Biomedical subjects

Chris Walker

Publications and source records attributed to Chris Walker.

7 recordsLinked to original sources

PubMed2005

Outcomes of Project Dulce: a culturally specific diabetes management program.

BACKGROUND: Diabetes mellitus is a common and costly chronic disease that increasingly affects minority populations; however, there is little evidence regarding the clinical effectiveness and costs of culturally appropriate disease management programs. OBJECTIVE: To determine the clinical outcomes and costs of Project Dulce, a combined stepped-care diabetes nurse case management program and culturally oriented peer-led self-empowerment training program. METHODS: Pre-post clinical outcome and cost analysis of Project Dulce participants were compared with a cohort of historical controls over a one-year period. Subjects included 348 persons with diabetes with coverage under County Medical Services who were receiving services in community health centers in San Diego, CA. Generalized regression models were used to estimate changes in clinical outcomes (hemoglobin [Hb] A1c, blood pressure, cholesterol level) and costs associated with participation in Project Dulce. RESULTS: Project Dulce participants had significant reductions in HbA1c (0.8%; p < 0.001), systolic (5.4 mm Hg; p = 0.001) and diastolic (8.0 mm Hg; p < 0.001) blood pressure, total cholesterol (28.1 mg/dL; p < 0.001), and low-density-lipoprotein cholesterol (15.6 mg/dL; p < 0.001). Expenditures for pharmacy ($3157 Dulce vs $1618 control) and disease management ($507 Dulce) increased. Total costs were higher during the first year of disease management ($5711 Dulce vs $4365 control; p < 0.001). CONCLUSIONS: Project Dulce was effective in improving clinical outcomes for control of diabetes and related conditions in a medically indigent, culturally diverse population. Our finding of reduced hospital expenditures, although statistically insignificant, is clinically and economically important and suggests that intervention might provide an immediate benefit to a high-risk population.

Antihypertensive Agents↗

PubMed2004

Identification of the RAG-1 as a suitable mouse model for mitochondrial DNA disease.

Previous studies have shown that transfer of human myoblasts carrying a mitochondrial DNA mutation into muscles of the severe combined immunodeficient mouse may provide an important animal model for mitochondrial myopathy. However, a major drawback of this mouse is its extreme sensitivity to ionising radiation, a pre-treatment which enhances the efficiency of myoblast transfer success. We implanted human myoblasts into the tibialis anterior muscles of another immunodeficient mouse, mutated in the recombinase activating gene-1 (RAG-1), to determine if this mouse could be an alternative to the severe combined immunodeficient for our mitochondrial myoblast transfer model. We also examined several different methods of muscle degeneration prior to myoblast transfer to determine which method resulted in the greatest amount of human tissue in implanted muscles. Our results show that the RAG-1 mouse displayed no sensitivity to the irradiation process compared to the high sensitivity in the severe combined immunodeficient mouse which resulted in early termination of the study. We also show that degeneration of host muscles by the myotoxin barium chloride (BaCl(2)) resulted in the greatest amount of regenerating human muscle fibres in both the severe combined immunodeficient and RAG-1 mice. In addition, the maximum amount of human fibres observed in transplanted muscles was similar in each mouse strain. The average number of fibres throughout muscles was significantly greater in severe combined immunodeficient mice injured by BaCl(2), but was similar between all other muscle groups. This study suggests that the RAG-1 mouse is a suitable host for the mitochondrial myoblast transfer model and may also prove valuable for other myoblast transfer models such as muscular dystrophy.

Analysis of Variance↗

PubMed2004

Measuring the impacts of community development initiatives: a new application of the adjusted interrupted time-series method.

The authors contribute to the development of empirical methods for measuring the impacts of place-based local development strategies by introducing the adjusted interrupted time-series (AITS) approach. It estimates a more precise counterfactual scenario, thus offering a stronger basis for drawing causal inferences about impacts. The authors applied the AITS approach to three community development initiatives using single-family home prices as the outcome indicator and found that it could measure impacts on both the base level of prices and the rate of price appreciation. The authors also found a situation in which the method appears unreliable, however. The AITS approach benefits from more recurrent data on outcomes during the pre-and post-intervention periods, with an intertemporal pattern that avoids great volatility. The AITS approach to measuring effects of community development initiatives holds strong promise, with caveats.

Housing↗

PubMed2004

Improvement in diabetes care of underinsured patients enrolled in project dulce: a community-based, culturally appropriate, nurse case management and peer education diabetes care model.

