N Ferrara

Yale University, New Haven, CT, United States

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Publications (110)838.06 Total impact

  • Biomedicine & Pharmacotherapy - BIOMED PHARMACOTHERAPY. 01/2005; 59.
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    ABSTRACT: New strategies for cancer therapy include the combination of angiogenesis inhibitors with cytotoxins. However, angiogenesis inhibitors may alter tumor microvessel structure and transendothelial permeability thereby reducing tumoral delivery of cytotoxic agents. The aim of this study was to estimate quantitatively the apparent permeability-surface area product (K(PS)) in tumors to a macromolecular contrast medium (MMCM), to follow changes in K(PS) induced by antibodies to vascular endothelial growth factor (anti-VEGF), and to correlate the findings with tumor accumulation of cisplatin, a highly protein-bound cytotoxin, and 5-fluorouracil (5-FU), a small unbound cytotoxin. Dynamic MRI enhanced with a MMCM (albumin-(Gd-DTPA)(30)) was analyzed using a two-compartment tumor tissue model (plasma and interstitial water) to quantitatively estimate K(PS). These estimates of K(PS) were correlated with cytotoxic drug accumulations in the tumors. Anti-VEGF treatment reduced K(PS) to MMCM in tumor tissue from 0.013 mL h(-1) cm(-3) (n = 9) at baseline to 0.003 mL h(-1) cm(-3) (n = 9) 24 h later (p <.05). The K(PS) values correlated significantly (r(2) =.78; p <.0001) with the tumor cisplatin accumulation. No correlation (r(2) =.001; p =.89) was found between K(PS) and tumor accumulation of the substantially smaller 5-FU molecule. MMCM-enhanced MRI can be used to detect and estimate changes in K(PS) to this contrast agent following a single dose of anti-VEGF antibody. The decline in K(PS) induced by this inhibitor of angiogenesis is associated with reduced tumor concentration of a protein-bound cytotoxin, similar in molecular weight to the contrast agent. MRI assays of microvascular status as performed here may be useful to clinically monitor responses to anti-angiogenesis drugs and to optimize the choice and timing of cytotoxic drug administration.
    Microcirculation 01/2004; 11(5):387-96. · 2.76 Impact Factor
  • Apunts Medicine de l'Esport 01/2003; 38(141):43–44.
  • J LeCouter, R Lin, N Ferrara
    Cold Spring Harbor Symposia on Quantitative Biology 02/2002; 67:217-21.
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    ABSTRACT: A mouse model of non-necrotic vascular deficiency in the adult heart was studied using cine-magnetic resonance imaging (MRI) and other techniques. The mice lacked cardiomyocyte-derived vascular endothelial growth factor (VEGF) following a targeted knockout in the ventricular cardiomyocytes. Quantitative endothelial labeling showed that the capillary density was significantly reduced in the hearts of knockout mice. Gene expression patterns suggested that they were hypoxic. Semiautomated MR image analysis was employed to obtain both global and regional measurements of left ventricular function at 10 or more time points through the cardiac cycle. MRI measurements showed a marked reduction in ejection fraction both at rest and under low- and high-dose dobutamine stress. Regional wall thickness, thickening, and displacement were all attenuated in the knockout mice. A prolonged high-dose dobutamine challenge was monitored by MRI. A maximal response was sustained for 90 minutes, suggesting that it did not depend on endogenous glycogen stores.
