Overview of the Canadian pediatric end-stage renal disease database

BACKGROUND

Performing clinical research among pediatric end-stage renal disease patients is challenging. Barriers to successful initiation and completion of clinical research projects include small sample sizes and resultant limited statistical power and lack of longitudinal follow-up for hard clinical end-points in most single center studies.

DESCRIPTION

Existing longitudinal organ failure disease registry and administrative health datasets available within a universal access health care system can be used to study outcomes of end-stage renal disease among pediatric patients in Canada. To construct the Canadian Pediatric End-Stage Renal Disease database, registry data were linked to administrative health data through deterministic linkage techniques creating a research database which consists of socio-demographic variables, clinical variables, all-cause hospitalizations, and relevant outcomes (death and renal allograft loss) for this patient population. The research database also allows study of major cardiovascular events using previously validated administrative data definitions.

CONCLUSION

Organ failure registry linked to health administrative data can be a powerful tool to perform longitudinal studies in pediatric end-stage renal disease patients. The rich clinical and demographic information found in this database will facilitate study of important medical and non-medical risk factors for death, graft loss and cardiovascular disease among pediatric end-stage renal disease patients.

Increased hemodialysis catheter use in Canada and associated mortality risk: data from the Canadian Organ Replacement Registry 2001-2004

BACKGROUND AND OBJECTIVES

The 1999 Canadian vascular access guidelines recommend the fistula as the access of choice. The study describes the trends in hemodialysis access use, variation among provinces, and the association with mortality from 2001 to 2004.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

An observational study of adult patients registered in Canadian Organ Replacement Registry on hemodialysis. Access trends were examined among incident and prevalent hemodialysis patients adjusted for age, sex, body mass index, late referral, race, smoking status, province, etiology of end-stage renal disease, and comorbidities. Cox proportional hazard regression analysis was used to analyze risk for death for patients followed to December 31, 2005.

RESULTS

From 2001 to 2004, incident catheter use increased from 76.8% to 79.1%, fistulas decreased from 21.6% to 18.6%, and grafts remained between 2.1% to 2.6%. Prevalent catheter use increased from 41.8% to 51.7%, and fistulas and grafts decreased from 46.8% to 41.6% and 11.4% to 6.7%, respectively. There was significant variation in incident and prevalent fistulae use among the provinces. Adjustment for differences in patient characteristics did not change these trends. Incident catheter use was associated with a 6 times greater risk of death compared with fistula or graft use combined.

CONCLUSIONS

In Canada there has been a decrease in fistulae and grafts with a subsequent increase in catheters that is not explained by changes in patient characteristics. Vascular access use varied by province, suggesting differences in practice patterns. Because incident catheter use was associated with increased mortality, urgent measures are needed to develop strategies to decrease catheter use.

Nonrandomized comparison of coronary stenting under intravascular ultrasound guidance of direct stenting without predilation versus conventional predilation with a semi-compliant balloon versus predilation with a new scoring balloon

This study was conducted to determine the influence of lesion preparation using the AngioSculpt balloon on final stent expansion. Stent expansion remains an important predictor of restenosis and subacute thrombosis, even in the drug-eluting stent (DES) era. In these patients, the role of different predilation strategies has yet to be established. Two hundred ninety-nine consecutive de novo lesions treated with 1 >2.5-mm DES (Cypher or Taxus) under intravascular ultrasound guidance without postdilation, using 3 implantation strategies, were studied: (1) direct stenting without predilation (n = 145), (2) predilation with a conventional semi-compliant balloon (n = 117), and (3) predilation with the AngioSculpt balloon (n = 37). Stent expansion was defined as the ratio of intravascular ultrasound-measured minimum stent diameter and minimum stent area to the manufacturer's predicted stent diameter and area. These ratios were larger after AngioSculpt predilation, and a greater percentage of stents had final minimum stent areas >5.0 mm(2) (another commonly accepted criterion of adequate DES expansion). Lesion morphology, stent and lesion length, and reference vessel size did not affect DES expansion. In conclusion, in this observational, nonrandomized study, pretreatment with the AngioSculpt balloon enhanced stent expansion and minimized the difference between predicted and achieved stent dimensions.

Development and validation of a prognostic risk score for major bleeding in patients undergoing percutaneous coronary intervention via the femoral approach

AIMS

Major bleeding after percutaneous coronary intervention (PCI) is an independent risk factor for early and late mortality. We developed and validated a risk score predictive of major bleeding after PCI using the femoral approach.

