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1.
Hum Immunol ; 85(3): 110813, 2024 May.
Article En | MEDLINE | ID: mdl-38749805

HLA matching in solid organ transplant is performed with the aim of assessing immunologic compatibility in order to avoid hyperacute rejection and assess the risk of future rejection events. Molecular mismatch algorithms are intended to improve granularity in histocompatibility assessment and risk stratification. PIRCHE-II uses HLA genotyping to predict indirectly presented mismatched donor HLA peptides, though most clinical validation studies rely on imputing high resolution (HR) genotypes from low resolution (LR) typing data. We hypothesized that use of bona fide HR typing could overcome limitations in imputation, improving accuracy and predictive ability for donor-specific antibody development and acute rejection. We performed a retrospective analysis of adult and pediatric kidney transplant donor/recipient pairs (N = 419) with HR typing and compared the use of imputed LR genotyping verses HR genotyping for PIRCHE-II analysis and outcomes. Imputation success was highly dependent on the reference population used, as using historic Caucasian reference populations resulted in 10 % of pairs with unsuccessful imputation while multiethnic reference populations improved successful imputation with only 1 % unable to be imputed. Comparing PIRCHE-II analysis with HR and LR genotyping produced notably different results, with 20 % of patients discrepantly classified to immunologic risk groups. These data emphasize the importance of using multiethnic reference panels when performing imputation and indicate HR HLA genotyping has clinically meaningful benefit for PIRCHE-II analysis compared to imputed LR typing.


Genotype , Graft Rejection , HLA Antigens , Histocompatibility Testing , Kidney Transplantation , Humans , HLA Antigens/genetics , HLA Antigens/immunology , Histocompatibility Testing/methods , Graft Rejection/genetics , Graft Rejection/immunology , Retrospective Studies , Adult , Female , Male , Child , Middle Aged , Adolescent , Histocompatibility , Genotyping Techniques/methods , Algorithms
2.
Prog Transplant ; 33(4): 335-340, 2023 Dec.
Article En | MEDLINE | ID: mdl-37941352

Introduction: The impact of each immunosuppressive agent on de novo donor-specific antibodies in kidney transplant recipients varies among extant literature. Project aims: Patterns in immunosuppression and the effects on incidence of de novo donor-specific antibodies were evaluated. Design: Adult kidney transplant recipients from 2017 to 2019 without preformed antibodies were sampled. Allograft function, de novo donor-specific antibodies, tacrolimus concentrations, duration of goal-dose antiproliferatives, and steroid doses were recorded. Outcomes included incidence of de novo donor-specific antibodies, and their relation to tacrolimus concentrations, time at goal-dose antiproliferatives, and steroid doses. Results: Recipients (N = 153) were followed for 1 year; all were crossmatch negative and received rabbit antithymocyte globulin induction. Sixteen (10%) recipients developed de novo donor-specific antibodies in a median of 31 days [interquartile range, IQR: 12-67 days], most were Class II antibodies (87.5%). Incidence of de novo donor-specific antibodies did not differ based on induction dosing. Tacrolimus levels in the first month were lower for patients with de novo donor-specific antibodies (8.8 ng/mL vs 10.4 ng/mL, P < .01). There was no difference in time on goal antiproliferative doses, but higher steroid doses (0.4 vs 0.3 mg/kg/d; P = .02) were noted in patients with antibodies. Steroid dosing was likely impacted by baseline risk factors. Conclusion: A significant association was found between lower tacrolimus concentrations early post-transplant and incidence of de novo donor-specific antibodies. This highlighted the importance of clinician attention to subtle changes in tacrolimus and the impact it can have on antibody risk in the early post-transplant period.


Kidney Transplantation , Adult , Humans , Kidney Transplantation/adverse effects , Tacrolimus/therapeutic use , Isoantibodies , Graft Rejection/epidemiology , Immunosuppressive Agents/therapeutic use , Steroids , Graft Survival , Retrospective Studies , HLA Antigens
3.
Am J Transplant ; 23(2): 291-293, 2023 02.
Article En | MEDLINE | ID: mdl-36804136

