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Biomedical subjects

Lin Ding

Publications and source records attributed to Lin Ding.

11 recordsLinked to original sources
PubMed2006

The reliability of survey assessments of characteristics of medical clinics.

OBJECTIVE: To assess the reliability of survey measures of organizational characteristics based on reports of single and multiple informants. DATA SOURCE: Survey of 330 informants in 91 medical clinics providing care to HIV-infected persons under Title III of the Ryan White CARE Act. STUDY DESIGN: Cross-sectional survey. DATA COLLECTION METHODS: Surveys of clinicians and medical directors measured the implementation of quality improvement initiatives, priorities assigned to aspects of HIV care, barriers to providing high-quality HIV care, and quality improvement activities. Reliability of measures was assessed using generalizability coefficients. Components of variance and clinician-director differences were estimated using hierarchical regression models with survey items and informants nested within organizations. PRINCIPAL FINDINGS: There is substantial item- and informant-related variability in clinic assessments that results in modest or low clinic-level reliability for many measures. Directors occasionally gave more optimistic assessments of clinics than did clinicians. CONCLUSIONS: For most measures studied, obtaining adequate reliability requires multiple informants. Using multiple-item scales or multiple informants can improve the psychometric performance of measures of organizational characteristics. Studies of such characteristics should report the organizational level reliability of the measures used.

Adult↗
PubMed2005

Quality of HIV care provided by nurse practitioners, physician assistants, and physicians.

BACKGROUND: Nurse practitioners (NPs) and physician assistants (PAs) are primary care providers for patients with HIV in some clinics, but little is known about the quality of care that they provide. OBJECTIVE: To compare the quality of care provided by NPs and PAs with that provided by physicians. DESIGN: Cross-sectional analysis. SETTING: 68 HIV care sites, funded by Ryan White Comprehensive AIDS Resources Emergency (CARE) Act Title III, in 30 different states. PARTICIPANTS: The authors surveyed 243 clinicians (177 physicians and 66 NPs and PAs) and reviewed medical records of 6651 persons with HIV or AIDS. MEASUREMENTS: 8 quality-of-care measures assessed by medical record review. RESULTS: After adjustments for patient characteristics, 6 of the 8 quality measures did not statistically significantly differ between NPs and PAs and either infectious disease specialists or generalist HIV experts. Adjusted rates of purified protein derivative testing and Papanicolaou smears were statistically significantly higher for NPs and PAs (0.63 and 0.71, respectively) than for infectious disease specialists (0.53 [P = 0.007] and 0.56 [P = 0.001], respectively) or generalist HIV experts (0.47 [P < 0.001] and 0.62 [P = 0.025], respectively). Nurse practitioners and PAs had statistically significantly higher performance scores than generalist non-HIV experts on 6 of the 8 quality measures. LIMITATIONS: These results may not be generalizable to care settings where on-site physician HIV experts are not accessible or to measures of more complex clinical processes. CONCLUSIONS: For the measures examined, the quality of HIV care provided by NPs and PAs was similar to that of physician HIV experts and generally better than physician non-HIV experts. Nurse practitioners and PAs can provide high-quality care for persons with HIV. Preconditions for this level of performance include high levels of experience, focus on a single condition, and either participation in teams or other easy access to physicians and other clinicians with HIV expertise.

Acquired Immunodeficiency Syndrome↗
PubMed2005

Predictors and consequences of negative physician attitudes toward HIV-infected injection drug users.

BACKGROUND: We evaluated physicians' training, experience, and practice characteristics and examined associations between their attitudes toward human immunodeficiency virus (HIV)-infected persons who are injection drug users (IDUs) and quality of care. METHODS: Cross-sectional surveys were conducted among a probability sample of noninstitutionalized HIV-infected individuals in the United States and their main HIV care physicians. Physician and practice characteristics, training, HIV knowledge, experience, attitudes toward HIV-infected IDUs, stress levels, and satisfaction with practice were assessed. The main quality-of-care measures were patient exposure to highly active antiretroviral therapy, reported problems, satisfaction with care, unmet needs, and perceived access to care. RESULTS: Nationally, 23.2% of HIV-infected patients had physicians with negative attitudes toward IDUs. Seeing more IDUs, having higher HIV treatment knowledge scores, and treating fewer patients per week were independently associated with more positive attitudes toward IDUs. Injection drug users who were cared for by physicians with negative attitudes had a significantly lower adjusted rate of exposure to highly active antiretroviral therapy by December 1996 (13.5%) than non-IDUs who were cared for by such physicians (36.1%) or IDUs who were cared for by physicians with positive attitudes (32.3%). Physician attitudes were not associated with other problems with care, satisfaction with care, unmet needs, or perceived access to care. CONCLUSIONS: Negative attitudes may lead to less than optimal care for IDUs and other marginalized populations. Providing education or experience-based exercises or ensuring that clinicians have adequate time to deal with complex problems might result in better attitudes and higher quality of care.

