The Journal of Heart and Lung Transplantation the Official Publication of the International Society For Heart Transplantation, 2006
Fear of transmission of donor organisms that may result in recipient pneumonia has a negative imp... more Fear of transmission of donor organisms that may result in recipient pneumonia has a negative impact on donor lung utilization. We reviewed our experience with routine donor bronchial aspiration and culture at the time of transplantation to study the impact of donor bronchial organisms on the development of recipient post-lung transplant pneumonia (PTP) and other outcomes. We reviewed 80 consecutive single and bilateral lung transplants (SLTs and BLTs) from August 1998 to August 2001. Pediatric recipients and those not surviving >3 days were excluded. All donors met standard criteria for donor acceptance. All recipients received broad-spectrum antibiotics pending the results of final operating room cultures. PTP required clinical evidence (fever, leukocytosis and hypoxia), radiologic evidence (infiltrate), and culture confirmation during initial hospitalization or within 30 days. Sixty-four donors for 71 recipients (39 SLTs, 32 BLTs) comprised the study population. Organisms were grown from 57 (89%) donors and 46 were polymicrobial. A total of 149 organisms were cultured consisting of 21 different species, with Staphylococcus (n = 35) and Streptococcus (n = 33) being the most common. PTP was seen in 31 (41%) recipients, with Pseudomonas species (n = 13) the most prevalent. Of the 71 donor-recipient pairs, 2 had both donor and recipient with no growth and PTP. The donor organisms had a sensitivity of 0.75 with a low specificity of 0.04 and were negatively correlated with development of PTP. PTP was an independent predictor of overall mortality. The presence of donor organisms does not predict PTP. Therefore, donor acceptance criteria need to be re-examined.
Journal of the National Comprehensive Cancer Network Jnccn, Sep 1, 2013
Although prior studies have shown underuse of appropriate therapy in patients with hepatocellular... more Although prior studies have shown underuse of appropriate therapy in patients with hepatocellular carcinoma (HCC), no studies to date have assessed the prevalence and clinical impact of therapeutic delays among patients with HCC. The goal of this study was to characterize and identify factors associated with underuse and delays in treatment of these patients. A retrospective cohort study was conducted of patients with cirrhosis diagnosed with HCC at a large urban safety net hospital between January 2005 and June 2012. Dates for HCC diagnosis and any treatments were recorded. Univariate and multivariate analysis was used to determine factors associated with treatment underuse and delayed treatment, which was defined as time from diagnosis to treatment exceeding 3 months. The authors identified 267 treatment-eligible patients with HCC, of whom only 62% received HCC therapy. On multivariate analysis, tumor stage (odds ratio [OR], 0.48; 95% CI, 0.36-0.65), Child-Pugh class (OR, 0.49; 95% CI, 0.28-0.84), and black race (OR, 0.55; 95% CI, 0.31-0.99) were associated with lower rates of treatment use. The median time to treatment was 1.7 months, with 31% of patients experiencing delayed treatment. Delayed treatment was associated with the presence of ascites (hazard ratio [HR], 2.8; 95% CI, 1.3-6.1) and current treatment with transarterial chemoembolization (HR, 4.8; 95% CI, 1.8-12.5). After adjusting for tumor stage and Child-Pugh class, treatment underuse (HR, 0.33; 95% CI, 0.24-0.46) and delayed treatment (HR, 0.50; 95% CI, 0.30-0.84) were both associated with significantly worse survival. Results showed that, in addition to one-third of patients not receiving HCC-directed therapy, another 30% experienced significant therapeutic delays, leading to worse survival.
