Sundeep G Keswani

Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, United States

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Publications (53)82.79 Total impact

  • Alice King, Sundeep G. Keswani
    Journal of Surgical Research 01/2014; 186(1):87–88. · 2.02 Impact Factor
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    ABSTRACT: Chylothorax is a frequent complication in congenital diaphragmatic hernia (CDH) infants and is associated with significant morbidity. The optimal treatment strategy remains unclear. We hypothesize that octreotide decreases chylous effusions in infants with CDH. This is a retrospective study of all infants with CDH admitted to our institution from October 2006 to October 2011. Eleven (12%) infants developed a chylothorax. Five infants were managed conservatively with thoracostomy and total parenteral nutrition. Six infants were started on octreotide therapy. None of the infants required surgical intervention to stop the effusion. There was no significant difference in survival to discharge, length of stay, or average daily chest tube output between groups. There appeared to be a temporally associated drop in chest tube output upon initiation of octreotide in two infants; however, the overall rate of decline in chest tube drainage was unchanged. In addition, there were infants in the conservative group who demonstrated a similar drop in daily chest tube output despite the absence of octreotide. Our data suggest that the majority of chylous effusions in CDH infants resolve with conservative therapy alone.
    Journal of Pediatric Surgery 11/2013; 48(11):2226-9. · 1.38 Impact Factor
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    ABSTRACT: In utero hematopoietic cellular transplantation (IUHCT) holds great promise for the treatment of congenital diseases of cellular dysfunction such as sickle cell disease, immunodeficiency disorders and inherited metabolic disorders. However, repeated failures in clinical cases of IUHCT that do not involve an immunodeficiency disease force a closer examination of the fetal immune system. While the mechanisms regulating T cell tolerance have been previously studied, the educational mechanisms leading to NK cell tolerance in prenatal chimeras remain unknown. As a low level of donor cells (1.8%) is required to induce and maintain this tolerance, it is likely that these mechanisms employ indirect host-donor interaction. This report examines donor-to-host MHC transfer (trogocytosis) as an intrinsic mechanism regulating the development and maintenance of NK cell tolerance in prenatal chimeras. The findings demonstrate that phenotypically tolerant host NK cells express low levels of transferred donor MHC antigens during development and later as mature cytotoxic lymphocytes. Further study is needed to understand how the cis-recognition of transferred donor MHC ligand influences the selection and maintenance of tolerant NK cells in prenatal chimeras.
    Chimerism. 10/2013; 4(4).
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    ABSTRACT: Postnatal vasculogenesis mediated via endothelial progenitor cells (EPCs) contributes to re-endothelialization and augments neovascularization after ischemia and tissue injury, providing a novel therapeutic application. However, controversy exists with respect to the origin, identification, and contributions of the EPCs to neovascularization, necessitating further study. Bone marrow (BM) or circulating cells expressing cd133/vascular endothelial growth factor receptor 2 include those with endothelial progenitor capacity. Increasing evidence suggests that there are additional BM-derived (myeloid; mesenchymal cells) and non-BM-derived (peripheral and cord-blood; tissue-resident) cell populations which also give rise to endothelial cells (ECs) and contribute to re-endothelialization and growth factor release after ischemia and tissue injury. Currently, EPCs are being used as diagnostic markers for the assessment of cardiovascular and tumor risk/progression. Techniques aimed at enhancing ex vivo expansion and the therapeutic potential of these cells are being optimized. Mobilization and EPC-mediated neovascularization are critically regulated. Stimulatory (growth factors, statins, and exercise) or inhibitory factors (obesity, diabetes, and other cardiovascular diseases) modulate EPC numbers and function. Recruitment and incorporation of EPCs require a coordinated sequence of signaling events, including adhesion, migration (by integrins), and chemoattraction. Finally, EPCs differentiate into ECs and/or secrete angiogenic growth factors. These cells are highly plastic, and depending on the microenvironment and presence of other cells, EPCs transdifferentiate and/or undergo cell fusion and become cells of a different lineage. Therefore, in vitro culture conditions should be optimized to mimic the in vivo milieu to fully characterize the biological function and contribution of EPCs to postnatal vasculogenesis. Advances in characterization of the EPC biology and enhancement of EPC functions are required. In addition, innovative tissue-engineered carrier matrices that permit embedding of EPCs and provide optimal conditions for EPC survival and endothelial outgrowth will further contribute to EPC-mediated therapeutic applications in wound healing and ischemia repair.