METHODS AND RESULTS

Baseline clinical and procedural variables from two contemporary, multicentre, randomized PCI trials were used for risk score development (the REPLACE-2 trial, n = 6002) and validation (the REPLACE-1 trial, n = 1056). On the basis of the odds ratio, independent risk factors were assigned a weighted integer, the sum of which comprised a total risk score. Seven variables were identified as independent correlates of major bleeding (age >55 years, female gender, estimated glomerular filtration rate <60 mL/min/1.73 m(2), pre-existing anaemia, administration of low-molecular-weight heparin within 48 h pre-PCI, use of glycoprotein IIb/IIIa inhibitors, and intraaortic balloon pump use). In the development set, the risk of major bleeding varied from 1.0% in patients without risk factors to 5.4% in high-risk patients. The discriminatory power of this risk model was confirmed in the validation data set (area under the receiver operating curve = 0.62).

CONCLUSION

A simple risk score of baseline clinical and procedural variables is useful to predict the incidence of major peri-procedural bleeding after contemporary PCI using the femoral approach.

Impact of time to treatment on myocardial reperfusion and infarct size with primary percutaneous coronary intervention for acute myocardial infarction (from the EMERALD Trial)

The impact of time to treatment on outcomes after primary percutaneous coronary intervention (PCI) is controversial, and there are few data about time to treatment and infarct size. The EMERALD trial randomly assigned 501 high-risk patients with ST-elevation myocardial infarction undergoing primary PCI to stenting with or without GuardWire (Medtronic, Santa Rosa, California) distal protection. Infarct size using sestamibi imaging at 5 to 14 days and clinical outcomes were examined by time to treatment. There were no differences in outcomes between distal protection and control patients. Shorter time to reperfusion (<2 vs 2 to 3 vs >3 to 4 vs >4 hours) was associated with smaller infarct size (2% vs 9% vs 12% vs 11%, p=0.026), trends for better myocardial blush (p=0.08), and lower 6-month mortality rates (0% vs 0% vs 2.4% vs 5.3%, p=0.06). Incremental delays in reperfusion after 2 hours had little impact on infarct size. Shorter time to reperfusion impacted on infarct size in patients with anterior infarction (0% vs 17% vs 20.5% vs 30.5%, p=0.026), but not nonanterior infarction (3% vs 7% vs 7.5% vs 10%, p=0.23, p=0.022 for interaction). In conclusion, very early reperfusion with primary PCI is associated with smaller infarct size and has a much greater impact in anterior versus nonanterior infarction. Incremental delays in reperfusion after 2 hours have less effect on infarct size. These data have implications regarding the triage of patients for primary PCI.

Prognostic significance of Id-1 and its association with EGFR in renal cell cancer

AIMS

Epidermal growth factor receptor (EGFR) is suggested as one of the positive regulators in the invasive progression of renal cell cancer (RCC). Recently, Id-1 (inhibitor of differentiation or DNA binding), a helix-loop-helix transcription factor, has been identified as one of the key factors in the EGFR signalling pathway. The aim of this study was to investigate the significance of Id-1 expression in renal cell cancer and to study its relationship with EGFR.

METHODS AND RESULTS

Id-1 and EGFR expression was examined in tissue microarray (TMA) samples of 107 RCC and 32 normal kidney specimens by immunohistochemistry. Relative Id-1 and EGFR protein expression was quantified by estimating the staining intensity on a four-grade scale. We found that while negative to weak expression of Id-1 and EGFR was observed in non-malignant kidney tissues, most RCCs showed significant positive Id-1 and EGFR expression in tumour cells. In addition, Id-1 immunostaining intensity was positively associated with increased tumour staging, grading and EGFR expression.

CONCLUSION

Overexpression of Id-1 is a novel marker for advanced RCC which is positively correlated with EGFR expression. Our results suggest that Id-1 may play an important role in the development of RCC and indicate that Id-1 is a potential marker of patients with a poor prognosis.

Impact of baseline platelet count in patients undergoing primary percutaneous coronary intervention in acute myocardial infarction (from the CADILLAC trial)

Despite the well-recognized role of platelets in the pathogenesis of acute myocardial infarction (AMI) and in the vascular responses to angioplasty, the relation between platelet count and outcomes after primary percutaneous coronary intervention (PCI) in AMI is unknown. We therefore determined the effect of baseline platelet count on clinical and angiographic outcomes of patients with AMI undergoing primary PCI. In the prospective, randomized CADILLAC trial, platelet count on admission was available in 2,021 of 2,082 patients (97.0%). Angiographic results and outcomes at 30 days and 1 year were stratified by quartiles of platelet count. Median platelet count was 231 x 10(9)/L (range 38 to 709). Primary PCI angiographic success rates were independent of platelet count. The 30-day incidence of target vessel thrombosis or reocclusion increased steadily across the higher quartiles of baseline platelet count (0.2%, 0.6%, 1.0%, and 2.0%, p = 0.027). At 1 year, patients with a baseline platelet count >or=234 versus <234 x 10(9)/L had higher rates of death or reinfarction (8.9% vs 4.5%, p <0.0001), death (5.8% vs 3.1%, p = 0.002), and reinfarction (3.4% vs 1.6%, p = 0.008). By multivariable analysis, a higher baseline platelet count was the strongest predictor of 1-year death or reinfarction (hazard ratio [HR] per 10,000 increase in platelet count 1.02, 95% confidence interval [CI] 1.02 to 1.07, p <0.0001) and independently predicted reinfarction (HR 1.06, 95% CI 1.02 to 1.09, p = 0.002) and cardiac mortality (HR 1.03, 95% CI 1.00 to 1.06, p = 0.055) at 1 year. In conclusion, a higher baseline platelet count in patients with AMI is a powerful independent predictor of death and reinfarction within the first year after primary PCI.

