21 results on '"Karhadkar SS"'
Search Results
2. Beyond Immunity: Challenges in Kidney Retransplantation Among Persons Living With HIV.
- Author
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Puntiel DA, Prudencio TM, Peticca B, Stanicki B, Liss J, Egan N, Di Carlo A, Chavin K, and Karhadkar SS
- Abstract
Introduction: While superb outcomes have been observed in the HIV-positive (HIV+) population, graft failure and subsequent need for kidney retransplantation (re-KT) remain a concern. This study aims to investigate the difference in success rates of re-KT allograft survival in the HIV+ versus HIV-negative (HIV-) population in the current era of transplantation (2014-2022)., Methods: Data was collected from the Organ Procurement and Transplantation Network on all kidney transplant donors and recipients who had their first re-KT between 2014 and 2022. Allograft survival was assessed using Kaplan-Meier analysis with a log-rank test, while risk factors for graft loss were assessed using Cox proportional hazards with statistical significance set to P = 0.05., Results: HIV+ recipients were significantly more likely to be Black (P < 0.001), have an HLA mismatch >3 (P = 0.018), delayed graft function (P = 0.023), and graft loss from primary nonfunction (P < 0.001). Their HIV- counterparts were more likely to be White (P < 0.001) and Hispanic (<0.001), lose their graft from acute rejection (P = 0.044), and have a living donor (P = 0.001). Being HIV+ was associated with a 1.68-fold increased risk of graft loss, an HLA mismatch >3 held a 1.18-fold increase, experiencing delayed graft function held a 1.89-fold increase, and having diabetes was associated with a 1.16-fold increased risk. Living donor kidneys were associated with a 15.8% decrease in risk for graft failure. Kaplan-Meier curves showed a significantly lower duration of kidney allograft survival in the HIV+ community (P = 0.02)., Conclusions: Disproportional graft failure and inadequate HLA mismatching persist within the HIV+ Re-KT community. Stronger organ matching and new approaches for desensitizing retransplant candidates are vital., (Published by Elsevier Inc.)
- Published
- 2024
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3. Challenges with non-descriptive compliance labeling of end-stage renal disease patients in accessibility for renal transplantation.
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Peticca B, Prudencio TM, Robinson SG, and Karhadkar SS
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Non-descriptive and convenient labels are uninformative and unfairly project blame onto patients. The language clinicians use in the Electronic Medical Record, research, and clinical settings shapes biases and subsequent behaviors of all providers involved in the enterprise of transplantation. Terminology such as noncompliant and nonadherent serve as a reason for waitlist inactivation and limit access to life-saving transplantation. These labels fail to capture all the circumstances surrounding a patient's inability to follow their care regimen, trivialize social determinants of health variables, and bring unsubstantiated subjectivity into decisions regarding organ allocation. Furthermore, insufficient Medicare coverage has forced patients to ration or stop taking medication, leading to allograft failure and their subsequent diagnosis of noncompliant . We argue that perpetuating non-descriptive language adds little substantive information, increases subjectivity to the organ allocation process, and plays a major role in reduced access to transplantation. For patients with existing barriers to care, such as racial/ethnic minorities, these effects may be even more drastic. Transplant committees must ensure thorough documentation to correctly encapsulate the entirety of a patient's position and give voice to an already vulnerable population., Competing Interests: Conflict-of-interest statement: None of the authors have any conflict of interest to disclose., (©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.)
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- 2024
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4. Pretransplant malignancy in pediatrics is not a risk factor for renal graft failure.