    Advances in wound care. 07/2013; 2(6):283-295.
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    ABSTRACT: BACKGROUND: Sacrococcygeal teratoma (SCT) is one of the most common neonatal and fetal tumors. SCT pelvic mass effect and the need for aggressive surgical resection, create potential for urologic co-morbidity. We reviewed our experience with SCTs and propose a rational plan for urologic surveillance. METHODS: We retrospectively reviewed all patients with SCT evaluated at our institution from 2004 to 2011. We collected data on the need for reconstructive surgery related to the urologic co-morbidity, the time to detection of urologic co-morbidity, and length of follow-up. RESULTS: We identified 28 patients evaluated during the study period with a median follow-up of 3.1 year (range 0.14-13.4). The Altman classifications were-type I: 7 (25%), II: 15 (53.6%), and III: 6 (21.4%). Eighteen (64.3%) patients had an associated urologic co-morbidity: 12 (42.9%) patients had hydronephrosis, VUR-10 (35.7%), NGB-13 (46.4%), and 4 (14.3%) developed ≥CKD2. When comparing the patients according to Altman classification, there was a trend towards more urologic co-morbidity in patients with increasing pelvic involvement, P = 0.06. Eleven patients (39.3%) had delayed urologic evaluation and five (17.9%) required reconstructive urologic surgery. In comparing these groups, 4 of 11 (36.4%) undergoing delayed urologic evaluation progressed to reconstruction, as opposed to only one of 17 (5.7%) with urologic evaluation within first year of life (P-value = 0.06). CONCLUSION: Urologic co-morbidities are common in children with SCT and appear most common in patients with more pelvic tumor involvement (≥Altman II). A risk-adapted approach to urologic surveillance is proposed. Pediatr Blood Cancer © 2013 Wiley Periodicals, Inc.
    Pediatric Blood & Cancer 06/2013; · 2.35 Impact Factor
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    ABSTRACT: The mucosa of alimentary tract heals more rapidly than cutaneous wounds. The underlying mechanisms of this enhanced healing have not been completely elucidated. Constant exposure to salivary growth factors has been shown to play a critical role in mucosal homeostasis and tissue repair. Angiogenesis also has an essential role in successful wound repair. One of the main angiogenic growth factors, vascular endothelial growth factor (VEGF), has a pleiotropic role in tissue repair via neovascularization, reepithelialization, and regulation of extracellular matrix. We have previously reported a critical role for salivary VEGF in bowel adaptation after small bowel resection. We hypothesize that salivary VEGF is an essential stimulus for oral mucosal tissue repair, and use the murine palatal wound model to test our hypothesis. In a loss-of-function experiment, we removed the primary source of VEGF production through selective submandibular gland (SMG) sialoadenectomy in a murine model and observed the effects on wound closure and neovascularization. We then performed a selective loss-of-function experiment using the protein VEGF-Trap to inhibit salivary VEGF. In a gain-of-function experiment, we supplemented oral VEGF following SMG sialoadenectomy. After SMG sialoadenectomy, there was significant reduction in salivary VEGF level, wound closure, and vessel density. Lower levels of salivary VEGF were correlated with impaired neovascularization and reepithelialization. The selective blockade of VEGF using VEGF-Trap resulted in a similar impairment in wound healing and neovascularization. The sole supplementation of oral VEGF after SMG sialoadenectomy rescued the impaired wound healing phenotype and restored neovascularization to normal levels. These data show a novel role for salivary-VEGF in mucosal wound healing, and provide a basis for the development of novel therapeutics aimed at augmenting wound repair of the oral mucosa, as well as wounds at other sites in the alimentary tract.
