the immunogenicity and protective efficacy of the targeted fusion DNA construct pGJA-P, which contains the signal peptide and extracellular regions of human CTLA4 gene, the hinge and Fc regions of human Iggamma1 gene, the glucan-binding domain of the Streptococcus mutans gtfB gene and the A-P fragment of the S. mutans pac gene, compared with the fusion DNA construct pGLUA-P, which contains only the glucan-binding domain of the S. mutansgtfB gene and the A-P fragment of the S. mutans pac gene. BALB/c mice were immunized with pGJA-P, pGLUA-P, or pCI (vector) by the intramuscular or intranasal route. Specific anti-PAc and anti-GTF-I serum IgG and salivary IgA antibody responses were assessed by an enzyme-linked immunosorbent assay. Wistar rats were orally challenged with S. mutans and immunized with pGJA-P, pGLUA-P, or pCI intramuscularly or intranasally, and caries activity was evaluated by the Keyes method. pGJA-P induced accelerated and increased serum and salivary antibody responses in mice compared with pGLUA-P. Rats immunized with pGJA-P had significantly fewer caries lesions than rats immunized with pGLUA-P (p < 0.01). Thus, this study demonstrates that the targeted DNA construct pGJA-P can enhance both systemic and mucosal immunity and may be a useful strategy for improving the protective efficacy of anticaries DNA vaccines.

Abatacept↗