We reviewed the evolution of practice and late results of aortic root replacement (ARR) in Marfan... more We reviewed the evolution of practice and late results of aortic root replacement (ARR) in Marfan syndrome patients at our institution. A retrospective clinical review of Marfan patients undergoing ARR at our institution was performed. Follow-up data were obtained from hospital and office records and from telephone contact with patients or their physicians. Between September 1976 and September 2006, 372 Marfan syndrome patients underwent ARR: 269 had a Bentall composite graft, 85 had valve-sparing ARR, 16 had ARR with homografts, and 2 had ARR with porcine xenografts. In the first 24 years of the study, 85% received a Bentall graft; during the last 8 years, 61% had a valve-sparing procedure. There was no operative or hospital mortality among the 327 patients who underwent elective repair; there were 2 deaths among the 45 patients (4.4%) who underwent emergent or urgent operative repair. There were 74 late deaths (70 Bentalls, 2 homograft, and 2 valve-sparing ARRs). The most frequent causes of late death were dissection or rupture of the residual aorta (10 of 74) and arrhythmia (9 of 74). Of the 85 patients who had a valve-sparing procedure, 40 had a David II remodeling operation; there was 1 late death in this group, and 5 patients required late aortic valve replacement for aortic insufficiency. A David I reimplantation procedure using the De Paulis Valsalva graft has been used exclusively since May 2002. All 44 patients in this last group have 0 to 1+ aortic insufficiency. Prophylactic surgical replacement of the ascending aorta in patients with Marfan syndrome has low operative risk and can prevent aortic catastrophe in most patients. Valve-sparing procedures, particularly using the reimplantation technique with the Valsalva graft, show promise but have not yet proven as durable as the Bentall.
Accelerated vascular smooth muscle cell (VSMC) proliferation contributes to the formation of athe... more Accelerated vascular smooth muscle cell (VSMC) proliferation contributes to the formation of atherosclerotic lesions. To investigate protein kinase C (PKC)-betaII functions with regard to glucose-induced VSMC proliferation, human VSMC from aorta (AoSMC), a clonal VSMC line of rat aorta (A10), and A10 cells overexpressing PKC-betaI (betaI-A10) and PKC-betaII (betaII-A10) were studied with the use of three techniques to evaluate glucose effects on aspects affecting proliferation. High glucose (25 mM) increased DNA synthesis and accelerated cell proliferation compared with normal glucose (5.5 mM) in AoSMC and A10 cells, but not in betaI-A10 and betaII-A10 cells. The PKC-betaII specific inhibitor CGP-53353 inhibited glucose-induced cell proliferation and DNA synthesis in AoSMC and A10 cells. In flow cytometry analysis, high glucose increased the percentage of A10 cells at 12 h after cell cycle initiation but did not increase the percentage of betaI-A10 or betaII-A10 cells entering S phase. PKC-betaII protein levels decreased before the peak of DNA synthesis, and high glucose further decreased PKC-betaII mRNA and protein levels in AoSMC and A10 cells. These results suggest that high glucose downregulates endogenous PKC-betaII, which then alters the normal inhibitory role of PKC-betaII in cell cycle progression, resulting in the stimulation of VSMC proliferation through acceleration of the cell cycle.
The Journal of Thoracic and Cardiovascular Surgery, 2015
Prophylactic aortic root replacement improves survival in patients with Marfan syndrome with aort... more Prophylactic aortic root replacement improves survival in patients with Marfan syndrome with aortic root aneurysms, but the optimal procedure remains undefined. Adult patients with Marfan syndrome who had Bentall or aortic valve-sparing root replacement (VSRR) procedures between 1997 and 2013 were identified. Comprehensive follow-up information was obtained from hospital charts and telephone contact. One hundred sixty-five adult patients with Marfan syndrome (aged > 20 years) had either VSRR (n = 98; 69 reimplantation, 29 remodeling) or Bentall (n = 67) procedures. Patients undergoing Bentall procedure were older (median, 37 vs 36 years; P = .03), had larger median preoperative sinus diameter (5.5 cm vs 5.0 cm; P = .003), more aortic dissections (25.4% vs 4.1%; P < .001), higher incidence of moderate or severe aortic insufficiency (49.3% vs 14.4%; P < .001) and more urgent or emergent operations (24.6% vs 3.3%; P < .001). There were no hospital deaths and 9 late deaths in more than 17 years of follow-up (median, 7.8 deaths). Ten-year survival was 90.5% in patients undergoing Bentall procedure and 96.3% in patients undergoing VSRR (P = .10). Multivariable analysis revealed that VSRR was associated with fewer thromboembolic or hemorrhagic events (hazard ratio, 0.16; 95% confidence interval, 0.03-0.85; P = .03). There was no independent difference in long-term survival, freedom from reoperation, or freedom from endocarditis between the 2 procedures. After prophylactic root replacement in patients with Marfan syndrome, patients undergoing Bentall and valve-sparing procedures have similar late survival, freedom from root reoperation, and freedom from endocarditis. However, valve-sparing procedures result in significantly fewer thromboembolic and hemorrhagic events.