    Wound Repair and Regeneration 06/2013; · 2.76 Impact Factor
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    ABSTRACT: Mid-gestational (E14.5) fetal wounds heal regeneratively with attenuated inflammation and high levels of hyaluronan (HA) in their extracellular matrix (ECM), whereas late-gestational (E18.5) fetal wounds heal with scarring. IL-10 plays an essential role in the fetal regenerative phenotype and is shown to recapitulate scarless wound healing postnatally. We hypothesize a novel role of IL-10 as a regulator of HA in the ECM. Murine fetal fibroblasts (FFb) from C57Bl/6 and IL-10-/- mice were evaluated in vitro. Pericellular matrix (PCM) and HA synthesis were quantified using a particle exclusion assay and ELISA. The effects of hyaluronidase and hyaluronan synthase (HAS) inhibitor (4-methylumbelliferone[4-MU]) were evaluated. An ex vivo fetal forearm culture incisional wound model comparing mid-gestation and late-gestation fetuses was used to evaluate IL-10's effect on HA-rich ECM production with pentachrome and immunohistochemistry. FFb produce a robust HA-rich PCM which is IL-10 dependent and attenuated with hyaluronidase and HAS inhibition. Mid-gestation fetal wounds produce more ground substance and HA than late-gestation fetal wounds. IL-10 in late-gestation fetal wounds results in elevated ground substance levels and HA staining. Our data demonstrate that IL-10 regulates an HA-rich ECM deposition, suggesting a novel non-immunoregulatory mechanism of IL-10 in mediating regenerative wound healing.
    Journal of Pediatric Surgery 06/2013; 48(6):1211-1217. · 1.38 Impact Factor
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    ABSTRACT: BACKGROUND: Sacrococcygeal teratoma is the most common neonatal tumor. Fetuses with large tumors may develop hydrops from a high cardiac output state (HCOS) and progress rapidly to fetal demise. We postulate that the prenatal solid tumor volume index (STVI), or the ratio of solid tumor volume to the estimated fetal weight (EFW), has greater impact than the total tumor volume in outcome prediction. METHODS: A retrospective chart review of all sacrococcygeal teratoma patients (n = 38) between 2005 and 2012 was conducted. Total tumor volume and percent of solid component were calculated by magnetic resonance imaging and then normalized by dividing them by either head circumference or EFW. Outcomes measured were survival, hydrops or high cardiac output state, defined as a combined ventricular output of >625 mL/min/kg with abnormal Doppler or echocardiogram findings. RESULTS: Thirty-one patients were included in the study. All deaths (n = 7) had either high cardiac output state or hydrops. At a total tumor volume/EFW >0.16, the patient was 17 times more likely to develop HCOS/hydrops (P = 0.001) with 81.25% sensitivity and 86.67% specificity. At a STVI >0.09, the patient was 120 times more likely to develop HCOS/hydrops (P < 0.0001) with 81.25% sensitivity and 100% specificity. CONCLUSIONS: While total tumor volume aids in stratifying patients into high risk categories, STVI (solid tumor volume/EFW) is a better predictor of adverse outcomes. This data will allow us to identify patients who are high risk for cardiac compromise and guide appropriate therapy.
    Journal of Surgical Research 05/2013; · 2.02 Impact Factor
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    ABSTRACT: BACKGROUND AND OBJECTIVE:Pediatric patients are at risk for developing pressure ulcers (PUs) and associated pain, infection risk, and prolonged hospitalization. Stage III and IV ulcers are serious, reportable events. The objective of this study was to develop and implement a quality-improvement (QI) intervention to reduce PUs by 50% in our ICUs.METHODS:We established a QI collaborative leadership team, measured PU rates during an initial period of rapid-cycle tests of change, developed a QI bundle, and evaluated the PU rates after the QI implementation. The prospective study encompassed 1425 patients over 54 351 patient-days in the PICU and NICU.RESULTS:The PU rate in the PICU was 14.3/1000 patient-days during the QI development and 3.7/1000 patient-days after QI implementation (P < .05), achieving the aim of 50% reduction. The PICU rates of stages I, II, and III conventional and device-related PUs decreased after the QI intervention. The PU rate in the NICU did not change significantly over time but remained at a mean of 0.9/1000 patient-days. In the postimplementation period, 3 points were outside the control limits, primarily due to an increase in PUs associated with pulse oximeters and cannulas.CONCLUSIONS:The collaborative QI model was effective at reducing PUs in the PICU. Pediatric patients, particularly neonates, are at risk for device-related ulcers. Heightened awareness, early detection, and identification of strategies to mitigate device-related injury are necessary to further reduce PU rates.