AL amyloidosis is a rare condition characterized by the overproduction of an unstable free light chain, protein misfolding and aggregation, and extracellular deposition that can progress to multiorgan involvement and failure. To our knowledge, this is the first worldwide report to describe triple organ transplantation for AL amyloidosis and triple organ transplantation using thoracoabdominal normothermic regional perfusion recovery with a donation from a circulatory death (DCD) donor. The recipient was a 40-year-old man with multiorgan AL amyloidosis with a terminal prognosis without multiorgan transplantation. An appropriate DCD donor was selected for sequential heart, liver, and kidney transplants via our center's thoracoabdominal normothermic regional perfusion pathway. The liver was additionally placed on an ex vivo normothermic machine perfusion, and the kidney was maintained on hypothermic machine perfusion while awaiting implantation. The heart transplant was completed first (cold ischemic time [CIT]: 131 minutes), followed by the liver transplant (CIT: 87 minutes, normothermic machine perfusion: 301 minutes). Kidney transplantation was performed the following day (CIT: 1833 minutes). He is 8 months posttransplant without evidence of heart, liver, or kidney graft dysfunction or rejection. This case highlights the feasibility of normothermic recovery and storage modalities for DCD donors, which can expand transplant opportunities for allografts previously not considered for multiorgan transplantations.


Immunoglobulin Light-chain Amyloidosis , Kidney Transplantation , Tissue and Organ Procurement , Male , Humans , Adult , Organ Preservation , Tissue Donors , Perfusion , Liver , Death
5.
Open Forum Infect Dis ; 9(11): ofac550, 2022 Nov.
Article En | MEDLINE | ID: mdl-36420058

A 7-day course of glecaprevir/pibrentasvir started in the preoperative period prevented transmission of hepatitis C virus (HCV) from viremic donors to 10 HCV-negative recipients (2 heart, 1 lung, 6 kidney, 1 heart/kidney) with 100% sustained virological response at 12 weeks.

7.
Prog Transplant ; 31(3): 267-270, 2021 09.
Article En | MEDLINE | ID: mdl-34114514

As organ procurement organizations nationwide see an increased opportunity to retransplant already transplanted hearts, we would like to share the overview and process of our 2 successful cases. Heart retransplantation increased our cardiac placement rates by 2.64% and 2% in 2015 and 2019, respectively. Spread across a nation that sees over 3500 heart placements annually, a 2% increase would be substantial. Since 2009, our cases stand as the only documented heart retransplantations in the United States. However, United Network for Organ Sharing data shows that potential exists. From a facilitation perspective, we have developed a protocol to ease the matching process. From a surgical perspective, these cases had no complications and saved 2 lives, with each heart now beating in a third person. We hope that by sharing our process and success, we can familiarize fellow organ procurement organizations and transplant communities with this viable opportunity.


Heart Transplantation , Tissue and Organ Procurement , Humans , Reoperation , United States
8.
J Clin Orthop Trauma ; 17: 118-122, 2021 Jun.
Article En | MEDLINE | ID: mdl-33816107

PURPOSE: Total Knee Arthroplasty (TKA) is one of the most successful operations in orthopedics. Still, a sizable percentage of patients (20%) remain dissatisfied after a well-executed TKA. The study aims to examine the excised synovium from the suprapatellar region in osteoarthritic knees during TKA and evaluate the histopathology (HP) report to know whether discrepant diagnoses affect the Forgotten Joint Score-12 at various time intervals. METHODS: This is a prospective cohort study. Two hundred (160 female; 40 male) end-stage osteoarthritis patients who underwent primary TKA were studied. An inclusion criterion was patient with end-stage osteoarthritis. Clinically and serologically proven rheumatoid arthritis patients were excluded from the study. The synovium excised during the TKA procedure was sent for the HP examination. The statistical significance was measured with the Chi-square test and two-sample t-test. RESULTS: A total of 184 out of the 200 patients (92%) knee synovium showed HP features of osteoarthritis. The discordant diagnoses and discrepant diagnosis rate was 8% and 7%, respectively, which is statistically significant by Chi-square test (p value < 0.0001 and p value = 0.0001). 14 of the patients (12 F:2 M) showed histological features of inflammatory/rheumatoid arthritis who were treated, two patients (all female) showed HP features of villonodular synovitis. The mean (SD) improvement in FJS-12 at six weeks in the concordant group (25.3 [17.6]) is significantly more than the discrepant group (15.3 [12.5]), p-value 0.0385. CONCLUSION: 8% of our patients exhibited unexpected results. The study showed a 7% rate of discrepant diagnosis. This discrepant diagnosis if missed and untreated, would have affected the function and long-term survival of the implanted TKA.