The 33rd IEEE International Conference on Plasma Science, 2006. ICOPS 2006. IEEE Conference Record - Abstracts., 2006
Summary form only given. The production of MeV protons by intense lasers is an area of great topi... more Summary form only given. The production of MeV protons by intense lasers is an area of great topical interest particularly with respect to the proposal to use protons to initiate burn in a fusion capsule. Following successful initial studies of focusing protons with hemishell targets, using a 10 J, 100 fs laser we extended the study to higher energy and
Journal of the National Comprehensive Cancer Network : JNCCN, 2015
Most patients with hepatocellular carcinoma (HCC) present at advanced stages. The prevalence and ... more Most patients with hepatocellular carcinoma (HCC) present at advanced stages. The prevalence and clinical impact of delays during diagnostic evaluation among patients with HCC is unclear. To identify and characterize factors associated with diagnostic delays among patients with HCC. Records were reviewed for consecutive patients with cirrhosis and HCC at a large urban hospital between January 2005 and July 2012. Time from presentation to diagnosis was determined using Kaplan-Meier analysis. Diagnostic delay was defined as time to diagnosis exceeding 3 months, and multivariate logistic regression was used to identify correlates of diagnostic delays. Among 457 patients with HCC, 226 (49.5%) were diagnosed as outpatients. Among these, median time-to-diagnosis was 2.2 months, with 87 patients (38.5%) experiencing a diagnostic delay. Diagnostic delays were positively associated with the presence of hepatic encephalopathy (odds ratio [OR], 2.29; 95% CI, 1.03-5.07) and negatively associate...
Familial hemophagocytic lymphohistiocytosis (F-HLH) and Griscelli syndrome type 2 (GS) are life-t... more Familial hemophagocytic lymphohistiocytosis (F-HLH) and Griscelli syndrome type 2 (GS) are life-threatening immunodeficiencies characterized by impaired cytotoxic T lymphocyte (CTL) and natural killer (NK) cell lytic activity. In the majority of cases, these disorders are caused by biallelic inactivating germline mutations in genes such as RAB27A (GS) and PRF1, UNC13D, STX11, and STXBP2 (F-HLH). Although monoallelic (ie, heterozygous) mutations have been identified in certain patients, the clinical significance and molecular mechanisms by which these mutations influence CTL and NK cell function remain poorly understood. Here, we characterize 2 novel monoallelic hemophagocytic lymphohistiocytosis (HLH)-associated mutations affecting codon 65 of STXPB2, the gene encoding Munc18-2, a member of the SEC/MUNC18 family. Unlike previously described Munc18-2 mutants, Munc18-2(R65Q) and Munc18-2(R65W) retain the ability to interact with and stabilize syntaxin 11. However, presence of Munc18-2...
Two necessary components of a patient blood management program are education regarding evidence-b... more Two necessary components of a patient blood management program are education regarding evidence-based transfusion guidelines and computerized provider order entry (CPOE) with clinician decision support (CDS). This study examines changes in red blood cell (RBC) utilization associated with each of these two interventions. We reviewed 5 years of blood utilization data (2009-2013) for 70,118 surgical patients from 10 different specialty services at a tertiary care academic medical center. Three distinct periods were compared: 1) before blood management, 2) education alone, and 3) education plus CPOE. Changes in RBC unit utilization were assessed over the three periods stratified by surgical service. Cost savings were estimated based on RBC acquisition costs. For all surgical services combined, RBC utilization decreased by 16.4% with education alone (p = 0.001) and then changed very little (2.5% increase) after subsequent addition of CPOE (p = 0.64). When we compared the period of education plus CPOE to the pre-blood management period, the overall decrease was 14.3% (p = 0.008; 2102 fewer RBC units/year, or a cost avoidance of $462,440/year). Services with the highest massive transfusion rates (≥10 RBC units) exhibited the least reduction in RBC utilization. Adding CPOE with CDS after a successful education effort to promote evidence-based transfusion practice did not further reduce RBC utilization. These findings suggest that education is an important and effective component of a patient blood management program and that CPOE algorithms may serve to maintain compliance with evidence-based transfusion guidelines.