DOPPS estimate of patient life years attributable to modifiable hemodialysis practices in Canada

We examined data from the Canadian Organ Replacement Registry, and from a special substudy of CORR, to determine whether changes have occurred in practice patterns before and after the 1999 Canadian Society of Nephrology guidelines were published. Second, we used data from the Dialysis Outcomes and Practice Patterns Study to calculate the impact of observed deviations from guideline targets and estimated potential gains in life years that might accrue if guideline targets were achieved in all Canadian hemodialysis patients. For dialysis dose and hemoglobin targets, there was a significant improvement in Canadian facility performance over time. On the other hand, vascular access care showed a worse pattern with increased catheter use. A calculation of attributable risk, which assumes causality, suggests that 49 percent of deaths could be averted if all patients currently outside the guidelines achieved them over the next five years. When expressed as an annual death rate per hundred patient years, this corresponds to a decrease from 18 to 10.1 deaths per 100 patient years. We conclude that promoting a facility-based culture of quality improvement based on achievement of guideline targets is supported by international and Canadian observational data from the DOPPS. In the future, the impact of such an approach should be assessed empirically by correlating changes in practice over time with changes in outcomes.

Intravascular ultrasound assessment of drug-eluting stent expansion

BACKGROUND

In the drug-eluting stent (DES) era, stent expansion remains an important predictor of restenosis and subacute thrombosis. Compliance charts are developed to predict final minimum stent diameter (MSD) and area (MSA). The objectives of the study were (1) to assess DES expansion by comparing intravascular ultrasound (IVUS)-measured MSD and MSA against the values predicted by compliance charts and (2) to compare each DES against its bare-metal stent (BMS) equivalent.

METHODS

We enrolled 200 patients with de novo coronary lesions treated with single, >2.5-mm Cypher (Cordis, Johnson & Johnson, Miami Lakes, FL) (sirolimus-eluting stent [SES], 133 patients) or Taxus (Boston Scientific, Natick, MA) (paclitaxel-eluting stent [PES], 67 patients) stent under IVUS guidance without another postdilation balloon. We used a comparison cohort of 65 equivalent BMS (Express 2 [Boston Scientific], 37 patients; Bx Velocity [Cordis, Johnson & Johnson], 28 patients) deployed under similar conditions.

RESULTS

The DES achieved only 75% +/- 10% of predicted MSD and 66% +/- 17% of predicted MSA; this was similar for SES and PES. Furthermore, 24% of SES and 28% of PES did not achieve a final MSA of 5 mm(2), a consistent predictor of DES failure. The SES achieved 75% +/- 10% of predicted MSA versus 75% +/- 9% for Bx Velocity (P = .9). The PES achieved 79.9% +/- 14% of predicted MSA versus 79% +/- 10% for Express 2 (P = .8). Lesion morphology, arc and length of calcium, stent diameter and length, and implantation pressures did not affect expansion.

CONCLUSIONS

Compliance charts fail to predict final MSD and MSA. A considerable percentage of DES does not achieve minimum standards of stent expansion. The SES and PES achieve similar expansion to their BMS platform, indicating that the polymer coating does not affect DES expansion in vivo. However, stent expansion cannot be predicted from preintervention IVUS lesion assessment.

Usefulness of routine unfractionated heparin infusion following primary percutaneous coronary intervention for acute myocardial infarction in patients not receiving glycoprotein IIb/IIIa inhibitors

We evaluated the utility of a routine postprocedure course of unfractionated heparin after primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) in patients not receiving glycoprotein IIb/IIIa inhibitors. In the CADILLAC study, 2,082 patients with AMI who underwent primary PCI were randomized to receive stents versus percutaneous transluminal coronary angioplasty (PTCA), each with or without abciximab. In a subset of 976 patients who did not receive abciximab, we compared outcomes of patients who received postprocedural heparin (n = 758; 78%; median duration 2 days) with those who did not. In 421 patients treated with PTCA, postprocedural heparin use was associated with lower in-hospital major adverse cardiac events (MACEs; 5.3% vs 11.4%, p = 0.069), 1-year MACEs (22% vs 31%, p = 0.08), and decreased in-hospital moderate/severe bleeding (2.3% vs 8.9%, p = 0.01). By multivariate analyses, heparin use correlated with freedom from in-hospital and 1-year MACEs in patients after PTCA. In contrast, in 555 patients who underwent stenting, postprocedural heparin use was associated with increased bleeding and hospitalization costs without a decrease in early or late MACEs. In conclusion, in patients with AMI treated with coronary stenting without glycoprotein IIb/IIIa inhibitors, routine postprocedural heparin was not associated with any significant benefits and may be safely omitted. However, in a subset of patients treated with PTCA, postprocedural heparin use was independently associated with fewer in-hospital and 1-year MACEs.

