Publications
Department of Medicine faculty members published more than 3,600 peer-reviewed articles in 2024.
2009
2009
The World Health Organization recommends the use of artemisinin-based combination therapies (ACTs) for the treatment of uncomplicated malaria. The two most widely adopted ACT regimens are artemether (AR)-lumefantrine (LR) (the combination is abbreviated AL) and amodiaquine (AQ)-artesunate (AS). Pharmacokinetic (PK) data informing the optimum dosing of these drug regimens is limited, especially in children. We evaluated PK parameters in Ugandan children aged 5 to 13 years with uncomplicated malaria treated with AL (n = 20) or AQ-AS (n = 21), with intensive venous sampling occurring at 0, 2, 4, 8, 24, and 120 h following administration of the last dose of 3-day regimens of AL (twice daily) or AQ-AS (once daily). AS achieved an estimated maximum concentration in plasma (C(max)) of 51 ng/ml and an area under the concentration-time curve from time zero to infinity (AUC(0-infinity)) of 113 ng.h/ml; and its active metabolite, dihydroartemisinin (DHA), achieved a geometric mean C(max) of 473 ng/ml and an AUC(0-infinity) of 1,404 ng.h/ml. AR-DHA exhibited a C(max) of 34/119 ng/ml and an AUC(0-infinity) of 168/382 ng.h/ml, respectively. For LR, C(max) and AUC(0-infinity) were 6,757 ng/ml and 210 microg.h/ml, respectively. For AQ and its active metabolite, desethylamodiaquine (DEAQ), the C(max)s were 5.2 ng/ml and 235 ng/ml, respectively, and the AUC(0-infinity)s were 39.3 ng.h/ml and 148 microg.h/ml, respectively. Comparison of the findings of the present study to previously published data for adults suggests that the level of exposure to LR is lower in children than in adults and that the level of AQ-DEAQ exposure is similar in children and adults. For the artemisinin derivatives, differences between children and adults were variable and drug specific. The PK results generated for children must be considered to optimize the dosing strategies for these widely utilized ACT regimens.
View on PubMed2009
Treatment decision-making can be difficult and complex for patients with low-risk prostate cancer. To the authors' knowledge, there is no consensus regarding an optimal treatment strategy and the choice of therapy involves tradeoffs between differing harms and benefits that are sensitive to patient values. In such situations, patients are often asked to participate actively in the decision-making process, and high-quality decisions require a well-informed patient whose values and preferences have been taken into consideration. Prior studies have indicated that patients have poor knowledge and unrealistic expectations regarding treatment, and physician judgments concerning patient preferences are often inaccurate. Decision aids (DAs) have been developed to help inform patients with low-risk prostate cancer about treatment options and assist in the decision-making process; however, little is currently known regarding the effects of such programs in this population. Thirteen studies of DAs for patients with prostate cancer were reviewed and it was found that the use of DAs can improve knowledge, encourage more active patient involvement in decision-making, and decrease levels of anxiety and distress. The effect of DAs on treatment choice was less clear, although fewer patients chose surgery compared with historical controls, particularly in Europe. Further studies are needed to determine how best to implement DAs into practice, and whether they improve the consistency between patient preferences and treatment choice.
View on PubMed2009
2009
2009
BACKGROUND
The processes that drive fibrotic diseases are complex and include an influx of peripheral blood monocytes that can differentiate into fibroblast-like cells called fibrocytes. Monocytes can also differentiate into other cell types, such as tissue macrophages. The ability to discriminate between monocytes, macrophages, fibrocytes, and fibroblasts in fibrotic lesions could be beneficial in identifying therapies that target either stromal fibroblasts or fibrocytes.