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Mandel A, Robinson SG, Peticca B, Prudencio TM, and Karhadkar SS
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- Adult, Humans, Child, Tissue Donors, Risk Factors, Postoperative Complications epidemiology, Graft Survival, Retrospective Studies, Graft Rejection, Kidney Transplantation, Wilms Tumor complications, Wilms Tumor surgery, Kidney Neoplasms
- Abstract
Background: In adults, pretransplant malignancy (PTM) negatively impacts patient survival due to immunosuppression regimens influencing post-transplantation tumor growth. Few reports investigate the outcomes of pediatric kidney transplantation with PTM. We compare transplant outcomes for pediatric patients with PTM to matched controls, including cancer types extending beyond Wilms tumor., Methods: The United Network of Organ Sharing Database was queried to identify pediatric transplant recipients with histories of PTM. All PTM patients were matched to non-PTM patients, at a 1:1 ratio, with 0.001 match tolerance. Matching variables included transplant year, recipient age, recipient gender, recipient race, donor type, and prior transplant. Death-censored graft and patient survival were analyzed. All statistics were reported with 95% confidence intervals (CI)., Results: After propensity matching, 285 PTM and 285 non-PTM patients were identified, with transplant dates from 1990 to 2020. Median Kidney Donor Profile Index values were comparable between cohorts, 17% and 12%, respectively (p = .065). Kaplan-Meier analysis revealed that PTM patients did not have a significantly different rate of death-censored graft failure, compared to the non-PTM group [HR 0.76; 95% CI (0.54-1.1)]. There was also no difference in the overall survival between the two groups of patients [HR 1.1; 95% CI (0.66-2.0)]., Conclusion: A history of pediatric malignancy has minimal independent effect on their post-transplant survival. Additionally, pediatric patients with PTM demonstrated equivalent rates of graft survival. Thus, in contrast to adults, renal failure in children with history of pediatric malignancies should not be considered a complicating factor for renal transplantation., (© 2024 Wiley Periodicals LLC.)
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- 2024
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5. Does race impact outcomes after parathyroidectomy for secondary and tertiary hyperparathyroidism?
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Green RL, Fagenson AM, Karhadkar SS, and Kuo LE
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- Humans, Parathyroidectomy, Alkaline Phosphatase, Morbidity, Reoperation, Retrospective Studies, Hyperparathyroidism surgery, Hyperparathyroidism, Secondary surgery
- Abstract
Background: Racial disparities in care exist for diseases with heterogeneous treatment guidelines. The impact of these disparities on outcomes after parathyroidectomy for secondary(2HPT) and tertiary hyperparathyroidism(3HPT) was explored., Methods: The 2015-2019 NSQIP datasets were used. Patients who underwent parathyroidectomy for 2HPT and 3HPT were identified and analyzed separately. Patients were stratified by race (white vs. non-white); demographics, comorbidities, and outcomes were compared. Studied outcomes included 30-day morbidity, mortality, unplanned reoperation, readmission, and postoperative length of stay(LOS)., Results: There were 1,150 patients with 2HPT and 262 with 3HPT. For 2HPT, 65.5% were non-white; morbidity, reoperation, and prolonged LOS(>3days) occurred disproportionately more often in non-white patients. Non-white race was independently associated with morbidity; higher ASA class and alkaline phosphatase levels were associated with prolonged LOS. For 3HPT, 53.1% were non-white; a prolonged LOS(>1day) occurred disproportionately more often in non-white patients. Higher alkaline phosphatase levels were independently associated with prolonged LOS., Conclusion: Race and markers of advanced disease negatively impact outcomes after parathyroidectomy for 2HPT and 3HPT. Attention to racial disparities and earlier referral may positively impact outcomes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships, with respect to employment, consultancies, stock ownership, honoraria, paid expert testimony, patent applications/registrations, research grants or other funding, that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)
- Published
- 2023
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6. Missed Opportunities to Diagnose and Treat Tertiary Hyperparathyroidism After Transplant.
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Green RL, Karhadkar SS, and Kuo LE
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- Humans, Calcium, Retrospective Studies, Parathyroidectomy, Parathyroid Hormone, Hyperparathyroidism diagnosis, Hyperparathyroidism etiology, Hyperparathyroidism therapy, Hypercalcemia diagnosis, Hypercalcemia etiology, Hypercalcemia therapy
- Abstract
Introduction: Tertiary hyperparathyroidism (3HPT) is common after renal transplant. However, guidelines for diagnosis are not clear and few patients are treated surgically. This study aims to determine rates of diagnosis and treatment of 3HPT in renal transplant patients with hypercalcemia., Materials and Methods: This retrospective chart review identified all renal transplant recipients at a single tertiary care institution between 2011 and 2021. Patients with post-transplant hypercalcemia (> 10.2 mg/dL) were identified. The time in months of index hypercalcemia was noted. Measurement of parathyroid hormone (PTH) levels after index hypercalcemia was determined and noted as elevated if > 64 pg/mL at least 6 mo after transplant. Documentation of symptoms of hyperparathyroidism, a diagnosis of hyperparathyroidism in the electronic medical record, and medical or surgical management of patients with classic 3HPT (elevated calcium and PTH) were determined., Results: Of 383 renal transplant recipients, hypercalcemia was identified in 132 patients. The majority of hypercalcemic patients had PTH levels measured (127, 96.2%). PTH was elevated in 109 (82.6%). Among the 109 patients with classic 3HPT, 54 (49.5%) had a documented diagnosis of hyperparathyroidism in the electronic medical record (P = 0.01). Kidney stones or abnormal DEXA scan were present in 16 (14.7%) and 18 (16.5%), respectively. Most patients were managed non-surgically (101, 92.6%); calcimimetics were prescribed for 42 (38.5%, P = 0.01). Eight (7.3%) patients with classic 3HPT were referred to a surgeon (P = 0.35); all were initially prescribed calcimimetics (P = 0.001)., Conclusions: 3HPT is underdiagnosed in patients with elevated calcium and PTH levels post-transplant. A significant percentage of these patients go without surgical referral and curative treatment., (Copyright © 2023 Elsevier Inc. All rights reserved.)