    Journal of Magnetic Resonance Imaging 11/2001; 14(4):374-82. · 2.57 Impact Factor
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    ABSTRACT: This report analyzes the role of vascular endothelial growth factor (VEGF)-induced angiogenesis in the immunoinflammatory lesion stromal keratitis induced by ocular infection with herpes simplex virus (HSV). Our results show that infection with replication-competent, but not mutant, viruses results in the expression of VEGF mRNA and protein in the cornea. This a rapid event, with VEGF mRNA detectable by 12 h postinfection (p.i.) and proteins detectable by 24 h p.i. VEGF production occurred both in the virus-infected corneal epithelium and in the underlying stroma, in which viral antigens were undetectable. In the stroma, VEGF was produced by inflammatory cells; these initially were predominantly polymorphonuclear leukocytes (PMN), but at later time points both PMN and macrophage-like cells were VEGF producers. In the epithelium, the major site of VEGF-expressing cells in early infection, the infected cells themselves were usually negative for VEGF. Similarly, in vitro infection studies indicated that the cells which produced VEGF were not those which expressed virus. Attesting to the possible role of VEGF-induced angiogenesis in the pathogenesis of herpetic stromal keratitis were experiments showing that VEGF inhibition with mFlt(1-3)-immunoglobulin G diminished angiogenesis and the severity of lesions after HSV infection. These observations are the first to evaluate VEGF-induced angiogenesis in the pathogenesis of stromal keratitis. Our results indicate that the control of angiogenesis represents a useful adjunct to therapy of herpetic ocular disease, an important cause of human blindness.
    Journal of Virology 11/2001; 75(20):9828-35. · 5.08 Impact Factor
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    ABSTRACT: The known endothelial mitogens stimulate growth of vascular endothelial cells without regard to their tissue of origin. Here we report a growth factor that is expressed largely in one type of tissue and acts selectively on one type of endothelium. This molecule, called endocrine-gland-derived vascular endothelial growth factor (EG-VEGF), induced proliferation, migration and fenestration (the formation of membrane discontinuities) in capillary endothelial cells derived from endocrine glands. However, EG-VEGF had little or no effect on a variety of other endothelial and non-endothelial cell types tested. Similar to VEGF, EG-VEGF possesses a HIF-1 binding site, and its expression is induced by hypoxia. Both EG-VEGF and VEGF resulted in extensive angiogenesis and cyst formation when delivered in the ovary. However, unlike VEGF, EG-VEGF failed to promote angiogenesis in the cornea or skeletal muscle. Expression of human EG-VEGF messenger RNA is restricted to the steroidogenic glands, ovary, testis, adrenal and placenta and is often complementary to the expression of VEGF, suggesting that these molecules function in a coordinated manner. EG-VEGF is an example of a class of highly specific mitogens that act to regulate proliferation and differentiation of the vascular endothelium in a tissue-specific manner.
    Nature 09/2001; 412(6850):877-84. · 38.60 Impact Factor
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    N Ferrara
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    ABSTRACT: Evidence accumulating over the last decade has established the fundamental role of vascular endothelial growth factor (VEGF) as a key regulator of normal and abnormal angiogenesis. The biological effects of VEGF are mediated by two tyrosine kinase receptors, Flt-1 (VEGFR-1) and KDR (VEGFR-2). The signaling and biological properties of these two receptors are strikingly different. VEGF is essential for early development of the vasculature to the extent that inactivation of even a single allele of the VEGF gene results in embryonic lethality. VEGF is also required for female reproductive functions and endochondral bone formation. Substantial evidence also implicates VEGF as an angiogenic mediator in tumors and intraocular neovascular syndromes, and numerous clinical trials are presently testing the hypothesis that inhibition of VEGF may have therapeutic value.
    AJP Cell Physiology 07/2001; 280(6):C1358-66. · 3.71 Impact Factor
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    ABSTRACT: The role of the cardiac myocyte as a mediator of paracrine signaling in the heart has remained unclear. To address this issue, we generated mice with cardiac myocyte-specific deletion of the vascular endothelial growth factor gene, thereby producing a cardiomyocyte-specific knockout of a secreted factor. The hearts of these mice had fewer coronary microvessels, thinned ventricular walls, depressed basal contractile function, induction of hypoxia-responsive genes involved in energy metabolism, and an abnormal response to beta-adrenergic stimulation. These findings establish the critical importance of cardiac myocyte-derived vascular endothelial growth factor in cardiac morphogenesis and determination of heart function. Further, they establish an adult murine model of hypovascular nonnecrotic cardiac contractile dysfunction.
