Biography:

In the past Richard P. Cambria has collaborated on articles with Mary F. Lopez and Wayne F. Patton. One of their most recent publications is Effect of various detergents on protein migration in the second dimension of two-dimensional gels. Which was published in journal Analytical Biochemistry.

More information about Richard P. Cambria research including statistics on their citations can be found on their Copernicus Academic profile page.

Richard P. Cambria's Articles: (39)

Effect of various detergents on protein migration in the second dimension of two-dimensional gels

AbstractTwo-dimensional gel electrophoresis (2D)1 is a powerful technique used to separate complex protein mixtures. The technique involves the separation of proteins by charge in the first dimension and by molecular weight in the second dimension. The effect of substituting various detergents for sodium dodecyl sulfate (SDS) in the second dimension (PAGE) was investigated. Individual C-10 through C-14 alkyl sulfates, C-11 through C-14 alkyl sulfonates, sodium N-lauroyl-N-methyltaurine, N-lauroylsarcosine, sodium laurate, or benzyldimethyl-n-hexadecylammonium chloride were substituted for SDS in equilibration buffer, gel buffer, and upper running buffer. The cationic benzyldimethyl-n-hexadecylammonium chloride system was run with reversed polarity. Dramatic effects on protein migration from human mesothelial cell extracts were observed when different detergents were utilized. The C-12 (SDS) through C-14 alkyl sulfates and sulfonates resulted in anomalous migration of the simple epithelial keratins. Unlike SDS, the C-10 and C-11 alkyl sulfates and C-11 sulfonate resulted in gels in which the keratins were separated accurately with respect to their gene sequence-determined molecular weights. However, with these shorter chain alkyl sulfates and sulfonate, resolution was compromised, especially with respect to the high-molecular-weight polypeptides. The C-12 alkyl sulfate (SDS) and alkyl sulfonate provided the best resolution of polypeptides. Mixtures of C-11 sulfate and SDS resulted in gels with better sequence molecular weight estimates and high resolution. In addition, trace amounts of sodium tetradecyl sulfate/sodium heptadecyl sulfate in commercial SDS preparations had an effect on polypeptide resolution.

Tris-tricine and Tris-borate buffer systems provide better estimates of human mesothelial cell intermediate filament protein molecular weights than the standard Tris-glycine system

AbstractHuman mesothelial cells contain a number of well defined intermediate filament proteins (IFs) that have been completely sequenced including vimentin and the cytokeratins (K7, K8, K18, and K19). The electrophoretic migration of these IFs was monitored as a function of second dimension gel buffer composition using various systems including Tris-glycine (pH 8.3 or 9.2), Tris-glycine with 20% methanol, Tris-borate, Tris-tricine, and sodium phosphate. All of the second dimension buffer chemistries yielded patterns of sufficient resolution to identify the major cytoskeletal proteins but differed in the relative mobilities of the IFs. Using gene sequence calculated molecular weight data, the major cytoskeletal polypeptides of human mesothelial cells were ranked from highest molecular weight to lowest molecular weight. This rank order of sequence calculated molecular weights was then compared to the rank order determined from the actual migration of the polypeptides in the different gel systems. With the Tris-tricine and the Tris-borate gel systems as well as gene sequence data, K8 = vimentin > β-tubulin = K7 > K18 > K19 > actin. With the pH 8.3 and 9.2 Tris-glycine systems, as well as the sodium phosphate gel system, the rank order of the polypeptides did not correspond to gene sequence data. Adding 20% methanol to the Tris-glycine system resulted in IF migration that more closely corresponded to the gene sequence derived data. Migration position of the IFs depended upon the temperature of the second dimension separation as well. In mesothelial cells, the migration of a total of 15–25% of the polypeptides was influenced by differing buffer systems. Besides the IFs, the migration of the tropomyosins and PCNA/cyclin depended upon the buffer system and temperature utilized in the second dimension separation. Amino acid sequence-based secondary structural analysis indicates that proteins with buffer sensitive migration contain twice as much α-helix as proteins unaffected by buffer composition. Some secondary structure may persist in the α-helical rod domain of the IF monomer during two-dimensional gel electrophoresis even in the presence of sodium dodecyl sulfate and this secondary structure may be influenced by gel buffer composition.