Adult↗
PubMed2005

Epstein-Barr virus encoded latent membrane protein 1 modulates nuclear translocation of telomerase reverse transcriptase protein by activating nuclear factor-kappaB p65 in human nasopharyngeal carcinoma cells.

Sustained proliferation of cancer cells requires that telomerase maintain chromosomal stability and prolong telomere length-regulated cell replication. Human telomerase reverse transcriptase (hTERT), the human telomerase catalytic subunit, and also the key determinant of the enzymatic activity of human telomerase, is regulated both at the transcriptional level and via phosphorylation and translocation. In this study, we show that latent membrane protein 1 (LMP1), the principal oncoprotein of Epstein-Barr virus (EBV), modulates telomerase activity by inducing the direct binding of hTERT to nuclear factor kappaB (NF-kappaB) p65 and translocation of both proteins from the cytoplasm to the nucleus in nasopharyngeal carcinoma cells (NPC). Conversely, a NF-kappaB nuclear translocation inhibitor, (benzylcarbonyl)-Leu-Leu-phenylalaninal (Z-LLF-CHO), and a dominant negative mutant of inhibitor of NFkappaB (IkappaBalpha), can block LMP1-induced hTERT nuclear translocation. These studies suggest a novel function of LMP1 and confirm that NF-kappaB plays an important role in regulating the activation and nuclear translocation of telomerase in NPC cells.

Antigens, Viral↗
PubMed2005

A national study of the relationship of care site HIV specialization to early adoption of highly active antiretroviral therapy.

BACKGROUND: Little is known about characteristics of organizations that predict early adoption of highly active antiretroviral therapy (HAART) for persons with HIV infection. OBJECTIVES: To describe characteristics of sites where HIV care is provided and to assess site characteristics that predict early adoption of HAART. DESIGN: Cross-sectional analysis of survey data from patients, HIV physicians, and medical directors. PATIENTS AND SETTING: Participants in the HIV Cost and Services Utilization Study, a national probability sample of persons with HIV who received outpatient care in the continental United States during 1996. MAIN OUTCOME MEASURE: Rates of exposure to HAART by December 1996. RESULTS: Nationally, 79% of patients were treated at sites specializing in HIV care (HIV sites). Over 90% of patients were cared for by physicians who were experts in HIV care, either infectious disease specialists (46%) or general medicine experts (45%). Adjusted rates of exposure to HAART by December 1996 varied from 0.02 to 0.79 across sites (mean rate, 0.33). In multivariable models, HIV specialization (odds ratio [OR], 3.6; P < 0.001), total patient volume of more than 20,000 visits a year (OR, 2.1; P < 0.01), and educational level of the zip code in which the site was located (OR, 1.2 for each 10% increase in college education) were associated with higher rates of exposure to HAART. These effects persisted after adjustment for physician HIV expertise. Site effects were more important than physician effects in explaining rates of exposure to HAART. CONCLUSION: In 1996 there were wide variations in rates of HAART use by site of care. Low-volume sites that do not specialize in HIV care should take measures to ensure that HIV expertise is available to their patients.

Adult↗
PubMed2005

Psychometric properties of a group-level Consumer Assessment of Health Plans Study (CAHPS) instrument.

BACKGROUND: Many different surveys have been used to evaluate the performance of medical groups, but there is a growing recognition that standardization could be helpful to consumers, purchasers, and others. OBJECTIVES: We sought to develop a version of the Consumer Assessment of Health Plans Study (CAHPS) survey for use with medical groups (G-CAHPS) and assess its reliability and validity. RESEARCH DESIGN: The research team reviewed existing instruments and conducted patient focus groups in 4 sites to identify aspects of care that were especially important to patients when evaluating medical groups. We tested a draft instrument in 75 cognitive interviews with adults 18 years of age or older in Knoxville, St. Louis, and California and pretests in 4 groups of adults in Boston and Denver. We then surveyed random samples of patients from medical groups and practice sites in California, Knoxville, St. Louis, and Denver. We analyzed the psychometric characteristics of the instrument. RESULTS: Data support the reliability and validity of 3 multi-item measures of access, office staff service, and patient clinician communication. Measures related to specialty care and preventive counseling did not differentiate among medical groups. CONCLUSIONS: The G-CAHPS instrument provides an assessment of selected aspects of care that are important to consumers and could be a useful complement to the plan-level CAHPS instrument.

Adult↗
PubMed2003

Phosphorylation of the AMPA receptor GluR1 subunit is required for synaptic plasticity and retention of spatial memory.