    Proceedings of the National Academy of Sciences 06/2001; 98(10):5780-5. · 9.81 Impact Factor
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    ABSTRACT: Lysophosphatidic acid (LPA) stimulates ovarian tumor growth at concentrations present in ascitic fluid. Vascular endothelial growth factor (VEGF) stimulates angiogenesis and plays a pivotal role in the formation of ovarian cancer-associated ascites. We examined whether LPA promotes ovarian tumor growth by increasing angiogenesis via VEGF. VEGF expression was examined in a simian virus 40 T-antigen-immortalized ovarian surface epithelial cell line (IOSE-29) and in ovarian cancer cell lines (OVCAR-3, SKOV-3, and CAOV-3) treated with LPA. VEGF promoter activity was measured in OVCAR-3 cells after transfection or cotransfection with c-Fos and c-Jun, components of AP1 transcription factor, potential binding sites for which are present in the VEGF promoter. The expression of the LPA receptors Edg2 and Edg4 was also assessed. All statistical tests were two-sided. LPA treatment increased steady-state VEGF messenger RNA (mRNA) levels in OVCAR-3 cells in a time- and dose-dependent fashion and stimulated VEGF promoter activity without prolonging mRNA half-life in these cells, but LPA had little effect on IOSE-29 cells. Forced overexpression of c-Jun and c-Fos in OVCAR-3 cells stimulated VEGF promoter activity fourfold. LPA also elevated VEGF protein levels by 1.5-fold in SKOV-3 cells (P =.0148), 1.9-fold in CAOV-3 cells (P<.001), and threefold in OVCAR-3 cells (P<.0001). Both Edg2 and Edg4 were detected in ovarian cancer cells; however, only Edg2 was present in normal ovarian surface epithelial cells and IOSE-29 cells. LPA stimulates ovarian tumor growth, at least in part, via induction of VEGF expression through transcriptional activation. However, this LPA response is not evident in normal ovarian surface epithelial cells. Our data suggest that Edg4, but not Edg2, plays a role in LPA stimulation of ovarian tumor growth.
    JNCI Journal of the National Cancer Institute 06/2001; 93(10):762-8. · 14.34 Impact Factor
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    ABSTRACT: Endothelial cells express two related vascular endothelial growth factor (VEGF) receptor tyrosine kinases, KDR (kinase-insert domain containing receptor, or VEGFR-2) and Flt-1 (fms-like tyrosine kinase, or VEGFR-1). Although considerable experimental evidence links KDR activation to endothelial cell mitogenesis, there is still significant uncertainty concerning the role of individual VEGF receptors for other biological effects such as vascular permeability. VEGF mutants that bind to either KDR or Flt-1 with high selectivity were used to determine which of the two receptors serves to mediate different VEGF functions. In addition to mediating mitogenic signaling, selective KDR activation was sufficient for the activation of intracellular signaling pathways implicated in cell migration. KDR stimulation caused tyrosine phosphorylation of both phosphatidylinositol 3-kinase and phospholipase Cgamma in primary endothelial cells and stimulated cell migration. KDR-selective VEGF was also able to induce angiogenesis in the rat cornea to an extent indistinguishable from wild type VEGF. We also demonstrate that KDR, but not Flt-1, stimulation is responsible for the induction of vascular permeability by VEGF.
    Journal of Biological Chemistry 03/2001; 276(5):3222-30. · 4.65 Impact Factor
  • N Ferrara, H P Gerber
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    ABSTRACT: Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen and an angiogenic inducer as well as a mediator of vascular permeability. The biological effects of VEGF are mediated by two tyrosine kinase receptors, Flt-1 (VEGFr-1) and KDR (VEGFR-2). VEGF is essential for developmental angiogenesis and is also required for female reproductive functions and endochondral bone formation. Substantial evidence also implicates VEGF in tumors and intraocular neovascular syndromes. Currently, several clinical trials are ongoing to test the hypothesis that inhibition of VEGF activity may be beneficial for these conditions.