Effect of various detergents on protein migration in the second dimension of two-dimensional gels

AbstractTwo-dimensional gel electrophoresis (2D)1 is a powerful technique used to separate complex protein mixtures. The technique involves the separation of proteins by charge in the first dimension and by molecular weight in the second dimension. The effect of substituting various detergents for sodium dodecyl sulfate (SDS) in the second dimension (PAGE) was investigated. Individual C-10 through C-14 alkyl sulfates, C-11 through C-14 alkyl sulfonates, sodium N-lauroyl-N-methyltaurine, N-lauroylsarcosine, sodium laurate, or benzyldimethyl-n-hexadecylammonium chloride were substituted for SDS in equilibration buffer, gel buffer, and upper running buffer. The cationic benzyldimethyl-n-hexadecylammonium chloride system was run with reversed polarity. Dramatic effects on protein migration from human mesothelial cell extracts were observed when different detergents were utilized. The C-12 (SDS) through C-14 alkyl sulfates and sulfonates resulted in anomalous migration of the simple epithelial keratins. Unlike SDS, the C-10 and C-11 alkyl sulfates and C-11 sulfonate resulted in gels in which the keratins were separated accurately with respect to their gene sequence-determined molecular weights. However, with these shorter chain alkyl sulfates and sulfonate, resolution was compromised, especially with respect to the high-molecular-weight polypeptides. The C-12 alkyl sulfate (SDS) and alkyl sulfonate provided the best resolution of polypeptides. Mixtures of C-11 sulfate and SDS resulted in gels with better sequence molecular weight estimates and high resolution. In addition, trace amounts of sodium tetradecyl sulfate/sodium heptadecyl sulfate in commercial SDS preparations had an effect on polypeptide resolution.

Tris-tricine and Tris-borate buffer systems provide better estimates of human mesothelial cell intermediate filament protein molecular weights than the standard Tris-glycine system

AbstractHuman mesothelial cells contain a number of well defined intermediate filament proteins (IFs) that have been completely sequenced including vimentin and the cytokeratins (K7, K8, K18, and K19). The electrophoretic migration of these IFs was monitored as a function of second dimension gel buffer composition using various systems including Tris-glycine (pH 8.3 or 9.2), Tris-glycine with 20% methanol, Tris-borate, Tris-tricine, and sodium phosphate. All of the second dimension buffer chemistries yielded patterns of sufficient resolution to identify the major cytoskeletal proteins but differed in the relative mobilities of the IFs. Using gene sequence calculated molecular weight data, the major cytoskeletal polypeptides of human mesothelial cells were ranked from highest molecular weight to lowest molecular weight. This rank order of sequence calculated molecular weights was then compared to the rank order determined from the actual migration of the polypeptides in the different gel systems. With the Tris-tricine and the Tris-borate gel systems as well as gene sequence data, K8 = vimentin > β-tubulin = K7 > K18 > K19 > actin. With the pH 8.3 and 9.2 Tris-glycine systems, as well as the sodium phosphate gel system, the rank order of the polypeptides did not correspond to gene sequence data. Adding 20% methanol to the Tris-glycine system resulted in IF migration that more closely corresponded to the gene sequence derived data. Migration position of the IFs depended upon the temperature of the second dimension separation as well. In mesothelial cells, the migration of a total of 15–25% of the polypeptides was influenced by differing buffer systems. Besides the IFs, the migration of the tropomyosins and PCNA/cyclin depended upon the buffer system and temperature utilized in the second dimension separation. Amino acid sequence-based secondary structural analysis indicates that proteins with buffer sensitive migration contain twice as much α-helix as proteins unaffected by buffer composition. Some secondary structure may persist in the α-helical rod domain of the IF monomer during two-dimensional gel electrophoresis even in the presence of sodium dodecyl sulfate and this secondary structure may be influenced by gel buffer composition.

Effect of various detergents on protein migration in the second dimension of two-dimensional gels

AbstractTwo-dimensional gel electrophoresis (2D)1 is a powerful technique used to separate complex protein mixtures. The technique involves the separation of proteins by charge in the first dimension and by molecular weight in the second dimension. The effect of substituting various detergents for sodium dodecyl sulfate (SDS) in the second dimension (PAGE) was investigated. Individual C-10 through C-14 alkyl sulfates, C-11 through C-14 alkyl sulfonates, sodium N-lauroyl-N-methyltaurine, N-lauroylsarcosine, sodium laurate, or benzyldimethyl-n-hexadecylammonium chloride were substituted for SDS in equilibration buffer, gel buffer, and upper running buffer. The cationic benzyldimethyl-n-hexadecylammonium chloride system was run with reversed polarity. Dramatic effects on protein migration from human mesothelial cell extracts were observed when different detergents were utilized. The C-12 (SDS) through C-14 alkyl sulfates and sulfonates resulted in anomalous migration of the simple epithelial keratins. Unlike SDS, the C-10 and C-11 alkyl sulfates and C-11 sulfonate resulted in gels in which the keratins were separated accurately with respect to their gene sequence-determined molecular weights. However, with these shorter chain alkyl sulfates and sulfonate, resolution was compromised, especially with respect to the high-molecular-weight polypeptides. The C-12 alkyl sulfate (SDS) and alkyl sulfonate provided the best resolution of polypeptides. Mixtures of C-11 sulfate and SDS resulted in gels with better sequence molecular weight estimates and high resolution. In addition, trace amounts of sodium tetradecyl sulfate/sodium heptadecyl sulfate in commercial SDS preparations had an effect on polypeptide resolution.