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- 2023
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7. Simple Prediction Score for Developing Surgical Site Infection after Clean Neck Operation.
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Zorbas KA, Karakousis GC, Karhadkar SS, Di Carlo A, Lau KN, Zorbas IA, Vamvakidis K, Lois W, and Shah AK
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- Databases, Factual, Humans, Logistic Models, Male, Operative Time, Risk Factors, United States, Surgical Wound Infection epidemiology, Surgical Wound Infection etiology
- Abstract
Background: Clean neck operations (thyroidectomies, parathyroidectomies, and lymph node resection) are among the most common procedures performed in the United States. Surgical site infections (SSIs) after clean neck operations are rare, but the consequences are devastating and often life-threatening. The aim of this study was to develop a score that will identify patients at high risk for developing a SSI after a clean neck procedure. Materials and Methods: Patients with either thyroidectomies, parathyroidectomies, or lymph node resection of the neck were identified from the 2016 and 2017 databases of the American College of Surgeons National Surgical Quality Improvement Program and were used for this analysis. Our primary goal was to build a scoring system with which we will be able to identify patients at high risk for SSI after a clean neck operation. Results: Of a total of 99,877 patients, 72,719 patients had a thyroidectomy, 22,043 patients had parathyroidectomy, and 5,115 patients had lymph node resection of the neck. Multivariable logistic regression identified the following independent risk factors associated with post-operative SSI: male gender (adjusted odds ratio [aOR], 1.25; 95% confidence interval [CI], 1.03-1.51), diabetes mellitus (aOR, 1.34; 95% CI, 1.07-1.67), smoking (aOR, 1.66; 95% CI, 1.36-2.04), pre-operative steroid use (aOR, 1.75; 95% CI, 1.21-2.53), cancer diagnosis (aOR, 1.44; 95% CI, 1.17-1.77), radical lymphadenectomies (aOR, 2.94; 95% CI, 2.16-4), and total operative time ≥198 minutes (aOR, 2.25; 95% CI, 1.82-2.78). Afterward, we developed a prognostic score for calculating the odds of having post-operative SSI. One point was allotted for each of the aforementioned factors, except lymphadenectomies where two points were allotted, and operative time was excluded. Our score was associated with a stepwise higher risk of post-operative SSI after a clean neck operation. Conclusions: Pre-operative and intra-operative factors can predict which patients undergoing a clean neck surgery may develop SSI. Our prognostic score may help guide surgeons identify patients at high-risk for SSI after clean neck surgery and these patients might benefit from prophylactic use of antibiotic agents.
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- 2022
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8. Fatty liver: The metabolic syndrome increases major hepatectomy mortality.