9.
Ann Surg Oncol ; 27(8): 2985-2996, 2020 Aug.
Article En | MEDLINE | ID: mdl-32040698

BACKGROUND: The surgical peritoneal cancer index (sPCI) is calculated based on a subjective evaluation of the extent of peritoneal disease during surgery. The pathologic PCI (pPCI) may be a more accurate and objective method for determining the PCI. This study aimed to compare the sPCI and pPCI and to study the potential pitfalls and clinical implications of using the pPCI. METHODS: This prospective study (July to December 2018) included all patients undergoing cytoreductive surgery (CRS). The pPCI was calculated for each patient and compared with the sPCI. The impact of potential confounding factors on the difference between pPCI and sPCI was evaluated. RESULTS: Among 191 patients undergoing CRS at four centers, the pPCI and sPCI were concordant for 37 patients (19.3%). The pPCI was lower than the sPCI for 125 patients (65.4%) and higher for 29 patients (15.1%). The concordance between the two groups was maximum for gastric cancer (38.8%) and colorectal cancer (27.6%) and least for mesothelioma (6.7%) and rare primary tumors (5.6%) (p = 0.04). The difference was 0 to 3 points for 119 patients (62.3%), 4 to 5 points for 27 patients (14.1%), and more than 5 points for 45 patients (23.5%). The rate of concordance was not influenced by the use of neoadjuvant chemotherapy (NACT) (p = 0.4), but the difference was greater when NACT was used (p = 0.03). CONCLUSIONS: The pPCI strongly differs from the sPCI for patients undergoing CRS for peritoneal disease and may provide a more accurate evaluation of the peritoneal disease extent. Further studies are needed to determine its prognostic value compared with sPCI, and consensus guidelines are needed for calculating it.


Peritoneal Neoplasms , Colorectal Neoplasms/therapy , Combined Modality Therapy , Cytoreduction Surgical Procedures , Humans , Peritoneal Neoplasms/therapy , Peritoneum , Prospective Studies , Survival Rate
10.
J Pharm Pract ; 33(6): 912-914, 2020 Dec.
Article En | MEDLINE | ID: mdl-31248333

Solid organ transplant recipients have increased cancer risk due in part to chronic immunosuppression and opportunistic oncogenic viral infections. The management of drug interactions in transplant recipients being treated for cancer is important both to minimize the likelihood of drug-related toxicities and to optimize therapeutic outcomes. We present a case of a 41-year-old woman with a stable living-related kidney transplant maintained on an immunosuppressive regimen of cyclosporine, mycophenolate mofetil, and prednisone, who was subsequently diagnosed with a metastatic lobular breast carcinoma and papillary thyroid cancer and started palbociclib, a time-dependent CYP3A inhibitor. After initiation of palbociclib, cyclosporine trough and peak concentrations were increased by 159% and 81%, respectively, relative to the average cyclosporine concentrations pre-palbociclib. Using the Drug Interaction Probability Scale (DIPS), the interaction between palbociclib and cyclosporine was rated as "probable." Dose reductions of immunosuppressive agents that are CYP3A substrates are warranted if palbociclib is initiated, followed by close monitoring of blood concentrations. This report also highlights the challenges of coadministering a time-dependent inhibitor with a narrow therapeutic index drug that is metabolized by the same enzyme, particularly when the inhibitor is given in cycles with off-treatment periods.


Kidney Transplantation , Adult , Cyclosporine/adverse effects , Female , Humans , Immunosuppressive Agents/adverse effects , Mycophenolic Acid , Piperazines/adverse effects , Pyridines/adverse effects
11.
Eur J Surg Oncol ; 46(4 Pt A): 582-589, 2020 04.
Article En | MEDLINE | ID: mdl-31757660

BACKGROUND: The aim was to study the patterns of target region (greater omentum, lesser omentum, falciform and umbilical round ligament) involvement in patients undergoing cytoreductive surgery (CRS) from various primary tumors, factors affecting involvement and implications on surgical practice. METHODS: All patients undergoing CRS from July 2018 to December 2018 were included in this prospective study. The incidence of target region involvement in presence and absence of visible disease and the impact of primary tumor site, PCI and other variables on target region involvement was evaluated. RESULTS: In 191 patients, greater omentum was involved in over 15% of patients irrespective of the primary tumor type and in 15.7% in absence of visible disease. 75% of these had PCI <20. The involvement of the other three target regions was higher than 20% in ovarian cancer, appendiceal tumors and peritoneal mesothelioma. Involvement of these 3 regions was associated with a higher PCI (p < 0.001 for all) and omental involvement (p < 0.001for all). 2.1% of colorectal cancer patients had umbilical round ligament involvement, 4.2% had falciform ligament involvement and none had lesser omentum involvement. CONCLUSIONS: Target region involvement varies according to primary tumour site and disease extent. Resection of the greater omentum should be performed during CRS for PM arising from all primary sites. Resection of other target organs may be performed for selected patients with ovarian cancer, peritoneal mesothelioma and mucinous appendiceal tumors in absence of visible disease. For other patients, it should be done only in presence of visible disease.


