Publications
Department of Medicine faculty members published more than 3,600 peer-reviewed articles in 2024.
2010
BACKGROUND
Venous thromboembolism (VTE) is common after lung transplantation. Enoxaparin is an approved therapy for VTE and anti-factor Xa level can be used to monitor enoxaparin activity. Some studies have demonstrated elevated anti-factor Xa levels are associated with an increased risk of hemorrhage. Having identified a high incidence of supratherapeutic anti-factor Xa levels in lung transplant recipients, we aimed to elucidate the relationship between enoxaparin dose and anti-factor Xa level in this patient population.
METHODS
We identified post-lung transplantation patients with VTE receiving therapeutic enoxaparin who had anti-factor Xa level measured. Standard enoxaparin dosing was defined as 0.9 to 1.1 mg/kg. After identifying a high incidence of supratherapeutic anti-factor Xa levels, we implemented "non-standard" dosing of 0.8 mg/kg. Multivariate linear regression analysis was used to examine the association between enoxaparin dose and anti-factor Xa level; age, body mass index (BMI) and creatinine clearance were included as covariates.
RESULTS
In the cohort, 18 patients received standard and 8 patients received non-standard enoxaparin dosing. Twelve of 18 patients (67%; 95% confidence interval [CI]: 43% to 91%) receiving standard dosing had supratherapeutic anti-factor Xa levels vs 0 of 8 patients (0%; 95% CI: 0% to 37%) receiving lower non-standard dosing (p = 0.002). Anti-factor Xa levels were significantly different between the two groups; the mean anti-factor Xa level was 1.3 IU/ml (95% CI: 1.06 to 1.53) in the standard group vs 0.79 IU/ml (95% CI: 0.67 to 0.91) in the non-standard group (p = 0.008). After controlling for covariates, for each 0.1-mg/kg increase in enoxaparin, the mean anti-factor Xa level increased by 0.18 IU/ml (95% CI: 0.05 to 0.31; p = 0.011; model r(2) = 0.53).
CONCLUSIONS
Standard dosing of enoxaparin in lung transplant recipients is associated with a high incidence of supratherapeutic anti-Xa levels. Further study will be required to correlate this finding with risk of hemorrhage.
View on PubMed2010
BACKGROUND
Older adults comprise an increasing proportion of the prison and homeless populations. While older age is associated with adverse post-release health events and incarceration is a risk factor for homelessness, the health status and homelessness risk of older pre-release prisoners are unknown. Moreover, most post-release services are geared towards veterans; it is unknown whether the needs of non-veterans differ from those of veterans.
OBJECTIVE
To assess health status and risk of homelessness of older pre-release prisoners, and to compare veterans with non-veterans.
DESIGN/PARTICIPANTS
Cross-sectional study of 360 prisoners (≥ 55 years of age) within 2 years of release from prison using data from the 2004 Survey of Inmates in State and Federal Correctional Facilities.
MAIN MEASURES
Veteran status, health status (based on self-report), and risk of homelessness (homelessness before arrest).
KEY RESULTS
Mean age was 61 years; 93.8% were men and 56.5% were white. Nearly 40% were veterans, of whom 77.2% reported likely VA service eligibility. Veterans were more likely to be white and to have obtained a high school diploma or GED. Overall, 79.1% reported a medical condition and 13.6% reported a serious mental illness. There was little difference in health status between veterans and non-veterans. Although 1 in 12 prisoners reported a risk factor for homelessness, the risk factors did not differ according to veteran status.
CONCLUSIONS
Older pre-release prisoners had a high burden of medical and mental illness and were at risk for post-release homelessness regardless of veteran status. Reentry programs linking pre-release older prisoners to medical and psychiatric services and to homelessness prevention programs are needed for both veterans and non-veterans.
View on PubMed2010
2010
2010
Type 2 immunity is a stereotyped host response to allergens and parasitic helminths that is sustained in large part by the cytokines IL-4 and IL-13. Recent advances have called attention to the contributions by innate cells in initiating adaptive immunity, including a novel lineage-negative population of cells that secretes IL-13 and IL-5 in response to the epithelial cytokines IL-25 and IL-33. Here, we use IL-4 and IL-13 reporter mice to track lineage-negative innate cells that arise during type 2 immunity or in response to IL-25 and IL-33 in vivo. Unexpectedly, lineage-negative IL-25 (and IL-33) responsive cells are widely distributed in tissues of the mouse and are particularly prevalent in mesenteric lymph nodes, spleen, and liver. These cells expand robustly in response to exogenous IL-25 or IL-33 and after infection with the helminth Nippostrongylus brasiliensis, and they are the major innate IL-13-expressing cells under these conditions. Activation of these cells using IL-25 is sufficient for worm clearance, even in the absence of adaptive immunity. Widely dispersed innate type 2 helper cells, which we designate Ih2 cells, play an integral role in type 2 immune responses.
View on PubMed2010
BACKGROUND
Ciguatoxins are extremely potent neurotoxins, produced by tropical marine dinoflagellates, that persistently enter into our food web. Over 100,000 people annually experience acute ciguatera poisoning from consuming toxic fish. Roughly 5% of these victims will develop chronic ciguatera (CC), a widespread, multisymptom, multisystem, chronic illness that can last tens of years. CC is marked by disproportionate disability and non-specific refractory symptoms such as fatigue, cognitive deficits and pain, and is suggestive of other illnesses. Its unknown pathophysiology makes both diagnosis and treatment difficult.
OBJECTIVES
We wanted to compare objective parameters of visual contrast sensitivity testing, measures of innate immune response and genetic markers in cases to controls to assess the potential for the presence of persistent inflammatory parameters that are demonstrated in other biotoxin associated illnesses at a single specialty clinic.
METHODS
Using 59 CC cases and 59 controls we present in retrospective review, in all cases, abnormalities in immune responses paralleling the chronic systemic inflammatory response syndrome seen in several other chronic diseases.
RESULTS
This study defines a preliminary case definition using medical history, total symptoms, visual contrast sensitivity, HLA DR genotype analysis, reduction of regulatory neuropeptides VIP and MSH, and multiple measures of inflammatory immune response, especially C4a and TGFβ1, thereby providing a basis for identification and targeted therapy.
CONCLUSIONS
CC provides a model for chronic human illness associated with initiation of inflammatory responses by biologically produced neurotoxins.
View on PubMed2010
2010
Analysis of lineage relationships in the naphthalene-injured tracheal epithelium demonstrated that two multipotential keratin 14-expressing cells (K14ECs) function as progenitors for Clara and ciliated cells. These K14EC were distinguished by their self-renewal capacity and were hypothesized to reside at the stem and transit amplifying tiers of a tissue-specific stem cell hierarchy. In this study, we used gene expression and histomorphometric analysis of the steady-state and naphthalene-injured trachea to evaluate the predictions of this model. We found that the steady-state tracheal epithelium is maintained by two progenitor cell pools, secretory and basal cells, and the latter progenitor pool is further divided into two subsets, keratin 14-negative and -positive. After naphthalene-mediated depletion of the secretory and ciliated cell types, the two basal cell pools coordinate to restore the epithelium. Both basal cell types up-regulate keratin 14 and generate a broadly distributed, abundant, and highly mitotic cell pool. Furthermore, basal cell proliferation is associated with generation of differentiated Clara and ciliated cells. The uniform distribution of basal cell progenitors and of their differentiated progeny leads us to propose that the hierarchical organization of tracheal reparative cells be revised to include a facultative basal cell progenitor pool.
View on PubMed2010