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Fagenson AM, Pitt HA, Moten AS, Karhadkar SS, Di Carlo A, and Lau KN
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- Aged, Female, Humans, Male, Middle Aged, Retrospective Studies, United States epidemiology, Fatty Liver complications, Hepatectomy mortality, Metabolic Syndrome complications
- Abstract
Background: As the obesity epidemic worsens, the prevalence of fatty liver disease has increased. However, minimal data exist on the impact of combined fatty liver and metabolic syndrome on hepatectomy outcomes. Therefore, the aim of this analysis is to measure the outcomes of patients who do and do not have a fatty liver undergoing hepatectomy in the presence and absence of the metabolic syndrome., Methods: Patients with fatty and normal livers undergoing major hepatectomy (≥3 segments) were identified in the 2014 to 2018 American College of Surgeon National Surgical Quality Improvement Program database. Patients undergoing partial hepatectomy and those with missing liver texture data were excluded. Propensity matching was used and adjusted for multiple variables. A subgroup analysis stratified by the metabolic syndrome (body mass index ≥30 kg/m
2 , hypertension and diabetes) was performed. Demographics and outcomes were compared by χ2 and Mann-Whitney tests., Results: Of 2,927 hepatectomies, 30% of patients (N = 863) had a fatty liver. The median body mass index was 28.6, and the metabolic syndrome was present in 6.3% of patients (N = 184). After propensity matching, 863 patients with fatty and 863 with normal livers were compared. Multiple outcomes were significantly worse in patients with fatty livers (P <.05), including serious morbidity (32% vs 24%), postoperative invasive biliary procedures (15% vs 10%), organ space infections (11% vs 7.8%), and pulmonary complications. Patients with fatty livers and the metabolic syndrome had significantly increased postoperative cardiac arrests, pulmonary embolisms, and mortality (P < .05)., Conclusion: Fatty liver disease is associated with significantly worse outcomes after major hepatectomy. The metabolic syndrome confers an increased risk of postoperative mortality., (Copyright © 2020 Elsevier Inc. All rights reserved.)- Published
- 2021
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9. Outcomes of Older Patients in the Recent Era of Heart Kidney Transplantation.
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Punnoose LR, Rao S, Ghanta MM, Karhadkar SS, and Alvarez R
- Subjects
- Adult, Age Factors, Aged, Cohort Studies, Female, Heart Failure complications, Heart Failure surgery, Humans, Male, Middle Aged, Registries, Renal Insufficiency complications, Renal Insufficiency surgery, Retrospective Studies, Young Adult, Heart Transplantation mortality, Kidney Transplantation mortality, Patient Selection, Treatment Outcome
- Abstract
Background and Objective: Variable age thresholds are often used at transplant centers for simultaneous heart and kidney transplantation (HKT). We hypothesize that selected older recipients enjoy comparable outcome to younger recipients in the current era of HKT., Methods: We performed a retrospective analysis of HKT outcomes in the United Network for Organ Sharing (UNOS) registry from 2006 to 2018, classifying patients by age at transplant as ≥ 65 or < 65 years. The primary outcome was patient death. Secondary outcomes included all-cause kidney graft failure and death-censored kidney allograft failure., Results: Of 973 patients, 774 (80%) were younger than 65 years (mean 52 ± 10 years) and 199 (20%) were 65 years or older (mean 67 ± 2 years). The older HKT cohort had fewer blacks (22% vs 35%, P = .01) and women (12 vs 18%, P = .04). Fewer older patients received dialysis (30% vs 54%, P < .001) and mechanical support (36% vs 45%, P = .03) before HKT. Older recipients received organs from slightly older donors. The median follow-up time was shorter for patients 65 years or older than for the younger group (2.3 vs 3.3 years, P < .001). Patient survival was similar between the groups (mean 8.8 vs 9.8 years, P = .3), with the most common causes of death being cardiovascular (29%) and infectious complications (28%). There was no difference in all-cause kidney graft survival (mean 8.7 vs 9.3 years, P = .8). Most commonly, recipients died with a functional renal allograft (59.8%), and this occurred more commonly in older patients (81.4% vs 54.8%, P = .001). Cox proportional hazard modeling showed that higher donor age (hazard ratio [HR] 1.015, P = .01; HR 1.022, P = .02) and use of pre-transplant dialysis (HR 1.5, P = .004; HR 1.8, P = .006) increased the risk for both all-cause and death-censored kidney allograft failure, respectively., Conclusions: Our study showed that carefully selected older patients have outcomes similar to those of a younger cohort and argues for comprehensive evaluation of the recipients with age as part of comorbidity assessment rather than use of an arbitrary age threshold for candidacy., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2021
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10. Liver Ischemia Reperfusion Injury, Enhanced by Trained Immunity, Is Attenuated in Caspase 1/Caspase 11 Double Gene Knockout Mice.