Global analysis of differentially expressed genes in androgen-independent prostate cancer

Progression to androgen independent (AI) is the main cause of death in prostate cancer, and the mechanism is still unclear. By reviewing the expression profiles of 26 prostate cancer samples in a holistic view, we found a group of genes differentially expressed in AI compared with androgen-dependent groups (P-value<0.01, t-test). Focusing on apoptosis, proliferation, hormone and angiogenesis, we found a group of genes such as thioredoxin domain containing 5 , tumor necrosis factor receptor superfamily, member 10a , ribosomal protein S19 and Janus kinase 2 upregulated in AI prostate cancer, could play important roles in the transition from AD to AI and could be biomarkers of prognosis.

Impact of routine angiographic follow-up on the clinical benefits of paclitaxel-eluting stents: results from the TAXUS-IV trial

OBJECTIVES

The objectives of the study were to evaluate the effect of angiographic follow-up on revascularization rates in the TAXUS-IV trial and to determine whether the relative benefit of paclitaxel-eluting stent implantation compared with bare metal stent implantation was modified by angiographic follow-up.

BACKGROUND

Although several clinical trials have demonstrated that drug-eluting stents (DES) reduce restenosis compared with bare-metal stents (BMS), virtually all of these studies have incorporated angiographic follow-up.

METHODS

In the TAXUS-IV trial, 1,314 percutaneous coronary intervention patients were randomized to receive paclitaxel-eluting stents (PES) (n = 662) or identical-appearing BMS (n = 652). Clinical outcomes were compared, stratified by assignment to angiographic follow-up or clinical follow-up alone.

RESULTS

Compared with clinical follow-up alone, angiographic follow-up patients had a significantly higher rate of target vessel revascularization (TVR) at 1 year (adjusted hazard ratio [HR] 1.46; p = 0.04), with similar relative increases in PES and BMS patients. Because PES reduced TVR by approximately 60% regardless of type of follow-up, assignment to angiographic follow-up tended to overestimate the absolute benefit of PES relative to clinical follow-up alone. In contrast, assessment of end points immediately before the time of follow-up angiography led to substantial underestimation of the absolute benefit of PES implantation.

CONCLUSIONS

Performance of mandatory angiographic follow-up increases rates of TVR among patients receiving both BMS and PES and overestimates the absolute clinical benefits of PES relative to clinical follow-up alone. Nonetheless, PES substantially reduces TVR regardless of assignment to mandatory angiographic follow-up or not. Future studies designed to determine the true clinical benefits of DES should either forgo routine angiographic follow-up or separate the time of repeat angiography from the primary clinical end point by as long as possible.

Drug-Eluting Stents in the Treatment of Intermediate Lesions

OBJECTIVES

To address the safety and efficacy of drug-eluting stents (DES) in the treatment of intermediate lesions, we performed a pooled analysis of four randomized DES versus bare-metal stent (BMS) trials and assessed outcomes among patients with intermediate lesions.

BACKGROUND

Before the introduction of DES, intermediate coronary lesions were commonly managed based on physiologic or anatomic assessment of lesion severity. The DES may challenge this paradigm.

METHODS

The study population involved 167 of 2,478 randomized patients (6.7%) with intermediate lesions (diameter stenosis <50% [mean 44%] by quantitative coronary angiography) from the Sirolimus-coated Bx Velocity Balloon Expandable Stent in the Treatment of Patients with De Novo Coronary Artery Lesions (SIRIUS), TAXUS-IV, and the First and Second First Use to Underscore Restenosis Reduction with Everolimus (FUTURE-I and -II) trials. End points examined included early (in-hospital and 30-day) and late (1-year) major adverse cardiac events (MACE), including cardiac death, myocardial infarction (MI), target vessel revascularization (TVR), stent thrombosis, and follow-up angiographic restenosis.

RESULTS

Patients with intermediate lesions randomized to DES versus BMS had low rates of 30-day MACE (1.1% vs. 4.0% respectively; p = 0.22). At one-year follow-up, patients treated with DES versus BMS had similar rates of cardiac death (0% vs. 2.7%, respectively; p = 0.11) and MI (3.4% vs. 5.4%; p = 0.49) but markedly lower rates of TVR (3.4% vs. 20.3%; p = 0.0004), MACE (5.6% vs. 25.4%; p = 0.0003), and binary angiographic restenosis (1.8% vs. 34.0%; p < 0.0001). No patient in either group developed stent thrombosis.