Carcinoma/surgery , Cytoreduction Surgical Procedures/methods , Mesothelioma/surgery , Omentum/pathology , Peritoneal Neoplasms/surgery , Appendiceal Neoplasms/pathology , Carcinoma/pathology , Carcinoma/secondary , Carcinoma, Ovarian Epithelial/pathology , Carcinoma, Ovarian Epithelial/secondary , Carcinoma, Ovarian Epithelial/surgery , Colorectal Neoplasms/pathology , Female , Humans , Male , Mesothelioma/pathology , Ovarian Neoplasms/pathology , Peritoneal Neoplasms/pathology , Peritoneal Neoplasms/secondary , Peritoneum/pathology , Stomach Neoplasms/pathology
12.
Indian J Nephrol ; 29(4): 278-281, 2019.
Article En | MEDLINE | ID: mdl-31423063

INTRODUCTION: There is no report of efficacy and safety of canagliflozin, a sodium glucose cotransporter 2 (SGLT2) inhibitor in post kidney transplant patients with diabetes. MATERIALS AND METHODS: A pilot study was undertaken in stable renal transplant recipients with preexisting diabetes or new onset diabetes after transplantation (NODAT) to look at the efficacy of SGLT2 inhibitor, cangliflozin. With the introduction of canagliflozin (100 mg), the dose of insulin and/or other oral hypoglycemic agents was reduced if the blood sugar control improved. The parameters monitored were body weight, blood pressure (BP), serum creatinine, HbA1c, and tacrolimus trough level. Safety was assessed by adverse event (AE) reports. Each patient was followed for a minimum period of 6 months. RESULTS: The study included 24 (23 males and 1 females) stable kidney transplant patients with diabetes. The mean age of the patients was 53.8 ± 7.12 years. The mean body weight of study subjects was 78.6 ± 12.1 kg before and 76.1 ± 11.2 kg 6 months after starting canagliflozin (P < 0.05). The mean systolic and diastolic BP (mm Hg) was 142 ± 21 and 81 ± 9 before and 134 ± 17 and 79 ± 8, 6 months after starting canagliflozin, respectively (P < 0.05 for systolic BP). There was no significant change in creatinine level (mg/dL). It was 1.1 ± 0.2 before and 1.1 ± 0.3 after starting canagliflozin. The tacrolimus level (ng/mL) was 6.7 ± 3.7 before and 6.1 ± 2, 6 months after starting canagliflozin. The mean HbA1c before was 8.5 ± 1.5%. At 6 months, it was 7.6 ± 1%. Hypoglycemia was not seen. There was no increase in infections. CONCLUSION: Canagliflozin provided reductions in body weight, BP, HbA1c, and the requirement of other hypoglycemic agents without any hypoglycemic episodes and without significant AEs.

13.
Eur J Surg Oncol ; 45(12): 2398-2404, 2019 Dec.
Article En | MEDLINE | ID: mdl-31337527

BACKGROUND AND AIM: The grade/histological subtype is one of the most important prognostic markers in patients undergoing cytoreductive surgery (CRS). Our aim was to study other potential prognostic information that can be derived from the pathological evaluation of CRS specimens and provide a broad outline for evaluation of these. METHODS: This prospective study (July to December 2018) included all patients undergoing cytoreductive surgery (CRS). A protocol for pathological evaluation was laid down which was based on existing practices at the participating centers and included evaluation of the pathological PCI, regional node involvement, response to chemotherapy, morphology of peritoneal metastases (PM) and distribution in the peritoneal cavity. RESULTS: In 191 patients undergoing CRS at 4 centers, the pathological and surgical PCI differed in over 75%. Nodes in relation to peritoneal disease were positive in 13.6%. Disease in normal peritoneum adjacent to tumor nodules was seen in >50% patients with ovarian cancer and mucinous apppendiceal tumors. 23.8% of evaluated colorectal PM patients had a complete response and 25.0% ovarian cancer patients had a near complete pathological response to chemotherapy. CONCLUSIONS: Pathological evaluation of extent and distribution of peritoneal disease differs from the surgical evaluation in majority of the patients. Lymph node involvement in relation of peritoneal disease is common. The morphological presentation of PM in ovarian cancer and mucinous appendiceal tumors merits evaluation of more extensive resections in these patients. Standardized methods of synoptic reporting of CRS specimens could help capture vital prognostic information that may in future influence how these patients are treated.