    Acta Haematologica 02/2001; 106(4):148-56. · 0.89 Impact Factor
  • N Ferrara
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    ABSTRACT: Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen and an angiogenic inducer as well as a mediator of vascular permeability. VEGF is essential for developmental angiogenesis and is also required for female reproductive functions and endochondral bone formation. Substantial evidence also implicates VEGF in tumors and intraocular neovascular syndromes. Currently, several clinical trials are ongoing to test the hypothesis that the inhibition of VEGF activity may be beneficial for these conditions.
    Current Opinion in Biotechnology 01/2001; 11(6):617-24. · 8.04 Impact Factor
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    ABSTRACT: Growth of the human rhabdomyosarcoma A673 cell line in nude mice is substantially reduced but not completely suppressed after systemic administration of the antihuman vascular endothelial growth factor (VEGF) monoclonal antibody (Mab) A.4.6.1. Potentially, such escape might be attributable to incomplete local penetration of the antibody because of a diffusion barrier associated with tumor growth. Alternatively, it might reflect a compensatory up-regulation of murine VEGF, produced by the stroma of the host, or of other angiogenic factor genes. To test these potential mechanisms, systemic administration of Mab A.4.6.1, was performed in conjunction with intratumoral administration of an irrelevant antibody, an antihuman VEGF Fab or mFlt(1-3)-IgG that neutralizes both human and murine VEGF. Tumor growth in the systemic-plus-intratumoral anti-VEGF group was not different from that in the systemic anti-VEGF-plus-intratumoral-control antibody group, arguing against the possibility that bioavailability is the factor that limits the antitumor efficacy of Mab A.4.6.1. However, intratumoral mFlt(l-3)-IgG administration dramatically enhanced the activity of systemic anti-VEGF Mab and resulted in complete suppression of tumor growth, which indicated that host VEGF significantly contributes to tumor growth. Systemic administration of mFlt(1-3)-IgG alone replicated these findings. Histological analysis of residual tumor tissues revealed an almost complete absence of host-derived vasculature and massive tumor-cell necrosis in the mFlt(1-3)-IgG groups. Such extensive necrotic areas were not present in the other groups. Real-time reverse transcription-PCR analysis of total RNA derived from tumor tissues indicated strong up-regulation of both human and murine VEGF as well as other genes regulated by hypoxia. Our findings emphasize the need to completely block VEGF for maximal inhibition of tumor growth.
    Cancer Research 12/2000; 60(22):6253-8. · 8.65 Impact Factor
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    ABSTRACT: Recent studies in experimental animals have shown that combining antiangiogenic therapy with radiation can enhance tumor response. Whether this enhancement is mainly attributable to angiogenesis inhibition, endothelial cell radiosensitivity, tumor cell apoptosis, or a decrease in the number of hypoxic cells (improved oxygenation) is not known. We designed this study to discern the role of tumor oxygenation. We chose an anti-vascular endothelial growth factor (anti-VEGF) monoclonal antibody (mAb) which has a known target, human VEGF. We also measured interstitial fluid pressure (IFP) to test the hypothesis that the decreased vascular permeability induced by the anti-VEGF mAb can lower IFP. The effect of anti-VEGF mAb on vascular density, partial oxygen tension (pO2), and apoptosis was also measured. Athymic NCr/Sed nu/nu mice bearing 6-mm xenograft of the human glioblastoma multiforme (U87), or colon adenocarcinoma (LS174T) were treated with anti-VEGF mAb injected i.p. on alternate days for a total of six injections at a dosage of 100 microg/injection/mouse. For combined anti-VEGF and radiation, single radiation doses were given under normal blood flow (20 and 30 Gy) or clamped hypoxic conditions (30 and 40 Gy) 24 h after the sixth injection of mAb. The inhibition of the growth of U87 and LS174T tumors by the anti-VEGF mAb was associated with a significant reduction in tumor vascular density and a relatively small increase in the number of apoptotic cells. Compared with size-matched controls, IFP decreased by 74% in LS174T, and 73% in U87 in mice treated with anti-VEGF mAb. After antibody treatment PO2 increased significantly in U87, but did not change in LS174T tumors. Combined treatment induced in U87 tumors a tumor-growth delay (TGD) which was greater than additive; in LS174T except for the 40-Gy hypoxic group, the effect was only additive. In both U87 and LS174T the TGD induced by the antibody was independent of oxygen levels in the tumor at the time of radiation. The fact that the increase in TGD occurred under both normoxic and hypoxic conditions suggests that anti-VEGF mAb treatment can compensate for the resistance to radiation induced by hypoxia.