CONCLUSIONS

Compared with BMS, treatment of intermediate lesions with DES appears safe and results in a marked reduction in clinical and angiographic restenosis. The efficacy of DES may require a reevaluation of current treatment paradigms for intermediate lesions.

Outcomes of patients consented but not randomized in a trial of primary percutaneous coronary intervention in acute myocardial infarction (the CADILLAC registry)

Baseline features, management, and outcomes of patients who had acute myocardial infarction (AMI) and were excluded from randomized trials of primary percutaneous coronary intervention (PCI) have not been well described. We examined the baseline features and outcomes of patients who had AMI and were excluded due to angiographic ineligibility from a randomized trial of primary PCI. The CADILLAC trial evaluated 4 primary PCI strategies in patients who had AMI without cardiogenic shock. Of 2,681 patients who consented, 599 (22.3%) were subsequently excluded from randomization due to protocol-specified angiographic findings. These patients were enrolled in a formal in-hospital registry and were treated at the discretion of attending physicians. Registry versus randomized patients were older (median age 61.9 vs 59.0 years, p = 0.002), more frequently had 3-vessel disease (52.4% vs 15.6%, p = 0.0001), and more frequently had lower left ventricular ejection fraction (45% vs 50%, p = 0.002). Registry patients were treated with PCI (n = 234), coronary artery bypass grafting (n = 136), or medically only (n = 226). In-hospital mortality rate among all patients who consented was 2.2% and was higher among registry than among randomized patients (4.0% vs 1.6%, relative risk 2.45, p = 0.001). Within the registry, covariate-adjusted risk of mortality was lower among patients who were treated by PCI compared with those who were treated medically (odds ratio 0.21, p=0.03). In conclusion, angiographic ineligibility for randomization in a large, prospective, primary PCI trial was associated with numerous high-risk demographic characteristics and higher short-term mortality. Nonetheless, the overall survival of patients who were referred for primary PCI was excellent, and performance of primary PCI versus medical therapy was associated with increased survival among excluded patients.

Impact of in-hospital acquired thrombocytopenia in patients undergoing primary angioplasty for acute myocardial infarction

Thrombocytopenia that develops after percutaneous coronary intervention (PCI) may result in hemorrhagic complications, requirement for blood product transfusions, and potentially thrombotic or ischemic complications. The incidence and prognostic significance of thrombocytopenia, in patients with acute myocardial infarction (AMI) who undergo primary PCI have not been evaluated. In the CADILLAC trial 2,082 patients who had AMI within 12 hours of onset without shock were prospectively randomized to receive balloon angioplasty with or without abciximab versus stenting with or without abciximab. Acquired thrombocytopenia, defined as a nadir platelet count <100 x 10(9)/L in patients who did not have baseline thrombocytopenia, developed in 50 of 1,975 qualifying patients (2.5%) after primary PCI. By multivariate analysis, acquired thrombocytopenia developed more frequently in patients who had non-insulin-requiring diabetes mellitus (odds ratio 3.88 [OR], p = 0.0002), previous statin administration (OR 3.28, p = 0.002), and use of abciximab (OR 2.06, p = 0.02) and less frequently in patients who had previous aspirin use (OR 0.26, p = 0.002), a higher baseline platelet count (OR 1.20, p < 0.0001), and greater body mass index (OR 0.90, p = 0.006). Patients who developed thrombocytopenia versus those who did not had higher in-hospital rates of major hemorrhagic complications (10.0% vs 2.7%, p = 0.01), greater requirement for blood transfusions (10.0% vs 3.9%, p = 0.05), longer hospital stay (median 4.8 vs 3.6 days, p = 0.008), and increased costs (median dollar 14,466 vs dollar 11,629, p = 0.001). All-cause mortality was markedly increased at 30 days (8.0% vs 1.6%, p = 0.0008) and at 1 year (10.0% vs 3.9%, p = 0.03) in patients who developed thrombocytopenia. In conclusion, thrombocytopenia that develops after primary PCI for AMI, although uncommon, is associated with increased hemorrhagic complications and decreased survival.

Low hematocrit predicts contrast-induced nephropathy after percutaneous coronary interventions

BACKGROUND

The relationship between low hematocrit and contrast-induced nephropathy has not been investigated.

METHODS

Of 6,773 consecutive patients treated with percutaneous coronary intervention, contrast-induced nephropathy (an increase of >/=25% or >/=0.5 mg/dL in preprocedure serum creatinine, at 48 hours postprocedure) occurred in 942 (13.9%) patients.