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Fagenson AM, Xu K, Saaoud F, Nanayakkara G, Jhala NC, Liu L, Drummer C, Sun Y, Lau KN, Di Carlo A, Jiang X, Wang H, Karhadkar SS, and Yang X
- Abstract
Ischemia reperfusion injury (IRI) during liver transplantation increases morbidity and contributes to allograft dysfunction. There are no therapeutic strategies to mitigate IRI. We examined a novel hypothesis: caspase 1 and caspase 11 serve as danger-associated molecular pattern (DAMPs) sensors in IRI. By performing microarray analysis and using caspase 1/caspase 11 double-knockout (Casp DKO) mice, we show that the canonical and non-canonical inflammasome regulators are upregulated in mouse liver IRI. Ischemic pre (IPC)- and post-conditioning (IPO) induce upregulation of the canonical and non-canonical inflammasome regulators. Trained immunity (TI) regulators are upregulated in IPC and IPO. Furthermore, caspase 1 is activated during liver IRI, and Casp DKO attenuates liver IRI. Casp DKO maintained normal liver histology via decreased DNA damage. Finally, the decreased TUNEL assay-detected DNA damage is the underlying histopathological and molecular mechanisms of attenuated liver pyroptosis and IRI. In summary, liver IRI induces the upregulation of canonical and non-canonical inflammasomes and TI enzyme pathways. Casp DKO attenuate liver IRI. Development of novel therapeutics targeting caspase 1/caspase 11 and TI may help mitigate injury secondary to IRI. Our findings have provided novel insights on the roles of caspase 1, caspase 11, and inflammasome in sensing IRI derived DAMPs and TI-promoted IRI-induced liver injury.
- Published
- 2020
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11. Endovascular intervention for iliac vein thrombosis after simultaneous kidney-pancreas transplant.
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Gunder M, Lakhter V, Lau K, Karhadkar SS, Di Carlo A, and Bashir R
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May-Thurner syndrome (MTS) is an anatomic variant where the overlying right common iliac artery compresses and chronically obstructs the left common iliac vein, leading to thrombosis. Interventions for symptomatic MTS include endovascular thrombectomy and stenting. Occluding venous thrombus can be fatal to transplanted allografts. No guidelines exist for patients with MTS after simultaneous kidney-pancreas transplant. A 57-year-old female with ESRD and diabetes mellitus underwent a kidney-pancreas transplant. Post-operative imaging revealed a compressed left CIV with an occlusive thrombus threatening the renal graft. Thrombectomy with stent placement was performed, maintaining patency of both allograft venous outflows. Post-intervention the patient has demonstrated preserved kidney and pancreas allograft function through 1 year of follow-up. Interventions for MTS in patients after transplant are challenging given the complex allograft vascular reconstruction. We present a case which demonstrates that angiographic interventions for MTS can be safely performed after simultaneous kidney-pancreas transplant.
- Published
- 2019
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12. Renal Cell Carcinoma in Kidney Transplant Candidates.
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Zorbas KA, Karhadkar SS, Lau KN, and Di Carlo A
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- Adult, Carcinoma, Renal Cell diagnostic imaging, Carcinoma, Renal Cell etiology, Female, Humans, Incidence, Kidney Failure, Chronic complications, Kidney Neoplasms diagnostic imaging, Kidney Neoplasms etiology, Male, Middle Aged, Nephrectomy methods, Preoperative Care, Renal Dialysis adverse effects, Retrospective Studies, Tomography, X-Ray Computed methods, Carcinoma, Renal Cell epidemiology, Kidney Failure, Chronic surgery, Kidney Neoplasms epidemiology, Kidney Transplantation statistics & numerical data
- Abstract
Background: An increased incidence of renal cell carcinoma (RCC) has been observed in patients with end-stage renal disease. However, the incidence of this pathological condition has not been studied adequately in kidney transplant candidates. The aim of this study was to examine the incidence of RCC and the clinical, imaging, and pathological characteristics in this population., Methods: At our institution, the majority of kidney transplant candidates undergo a non-contrast abdominal computerized tomography (CT) scan as a pre-transplant screening evaluation method. We retrospectively reviewed the medical data from 637 patients who were referred to our institution for kidney transplant evaluation during a period of 2 years. Of these, 174 were found ineligible and were excluded from the study; the final population consisted of 463 patients. Radical nephrectomy was proposed and performed in all the patients with findings highly suspicious of malignancy., Results: A total of 20 patients had findings suspicious for kidney malignancy on non-contrast CT scan and underwent a total nephrectomy before transplantation. At the pathological examination, 13 patients had malignant lesions and 4 patients had benign lesions. All patients with malignancy were male, and 9 of 13 patients with malignancy had papillary RCC., Conclusions: This study confirms the increased incidence of RCC in kidney transplant candidates and underlines the utility of non-contrast CT scan without an intravenous contrast agent as a very useful screening tool in the pre-operative evaluation of kidney transplant candidates. Hence, we recommend the implementation of routine screening with non-contrast CT scan in all kidney transplant candidates who undergo hemodialysis., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2017
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13. Tissue repair and stem cell renewal in carcinogenesis.