The Journal of Heart and Lung Transplantation the Official Publication of the International Society For Heart Transplantation, 2006
Fear of transmission of donor organisms that may result in recipient pneumonia has a negative imp... more Fear of transmission of donor organisms that may result in recipient pneumonia has a negative impact on donor lung utilization. We reviewed our experience with routine donor bronchial aspiration and culture at the time of transplantation to study the impact of donor bronchial organisms on the development of recipient post-lung transplant pneumonia (PTP) and other outcomes. We reviewed 80 consecutive single and bilateral lung transplants (SLTs and BLTs) from August 1998 to August 2001. Pediatric recipients and those not surviving >3 days were excluded. All donors met standard criteria for donor acceptance. All recipients received broad-spectrum antibiotics pending the results of final operating room cultures. PTP required clinical evidence (fever, leukocytosis and hypoxia), radiologic evidence (infiltrate), and culture confirmation during initial hospitalization or within 30 days. Sixty-four donors for 71 recipients (39 SLTs, 32 BLTs) comprised the study population. Organisms were grown from 57 (89%) donors and 46 were polymicrobial. A total of 149 organisms were cultured consisting of 21 different species, with Staphylococcus (n = 35) and Streptococcus (n = 33) being the most common. PTP was seen in 31 (41%) recipients, with Pseudomonas species (n = 13) the most prevalent. Of the 71 donor-recipient pairs, 2 had both donor and recipient with no growth and PTP. The donor organisms had a sensitivity of 0.75 with a low specificity of 0.04 and were negatively correlated with development of PTP. PTP was an independent predictor of overall mortality. The presence of donor organisms does not predict PTP. Therefore, donor acceptance criteria need to be re-examined.
Journal of the National Comprehensive Cancer Network Jnccn, Sep 1, 2013
Although prior studies have shown underuse of appropriate therapy in patients with hepatocellular... more Although prior studies have shown underuse of appropriate therapy in patients with hepatocellular carcinoma (HCC), no studies to date have assessed the prevalence and clinical impact of therapeutic delays among patients with HCC. The goal of this study was to characterize and identify factors associated with underuse and delays in treatment of these patients. A retrospective cohort study was conducted of patients with cirrhosis diagnosed with HCC at a large urban safety net hospital between January 2005 and June 2012. Dates for HCC diagnosis and any treatments were recorded. Univariate and multivariate analysis was used to determine factors associated with treatment underuse and delayed treatment, which was defined as time from diagnosis to treatment exceeding 3 months. The authors identified 267 treatment-eligible patients with HCC, of whom only 62% received HCC therapy. On multivariate analysis, tumor stage (odds ratio [OR], 0.48; 95% CI, 0.36-0.65), Child-Pugh class (OR, 0.49; 95% CI, 0.28-0.84), and black race (OR, 0.55; 95% CI, 0.31-0.99) were associated with lower rates of treatment use. The median time to treatment was 1.7 months, with 31% of patients experiencing delayed treatment. Delayed treatment was associated with the presence of ascites (hazard ratio [HR], 2.8; 95% CI, 1.3-6.1) and current treatment with transarterial chemoembolization (HR, 4.8; 95% CI, 1.8-12.5). After adjusting for tumor stage and Child-Pugh class, treatment underuse (HR, 0.33; 95% CI, 0.24-0.46) and delayed treatment (HR, 0.50; 95% CI, 0.30-0.84) were both associated with significantly worse survival. Results showed that, in addition to one-third of patients not receiving HCC-directed therapy, another 30% experienced significant therapeutic delays, leading to worse survival.