    PEDIATRICS 05/2013; · 4.47 Impact Factor
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    ABSTRACT: BACKGROUND: The midgestational fetus is capable of regenerative healing. We have recently demonstrated a novel role for the anti-inflammatory cytokine interleukin 10 (IL-10) as a regulator of hyaluronan (HA) in the extracellular matrix. The signaling pathway of IL-10 has been studied in monocytes but is unknown in dermal fibroblasts. We hypothesized IL-10 signals through its primary receptor, IL-10R1, to activate STAT3, resulting in HA synthesis. METHODS: Murine midgestational (E14.5) fetal fibroblasts were evaluated in vitro. Pericellular matrix was quantified using a particle exclusion assay. STAT3 levels and cellular localization were evaluated by Western blot/band densitometry and immunocytochemistry/confocal microscopy. HA levels were quantified by enzyme-linked immunosorbent assay. The effects of IL-10R1 signal blockade by a neutralizing antibody and STAT3 inhibition were evaluated. An ex vivo midgestation fetal forearm culture incisional wound model in control and transgenic IL-10-/- mice was used to evaluate the role of STAT3 on the extracellular matrix. RESULTS: Fetal fibroblasts produce a robust hyaluronan-rich pericellular matrix that is IL-10R1 and STAT3 dependent. Inhibition of IL-10R1 signaling results in decreased phosphorylated STAT3 levels and inhibition of nuclear localization. Inhibition of STAT3 results in decreased HA production. At day 3, midgestation fetal wounds have efficient re-epithelialization, which is significantly slowed in IL-10-/- wounds at the same gestation and with inhibition of STAT3. CONCLUSIONS: Our data demonstrate that IL-10 regulates HA synthesis through its primary receptor IL-10R1 and STAT3 activation. This supports a novel nonimmunoregulatory mechanism of IL-10 in its role in fetal regenerative wound healing.
    Journal of Surgical Research 04/2013; · 2.02 Impact Factor
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    ABSTRACT: Background/Purpose Ovarian torsion (OT) is a clinical diagnosis with a variable presentation. The aim of this study was to develop a practical scoring system to predict patients with OT in the pediatric population to facilitate more accurate diagnosis.Methods A retrospective study evaluating menarchal pediatric patients (1998 to 2005) with surgically confirmed OT (n = 28) compared with patients with abdominal pain and surgically confirmed non-OT (n = 26). Histogram analysis was performed to determine threshold values and used to generate the OT composite index (OT-CI).Results Four factors were independently associated with OT: ovarian ratio, ovarian volume, nausea, and duration of pain. Arterial and venous Doppler flows were not associated with OT. The OT-CI was more accurate than any individual factor. There were no cases of OT in patients with OT-CI scores < 3. Patients with score ≥ 3 had 100% sensitivity and 65.3% specificity. A score ≥ 5 has 100% specificity.Conclusions The OT-CI is a practical scoring system combining clinical and radiologic findings to more accurately predict OT. An OT-CI score < 3 is strong evidence against OT in pediatric menarchal patients, which may minimize unnecessary surgical intervention. In contrast, scores ≥ 3 should be considered for surgical intervention to maximize ovarian salvage.
    European Journal of Pediatric Surgery 04/2013; · 0.84 Impact Factor
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    ABSTRACT: BACKGROUND: The current research environment for academic surgeons demands that extramural funding be obtained. Financial support from the National Institutes of Health (NIH) is historically the gold standard for funding in the biomedical research community, with the R01 funding mechanism viewed as indicator of research independence. The NIH also supports a mentor-based career development mechanism (K-series awards) in order to support early-stage investigators. The goal of this study was to investigate the grants successfully awarded to pediatric surgeon-scientists and then determine the success of the K-series award recipients at achieving research independence. METHODS: In July 2012, all current members of the American Pediatric Surgery Association (APSA) were queried in the NIH database from 1988-2012 through the NIH Research Portfolio Online Reporting Tools. The following factors were analyzed: type of grant, institution, amount of funding, and funding institute or center. RESULTS: Among current APSA members, there have been 83 independent investigators receiving grants, representing 13% of the current APSA membership, with 171 independent grants funded through various mechanisms. Six percent currently have active NIH funding, with $7.2 million distributed in 2012. There have been 28 K-series grants awarded. Of the recipients of expired K08 awards, 39% recipients were subsequently awarded an R01 grant. A total of 63% of these K-awarded investigators transitioned to an independent NIH award mechanism. CONCLUSIONS: Pediatric surgeon-scientists successfully compete for NIH funding. Our data suggest that although the K-series funding mechanism is not the only path to research independence, over half of the pediatric surgeons who receive a K-award are successful in the transition to independent investigator.