RESULTS

Rates of contrast-induced nephropathy steadily increased as baseline hematocrit quintile decreased (from 10.3% in the highest quintile to 23.3% in the lowest quintile) (chi(2) for trend, P < 0.0001). Stratification by baseline estimated glomerular filtration rate (eGFR) and baseline hematocrit showed that the rates of contrast-induced nephropathy were the highest (28.8%) in patients who had the lowest level for both baseline eGFR and hematocrit. Patients with the lowest eGFR but relatively high baseline hematocrit values had remarkably lower rates of contrast-induced nephropathy (15.8%, 12.3%, 17.1%, and 15.4% in 2nd, 3rd, 4th, and 5th quintiles of baseline hematocrit, respectively) (P < 0.0001). The rates of contrast-induced nephropathy increased with increment in change in hematocrit. Patients in the lowest quintile of baseline hematocrit with absolute hematocrit drop >5.9% had almost doubled rates of contrast-induced nephropathy compared with patients with hematocrit change <3.4% (38.1% vs. 18.8%, respectively) (P < 0.0001). By multivariate analysis, lower baseline hematocrit was an independent predictor of contrast-induced nephropathy; each 3% decrease in baseline hematocrit resulted in a significant increase in the odds of contrast-induced nephropathy in patients with and without chronic kidney disease (11% and 23%, respectively). When introduced into the multivariate model instead of baseline hematocrit, change in hematocrit also showed a significant association with contrast-induced nephropathy.

CONCLUSION

Lower hematocrit is an important risk factor for contrast-induced nephropathy. Whether correcting the hematocrit prepercutaneous coronary intervention might decrease the rates of contrast-induced nephropathy should be addressed in a prospectively designed trial.

Impact of anemia on outcomes of patients undergoing percutaneous coronary interventions

Of 6,929 consecutive patients who were treated with percutaneous coronary intervention, 1,708 (24.6%) had anemia according to criteria of the World Health Organization. Compared with patients who did not have anemia, those who did have anemia were older, more frequently women and African-American, had a smaller body mass index, and higher frequencies of cardiovascular risk factors and co-morbid conditions. Patients who had anemia compared with those who did not have anemia had significantly (p <0.0001) higher mortality rates during hospitalization (1.9% vs 0.4%) and at 1 year (12.8% vs 3.5%). After adjustment for potential confounders, baseline hematocrit remained a significant predictor of a 1-year mortality rate (hazard ratio 0.93 per 1% increase in hematocrit, 95% confidence interval 0.91 to 0.95).

Prognostic significance of cerebrovascular and peripheral arterial disease in patients having percutaneous coronary interventions

This study shows that cerebrovascular and peripheral arterial diseases frequently co-exist in patients with coronary artery disease who undergo percutaneous coronary interventions. These 2 conditions are associated with adverse in-hospital and 1-year outcomes and independently predict early and 1-year mortality.

Silencing mediator of retinoid and thyroid hormone receptors and activating signal cointegrator-2 as transcriptional coregulators of the orphan nuclear receptor Nur77

For the orphan nuclear receptor subfamily that includes Nur77 (NGFI-B), Nurr1, and NOR-1, no transcriptional coregulators have been identified thus far. In this report, we found that Ca(2+)/calmodulin-dependent protein kinase IV enhances Nur77 transactivation in cotransfections either alone or in synergy with AF2dependent coactivator ASC-2, whereas corepressor silencing mediator for retinoid and thyroid hormone receptors (SMRT) is repressive. Interestingly, Nur77 interacted with SMRT but did not directly bind ASC-2, and accordingly, the putative AF2 core domain of Nur77 did not affect the Nur77 transactivation. SMRT harbors transferable repression domains that associate with various histone deacetylases. Surprisingly, histone deacetylase inhibitor trichostatin A was unable to block the repressive effect of SMRT while dramatically stimulating the Nur77 transactivation. These results suggest that SMRT and ASC-2 are specific coregulators of Nur77 and that SMRT may dynamically compete with a putative adaptor molecule, which links ASC-2 to Nur77, for the identical binding sites within Nur77 in vivo.

Synthesis, DNA cross-linking activity, and cytotoxicity of dimeric mitomycins

Dimeric DNA cross-linking compounds have emerged as important new antitumor agents. We report the synthesis and biochemical evaluation of a select set of dimeric mitomycins in which the two mitomycin units are tethered at either the mitomycin C(7) amino or the aziridine N(1a) positions. Significantly, mitomycin C (1) itself is the prototypical bioreductive DNA cross-linking agent. DNA cross-linking experiments using a denaturing-gel-electrophoresis-based assay showed that the extent of DNA cross-linking for select dimeric mitomycins can exceed that of the parent compound, mitomycin C, and that the reaction proceeds, in part, at the two distal C(1) sites in the mitomycins. The efficiency of DNA cross-linking depended on the nature of the linker and the position of linker unit's attachment. When we compared the efficiency of DNA cross-linking for the dimeric mitomycins with their in vitro cytotoxicities in cultured human tumor cells, we observed a poor correlation. The mitomycins that gave the highest levels of DNA cross-linked adducts displayed the weakest cytotoxicities. These findings determined that the denaturing-gel-electrophoresis-based assay was a poor predictor of cytotoxic activity.