Cytoreduction Surgical Procedures , Peritoneal Neoplasms/secondary , Peritoneal Neoplasms/surgery , Aged , Chemotherapy, Adjuvant , Female , Humans , Lymphatic Metastasis , Male , Middle Aged , Neoadjuvant Therapy , Peritoneal Neoplasms/drug therapy , Prognosis , Prospective Studies
14.
Obes Surg ; 29(8): 2562-2570, 2019 08.
Article En | MEDLINE | ID: mdl-31016455

BACKGROUND: The prevalence of NAFLD increases in obese diabetics. Accurate diagnosis of NAFLD requires invasive liver biopsies, which is costly, and time consuming and labor intensive. Currently, there is a lack of non-invasive diagnostic methods to identify those with NASH, in obese Indians. OBJECTIVES: To develop an accurate non-invasive scoring system using clinical and biochemical parameters to predict the risk of developing non-alcoholic steatohepatitis (NASH). METHODS: Clinical and biochemical parameters were recorded pre-operatively from 290 patients who were posted for bariatric/metabolic surgery, between September 2017 and October 2018 and compared with the result of intra-operative liver biopsy NAFLD activity scores (NAS). RESULTS: The mean weight and BMI of the patients were 120.3 ± 24.6 and 45.5 ± 7.8 respectively. In the final histopathological examination, 196/290 (67.6%) had simple steatosis, 92/290 (31.7%) had NASH, and 2/290 (0.007%) had cirrhosis. Binary logistic regression analysis of multiple independent predictors yielded five independent factors that were statistically significant (HbA1c, AST, ALT, liver span on USG, and serum triglycerides). These were used to create a scoring system, with a range of scores from 0 to 6, with maximum predictability at a score of 6. Patients with scores of ≧ 3 were at high risk of NASH diagnosis. The sensitivity of this scoring system was 85.87% and diagnostic accuracy was 75.35%. CONCLUSIONS: Our study not only confirms the significant association of NAFLD with obesity but also outlines a simple non-invasive scoring system to identify obese individuals at high risk for NASH.


Models, Statistical , Non-alcoholic Fatty Liver Disease/complications , Non-alcoholic Fatty Liver Disease/diagnosis , Obesity/complications , Obesity/diagnosis , Adult , Bariatric Surgery , Biopsy , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/pathology , Diabetes Mellitus, Type 2/surgery , Female , Humans , Liver Cirrhosis/complications , Liver Cirrhosis/diagnosis , Liver Cirrhosis/pathology , Liver Cirrhosis/surgery , Male , Middle Aged , Non-alcoholic Fatty Liver Disease/pathology , Non-alcoholic Fatty Liver Disease/surgery , Obesity/pathology , Obesity/surgery , Obesity, Morbid/complications , Obesity, Morbid/diagnosis , Obesity, Morbid/pathology , Obesity, Morbid/surgery , Predictive Value of Tests , Prognosis , Reproducibility of Results , Research Design
15.
Case Rep Transplant ; 2018: 2695178, 2018.
Article En | MEDLINE | ID: mdl-29955411

Acute kidney injury is common among kidney transplant recipients. Postinfectious glomerulonephritis secondary to nephritogenic streptococci is one of the oldest known etiologies of acute kidney injury in native kidneys but rarely reported among kidney transplant recipients. This report is of a biopsy-proven case of acute kidney injury in a renal allograft recipient caused by de novo poststreptococcal glomerulonephritis.