    Journal of Surgical Research 04/2013; · 2.02 Impact Factor
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    ABSTRACT: BACKGROUND: Cell-specific gene transfer and sustained transgene expression are goals of cutaneous gene therapy. Pseudotyping strategy with adeno-associated viral (AAV) vectors has the potential to confer unique cellular tropism and transduction efficiency. We hypothesize that pseudotyped AAV vectors have differential tropism and transduction efficiency under normal and wound conditions in dermal fibroblasts. MATERIALS AND METHODS: We packaged AAV2 genome with green fluorescent protein reporter in capsids of other serotypes, AAV5, AAV7, and AAV8, producing pseudotyped vectors AAV2/5, AAV2/7, and AAV2/8, respectively. Murine and human dermal fibroblasts were transduced by the different pseudotypes for 24 h at multiplicities of infection 10(2), 10(3), 10(4), and 10(5). We assessed transduction efficiency at days 3 and 7. Experiments were repeated in a simulated wound environment by adding 10 ng/mL platelet-derived growth factor-B to culture media. RESULTS: Transduction efficiency of the pseudotyped AAV vectors was dose dependent. Multiplicity of infection 10(5) resulted in significantly higher gene transfer. Under normal culture conditions, the pseudotyping strategy conferred differential transduction of dermal fibroblasts, with significantly enhanced transduction of murine cells by AAV2/5 and AAV2/8 compared with AAV2/2. Adeno-associated virus 2/8 was more efficacious in transducing human cells. Under wound conditions, transduction efficiency of AAV2/2, 2/5, and 2/8 was significantly lower in murine fibroblasts. At day 3 under wound conditions, all vectors demonstrated similar transduction efficiency, but by day 7, the three pseudotyped vectors transduced significantly more murine cells compared with AAV2/2. However, in human cells, there was no significant difference in the transduction efficiency of each pseudotype between normal and wound conditions at both 3 and 7 d. CONCLUSIONS: The AAV pseudotyping strategy represents a gene transfer technology that can result in differential transduction of dermal fibroblasts. The differences in transduction efficiency in murine and human dermal fibroblasts in both the normal and wound environment highlight issues with translatability of gene transfer techniques. These data provide a template for using pseudotyped AAV vectors in cutaneous applications.
    Journal of Surgical Research 04/2013; · 2.02 Impact Factor
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    ABSTRACT: Objective: To determine whether total fetal lung volumes estimated by MRI could predict lethal pulmonary hypoplasia in a cohort of fetuses with cervical teratomas. Methods: We performed a retrospective cohort study of fetal cervical teratomas from January 1, 2005, through April 1, 2012. The primary outcome was the ability of total lung volumes measured by MRI to predict neonatal mortality specifically due to pulmonary hypoplasia. Measured lung volumes were compared to previously reported normal values. The percent of observed-to-expected lung volume and the percent predicted lung volume were calculated. The positive and negative predictive values were calculated for each variable. Results: Fetal MRI-derived total lung volumes 1 standard deviation below the median for gestational age had a positive predictive value of 100% in predicting lethal pulmonary hypoplasia. Conversely, total lung volumes above this level were uniformly associated with pulmonary survival (100% negative predictive value). Additionally, percent predicted lung volume ≤75.7 and observed-to-expected lung volume ≤68.3 were associated with lethal pulmonary hypoplasia. Conclusion: In this small cohort, MRI-estimated lung volumes were helpful in predicting the presence of pulmonary hypoplasia complicating fetal cervical teratoma.