Tris-tricine and Tris-borate buffer systems provide better estimates of human mesothelial cell intermediate filament protein molecular weights than the standard Tris-glycine system

AbstractHuman mesothelial cells contain a number of well defined intermediate filament proteins (IFs) that have been completely sequenced including vimentin and the cytokeratins (K7, K8, K18, and K19). The electrophoretic migration of these IFs was monitored as a function of second dimension gel buffer composition using various systems including Tris-glycine (pH 8.3 or 9.2), Tris-glycine with 20% methanol, Tris-borate, Tris-tricine, and sodium phosphate. All of the second dimension buffer chemistries yielded patterns of sufficient resolution to identify the major cytoskeletal proteins but differed in the relative mobilities of the IFs. Using gene sequence calculated molecular weight data, the major cytoskeletal polypeptides of human mesothelial cells were ranked from highest molecular weight to lowest molecular weight. This rank order of sequence calculated molecular weights was then compared to the rank order determined from the actual migration of the polypeptides in the different gel systems. With the Tris-tricine and the Tris-borate gel systems as well as gene sequence data, K8 = vimentin > β-tubulin = K7 > K18 > K19 > actin. With the pH 8.3 and 9.2 Tris-glycine systems, as well as the sodium phosphate gel system, the rank order of the polypeptides did not correspond to gene sequence data. Adding 20% methanol to the Tris-glycine system resulted in IF migration that more closely corresponded to the gene sequence derived data. Migration position of the IFs depended upon the temperature of the second dimension separation as well. In mesothelial cells, the migration of a total of 15–25% of the polypeptides was influenced by differing buffer systems. Besides the IFs, the migration of the tropomyosins and PCNA/cyclin depended upon the buffer system and temperature utilized in the second dimension separation. Amino acid sequence-based secondary structural analysis indicates that proteins with buffer sensitive migration contain twice as much α-helix as proteins unaffected by buffer composition. Some secondary structure may persist in the α-helical rod domain of the IF monomer during two-dimensional gel electrophoresis even in the presence of sodium dodecyl sulfate and this secondary structure may be influenced by gel buffer composition.

Effect of various detergents on protein migration in the second dimension of two-dimensional gels

AbstractTwo-dimensional gel electrophoresis (2D)1 is a powerful technique used to separate complex protein mixtures. The technique involves the separation of proteins by charge in the first dimension and by molecular weight in the second dimension. The effect of substituting various detergents for sodium dodecyl sulfate (SDS) in the second dimension (PAGE) was investigated. Individual C-10 through C-14 alkyl sulfates, C-11 through C-14 alkyl sulfonates, sodium N-lauroyl-N-methyltaurine, N-lauroylsarcosine, sodium laurate, or benzyldimethyl-n-hexadecylammonium chloride were substituted for SDS in equilibration buffer, gel buffer, and upper running buffer. The cationic benzyldimethyl-n-hexadecylammonium chloride system was run with reversed polarity. Dramatic effects on protein migration from human mesothelial cell extracts were observed when different detergents were utilized. The C-12 (SDS) through C-14 alkyl sulfates and sulfonates resulted in anomalous migration of the simple epithelial keratins. Unlike SDS, the C-10 and C-11 alkyl sulfates and C-11 sulfonate resulted in gels in which the keratins were separated accurately with respect to their gene sequence-determined molecular weights. However, with these shorter chain alkyl sulfates and sulfonate, resolution was compromised, especially with respect to the high-molecular-weight polypeptides. The C-12 alkyl sulfate (SDS) and alkyl sulfonate provided the best resolution of polypeptides. Mixtures of C-11 sulfate and SDS resulted in gels with better sequence molecular weight estimates and high resolution. In addition, trace amounts of sodium tetradecyl sulfate/sodium heptadecyl sulfate in commercial SDS preparations had an effect on polypeptide resolution.