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Beachy PA, Karhadkar SS, and Berman DM
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- Animals, Hedgehog Proteins, Humans, Neoplasms metabolism, Proto-Oncogene Proteins metabolism, Regeneration, Stem Cells metabolism, Trans-Activators metabolism, Wnt Proteins, Cell Transformation, Neoplastic, Neoplasms pathology, Stem Cells pathology
- Abstract
Cancer is increasingly being viewed as a stem cell disease, both in its propagation by a minority of cells with stem-cell-like properties and in its possible derivation from normal tissue stem cells. But stem cell activity is tightly controlled, raising the question of how normal regulation might be subverted in carcinogenesis. The long-known association between cancer and chronic tissue injury, and the more recently appreciated roles of Hedgehog and Wnt signalling pathways in tissue regeneration, stem cell renewal and cancer growth together suggest that carcinogenesis proceeds by misappropriating homeostatic mechanisms that govern tissue repair and stem cell self-renewal.
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- 2004
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14. Hedgehog signalling in prostate regeneration, neoplasia and metastasis.
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Karhadkar SS, Bova GS, Abdallah N, Dhara S, Gardner D, Maitra A, Isaacs JT, Berman DM, and Beachy PA
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- Animals, Cell Division drug effects, Cell Line, Cell Line, Tumor, Female, Gene Expression Regulation, Neoplastic, Hedgehog Proteins, Humans, Ligands, Male, Membrane Proteins genetics, Mice, Mice, Inbred C57BL, Neoplasm Invasiveness, Oncogene Proteins genetics, Patched Receptors, Prostate cytology, Prostate pathology, Prostatic Neoplasms genetics, RNA, Messenger genetics, RNA, Messenger metabolism, Receptors, Cell Surface, Receptors, G-Protein-Coupled genetics, Smoothened Receptor, Stem Cells cytology, Stem Cells metabolism, Stem Cells pathology, Transcription Factors genetics, Veratrum Alkaloids pharmacology, Zinc Finger Protein GLI1, Neoplasm Metastasis, Prostate metabolism, Prostatic Neoplasms metabolism, Prostatic Neoplasms pathology, Regeneration, Signal Transduction, Trans-Activators metabolism
- Abstract
Metastatic cancers adopt certain properties of normal cells in developing or regenerating organs, such as the ability to proliferate and alter tissue organization. We find here that activity of the Hedgehog (Hh) signalling pathway, which has essential roles in developmental patterning, is required for regeneration of prostate epithelium, and that continuous pathway activation transforms prostate progenitor cells and renders them tumorigenic. Elevated pathway activity furthermore distinguishes metastatic from localized prostate cancer, and pathway manipulation can modulate invasiveness and metastasis. Pathway activity is triggered in response to endogenous expression of Hh ligands, and is dependent upon the expression of Smoothened, an essential Hh response component that is not expressed in benign prostate epithelial cells. Monitoring and manipulating Hh pathway activity may thus offer significant improvements in diagnosis and treatment of prostate cancers with metastatic potential.
- Published
- 2004
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15. Mending and malignancy.
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Beachy PA, Karhadkar SS, and Berman DM
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- Carcinogens pharmacology, Chronic Disease, Hedgehog Proteins, Humans, Neoplasms genetics, Neoplasms metabolism, Proto-Oncogene Proteins metabolism, Signal Transduction, Stem Cells cytology, Stem Cells metabolism, Stem Cells pathology, Trans-Activators metabolism, Wnt Proteins, Wounds and Injuries chemically induced, Wounds and Injuries pathology, Models, Biological, Neoplasms etiology, Neoplasms pathology, Wound Healing physiology, Wounds and Injuries complications, Wounds and Injuries physiopathology
- Published
- 2004
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16. Roles for Hedgehog signaling in androgen production and prostate ductal morphogenesis.