    Fetal Diagnosis and Therapy 02/2013; · 1.90 Impact Factor
  • Sundeep G Keswani, Alice King
    Journal of Surgical Research 02/2013; · 2.02 Impact Factor
  • Alice King, Swathi Balaji, Sundeep G Keswani
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    ABSTRACT: The development of the integumentary system is a series of events that starts in utero and continues throughout life. Although at birth, skin in full-term infants is anatomically mature, functional maturity develops during the first year of life. Pediatric skin transitions again with the onset of puberty. At each stage, there are changes in transepidermal water loss, skin hydration, and skin acidity that define the specific period of development.
    Facial plastic surgery clinics of North America 02/2013; 21(1):1-6.
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    ABSTRACT: Mesenchymal stem cells (MSCs) are key to regenerative wound healing. MSCs have spatial memory and respond to local environment. MSCs orchestrate wound repair by: (1) structural repair via cellular differentiation; (2) immune-modulation; (3) secretion of growth factors that drive neovascularization and re-epithelialization; and (4) mobilization of resident stem cells. Autologous bone-marrow-derived cells and MSCs demonstrate improved healing and tissue-integrity in animal models and clinical trials. However, the effects are variable and the mechanisms of MSC-mediated wound healing are not fully understood. The mammalian MSC niche and signaling sequences and factors affecting their homing, differentiation, viability, and safety need to be characterized to get full benefits of MSC cellular therapy. MSCs can be isolated from bone-marrow, and less-invasive tissues such as adipose, gingiva, muscle, and umbilical cord, with similar functional effects. However, isolation, culture conditions, and markers used to identify and trace the lineage of these MSCs have not been standardized, which is crucial to determine the extent to which MSCs act as multipotent stem cells or sources of secreted factors in wounds. In chronic nonhealing wounds, where efficacy of conventional therapies is unsatisfactory, autotransplantation of MSCs could accelerate wound healing, promote regeneration and restoration of tissue integrity, and reduce recurrence of wounds at characteristically predisposed sites. Regenerative medicine and novel wound therapies using autologous stem cells holds great promise for clinical management of difficult wounds. The ideal candidate stem cells can be used to repopulate the wound bed to mediate appropriate epidermal and dermal regeneration and promote efficient wound repair, while modulating the immune system to prevent infection.
    Advances in wound care. 08/2012; 1(4):159-165.
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    ABSTRACT: Cell specific gene transfer and sustained transgene expression are goals of cutaneous gene therapy for tissue repair and regeneration. Adeno-associated virus serotype 2 (AAV2/2) mediated gene transfer to the skin results in stable transgene expression in the muscle fascicles of the panniculus carnosus in mice, with minimal gene transfer to the dermal or epidermal elements. We hypothesized that pseudotyped AAV vectors may have a unique and characteristic tropism and transduction efficiency profile for specific cells in the cutaneous wounds. We compared transduction efficiencies of cells in the epidermis, cells in the dermis, and the fascicles of the panniculus carnosus by AAV2/2 and three pseudotyped AAV vectors, AAV2/5, AAV2/7, and AAV2/8 in a murine excisional wound model. AAV2/5 and AAV2/8 result in significantly enhanced transduction of cells both in the epidermis and the dermis compared to AAV2/2. AAV2/5 transduces both the basilar and supra-basilar keratinocytes. In contrast, AAV2/8 transduces mainly supra-basilar keratinocytes. Both AAV2/7 and AAV2/8 result in more efficient gene transfer to the muscular panniculus carnosus compared to AAV2/2. The capsid of the different pseudotyped AAV vectors produces distinct tropism and efficiency profiles in the murine wound healing model. Both AAV2/5 and AAV2/8 administration result in significantly enhanced gene transfer. To further characterize cell specific transduction and tropism profiles of the AAV pseudotyped vectors, we performed in vitro experiments using human and mouse primary dermal fibroblasts. Our data demonstrate that pseudotyping strategy confers a differential transduction of dermal fibroblasts, with higher transduction of both human and murine cells by AAV2/5 and AAV2/8 at early and later time points. At later time points, AAV2/2 demonstrates increased transduction. Interestingly, AAV2/8 appears to be more efficacious in transducing human cells as compared to AAV2/5. The pseudotype-specific pattern of transduction and tropism observed both in vivo and in vitro suggests that choice of AAV vectors should be based on the desired target cell and the timing of transgene expression in wound healing for gene transfer therapy in dermal wounds.