Tris-tricine and Tris-borate buffer systems provide better estimates of human mesothelial cell intermediate filament protein molecular weights than the standard Tris-glycine system

AbstractHuman mesothelial cells contain a number of well defined intermediate filament proteins (IFs) that have been completely sequenced including vimentin and the cytokeratins (K7, K8, K18, and K19). The electrophoretic migration of these IFs was monitored as a function of second dimension gel buffer composition using various systems including Tris-glycine (pH 8.3 or 9.2), Tris-glycine with 20% methanol, Tris-borate, Tris-tricine, and sodium phosphate. All of the second dimension buffer chemistries yielded patterns of sufficient resolution to identify the major cytoskeletal proteins but differed in the relative mobilities of the IFs. Using gene sequence calculated molecular weight data, the major cytoskeletal polypeptides of human mesothelial cells were ranked from highest molecular weight to lowest molecular weight. This rank order of sequence calculated molecular weights was then compared to the rank order determined from the actual migration of the polypeptides in the different gel systems. With the Tris-tricine and the Tris-borate gel systems as well as gene sequence data, K8 = vimentin > β-tubulin = K7 > K18 > K19 > actin. With the pH 8.3 and 9.2 Tris-glycine systems, as well as the sodium phosphate gel system, the rank order of the polypeptides did not correspond to gene sequence data. Adding 20% methanol to the Tris-glycine system resulted in IF migration that more closely corresponded to the gene sequence derived data. Migration position of the IFs depended upon the temperature of the second dimension separation as well. In mesothelial cells, the migration of a total of 15–25% of the polypeptides was influenced by differing buffer systems. Besides the IFs, the migration of the tropomyosins and PCNA/cyclin depended upon the buffer system and temperature utilized in the second dimension separation. Amino acid sequence-based secondary structural analysis indicates that proteins with buffer sensitive migration contain twice as much α-helix as proteins unaffected by buffer composition. Some secondary structure may persist in the α-helical rod domain of the IF monomer during two-dimensional gel electrophoresis even in the presence of sodium dodecyl sulfate and this secondary structure may be influenced by gel buffer composition.

Fibronectin enhances early shear stress resistance of seeded adult human venous endothelial cells☆

AbstractAn in vitro parallel plate perfusion chamber was used to study the shear stress resistance of seeded adult human saphenous vein endothelial cells (AHSVECs) on glass surfaces coated with different substrates. Endothelial cells were seeded onto glass slides precoated with these substrates and then exposed to pulsatile flow with an average shear stress of 8 dyn/cm2 for 1 hr. After AHSVEC attachment periods of 15 min, 1 hr, and 2 hr, flow dislodged all but 1.4, 30.4, and 72.2%, respectively, of cells that had been seeded onto 1% gelatin. Control slides that were not exposed to flow retained 12.9% (P < 0.03), 49.8% (NS), and 95.2% (NS) of seeded cells. Precoating the slides with 10 μg/ml fibronectin resulted in 69.4, 89.5, and 97.7% of cells remaining after flow, compared with 6.4% (P < 0.03), 53.7% (NS), and 93.3% (NS), respectively, when using matched slides coated with 1% gelatin. Results with 20% fetal bovine serum as the substrate were not statistically different from those obtained with 1% gelatin. We conclude that fibronectin enhances the early attachment of AHSVECs to artificial surfaces and is, therefore, potentially useful for increasing attached cell yields on arterial prostheses prepared with immediate cell seeding techniques.

Case ReportsAcute dissection originating in the abdominal aorta*

AbstractA primary abdominal aortic dissection was encountered in a 53-year-old hypertensive man who was admitted with a 2-week history of back pain. Treatment with an infrarenal aortic bifurcation graft complemented by reconstruction of the proximal aortic cuff was curative. (J VASC SURG 1987;5:495-7.)

Original Articles from the Society for Vascular SurgerySimultaneous carotid and coronary disease: Safety of the combined approach***

AbstractInvoking unacceptable operative risks, many institutions have adopted a conservative policy toward carotid stenosis in patients who require cardiopulmonary bypass (CPB). We have continued to apply simultaneous carotid endarterectomy/coronary artery bypass grafting (CEA/CABG) in selected patients, and in order to place operative risk in perspective, our experience with CEA/CABG was reviewed and contrasted with both CEA and CABG performed as isolated procedures. Seventy-one CEA/CABG were performed from 1978 to 1987, with the bulk of the experience (51/71) accumulated over the past 5 years. CEA/CABG was applied when the carotid lesion was severe (≥75% diameter stenosis). Clinical characteristics of patients with CEA/CABG (e.g., presence of unstable angina, left main coronary artery disease, and impairment of ventricular function) suggested these patients were at higher risk for complications when compared to patients with CABG alone. Yet, other factors influencing stroke risk during cardiopulmonary bypass (patient age, duration of CPB time) were similar between patients with CEA/CABG and patients with only CABG. Most complications in patients with CEA/CABG occurred in the early years of the study. Considering the recent (1983–87) patient cohorts of CEA/CABG and isolated CABG, respectively, there was no significant difference in either operative mortality (2.0% as compared to 2.2%) or perioperative stroke (2.0% as compared to 0.6%). Whereas precise patient selection criteria remain undefined, these findings verify the safety of the combined CEA/CABG approach for most patients who require treatment of both lesions. (J Vasc Surg 1989;9:56–64.)