We reviewed the evolution of practice and late results of aortic root replacement (ARR) in Marfan... more We reviewed the evolution of practice and late results of aortic root replacement (ARR) in Marfan syndrome patients at our institution. A retrospective clinical review of Marfan patients undergoing ARR at our institution was performed. Follow-up data were obtained from hospital and office records and from telephone contact with patients or their physicians. Between September 1976 and September 2006, 372 Marfan syndrome patients underwent ARR: 269 had a Bentall composite graft, 85 had valve-sparing ARR, 16 had ARR with homografts, and 2 had ARR with porcine xenografts. In the first 24 years of the study, 85% received a Bentall graft; during the last 8 years, 61% had a valve-sparing procedure. There was no operative or hospital mortality among the 327 patients who underwent elective repair; there were 2 deaths among the 45 patients (4.4%) who underwent emergent or urgent operative repair. There were 74 late deaths (70 Bentalls, 2 homograft, and 2 valve-sparing ARRs). The most frequent causes of late death were dissection or rupture of the residual aorta (10 of 74) and arrhythmia (9 of 74). Of the 85 patients who had a valve-sparing procedure, 40 had a David II remodeling operation; there was 1 late death in this group, and 5 patients required late aortic valve replacement for aortic insufficiency. A David I reimplantation procedure using the De Paulis Valsalva graft has been used exclusively since May 2002. All 44 patients in this last group have 0 to 1+ aortic insufficiency. Prophylactic surgical replacement of the ascending aorta in patients with Marfan syndrome has low operative risk and can prevent aortic catastrophe in most patients. Valve-sparing procedures, particularly using the reimplantation technique with the Valsalva graft, show promise but have not yet proven as durable as the Bentall.
Accelerated vascular smooth muscle cell (VSMC) proliferation contributes to the formation of athe... more Accelerated vascular smooth muscle cell (VSMC) proliferation contributes to the formation of atherosclerotic lesions. To investigate protein kinase C (PKC)-betaII functions with regard to glucose-induced VSMC proliferation, human VSMC from aorta (AoSMC), a clonal VSMC line of rat aorta (A10), and A10 cells overexpressing PKC-betaI (betaI-A10) and PKC-betaII (betaII-A10) were studied with the use of three techniques to evaluate glucose effects on aspects affecting proliferation. High glucose (25 mM) increased DNA synthesis and accelerated cell proliferation compared with normal glucose (5.5 mM) in AoSMC and A10 cells, but not in betaI-A10 and betaII-A10 cells. The PKC-betaII specific inhibitor CGP-53353 inhibited glucose-induced cell proliferation and DNA synthesis in AoSMC and A10 cells. In flow cytometry analysis, high glucose increased the percentage of A10 cells at 12 h after cell cycle initiation but did not increase the percentage of betaI-A10 or betaII-A10 cells entering S phase. PKC-betaII protein levels decreased before the peak of DNA synthesis, and high glucose further decreased PKC-betaII mRNA and protein levels in AoSMC and A10 cells. These results suggest that high glucose downregulates endogenous PKC-betaII, which then alters the normal inhibitory role of PKC-betaII in cell cycle progression, resulting in the stimulation of VSMC proliferation through acceleration of the cell cycle.
The Journal of Thoracic and Cardiovascular Surgery, 2015
Prophylactic aortic root replacement improves survival in patients with Marfan syndrome with aort... more Prophylactic aortic root replacement improves survival in patients with Marfan syndrome with aortic root aneurysms, but the optimal procedure remains undefined. Adult patients with Marfan syndrome who had Bentall or aortic valve-sparing root replacement (VSRR) procedures between 1997 and 2013 were identified. Comprehensive follow-up information was obtained from hospital charts and telephone contact. One hundred sixty-five adult patients with Marfan syndrome (aged > 20 years) had either VSRR (n = 98; 69 reimplantation, 29 remodeling) or Bentall (n = 67) procedures. Patients undergoing Bentall procedure were older (median, 37 vs 36 years; P = .03), had larger median preoperative sinus diameter (5.5 cm vs 5.0 cm; P = .003), more aortic dissections (25.4% vs 4.1%; P < .001), higher incidence of moderate or severe aortic insufficiency (49.3% vs 14.4%; P < .001) and more urgent or emergent operations (24.6% vs 3.3%; P < .001). There were no hospital deaths and 9 late deaths in more than 17 years of follow-up (median, 7.8 deaths). Ten-year survival was 90.5% in patients undergoing Bentall procedure and 96.3% in patients undergoing VSRR (P = .10). Multivariable analysis revealed that VSRR was associated with fewer thromboembolic or hemorrhagic events (hazard ratio, 0.16; 95% confidence interval, 0.03-0.85; P = .03). There was no independent difference in long-term survival, freedom from reoperation, or freedom from endocarditis between the 2 procedures. After prophylactic root replacement in patients with Marfan syndrome, patients undergoing Bentall and valve-sparing procedures have similar late survival, freedom from root reoperation, and freedom from endocarditis. However, valve-sparing procedures result in significantly fewer thromboembolic and hemorrhagic events.