OBJECTIVE: To improve clinical diabetes care, patient knowledge, and treatment satisfaction and to reduce health-adverse culture-based beliefs in underserved and underinsured populations with diabetes. RESEARCH DESIGN AND METHODS: A total of 153 high-risk patients with diabetes recruited from six community clinic sites in San Diego County, California were enrolled in a nurse case management (NCM) and peer education/empowerment group. Baseline and 1-year levels of HbA(1c), lipid parameters, systolic and diastolic blood pressure, knowledge of diabetes, culture-based beliefs in ineffective remedies, and treatment satisfaction were prospectively measured. The NCM and peer education/empowerment group was compared with 76 individuals in a matched control group (CG) derived from patients referred but not enrolled in Project Dulce. RESULTS: After 1 year in Project Dulce, the NCM and peer education/empowerment group had significant improvements in HbA(1c) (12.0-8.3%, P < 0.0001), total cholesterol (5.82-4.86 mmol/l, P < 0.0001), LDL cholesterol (3.39-2.79 mmol/l, P < 0.0001), and diastolic blood pressure (80-76 mmHg, P < 0.009), which were significantly better than in the CG, in which no significant changes were noted. Accepted American Diabetes Association standards of diabetes care, knowledge of diabetes (P = 0.024), treatment satisfaction (P = 0.001), and culture-based beliefs (P = 0.001) were also improved. CONCLUSIONS: A novel, culturally appropriate, community-based, nurse case management/peer education diabetes care model leads to significant improvement in clinical diabetes care, self-awareness, and understanding of diabetes in underinsured populations.

Adolescent↗

PubMedDate not supplied

Alphavirus replicon particles as candidate HIV vaccines.

Replicon particles based on Venezuelan equine encephalitis virus (VEE) contain a self-replicating RNA encoding the VEE replicase proteins and expressing a gene of interest in place of the viral structural protein genes. Structural proteins for packaging of replicon RNA into VEE replicon particles (VRPs) are expressed from separate helper RNAs. Aspects of the biology of VEE that are exploited in VRP vaccines include 1) expression of very high levels of immunogen, 2) expression of immunizing proteins in cells in the draining lymph node, and 3) the ability to induce mucosal immunity from a parental inoculation. Results of experiments with VRPs expressing green fluorescent protein or influenza virus hemagglutinin (HA) demonstrated that specific mutations in the VRP envelope glycoproteins affect both targeting in the draining lymph node and efficiency of the immune response in mice. VRPs expressing either the matrix-capsid portion of Gag, the full-length envelope gp160, or the secreted gp140 of cloned SIVsm H-4i were mixed in a cocktail and used to immunize macaques at 0, 1, and 4 months. Neutralizing antibodies against SIVsm H-4 were induced in 6 of 6 vaccinates and CTL in 4 of 6. An intrarectal challenge with the highly pathogenic SIVsm E660 was given at 5 months. A vaccine effect was seen in reduced peak virus loads, reduced virus loads both at set point and at 41 weeks postchallenge, and preserved or increased CD4 counts compared to controls. A candidate VRP HIV vaccine expressing Clade C Gag contains a sequence that is very close to the South African Clade C consensus and was selected from a recent seroconverter in the Durban cohort to represent currently circulating genotypes in South Africa. A GMP lot of this vaccine has been manufactured and tested for a phase I trial in the first months of 2002.

AIDS Vaccines↗

PubMedDate not supplied

Glycemic control with insulin glargine as part of an ethnically diverse, community-based diabetes management program.

OBJECTIVE: To evaluate the contribution of long-acting basal insulin therapy (insulin glargine) to glycemic control in a predominantly Hispanic population participating in a community-based diabetes management program, Project Dulce. RESEARCH DESIGN AND METHODS: This retrospective analysis included 3122 adult patients with diabetes from 17 community clinics in San Diego County, California who participated in Project Dulce between July 2000 and March 2003. A subset of 180 patients received insulin glargine because of ongoing, inadequate glycemic control (ie, elevated HbA1c). Glycemic control was evaluated by mean adjusted HbA1c during follow-up clinical visits using hierarchical linear modeling, with values determined separately before and after initiation of insulin glargine. RESULTS: At baseline, the mean number of individuals with hypoglycemia, presence of diabetic complications, and duration of diabetes were greater in the glargine group that in the reference group. HbA1c at baseline was 8.79 and 9.44 (P = 0.019) in the reference and glargine groups, respectively. Mean adjusted HbA1c in the glargine group was 8.80 at baseline, 7.89 before initiation of insulin glargine (P < 0.001 vs baseline), and 7.34 after adding insulin glargine (P < 0.001 vs pre-glargine). In the reference group, mean adjusted HbA1c decreased from 8.81 at baseline to 7.40 during follow-up (P < 0.001 vs baseline). CONCLUSIONS: A comprehensive program of diabetes care in Project Dulce improved HbA1c significantly in a predominantly Hispanic population. Adding long-acting basal insulin therapy with insulin glargine produced significant incremental improvement in HbA1c.

Adolescent↗

PubMedDate not supplied

The patient factor.

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Adolescent↗