Original Articles from the Society for Vascular SurgeryTransperitoneal versus retroperitoneal approach for aortic reconstruction: A randomized prospective study*

AbstractA prospective, randomized study was conducted to compare the retroperitoneal versus transperitoneal approach for elective aortic reconstruction. One hundred thirteen patients (transperitoneal = 59, retroperitoneal = 54) were randomized between March 1987 and October 1988. In addition, to assess the changing course of patients undergoing aortic reconstruction similar data were gathered retrospectively on a group of 56 patients undergoing aortic reconstruction by the same surgeons performed via a transperitoneal approach in 1984 to 1985. Randomized patients were identical in age, male to female ratio, smoking history, incidence and severity of cardiopulmonary disease, indication for operation, and use of epidural anesthetics. Details of operation including operative and aortic cross-clamp times, crystalloid and transfusion requirements, degree of hypothermia on arrival at the intensive care unit, and perioperative fluid and blood requirements did not differ significantly for patients undergoing transperitoneal versus retroperitoneal reconstruction. Respiratory morbidity, as assessed by percent of patients requiring postoperative ventilation, deterioration in pulmonary function tests, and the incidence of respiratory complications, was identical in randomized patients. Other aspects of postoperative recovery including recovery of gastrointestinal function, the requirement for narcotics, metabolic parameters of operative stress, the incidence of major and minor complications, and the duration of hospital stay were similar for randomized patients undergoing transperitoneal and retroperitoneal reconstruction. When compared to retrospectively reviewed patients having aortic reconstruction, randomized patients undergoing transperitoneal and retroperitoneal operations had highly significant (p < 0.001) reductions in postoperative ventilation, transfusion requirements, and length of hospital stay. Such trends were all independent of transperitoneal versus retroperitoneal approach. We could demonstrate no important advantage for the retroperitoneal approach, and thus no support for its adoption as the preferred technique for routine aortic reconstruction. (J VASC SURG 1990;11:314-25.)

Original Articles from the International Society for Cardiovascular Surgery, North American ChapterAortocaval and iliac arteriovenous fistulas: Recognition and treatment☆☆☆

AbstractDespite the well characterized physiologic effects of aortocaval or iliac arteriovenous fistulas, patients with such uncommon lesions may manifest a diverse array of symptoms, and diagnosis is often delayed or overlooked. To examine clinical features that facilitate recognition and allow successful repair, a 30-year experience with 20 such fistulas was reviewed. Fourteen fistulas were caused by aneurysm erosion, four followed iatrogenic injury during lumbar disk surgery, and two developed from abdominal gunshot wounds. The interval from presumed occurrence to diagnosis ranged from 3 hours to 8 years. The diagnosis was not recognized before surgery in five (25%) patients. Back pain (70%) was the most common symptom. The presence of a typical abdominal bruit (80%) was the most reliable physical finding, but its significance was occasionally overlooked or misinterpreted. Congestive heart failure was prominent in only seven (35%) patients. Severe lower extremity edema and mottling was the primary manifestation in eight cases, often causing initial confusion with venous thrombosis. Hematuria (5 patients) and oliguric renal failure (4 patients), both fully reversible after fistula repair, also caused diagnostic uncertainty. The mean preoperative cardiac output was 12.2 L/min, falling to 5.4 L/min with fistula repair. Mean blood loss was 5960 ml, supporting use of intraoperative autotransfusion. Two operative deaths (10%) occurred, both in patients not correctly diagnosed before surgery. Despite varied modes of presentation, prompt recognition and use of appropriate operative techniques should achieve successful repair. (J VASC SURG 1991;13:253-65.)

Original Articles from the International Society for Cardiovascular Surgery, North American ChapterThe impact of selective use of dipyridamole-thallium scans and surgical factors on the current morbidity of aortic surgery☆