16.
Front Physiol ; 9: 673, 2018.
Article En | MEDLINE | ID: mdl-29915545

Continuous glucose monitoring (CGM), a technique that records blood glucose at a regular intervals. While CGM is more commonly used in type 1 diabetes, it is increasingly becoming attractive for treating type 2 diabetic patients. The time series obtained from a CGM provides a rich picture of the glycemic state of the subjects and may help have tighter control on blood sugar by revealing patterns in their physiological responses to food. However, despite its importance, the biophysical understanding of CGM is far from complete. CGM data series is complex not only because it depends on the composition of the food but also varies with individual physiology. All of these make a full modeling of CGM data a difficult task. Here we propose a simple model to explain CGM data in type 2 diabetes. The model combines a relatively simple glucose-insulin dynamics with a two-compartment food model. Using CGM data of a healthy and a diabetic individual we show that this model can capture liquid meals well. The model also allows us to estimate the parameters in a relatively straightforward manner. This opens up the possibility of personalizing the CGM data. The model also predicts insulin time series from the model, and the rate of appearance of glucose due to food. Our methodology thus paves the way for novel analyses of CGM which have not been possible before.

17.
Eur J Surg Oncol ; 44(7): 1105-1111, 2018 07.
Article En | MEDLINE | ID: mdl-29685759

INTRODUCTION: The pathological classification of PMP of appendiceal origin has prognostic and treatment implications. Our goals were to • Classify low grade mucinous carcinoma peritonei (LGMCP) into prognostically distinct subgroups based on histological features. • Compare the reproducibility of the WHO and the PSOGI classifications for both PMP and the appendiceal primary tumor. PATIENTS AND METHODS: A retrospective analysis of patients undergoing CRS and HIPEC or debulking surgery was done. All the tumors were re-classified according to the PSOGI classification. LGMCP was further classified into three histological subgroups and the impact on survival was evaluated. RESULTS: From Jun 2011 to June 2016, 101 patients underwent CRS with HIPEC (n = 89) or debulking surgery (n=12). The median PCI was 28 (3-39) and 74.1% patients had CC-0/1 resections. Of the 76.2% patients who had LGMCP, 4 patients (5.1%) were classified as group 1, 54 (70.1%) as group 2 and 19 patients (24.6%) as group 3. At a median follow up of 21 months, the disease free survival was not reached, 30 months and 14 months for groups 1, 2 and 3 respectively (p = 0.09). There was no difference in overall survival. Using the WHO classification, there was a discordance in the grade of the primary tumor and the peritoneal lesions in 19.8% and conflicting terminology was used in 62% of patients. CONCLUSIONS: The subgroups of LGMCP described here are prognostically different though this needs further prospective evaluation in larger series. The PSOGI classification is more uniformly reproducible and should be preferred to the WHO classification.


Adenocarcinoma, Mucinous/therapy , Antineoplastic Agents/administration & dosage , Appendiceal Neoplasms/pathology , Cytoreduction Surgical Procedures/methods , Hyperthermia, Induced/methods , Peritoneal Neoplasms/therapy , Pseudomyxoma Peritonei/therapy , Adenocarcinoma, Mucinous/classification , Adenocarcinoma, Mucinous/pathology , Adenocarcinoma, Mucinous/secondary , Female , Humans , Infusions, Parenteral , Kaplan-Meier Estimate , Male , Middle Aged , Neoplasm Grading , Peritoneal Neoplasms/classification , Peritoneal Neoplasms/pathology , Peritoneal Neoplasms/secondary , Prognosis , Proportional Hazards Models , Pseudomyxoma Peritonei/classification , Pseudomyxoma Peritonei/pathology , Retrospective Studies
18.
Case Rep Transplant ; 2014: 548243, 2014.
Article En | MEDLINE | ID: mdl-24575309

Purpose. The case of a kidney transplant recipient who experienced a probable drug interaction between sirolimus and ranolazine is reported. Summary. The narrow therapeutic window of immunosuppressive therapy in transplant recipients requires close monitoring for potential drug-drug interactions. The patient, a 57-year-old Caucasian male kidney transplant recipient, was stable for years on sirolimus as his primary immunosuppressive agent and had a history of chronic angina, for which he was prescribed ranolazine. Upon addition and dose escalation of ranolazine, whole blood sirolimus levels more than tripled, rising to immeasurably high concentrations. After holding sirolimus on multiple occasions and reducing dosage more than 50%, blood levels returned to therapeutic range, while continuing ranolazine. Conclusion. Since ranolazine is a documented P-GP and CYP3A inhibitor, and sirolimus a known substrate for both pathways, it is proposed that ranolazine inhibition of P-GP and CYP3A4 contributed to the significant elevation in sirolimus exposure. No alternative causes for the rise in sirolimus exposure were found, and assessment with the Drug Interaction Probability Scale finds this interaction to be probable. Clinicians should be aware of the potential for this interaction to cause elevated sirolimus exposure and subsequent increase in clinical effect or toxicity, in this case overimmunosuppression.

