Publications
Department of Medicine faculty members published more than 3,600 peer-reviewed articles in 2024.
2008
2008
In contrast to many years of important research and clinical attention to the pathological effects of alcohol (ethanol) abuse, the past several decades have seen the publication of a number of peer-reviewed studies indicating the beneficial effects of light-moderate, nonbinge consumption of varied alcoholic beverages, as well as experimental demonstrations that moderate alcohol exposure can initiate typically cytoprotective mechanisms. A considerable body of epidemiology associates moderate alcohol consumption with significantly reduced risks of coronary heart disease and, albeit currently a less robust relationship, cerebrovascular (ischemic) stroke. Experimental studies with experimental rodent models and cultures (cardiac myocytes, endothelial cells) indicate that moderate alcohol exposure can promote anti-inflammatory processes involving adenosine receptors, protein kinase C (PKC), nitric oxide synthase, heat shock proteins, and others which could underlie cardioprotection. Also, brain functional comparisons between older moderate alcohol consumers and nondrinkers have received more recent epidemiological study. In over half of nearly 45 reports since the early 1990s, significantly reduced risks of cognitive loss or dementia in moderate, nonbinge consumers of alcohol (wine, beer, liquor) have been observed, whereas increased risk has been seen only in a few studies. Physiological explanations for the apparent CNS benefits of moderate consumption have invoked alcohol's cardiovascular and/or hematological effects, but there is also experimental evidence that moderate alcohol levels can exert direct "neuroprotective" actions-pertinent are several studies in vivo and rat brain organotypic cultures, in which antecedent or preconditioning exposure to moderate alcohol neuroprotects against ischemia, endotoxin, beta-amyloid, a toxic protein intimately associated with Alzheimer's, or gp120, the neuroinflammatory HIV-1 envelope protein. The alcohol-dependent neuroprotected state appears linked to activation of signal transduction processes potentially involving reactive oxygen species, several key protein kinases, and increased heat shock proteins. Thus to a certain extent, moderate alcohol exposure appears to trigger analogous mild stress-associated, anti-inflammatory mechanisms in the heart, vasculature, and brain that tend to promote cellular survival pathways.
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OBJECTIVE
The objective of the study was to examine the relationship between bilateral oophorectomy (BSO) and risk of coronary heart disease (CHD).
STUDY DESIGN
We searched PubMed, EMBASE, meeting abstracts, and reference lists for studies that compared women with BSO at the time of hysterectomy with: (1) women with hysterectomy and ovarian conservation, (2) naturally menopausal women, (3) premenopausal women, or (4) women with no history of hysterectomy or BSO but unreported menopausal status. The primary outcome was fatal or nonfatal CHD.
RESULTS
We reviewed 1956 citations. Seven observational studies met inclusion criteria. Heterogeneity among studies precluded formal metaanalysis. Four studies reported BSO increases risk for CHD but only in some subgroups of women or not in fully adjusted multivariate models. Three studies found no increased risk of CHD following BSO, but these studies had significant limitations.
CONCLUSION
The existing evidence is inconclusive to determine the effect of BSO on risk of CHD.
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Activation of sphingosine kinase/sphingosine-1-phosphate (SK/S1P)-mediated signalling has been recognized as critical for cardioprotection in response to acute ischaemia/reperfusion injury. Incubation of S1P with cultured cardiac myocytes subjected to hypoxia or treatment of isolated hearts either before ischaemia or at the onset of reperfusion (pharmacologic pre- or postconditioning) results in reduced myocyte injury. Synthetic agonists active at S1P receptors mimic these responses. Gene-targeted mice null for the SK1 isoform whose hearts are subjected to ischaemia/reperfusion injury exhibit increased infarct size and respond poorly either to ischaemic pre- or postconditioning. Measurements of cardiac SK activity and S1P parallel these observations. Ischaemic postconditioning combined with sphingosine and S1P rescues the heart from prolonged ischaemia. These observations may have considerable relevance for future therapeutic approaches to acute and chronic myocardial injury.
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Echocardiography in hypertrophic cardiomyopathy: the role of conventional and emerging technologies.
2008
2008
BACKGROUND
Although alveolar epithelial injury is a major determinant of outcome in patients with acute lung injury, there is no reliable biological marker of alveolar epithelial injury. The primary objective was to determine whether elevated levels of the receptor for advanced glycation end products (RAGE), a marker of alveolar epithelial injury, reflect impaired alveolar fluid clearance (AFC) in an ex vivo perfused human lung preparation. A second objective was to determine whether levels of a marker of endothelial injury, von Willebrand factor antigen (vWF:Ag), are associated with impaired AFC.
METHODS
Human lungs (N = 30) declined for transplantation by the California Transplant Donor Network were perfused at a constant pulmonary artery pressure of 12 mm Hg. Following rewarming to 36 degrees C, the lungs were inflated with a continuous positive airway pressure of 10 cm H(2)O. RAGE and vWF:Ag levels and AFC rates were then measured.
RESULTS
The rate of AFC was inversely correlated with RAGE levels in the alveolar fluid (p < 0.005). Similarly, the concentration of RAGE in the alveolar fluid was significantly higher in lungs with submaximal AFC, defined in a prespecified analysis as
CONCLUSIONS
RAGE may be a useful biological marker of alveolar epithelial injury and impaired AFC in donor lungs prior to transplant and perhaps in patients with acute lung injury.
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Half-life (t (1/2)) is the oldest but least well understood pharmacokinetic parameter, because most definitions are related to hypothetical 1-compartment body models that don't describe most drugs in humans. Alternatively, terminal half-life (t (1/2,z)) is utilized as the single defining t (1/2) for most drugs. However, accumulation at steady state may be markedly over predicted utilizing t (1/2, z). An apparent multiple dosing half-life (t (1/2, app)) was determined from peak and trough steady-state ratios and found to be significantly less than reported terminal t (1/2)s for eight orally dosed drugs with t (1/2,z) values longer than one day. We define a new parameter, "operational multiple dosing half-life" (t (1/2, op)), as equal to the dosing interval at steady-state where the maximum concentration at steady-state is twice the maximum concentration found for the first dose. We demonstrate for diazepam that the well-accepted concept that t (1/2,z) representing the great majority of the AUC will govern accumulation can be incorrect. Using oral diazepam, we demonstrate that t (1/2, op) is remarkably sensitive to the absorption t (1/2), even when this absorption t (1/2) is much less than t (1/2,z,) and describe the relevance of this in designing extended release dosage forms. The t (1/2, op) is compared with previously proposed half-lives for predicting accumulation.
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Lymphocyte and platelet recovery may influence outcomes of allo-SCT for treatment of AML. It is not clear, however, if this impact is independent of patient and transplant characteristics. To investigate this question, we evaluated the influence of pre- or post transplant factors on day +30 absolute lymphocyte count (ALC) and the speed of platelet engraftment. We studied 106 AML patients treated with fludarabine and melphalan reduced-intensity conditioning and allo-SCT. Twenty nine percent of patients were in CR at the initiation of the conditioning, 39% had active disease with circulating blasts and 32% had active disease without circulating blasts. The graft source was peripheral blood from a matched sibling donor in 55% and BM from a matched unrelated donor in 45%. Our data showed that the presence of circulating blasts before transplantation is significantly correlated with low post-SCT day +30 ALC and slow platelet engraftment. This finding suggests that the impact of early ALC and platelet recovery on transplant outcome may not be independent of disease status at transplantation.
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