AbstractPreoperative cardiac testing in patients undergoing vascular surgery remains controversial. We have advocated selective use of dipyridamole-thallium scans based on clinical markers of coronary artery disease before aortic surgery. The present study assessed both the efficacy of this policy and the role of surgical factors in the current morbidity of aortic reconstruction. Two hundred two elective aortic reconstructions (151 abdominal aortic aneurysms, 51 aortoiliac occlusive disease) performed in the period from January 1989 to June 1990 were reviewed. Preoperative dipyridamole-thallium scanning was performed in 29% of all patients, prompting coronary angiograms in 11% and coronary artery bypass grafting/percutaneous transluminal coronary angioplasty in 9% of patients before aortic reconstruction. The overall operative mortality rate was 2%, with one cardiac-related death. Major cardiac (nonfatal myocardial infarction, unstable angina) and pulmonary complications occurred in an additional 4% and 6%, respectively, of patients. Coronary artery disease clinical markers and surgical factors were analyzed with stepwise logistic regression for the prediction of operative mortality rates and major cardiopulmonary complications. Variables retaining significance in predicting postoperative death or cardiopulmonary complications included prolonged (more than 5-hour) operative time (p < 0.004), operation for aortoiliac occlusive disease (p < 0.010), and a history of ventricular ectopy (p < 0.002). Prolonged operative time (p < 0.006) and the detection of intraoperative myocardial ischemia (p < 0.030) were predictive of major cardiac complications after univariate analysis. Selective use of the dipyridamole-thallium scan based on certain clinical markers of coronary artery disease will identify the approximately 10% of patients undergoing aortic reconstruction in whom preoperative invasive treatment of coronary artery disease is appropriate. Thereafter, the overall morbidity of aortic reconstruction, albeit minimal, is dominated by surgical factors rather than the extent of antecedent coronary artery disease. (J Vasc Surg 1992;15:43–51.)

Original Articles from the Eastern Vascular SocietyAmbient oxygen tension modulates endothelial fibrinolysis*

AbstractPurpose: Vascular procedures reoxygenate ischemic endothelial cells (EC) and arterialize saphenous vein (HSV) EC. The balance between the EC-derived fibrinolytic components, plasmingogen activator (tPA), and plasminogen inhibitor (PAI-I) contributes to maintaining thromboresistance. This balance also affects proteolysis through plasmin generation, mediating matrix metabolism endothelial migration, angiogenesis, and theoretically affecting the development of intimal hyperplasia. Methods: To explore the impact of varying oxygen tensions on EC fibrinolysis, HSV and human umbilical vein (HUV) were subjected to PO2 of 40 mm Hg for 24 hours with restoration of PO2 to 150 mm Hg for 24 hours. The tPA and PAI-1 antigen and tPA/PAI-1 antigen ratio in conditioned media (CM), expressed as ↑ or ↓ % change, normalized for cell count, versus controls, were analyzed by enzyme-linked immunosorbent assay. Cellular tPA and PAI-1 mRNAs were assessed by Northern analysis. Results: The tPA but not PAI-1 was significantly decreased after the first 24 hours in HSVEC and significantly decreased after 48 hours in both HUVEC and HSVEC when compared with controls. Messenger RNA for tPA was unchanged but PAI-1 mRNA increased significantly for HSVEC and HUVEC after 24 hours of PO2 of 40 mm Hg, returning to baseline within 24 hours of PO2 to 150 mm Hg restoration. Conclusions: These data support the hypothesis of a fibrinolytic shift after altered ambient O2 tensions exposure in endothelium and demonstrate that HSVEC are more sensitive to altered O2 tension than HUVEC. Altered O2 tensions depress EC fibrinolysis in this model. (J VASC SURG 1993;18:939-46.)

Scientific (Exp)/researchPJ34, a poly-ADP-ribose polymerase inhibitor, modulates visceral mitochondrial activity and CD14 expression following thoracic aortic ischemia-reperfusion

AbstractBackgroundVisceral ischemia-reperfusion injury (VI) contributes to adverse outcomes following the repair of thoracoabdominal aneurysms. Experiments were designed to determine whether a poly–adenosine diphosphate–ribose polymerase (PARP) inhibitor modulates indexes of metabolic function (mitochondrial activity), inflammatory cell activation, and tissue inflammation (lipopolysaccharide receptor CD14 messenger ribonucleic acid) following VI.Methods129S1/SvImj mice were subjected to thoracic aortic occlusion followed by 48 hours of reperfusion. Normal saline was administered to 25 untreated control mice and PJ34 to 21 mice before and immediately after thoracic aortic ischemia-reperfusion. Sham mice (n = 13) underwent median sternotomy alone. At 48 hours, all animals were euthanized and tissues harvested for quantitative analysis.ResultsPJ34 improved intestinal (P < .05) but not hepatic mitochondrial activity following reperfusion. CD14 messenger ribonucleic acid levels in liver (P < .004), kidney (P < .003), and spinal cord (P < .03) tissue were less in PJ34-treated mice.ConclusionsPJ34 preserved the metabolic function of intestinal but not hepatic tissue during reperfusion. PJ34 uniformly decreased the expression of an important marker of inflammatory cell activation and tissue inflammation in visceral tissue following VI. PARP inhibitors may serve as a therapeutic modality to abrogate the stress response to VI.