19.
Mech Dev ; 128(7-10): 342-58, 2011.
Article En | MEDLINE | ID: mdl-21801833

Many organisms across the Metazoa have regenerative abilities with potentially conserved genetic mechanisms that can enlighten both medicine and evolutionary studies. Here, the role of canonical Wnt signaling was examined in the red flour beetle Tribolium castaneum in order to explore its role during metamorphosis and larval leg regeneration. Double-stranded RNA mediated silencing of Wnt-1 signaling resulted in a loss of wings and appendages with a dramatic reduction in width, indicating that the Wnt-1 signaling pathway is necessary for proper post-embryonic appendage development in T. castaneum. Furthermore, disruption of canonical Wnt signaling led to the complete impairment of limb regeneration in T. castaneum. Our findings suggest that Wnt-1 signaling is a conserved mechanism for appendage development across all holometabolous insects and indicate that the role of Wnt-1 signaling in limb regeneration has been retained across all insects as various modes of limb development evolved. Importantly, this study shows that the availability of the genome sequence and the ease of performing leg ablations make Tribolium an excellent holometabolous insect model for studying regeneration.


Armadillo Domain Proteins/metabolism , Extremities/physiology , Metamorphosis, Biological/physiology , Regeneration , Wnt Proteins/metabolism , Wnt Signaling Pathway/physiology , Animals , Armadillo Domain Proteins/genetics , Extremities/growth & development , Gene Knockdown Techniques , Models, Biological , RNA, Double-Stranded , Tribolium , Wnt Proteins/genetics
20.
Dev Biol ; 356(1): 19-27, 2011 Aug 01.
Article En | MEDLINE | ID: mdl-21600196

Heparan sulfate proteoglycans (HSPGs) are found in the basement membrane and at the cell-surface where they modulate the binding and activity of a variety of growth factors and other molecules. Most of the functions of HSPGs are mediated by the variable sulfated glycosaminoglycan (GAG) chains attached to a core protein. Sulfation of the GAG chain is key as evidenced by the renal agenesis phenotype in mice deficient in the HS biosynthetic enzyme, heparan sulfate 2-O sulfotransferase (Hs2st; an enzyme which catalyzes the 2-O-sulfation of uronic acids in heparan sulfate). We have recently demonstrated that this phenotype is likely due to a defect in induction of the metanephric mesenchyme (MM), which along with the ureteric bud (UB), is responsible for the mutually inductive interactions in the developing kidney (Shah et al., 2010). Here, we sought to elucidate the role of variable HS sulfation in UB branching morphogenesis, particularly the role of 6-O sulfation. Endogenous HS was localized along the length of the UB suggesting a role in limiting growth factors and other molecules to specific regions of the UB. Treatment of cultures of whole embryonic kidney with variably desulfated heparin compounds indicated a requirement of 6O-sulfation in the growth and branching of the UB. In support of this notion, branching morphogenesis of the isolated UB was found to be more sensitive to the HS 6-O sulfation modification when compared to the 2-O sulfation modification. In addition, a variety of known UB branching morphogens (i.e., pleiotrophin, heregulin, FGF1 and GDNF) were found to have a higher affinity for 6-O sulfated heparin providing additional support for the notion that this HS modification is important for robust UB branching morphogenesis. Taken together with earlier studies, these findings suggest a general mechanism for spatio-temporal HS regulation of growth factor activity along the branching UB and in the developing MM and support the view that specific growth factor-HSPG interactions establish morphogen gradients and function as developmental switches during the stages of epithelial organogenesis (Shah et al., 2004).


Growth Substances/physiology , Heparitin Sulfate/physiology , Kidney/embryology , Morphogenesis/physiology , Ureter/embryology , Animals , Carrier Proteins/pharmacology , Carrier Proteins/physiology , Cells, Cultured , Cytokines/pharmacology , Cytokines/physiology , Fibroblast Growth Factor 1/metabolism , Glial Cell Line-Derived Neurotrophic Factor/metabolism , Growth Substances/pharmacology , Heparitin Sulfate/pharmacology , Kidney/metabolism , Morphogenesis/drug effects , Organ Culture Techniques , Rats , Rats, Sprague-Dawley , Ureter/metabolism
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