Suppression subtractive hybridization for identifying differentially expressed genes in renal cell carcinoma

OBJECTIVE

To construct a renal cell carcinoma (RCC) cDNA subtractive library using suppression subtractive hybridization.

METHODS

Polyadenylated RNA [Poly (A)+ RNA] was isolated from tissues of RCC and normal kidney, and single-strand cDNAs and double-strand cDNAs were synthesized in turn. RCC cDNAs were divided into two groups and ligated to the specific adaptors I and 2, and then hybridized with normal kidney cDNA twice with two rounds of suppression PCR. Second round PCR products were cloned to T/A plasmid vectors to set up the subtractive library. One hundred clones were randomly picked to perform enzyme digest analysis, and some underwent sequence analysis and Northern blot to identify RCC specifically expressed genes. SMART RACE procedure was operated to clone full length novel RCC specifically expressed genes.

RESULTS

A human RCC subtractive library with high subtractive efficiency was successfully set up. The amplified library contains 350 positive clones. Random analysis of 100 clones with enzyme restriction showed that 85 plasmids in the clones contained 50-400 bp inserts. Sequence analysis was performed for 10 clones. All the 10 sequences were unknown before and derived from 6 unique, novel genes among which the cDNA insert RCC18 had five copies. Northern blot analysis showed that RCC18 cDNA was highly expressed in RCC, but no signal could be detected in normal kidney. Using SMART RACE technique, we obtained the full length of the novel gene RCC18.

CONCLUSIONS

The constructed cDNA subtractive library of human RCC is a highly efficient one and lays a solid foundation for large scale screening and cloning new and specific oncogenes or tumor suppressor genes of RCC. The novel specifically expressed genes provided an important clue for studying the mechanisms of occurrence and development of RCC.

The effect of surfactant on birthweight-specific neonatal mortality rate, New York City

PURPOSE

Surfactant has been shown to cause decreased neonatal mortality rate (NMR) in randomized studies of preterm infants. It is not clear whether the introduction of surfactant caused a decrease in neonatal mortality in a community. This study explores the hypothesis that the introduction of surfactant in 1990 to 1991 explains a decrease in neonatal mortality in New York City (NYC) among infants with birthweight of 500 to 1499 g.

METHODS

For each of the 20 hospitals in New York City that began using surfactant in 1990 or 1991, we compared the NMR in the 2 years before the introduction of surfactant with the NMR in the 2 years after its introduction. Poisson regression models were fit to the death rates, adjusting for birthweight and other determinants of neonatal mortality.

RESULTS

NMR in the 20 hospitals decreased by 13.7% (from 231.3 to 199.6 neonatal deaths per 1000 live births). This decrease remained significant after adjusting for birthweight and other risk factors. Infants with birthweight 1000 to 1249 grams benefited most from the introduction of surfactant; their NMR decreased by 19.6%. After adjusting for birthweight, those born before the introduction of surfactant were 1.18 times as likely to die in the first 27 days as those born after the introduction of surfactant (95% CI 1.04, 1.33).

CONCLUSION

It appears that surfactant had a significant impact on NMR in NYC among very low birthweight babies.

Catalytic and highly efficient 1,4-addition of terminal alkynes to conjugated enones by [RuCl(2)(p-cymene)]2/pyrrolidine

[reaction: see text] A wide range of terminal alkynes was added to conjugated enones in a 1,4-fashion by a ruthenium catalyst in the presence of catalytic amounts of an amine base, and the corresponding gamma,delta-alkynyl ketones were obtained in good to excellent yields.

[Cloning and identifying of renal cell carcinoma differentially expressed genes]

OBJECTIVE

To clone and identify RCC specially expressed genes different with normal kidney tissue.

METHODS

A technique called suppression subtractive hybridization was used to construct the library which contains the differently expressing cDNAs between RCC and normal kidney. Then the RCC specially expressed genes were cloned from it.

RESULTS

Human RCC subtractive library with high subtractive efficiency was set up successfully. The amplified library contains 350 positive clones. Sequence analysis was performed in 5 clones. All of the sequences were unknown before and the cDNA inserting GYLZ-RCC18 had three copies. Northern blot analysis showed that GYLZ-RCC18 cDNA expressed highly in RCC, but there was no any signal could be detected in normal kidney. Using SMART RACE technique, we obtained the full length of novel gene of GYLZ-RCC18. We also identified that GYLZ-RCC18 family contains 3 subtype genes.

CONCLUSIONS

The highly efficient cDNA subtractive library lays a solid foundation for screening and cloning new and specific oncogenes or tumor suppressor genes of RCC. The novel differentially expressed genes provide an important clue to studying the mechanism of the occurrence and development of RCC.

[Combined retropubo-perineal radical prostatectomy and a new method of reconstructing the posterior urethra]

OBJECTIVE

To evaluate the efficacy of a new method of reconstructing the posterior urethra for the combined retropubo-perineal radical prostatectomy.