Surgery-specific considerations in the cardiac patient undergoing noncardiac surgery

Myocardial infarction after noncardiac surgery in patients with coronary artery disease results from the interplay of patient-specific, anesthetic-specific, and surgery-specific factors. Surgery-specific factors include the stress response to injury, both neurohormonal and hemostatic alterations, and clinically-significant operative parameters such as urgency, duration, blood loss, body core temperature, fluid shifts, and location of surgery. The impact of these factors bears out during the entire perioperative period and influences preoperative risk assessment, cardiac evaluation and intervention, intraoperative strategy, and postoperative management. Overall, the morbidity and mortality of surgery is minimal even in high-risk patients, and the contribution of surgery-specific factors to operative risk is subtle compared with that of patient specific-factors such as severity of coronary disease and other comorbid conditions. Nonetheless, the optimal surgical management of patients with coronary disease requires the collaborative effort of the anesthesiologist, cardiologist, and surgeon.

Clinical research study from the American Association for Vascular SurgeryPreservation of renal function with surgical revascularization in patients with atherosclerotic renovascular disease☆

AbstractObjectiveClinical and anatomic factors predictive of a favorable response to renal revascularization performed for renal function salvage remain poorly defined. To clarify decision making in such patients we reviewed a contemporary experience of surgical renal artery revascularization (RAR) performed primarily for preservation of renal function.MethodsBetween June 1990 and March 2001 (ensuring 1 year minimum follow-up), 96 patients with renal insufficiency (serum creatinine [Cr] concentration ≥1.5 mg/dL) and hypertension underwent RAR for preservation of renal function. Study end points included early and late renal function response, progression to dialysis dependence, and long-term survival. Variables potentially associated with these end points were assessed with univariate analysis, Cox regression analysis, and logistic regression analysis, and survival was assessed with the Kaplan-Meier method.ResultsPerioperative failure of RAR occurred in 3 patients (3%), with perioperative mortality in 4 patients (4.1%); thus 92 patients were available for long-term follow-up (mean, 39 months). Mean patient age was 70 ± 9 years with a mean baseline Cr of 2.6 mg/dL (range, 1.5-7.8 mg/dL). Operative management consisted of aortorenal bypass in 38% of patients, extraanatomic bypass in 38% of patients, and endarterectomy in 24% of patients; 32% of patients required combined aortic revascularization and RAR, and 27% underwent bilateral RAR. At hospital discharge renal function had improved (20% decrement in Cr) in 41 (43%) patients, including 7 patients who were removed from dialysis; remained unchanged in 40 (41%) patients; and declined (20% increase in Cr) in 15 (16%) patients. At last follow-up renal function was either improved or unchanged in 72% of patients. Predictors of a favorable response to RAR at last follow-up included stable Cr at hospital discharge (odds ratio [OR], 7.1; 95% confidence interval [CI], 2.5-21.8; P = .0004) and decreased Cr at hospital discharge (OR, 16; 95% CI, 1.6-307.8; P < .0001); bilateral renal artery repair (OR, 3.1; 95% CI, 0.9-10.6; P = .07) approached clinical significance. Predictors of worsened excretory function at last follow-up included decline of renal function at hospital discharge (OR, 28.9; 95% CI, 5.0-165.4; P = .0002), intervention to treat unilateral renal artery stenosis (OR, 3.8; 95% CI, 0.8-16.6; P = .05), and level of baseline Cr (OR, 3.0; 95% CI, 1.0-4.0; P = .04). Progression to dialysis occurred in 16 (17%) patients. Dialysis-free survival at 5 years was 50%, and overall actuarial survival at 5 years was 59%. Predictors of progression to dialysis during follow-up included treatment of complete renal artery occlusion (OR, 6.2; 95% CI, 1.3-29.5; P = .02), early failure of RAR (OR, 3.1; 95% CI, 0.7-14.2; P = .04) and baseline Cr (OR, 2.9; 95% CI, 1.3-6.1; P = .006).ConclusionLong-term clinical success in the preservation of renal function, noted in 70% of patients, can be predicted by the initial response to RAR and by anatomic factors, in particular, bilateral repair. While extreme (mean Cr ≥3.2 mg/dL) renal dysfunction generally is predictive of poor long-term outcome, a subset of patients will experience favorable results, even to the extent of rescue from dialysis. These results may facilitate clinical decision making in the application of RAR for renal function salvage.

Basic Research StudiesPoly(adenosine diphosphate ribose) polymerase inhibition modulates spinal cord dysfunction after thoracoabdominal aortic ischemia-reperfusion