Plasticity of the nervous system is dependent on mechanisms that regulate the strength of synaptic transmission. Excitatory synapses in the brain undergo long-term potentiation (LTP) and long-term depression (LTD), cellular models of learning and memory. Protein phosphorylation is required for the induction of many forms of synaptic plasticity, including LTP and LTD. However, the critical kinase substrates that mediate plasticity have not been identified. We previously reported that phosphorylation of the GluR1 subunit of AMPA receptors, which mediate rapid excitatory transmission in the brain, is modulated during LTP and LTD. To test if GluR1 phosphorylation is necessary for plasticity and learning and memory, we generated mice with knockin mutations in the GluR1 phosphorylation sites. The phosphomutant mice show deficits in LTD and LTP and have memory defects in spatial learning tasks. These results demonstrate that phosphorylation of GluR1 is critical for LTD and LTP expression and the retention of memories.

Animals↗
PubMed2003

[Epstein-Barr virus inhibits P16INK4a expression in human fetal nasopharyngeal epithelial cells escaping from the replicative senenscence].

Cell cycle deregulation is regarded as an important event to involve in cellular immortalization. To confirm the role of cell cycle deregulation in human fetal nasopharyngeal epithelial cells escaping from the replicative senescence induced by Epstein-Barr virus infection, we detected expression of cell cycle regulators, such as p16INK4a, p21WAF1/CIP1, p53, and E2F1 with Western blotting and immunocytochemisty in this study. Our results found that Epstein-Barr virus inhibited the expression of p16INK4a, at the same time, E2F1 expression were strongly increased in EBV-infected cells, however, as for the expression of p53 and p21WAF1/CIP1, there was no difference between EBV-infected cells and non-infected cells. The results show that EBV inactivates p16INK4a/pRB pathway and then induces E2F1 activity and it is implicated that Epstein-Barr virus-medicated cell cycle deregulation plays an important role in the immortalization of human nasopharyngeal epithelial cells. These data will be helpful for further studying the carcinogenesis of nasopharyngeal carcinoma.

Cell Transformation, Neoplastic↗
PubMed2002

HIV patients' experiences with inpatient and outpatient care: results of a national survey.

CONTEXT: Little is known about HIV patients' care experiences. OBJECTIVE: To assess HIV patients' experiences with inpatient and outpatient care, and to assess the relationship and relative influence of patient characteristics and site of care on care experiences. DESIGN: Cohort study. SETTING: Patients with HIV receiving care outside of emergency rooms, prisons, or the military throughout the continental United States. One thousand seventy-four patients provided ratings of an inpatient stay and 2204 rated an outpatient visit; 818 patients provided evaluations of both inpatient and outpatient care. PATIENTS: A national probability sample of persons in care for HIV from the HIV Cost and Services Utilization Study. MEASUREMENTS: Outcome variables were rates of problems with, and global ratings of, inpatient and outpatient care. RESULTS: Mean problem rates were 20.9% and 8.4% (lower score means fewer problems) for inpatient and outpatient care, respectively. On 9 of 10 of the individual inpatient report items, 15% or more of respondents reported problems. Global ratings of inpatient and outpatient care were 65.3 and 75.0 (0-100 scale, higher scores indicate better ratings), respectively. In multivariable models that controlled for site effects, the only patient characteristic that was consistently associated with problem rates and global ratings of care was mental health (P <0.0001 for both inpatient and outpatient care). Models including site effects explained two to four times as much variance as models excluding site effects. CONCLUSIONS: Inpatients with HIV reported higher problem rates with inpatient than outpatient care. Better provider-patient communication during inpatient stays is needed. For both inpatient and outpatient care, quality improvement efforts may be most productively focused on providers and processes of care at sites rather than on specific patient subgroups.

Adult↗
PubMedDate not supplied

Gender differences in quality of HIV care in Ryan White CARE Act-funded clinics.

BACKGROUND: Women with HIV infection have lagged behind men in receipt of critical health care, but it is not known if those disparities are due in part to where women receive care. We examined differences in care received by HIV-infected women and men in a national sample of Ryan White CARE Act-funded clinics and explored the influence of clinic characteristics on care quality. METHODS: Record review was done on a sample of 9,015 patients who received care at 69 CARE Act-funded HIV primary care clinics that participated in a quality improvement study. Outcome measures studied were highly active antiretroviral therapy (HAART) use, HIV viral suppression, Pneumocystis jiroveci pneumonia (PCP) prophylaxis, screening, and other disease prevention efforts. RESULTS: Women were less likely than men to receive HAART (78% versus 82%, p < .001), receive PCP prophylaxis (65% versus 75%, p < .0001), or have their hepatitis C virus status known (87% versus 88%, p = .02) despite being seen more regularly (69% versus 66%, p = .04). Sites serving high percentages of women delivered similar or better care for both men and women than other sites. Although sites serving a higher percent of women had more support services such as case management and onsite obstetrician-gynecologists and provided Pap smears at higher rates, women at such sites remained less likely than men to receive important HIV care including HAART and PCP prophylaxis. CONCLUSIONS: The gap in the quality of care provided to HIV-infected men and women in critical areas persists, and is not explained by the types of sites where men and women receive care.

AIDS-Related Opportunistic Infections↗