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Berman DM, Desai N, Wang X, Karhadkar SS, Reynon M, Abate-Shen C, Beachy PA, and Shen MM
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- Animals, DNA Primers, Dihydrotestosterone pharmacology, Female, Hedgehog Proteins, Immunohistochemistry, In Situ Hybridization, Male, Mice, Mice, Knockout, Morphogenesis, Pregnancy, Prostate drug effects, Reverse Transcriptase Polymerase Chain Reaction, Signal Transduction drug effects, Trans-Activators metabolism, Triolein pharmacology, Veratrum Alkaloids pharmacology, Androgens biosynthesis, Gene Expression Regulation, Developmental, Prostate embryology, Signal Transduction physiology, Trans-Activators physiology
- Abstract
Previous studies have demonstrated that the Hedgehog (Hh) signaling pathway plays a critical role in the development and patterning of many endodermally derived tissues. We have investigated the role of Sonic hedgehog (Shh) in formation of the prostate gland by examining the urogenital phenotype of Shh mutant fetuses. Consistent with earlier work reporting an essential role for Shh in prostate induction, we have found that Shh mutant fetuses display abnormal urogenital development and fail to form prostate buds. Unexpectedly, however, we have discovered that this prostate defect could be rescued by three different methods: renal grafting, explant culture in the presence of androgens, and administration of dihydrotestosterone (DHT) to pregnant mice, indicating that the prostate defect in Shh mutants is due to insufficient levels of androgens. Furthermore, we find that the inhibition of Hh pathway signaling by treatment with cyclopamine does not block prostate formation in explant culture, but instead produces morphological defects consistent with a role for Hh signaling in ductal patterning. Taken together, our studies indicate that the initial organogenesis of the prostate proceeds independently of Shh, but that Shh or other Hh ligands may play a role in subsequent events that pattern the prostate.
- Published
- 2004
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17. Widespread requirement for Hedgehog ligand stimulation in growth of digestive tract tumours.
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Berman DM, Karhadkar SS, Maitra A, Montes De Oca R, Gerstenblith MR, Briggs K, Parker AR, Shimada Y, Eshleman JR, Watkins DN, and Beachy PA
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- Animals, Cell Division drug effects, Cell Line, Tumor, Digestive System cytology, Digestive System drug effects, Digestive System metabolism, Digestive System pathology, Gastrointestinal Neoplasms drug therapy, Gastrointestinal Neoplasms genetics, Gene Deletion, Hedgehog Proteins, Humans, Ligands, Membrane Proteins genetics, Membrane Proteins metabolism, Mice, Mice, Nude, Mutation, Neoplasm Transplantation, Patched Receptors, RNA, Messenger genetics, RNA, Messenger metabolism, RNA, Neoplasm genetics, RNA, Neoplasm metabolism, Receptors, Cell Surface, Trans-Activators antagonists & inhibitors, Transplantation, Heterologous, Veratrum Alkaloids pharmacology, Veratrum Alkaloids therapeutic use, Gastrointestinal Neoplasms metabolism, Gastrointestinal Neoplasms pathology, Gene Expression Regulation, Neoplastic, Signal Transduction drug effects, Trans-Activators genetics, Trans-Activators metabolism
- Abstract
Activation of the Hedgehog (Hh) signalling pathway by sporadic mutations or in familial conditions such as Gorlin's syndrome is associated with tumorigenesis in skin, the cerebellum and skeletal muscle. Here we show that a wide range of digestive tract tumours, including most of those originating in the oesophagus, stomach, biliary tract and pancreas, but not in the colon, display increased Hh pathway activity, which is suppressible by cyclopamine, a Hh pathway antagonist. Cyclopamine also suppresses cell growth in vitro and causes durable regression of xenograft tumours in vivo. Unlike in Gorlin's syndrome tumours, pathway activity and cell growth in these digestive tract tumours are driven by endogenous expression of Hh ligands, as indicated by the presence of Sonic hedgehog and Indian hedgehog transcripts, by the pathway- and growth-inhibitory activity of a Hh-neutralizing antibody, and by the dramatic growth-stimulatory activity of exogenously added Hh ligand. Our results identify a group of common lethal malignancies in which Hh pathway activity, essential for tumour growth, is activated not by mutation but by ligand expression.
- Published
- 2003
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18. Medulloblastoma growth inhibition by hedgehog pathway blockade.