METHODOLOGY/PRINCIPAL FINDINGS
We have identified markers that discriminate between human peripheral blood monocytes, tissue macrophages, fibrocytes, and fibroblasts. Amongst these four cell types, only peripheral blood monocytes express the combination of CD45RO, CD93, and S100A8/A9; only macrophages express the combination of CD45RO, 25F9, S100A8/A9, and PM-2K; only fibrocytes express the combination of CD45RO, 25F9, and S100A8/A9, but not PM-2K; and only fibroblasts express the combination of CD90, cellular fibronectin, hyaluronan, and TE-7. These markers are effective both in vitro and in sections from human lung. We found that markers such as CD34, CD68, and collagen do not effectively discriminate between the four cell types. In addition, IL-4, IL-12, IL-13, IFN-gamma, and SAP differentially regulate the expression of CD32, CD163, CD172a, and CD206 on both macrophages and fibrocytes. Finally, CD49c (alpha3 integrin) expression identifies a subset of fibrocytes, and this subset increases with time in culture.
CONCLUSIONS/SIGNIFICANCE
These results suggest that discrimination of monocytes, macrophages, fibrocytes, and fibroblasts in fibrotic lesions is possible, and this may allow for an assessment of fibrocytes in fibrotic diseases.
View on PubMed2009
2009
CONTEXT
Primary hyperparathyroidism (PHPT) is characterized by chronically elevated serum calcium and inappropriately normal or increased PTH.
OBJECTIVE
Our objective was to evaluate long-term tolerability, safety, and efficacy of cinacalcet in PHPT patients.
DESIGN AND SETTING
A 4.5-yr open-label extension study was conducted at 14 study centers in the United States.
PATIENTS OR OTHER PARTICIPANTS
Forty-five subjects with PHPT from a double-blind, placebo-controlled, 1-yr trial were continued into this study.
INTERVENTIONS
After the parent study, all subjects were treated with 30 mg cinacalcet twice daily, increasing to 50 mg twice daily during the 12-wk titration if serum calcium levels were 10.3 mg/dl or higher and then maintained on cinacalcet for up to 4.5 yr.
MAIN OUTCOME MEASURES
Assessments included serum calcium, PTH, phosphate and alkaline phosphatase, and areal bone mineral density (aBMD). Vital signs, safety chemistries and hematology, and adverse events were monitored throughout.
RESULTS
Compared with baseline, cinacalcet treatment improved biochemical measures of PHPT including reducing serum calcium and PTH and increasing serum phosphate with slight increases in alkaline phosphatase. No changes in z-scores of aBMD at spine, hip, or wrist were seen with annual percent changes, consistent with reports for untreated postmenopausal women or PHPT patients. Safety biochemistries remained normal, and adverse events (most commonly arthralgia, myalgia, diarrhea, respiratory infection, and nausea) were mild to moderate in severity.
CONCLUSIONS
Treatment of PHPT patients with cinacalcet for up to 5.5 yr maintained normocalcemia, reduced plasma PTH, increased serum phosphate and alkaline phosphatase with no significant effects on aBMD, and was well tolerated.
View on PubMed2009
BACKGROUND
Psychologic factors affect how patients with COPD respond to attempts to improve their self-management skills. Learned helplessness may be one such factor, but there is no validated measure of helplessness in COPD.
METHODS
We administered a new COPD Helplessness Index (CHI) to 1,202 patients with COPD. Concurrent validity was assessed through association of the CHI with established psychosocial measures and COPD severity. The association of helplessness with incident COPD exacerbations was then examined by following subjects over a median 2.1 years, defining COPD exacerbations as COPD-related hospitalizations or ED visits.
RESULTS
The CHI demonstrated internal consistency (Cronbach alpha = 0.75); factor analysis was consistent with the CHI representing a single construct. Greater CHI-measured helplessness correlated with greater COPD severity assessed by the BODE (Body-mass, Obstruction, Dyspnea, Exercise) Index (r = 0.34; P < .001). Higher CHI scores were associated with worse generic (Short Form-12, Physical Component Summary Score) and respiratory-specific (Airways Questionnaire 20) health-related quality of life, greater depressive symptoms, and higher anxiety (all P < .001). Controlling for sociodemographics and smoking status, helplessness was prospectively associated with incident COPD exacerbations (hazard ratio = 1.31; P < .001). After also controlling for the BODE Index, helplessness remained predictive of COPD exacerbations among subjects with BODE Index
CONCLUSIONS
The CHI is an internally consistent and valid measure, concurrently associated with health status and predictively associated with COPD exacerbations. The CHI may prove a useful tool in analyzing differential clinical responses mediated by patient-centered attributes.
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