    Wound Repair and Regeneration 06/2012; 20(4):592-600. · 2.76 Impact Factor
  • Alice Leung, Timothy M Crombleholme, Sundeep G Keswani
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    ABSTRACT: The mid-gestation fetus is capable of regenerative healing with wound healing indistinguishable from surrounding skin. This review aims to evaluate the current knowledge of how the mid-gestation fetus heals without scar and the implications of these findings in efforts to recapitulate the fetal regenerative phenotype in the postnatal environment. It has been over 30 years since the empirical observation that the fetus heals without scar; yet, the underlying mechanisms of this phenomenon have not been elucidated. Fetal wound healing is characterized by a distinct growth factor profile, an attenuated inflammatory response with an anti-inflammatory cytokine profile, an extracellular matrix rich in type III collagen and hyaluronan, attenuated biomechanical stress, and a potential role for stem cells. Current therapies to minimize scarring in postnatal wounds have attempted to recapitulate singular aspects of the fetal regenerative phenotype and have met with varying degrees of clinical success. We now have the molecular tools to more completely comprehend the fundamental mechanisms of fetal regenerative wound repair, which has the potential to provide insights into the identification of therapeutic targets to minimize the scar formation. Successful therapies that help minimize postnatal scar formation can be realized through understanding the cellular and molecular mechanisms of fetal regenerative wound healing. These insights will have implications not only for cutaneous wound healing, but also potentially for any disease process characterized by excessive fibroplasia.
    Current opinion in pediatrics 06/2012; 24(3):371-8. · 2.01 Impact Factor
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    ABSTRACT: Lung disease including airway infection and inflammation currently causes the majority of morbidities and mortalities associated with cystic fibrosis (CF), making the airway epithelium and the submucosal glands (SMG) novel target cells for gene therapy in CF. These target cells are relatively inaccessible to postnatal gene transfer limiting the success of gene therapy. Our previous work in a human-fetal trachea xenograft model suggests the potential benefit for treating CF in utero. In this study, we aim to validate adeno-associated virus serotype 2 (AAV2) gene transfer in a human fetal trachea xenograft model and to compare transduction efficiencies of pseudotyping AAV2 vectors in fetal xenografts and postnatal xenograft controls. Human fetal trachea or postnatal bronchus controls were xenografted onto immunocompromised SCID mice for a four-week engraftment period. After injection of AAV2/2, 2/1, 2/5, 2/7 or 2/8 with a LacZ reporter into both types of xenografts, we analyzed for transgene expression in the respiratory epithelium and SMGs. At 1 month, transduction by AAV2/2 and AAV2/8 in respiratory epithelium and SMG cells was significantly greater than that of AAV2/1, 2/5, and 2/7 in xenograft tracheas. Efficiency in SMG transduction was significantly greater in AAV2/8 than AAV2/2. At 3 months, AAV2/2 and AAV2/8 transgene expression was >99% of respiratory epithelium and SMG. At 1 month, transduction efficiency of AAV2/2 and AAV2/8 was significantly less in adult postnatal bronchial xenografts than in fetal tracheal xenografts. Based on the effectiveness of AAV vectors in SMG transduction, our findings suggest the potential utility of pseudotyped AAV vectors for treatment of cystic fibrosis. The human fetal trachea xenograft model may serve as an effective tool for further development of fetal gene therapy strategies for the in utero treatment of cystic fibrosis.
    PLoS ONE 01/2012; 7(8):e43633. · 3.73 Impact Factor

Publication Stats

229 Citations
82.79 Total Impact Points

Institutions

  • 2007–2014
    • Cincinnati Children's Hospital Medical Center
      • Division of Pediatric General and Thoracic Surgery
      Cincinnati, Ohio, United States
  • 2003–2013
    • The Children's Hospital of Philadelphia
      • Children's Institute for Surgical Science
      Philadelphia, Pennsylvania, United States
    • Hospital of the University of Pennsylvania
      Philadelphia, Pennsylvania, United States
  • 2004–2012
    • University of Cincinnati
      • College of Medicine
      Cincinnati, Ohio, United States
  • 2002
    • Louisiana State University Health Sciences Center New Orleans
      • Department of Surgery
      Baton Rouge, LA, United States