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Berman DM, Karhadkar SS, Hallahan AR, Pritchard JI, Eberhart CG, Watkins DN, Chen JK, Cooper MK, Taipale J, Olson JM, and Beachy PA
- Subjects
- Animals, Cell Differentiation drug effects, Cell Division drug effects, Disease Models, Animal, Hedgehog Proteins, Humans, Membrane Proteins genetics, Mice, Mice, Nude, Patched Receptors, Receptors, Cell Surface, Signal Transduction drug effects, Trans-Activators metabolism, Tumor Cells, Cultured, Antineoplastic Agents therapeutic use, Bicuculline therapeutic use, Cerebellar Neoplasms drug therapy, Medulloblastoma drug therapy, Trans-Activators antagonists & inhibitors
- Abstract
Constitutive Hedgehog (Hh) pathway activity is associated with initiation of neoplasia, but its role in the continued growth of established tumors is unclear. Here, we investigate the therapeutic efficacy of the Hh pathway antagonist cyclopamine in preclinical models of medulloblastoma, the most common malignant brain tumor in children. Cyclopamine treatment of murine medulloblastoma cells blocked proliferation in vitro and induced changes in gene expression consistent with initiation of neuronal differentiation and loss of neuronal stem cell-like character. This compound also caused regression of murine tumor allografts in vivo and induced rapid death of cells from freshly resected human medulloblastomas, but not from other brain tumors, thus establishing a specific role for Hh pathway activity in medulloblastoma growth.
- Published
- 2002
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19. Balloon dilatation of ureteric strictures.
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Punekar SV, Rao SR, Swami G, Soni AB, Kinne JS, and Karhadkar SS
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- Adolescent, Adult, Female, Humans, Male, Treatment Outcome, Ureteral Obstruction etiology, Catheterization, Ureteral Obstruction therapy
- Abstract
Aims: Evaluation of dilatation as a minimally invasive technique for the treatment of ureteric strictures., Material and Methods: We evaluated this technique in 16 patients with ureteric and secondary pelviureteric junction strictures from June 1998. Of these, 7 were men and 9 were women. The age range was from 14 to 40 years., Results: Balloon dilatation was successful in 69% of patients. Strictures secondary to previous surgery had nearly 100% success. Of the 8 cases diagnosed as genitourinary tuberculosis, success rate was 50%., Conclusions: Factors affecting success of balloon dilatation are: a) age of the stricture b) length of the stricture and c) etiology of the stricture. In a select group of patients with fresh post-operative or post-inflammatory strictures, balloon dilatation may be an attractive alternative to surgery.
- Published
- 2000
20. Xanthogranulomatous pyelonephritis presenting as emphysematous pyelonephritis: a rare association.
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Punekar SV, Kinne JS, Rao SR, Madiwale C, and Karhadkar SS
- Subjects
- Aged, Female, Humans, Pyelonephritis complications, Pyelonephritis, Xanthogranulomatous complications
- Abstract
Xanthogranulomatous and emphysematous pyelonephritis are two rare variants of pyelonephritis. Their combined occurrence is a very rare condition, which has been documented in our case.
- Published
- 1999
21. Martius' labial fat pad interposition and its modification in complex lower urinary fistulae.
- Author
-
Punekar SV, Buch DN, Soni AB, Swami G, Rao SR, Kinne JS, and Karhadkar SS
- Subjects
- Female, Humans, Recurrence, Surgical Flaps, Urethral Diseases surgery, Urinary Fistula surgery, Vesicovaginal Fistula surgery
- Abstract
Objective: To assess the results of Martius' labial fat pad interposition and its modification using skin island in the repair of giant and recurrent vesicovaginal and urethrovaginal fistulae., Patients and Methods: Fifteen patients of urethrovaginal and vesicovaginal fistulae underwent Martius' labial fat pad interposition and its skin island modification during 1996 to 1999. Ten of these were recurrent (66%) and five were giant fistulae (34%) i.e. more than five cms., Results: Results were very gratifying with a successful repair in 14 patients (93%). Two patients had transient, low-grade stress incontinence, which did not need any additional procedure. In one patient, there was failure of repair, which was later successfully repaired using fat pad from opposite labia., Conclusion: Martius' fat pad interposition provides vascularity and surface for epithelialisation and also prevents overlapping of vesical/urethral and vaginal suture lines. Martius' repair has good results with low morbidity in the treatment of giant and recurrent urethrovaginal and vesicovaginal fistulae.
- Published
- 1999
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