    Cancer Research 11/2000; 60(19):5565-70. · 8.65 Impact Factor
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    ABSTRACT: Magnetic resonance imaging enhanced with macromolecular contrast medium was used to monitor effects of angiogenesis inhibition on tumor microvascular permeability and ascites volume in an athymic rat model of human ovarian cancer. Groups of 6 athymic rats implanted intraperitoneally with SKOV-3, a human ovarian cancer cell line, were treated through a 14-day course with antibody to vascular endothelial growth factor or with saline solution for control animals. Dynamic magnetic resonance imaging was performed with a 92,000-d contrast agent, albumin-(gadolinium-diethylenetriaminepentaacetic acid)(30). Vascular permeability was estimated from dynamic enhancement data that were analyzed with a unidirectional 2-compartment kinetic model. Animals treated with vascular endothelial growth factor antibody accumulated significantly smaller volumes of peritoneal ascites (P <.05) and showed significantly lower magnetic resonance imaging-assayed tumor microvascular permeabilities (P <.05) than did control animals. Magnetic resonance imaging enhanced with a macromolecular contrast agent in an athymic rat model of human ovarian cancer treated with anti-vascular endothelial growth factor antibody can be used to measure a reduction in tumor microvascular permeability, corresponding to a reduction in ascites production.
    American Journal of Obstetrics and Gynecology 10/2000; 183(4):956-63. · 3.88 Impact Factor
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    ABSTRACT: Vascular endothelial growth factor (VEGF) has two highly homologous tyrosine kinase receptors: Flt-1 (VEGFR-1) and KDR (VEGFR-2). KDR is strongly phosphorylated on tyrosines and can transmit mitogenic and motogenic signals following VEGF binding, while Flt-1 is markedly less effective in mediating such functions. To dissect the regions that account for the differences between the two receptors, we generated a series of chimeric Flt-1-KDR molecules. We found that the juxtamembrane region of Flt-1 prevents key signaling functions. When the juxtamembrane region of Flt-1 is replaced by that of KDR, Flt-1 becomes competent to mediate endothelial cell migration and phosphatidylinositol 3'-kinase activation in response to VEGF. Further mutational analysis shows that a short divergent sequence is responsible for such repressor function. However, mutant Flt-1 receptors lacking this sequence do not transmit effective proliferative signals, suggesting that this receptor function is regulated separately. These results define a novel functional domain that serves to repress Flt-1 activity in endothelial cells.
    The EMBO Journal 09/2000; 19(15):4064-73. · 9.82 Impact Factor
  • H P Gerber, N Ferrara
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    ABSTRACT: Vascularization of the growth plate region represents a key mechanism for the coupling of two fundamental processes determining the rate of bone growth, chondrogenesis (cartilage production) and osteogenesis (bone formation). Precise coupling is crucial during periods of rapid bone growth or fracture repair in adults, and changes in the balance might induce pathologic conditions such as osteoarthritis and ectopic bone formation. During the formation of the growth plates of long bones, there is a close and dynamic interaction between developing vascular structures and the cartilage, which is one of the least vascular tissues in the body. Recent experimental findings provide an explanation why the close proximity of cartilage and vasculature is mutually exclusive: vascular invasion of cartilage is associated with chondrocyte apoptosis and consequently, inhibition of angiogenesis in the growth plate delays chondrocyte cell death, resulting in a massive expansion in the number of hypertrophic cartilage cells in the growth plate. The fundamental importance of chondrocytes in the growth, development and repair of the skeleton has led to intense investigation of the mechanisms that regulate chondrocyte maturation and apoptosis.