ObjectiveSpinal cord injury (SCI) remains a source of morbidity after thoracoabdominal aortic reconstruction. These studies were designed to determine whether PJ34, a novel ultrapotent inhibitor of the nuclear enzyme poly(adenosine diphosphate ribose) polymerase (PARP) could modulate neurologic injury after thoracic aortic ischemia reperfusion (TAR) in a murine model of SCI.MethodsForty-one anesthetized male mice were subject to thoracic aortic occlusion (11 minutes) through a cervical mediastinotomy followed by 48 hours of reperfusion (TAR) under normothermic conditions. PJ34-treated mice (PJ, n = 12) were given 10 mg/kg PJ34 intraperitoneally 1 hour before ischemia and 1 hour after unclamping. The control group (UN, n = 21) received normal saline intraperitoneally 1 hour before ischemia and 1 hour after unclamping. Sham animals (n = 10) were subject to thoracic aortic exposure with no aortic clamping and similar intraperitoneal normal saline injections. PARP-1−/− (KO, n = 8) mice were subjected to the same conditions as the UN mice. Blinded observers rated murine neurologic status after TAR by using an established rodent paralysis scoring system. Murine spinal cords were subjected to cytokine (GRO-1) protein analysis as a marker of inflammation and immunohistochemical analysis (hematoxylin-eosin and PAR staining). Paralysis scores (PS) and GRO-1 levels were compared with analysis of variance, and survival data were compared with χ2.ResultsImmediately after TAR, UN and PJ mice had severe neurologic dysfunction (PS = 5.8 ± 0.1 and 4.6 ± 0.6, respectively; P > .05), which was significantly worse than the KO mice (PS = 1.0 ± 0.7, P < .001). After 6, 24, and 48 hours KO mice had no discernable neurologic injury (PS = 0). Six hours after TAR, PJ mice significantly improved (PS = 1.1 ± 0.73, P < .001) and remained improved at 24 (PS = 0.7 ± 0.6) and 48 hours (PS = 0.6 ± 0.6). UN mice did not improve their PS, and Sham mice showed no neurologic abnormality at any time during these experiments. The mortality at 48 hours was 0% for PJ and KO mice, 43% for UN (P = .012), and 0% for Sham. GRO-1 levels were significantly decreased in PJ and KO versus UN mice (UN, 583 ± 119 vs PJ, 5.8 ± 0 vs KO, 5.3 ± 1.4 mg/pg; P < .0001). Immunohistochemistry showed evidence of decreased PAR staining and ventral motor neuron injury in PJ mice.ConclusionsGenetic deletion of PARP or inhibition of its activity (PJ34) rescued neurologic function in mice subjected to TAR. PARP inhibition might represent a novel therapeutic approach for prevention of SCI after TAR.

Clinical Research StudiesFrom the Society for Vascular SurgeryEndovascular treatment of thoracic aortic aneurysms: Results of the phase II multicenter trial of the GORE TAG thoracic endoprosthesis

ObjectiveA decade after the first report of descending thoracic aortic aneurysm (DTA) repair with endografts, a commercial device is yet to be approved in the United States. The GORE TAG endoprosthesis, an investigational nitinol-supported expanded polytetrafluoroethylene tube graft with diameters of 26 to 40 mm, is the first DTA device to enter phase II trials in the United States and has been used worldwide for a host of thoracic pathologies.MethodsA multicenter prospective nonrandomized phase II study of the GORE TAG endoprosthesis was conducted at 17 sites. Enrollment was from September 1999 to May 2001. Preoperative workup included arteriography and spiral computed tomography scans of the chest, abdomen, and pelvis. Follow-up radiographs and computed tomography scans were obtained at 1, 6, and 12 months and yearly thereafter.ResultsA total of 139 (98%) of 142 patients had a successful implantation of the device. Inadequate arterial access was responsible for the 3 failures. The mean DTA size was 64.1 ± 15.4 mm. Men slightly outnumbered women (57.7%), with an average age of 71 years, and 88% of the patients were white. Ninety percent were American Society of Anesthesiologists category III or IV. One device was used in 44% of patients, and 56% required two or more devices to bridge the thoracic aorta. The left subclavian artery was covered in 28 patients, with planned carotid-subclavian transposition. The procedure time averaged 150 minutes, estimated blood loss averaged 506 mL, intensive care unit stay averaged 2.6 days, and hospital stay averaged 7.6 days. Within 30 days, 45 (32%) patients had at least 1 major adverse event: 5 (4%) experienced a stroke, 4 (3%) demonstrated temporary or permanent paraplegia, 20 (14%) experienced vascular trauma or thrombosis, and 2 (1.5%) died. Mean follow-up was 24.0 months. Four patients had aneurysm-related deaths. Three patients underwent endovascular revisions for endoleak. No ruptures have been reported. Twenty wire fractures have been identified in 19 patients; 18 (90%) of these occurred in the longitudinal spine, and only 1 patient required treatment. At 2 years, aneurysm-related and overall survival rates are 97% and 75%, respectively.ConclusionsThe GORE TAG thoracic endoprosthesis provides a safe alternative for the treatment of DTAs, with low mortality, relatively low morbidity, and excellent 2-year freedom from aneurysm-related death. Longitudinal spine fractures have so far been associated with rare clinical events.

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