The 33rd IEEE International Conference on Plasma Science, 2006. ICOPS 2006. IEEE Conference Record - Abstracts., 2006
Summary form only given. The production of MeV protons by intense lasers is an area of great topi... more Summary form only given. The production of MeV protons by intense lasers is an area of great topical interest particularly with respect to the proposal to use protons to initiate burn in a fusion capsule. Following successful initial studies of focusing protons with hemishell targets, using a 10 J, 100 fs laser we extended the study to higher energy and
Journal of the National Comprehensive Cancer Network : JNCCN, 2015
Most patients with hepatocellular carcinoma (HCC) present at advanced stages. The prevalence and ... more Most patients with hepatocellular carcinoma (HCC) present at advanced stages. The prevalence and clinical impact of delays during diagnostic evaluation among patients with HCC is unclear. To identify and characterize factors associated with diagnostic delays among patients with HCC. Records were reviewed for consecutive patients with cirrhosis and HCC at a large urban hospital between January 2005 and July 2012. Time from presentation to diagnosis was determined using Kaplan-Meier analysis. Diagnostic delay was defined as time to diagnosis exceeding 3 months, and multivariate logistic regression was used to identify correlates of diagnostic delays. Among 457 patients with HCC, 226 (49.5%) were diagnosed as outpatients. Among these, median time-to-diagnosis was 2.2 months, with 87 patients (38.5%) experiencing a diagnostic delay. Diagnostic delays were positively associated with the presence of hepatic encephalopathy (odds ratio [OR], 2.29; 95% CI, 1.03-5.07) and negatively associate...
Familial hemophagocytic lymphohistiocytosis (F-HLH) and Griscelli syndrome type 2 (GS) are life-t... more Familial hemophagocytic lymphohistiocytosis (F-HLH) and Griscelli syndrome type 2 (GS) are life-threatening immunodeficiencies characterized by impaired cytotoxic T lymphocyte (CTL) and natural killer (NK) cell lytic activity. In the majority of cases, these disorders are caused by biallelic inactivating germline mutations in genes such as RAB27A (GS) and PRF1, UNC13D, STX11, and STXBP2 (F-HLH). Although monoallelic (ie, heterozygous) mutations have been identified in certain patients, the clinical significance and molecular mechanisms by which these mutations influence CTL and NK cell function remain poorly understood. Here, we characterize 2 novel monoallelic hemophagocytic lymphohistiocytosis (HLH)-associated mutations affecting codon 65 of STXPB2, the gene encoding Munc18-2, a member of the SEC/MUNC18 family. Unlike previously described Munc18-2 mutants, Munc18-2(R65Q) and Munc18-2(R65W) retain the ability to interact with and stabilize syntaxin 11. However, presence of Munc18-2...
Two necessary components of a patient blood management program are education regarding evidence-b... more Two necessary components of a patient blood management program are education regarding evidence-based transfusion guidelines and computerized provider order entry (CPOE) with clinician decision support (CDS). This study examines changes in red blood cell (RBC) utilization associated with each of these two interventions. We reviewed 5 years of blood utilization data (2009-2013) for 70,118 surgical patients from 10 different specialty services at a tertiary care academic medical center. Three distinct periods were compared: 1) before blood management, 2) education alone, and 3) education plus CPOE. Changes in RBC unit utilization were assessed over the three periods stratified by surgical service. Cost savings were estimated based on RBC acquisition costs. For all surgical services combined, RBC utilization decreased by 16.4% with education alone (p = 0.001) and then changed very little (2.5% increase) after subsequent addition of CPOE (p = 0.64). When we compared the period of education plus CPOE to the pre-blood management period, the overall decrease was 14.3% (p = 0.008; 2102 fewer RBC units/year, or a cost avoidance of $462,440/year). Services with the highest massive transfusion rates (≥10 RBC units) exhibited the least reduction in RBC utilization. Adding CPOE with CDS after a successful education effort to promote evidence-based transfusion practice did not further reduce RBC utilization. These findings suggest that education is an important and effective component of a patient blood management program and that CPOE algorithms may serve to maintain compliance with evidence-based transfusion guidelines.
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Papers by Nishant Patel