    Trends in Cardiovascular Medicine 08/2000; 10(5):223-8. · 1.47 Impact Factor
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    ABSTRACT: VEGF-A has been implicated in regulating the initial angiogenic invasion events that are essential for endochondral bone formation. VEGF-A mRNA expression was indeed found in the sclerotome of the developing somite and in the limb-bud mesenchyme at E10.5 in mouse development but declined during chondrogenesis and became upregulated in hypertrophic chondrocytes prior to angiogenic invasion. To determine the functional importance of VEGF-A expression in the developing chondrogenic tissues, VEGF-A was conditionally inactivated during early embryonic development using Collagen2a1-Cre transgenic lines. Deletion of a single VEGF-A allele in Collagen2a1-Cre-expressing cells results in embryonic lethality around E10.5. This lethality is characterized by aberrant development of the dorsal aorta and intersomitic blood vessels, along with defects in the developing endocardial and myocardial layers of the heart. A small percentage of VEGF(Flox)/+, Collagen2a1-Cre fetuses survive until E17.5, show aberrant endochondral bone formation and develop a heart phenotype resembling a dilated form of ischemic cardiomyopathy. These results provide insights into the function of VEGF-A in heart and endochondral bone formation and underscore the importance of tightly controlled levels of VEGF-A during development.
    Development 05/2000; 127(7):1445-53. · 6.21 Impact Factor
  • N Ferrara
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    ABSTRACT: The development of a vascular supply is essential not only for organ development and differentiation during embryogenesis but also for wound healing and reproductive functions in the adult Folkman, 1995). Angiogenesis is also implicated in the pathogenesis of a variety of disorders: proliferative retinopathies, age-related macular degeneration, tumors, rheumatoid arthritis, and psoriasis (Folkman, 1995; Garner, 1994). Several potential regulators of angiogenesis have been identified, including fibroblast growth factor-a (aFGF), bFGF, transforming growth factor-alpha (TGF-alpha), TGF-beta, hepatocyte growth factor/scatter factor (HGF/SF), tumor necrosis factor-alpha (TNF-alpha), angiogenin, and interleukin-8 (IL-8) (Folkman and Shing, 1992; Risau, 1997). More recently, the angiopoietins, the ligands of the Tie-2 receptor (Suri et al., 1996; Maisonpierre et al., 1997), have been identified. Vascular endothelial growth factor (VEGF) is an endothelial-cell-specific mitogen. The finding that VEGF was potent and specific for vascular endothelial cells and, unlike bFGF, freely diffusible, led to the hypothesis that this molecule plays a unique role in the regulation of physiological and pathological angiogenesis (Ferrara and Henzel, 1989: Leung et al., 1989). Over the last few years, several additional members of the VEGF gene family have been identified, including placenta growth factor (PIGF) (Maglione et al., 1991,1993), VEGF-B (Olofsson et al., 1996), VEGF-C (Joukov et al., 1996; Lee et al., 1996), and VEGF-D (Orlandini et al., 1996. Achen et al., 1998). There is compelling evidence that VEGF plays an essential role in the development and differentiation of the cardiovascular system (Ferrara and Davis-Smyth, 1997).
    Recent Progress in Hormone Research 02/2000; 55:15-35; discussion 35-6.

Publication Stats

30k Citations
838.06 Total Impact Points

Institutions

  • 2001
    • Yale University
      • School of Medicine
      New Haven, CT, United States
  • 1998–2001
    • Genentech
      • Department of Molecular Oncology
      San Francisco, CA, United States
  • 1994–2001
    • University of California, San Francisco
      • • Center for Reproductive Sciences
      • • Department of Obstetrics, Gynecology and Reproductive Sciences
      • • Department of Surgery
      San Francisco, CA, United States
  • 1994–1996
    • Northwestern University
      • Department of Medicine
      Evanston, IL, United States
    • Tufts University
      • Department of Medicine
      Medford, MA, United States
  • 1995
    • St. Elizabeth's Medical Center
      Boston, Massachusetts, United States