METHODS

Six cases of prostate cancer were treated by operative method mentioned previously. For the operation, the routine retropubic radical prostatectomy was carried out first and then through the perineal incision, 4-6 cm of the residual urethra was seperated, held upward and anastomosed with the bladder neck.

RESULTS

The urinary catheter was maintained for 14-28 days postoperatively on an average of 21.6 days. After 2-17 (average, 7.3) months of follow-up, 5 cases urinated smoothly and were completely dry for voiding. One case suffered from the infection of the perineal incision and dysuria after the removal of the urinary catheter and needed urethral dilatation periodically.

CONCLUSION

The new method of reconstruction of the posterior urethra for the combined retropubo-perineal radical prostatectomy makes a better operative exposure, a better mucoso-mucosa anastomosis, and reduces the tension of anastomosis. It can decrease the incidence of urinary incontinence and urethral stenosis obviously. Its long-term efficacy should be observed in more cases with longer follow-up.

Loss of heterozygosity in (LewisxF344)F1 rat urinary bladder tumors induced with N-butyl-N-(4-hydroxybutyl)nitrosamine followed by dimethylarsinic acid or sodium L-ascorbate

Dimethylarsinic acid (DMA), a main metabolite of arsenicals which are carcinogenic in man, exerts tumor-promoting activity on rat urinary bladder carcinogenesis initiated with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN). Sodium L-ascorbate (Na-AsA) is also a strong tumor promoter in this animal model. In this study, we used (LewisxF344)F, rats to compare molecular alterations in urinary bladder tumors caused by BBN followed by DMA or Na-AsA. Male, 6-week-old rats were given 0.05% BBN in their drinking water for 4 weeks, and then the rats in group 1 were maintained with no further treatment for 40 weeks. The animals of groups 2 and 3 were administered 0.01% DMA in their drinking water (group 2) or 5% Na-AsA in the powder diet (group 3) after the BBN treatment. Group 4 rats were given 0.05% BBN continuously for 36 weeks. At weeks 12, 20, 36 and 44, subgroups of rats were killed. Histopathological examination revealed promoting activity for DMA and, to a greater extent, Na-AsA on urinary bladder carcinogenesis. Loss of heterozygosity (LOH), detected with the polymerase chain reaction using 36 microsatellite markers, was found to be present in 2 of 9 (22%) urinary bladder tumors after treatment with DMA and 3 of 22 (14%) induced by continuous administration with BBN. No LOH was, however, detected in urinary bladder tumors after treatment with Na-AsA. The results thus suggest that the mechanisms of action of these two promoters, DMA and Na-AsA, may differ in rat urinary bladder carcinogenesis.

[The effect of combined endocrine therapy on prostate and testis]

OBJECTIVE

To study the pathological changes of the effect of combined endocrine therapy on normal prostate, benign prostatic hyperplasia, prostatic adenocarcinoma and testis.

METHODS

11 radical prostatectomy specimens, 3 core-needle biopsies of prostate and 3 testes obtained after at least 3 months of enatone-flutamide inhibition therapy were studied. Step-section was performed on radical specimens and average 16 sections per case were reviewed. PSA, PSAP and AE1/AE3 were immunostained on 14 cases of prostate cancer and a comparative study pre- and post-treatment was made.

RESULTS

No residual tumor was recognized in 2 cases. Such characteristic changes were found in 9 cases as prominent acinar atrophy, decreased ratio of acini to stroma, stromal fibrosis, squamous metaplasia of carcinoma, cytoplasmic vaculation, nuclear shrinkage, and nucleolar shrinkage. No apparent change was discovered in 3 cases. Secretory epithelial atrophy and basal cell hyperplasia were the popular change in BPH and normal prostate. The expressions of both PSA and PSAP were markedly reduced in prostate carcinoma and nonneoplastic glands. Pathological downstaging of the tumor was not found statistically. Epithelial atrophy also existed in seminal vesicles and Leydig cells of the testes after hormone therapy.

CONCLUSIONS

Combined endocrine therapy results in histologically distinctive changes that can be found in both nonneoplastic and neoplastic prostate tissue. However, the drugs can not eradicate prostate cancer completely. Testis atrophy is the direct action of the therapy.

Breast-feeding initiation in New York City, 1979 to 1996

OBJECTIVES

The purpose of this study was to explore changes in breast-feeding initiation from 1979 to 1996 among infants born in New York City hospitals.

METHODS

All New York City hospitals were surveyed every 2 years. Hospital staff reported feeding method at newborn discharge.

RESULTS

New York City breast-feeding initiation rates increased consistently from 1979 to 1996 (from 29% to 58%, P < .0001), including 1984 to 1990, when rates decreased nationally.

CONCLUSIONS

A 1984 New York State regulation requiring each hospital to designate a lactation coordinator may have been associated with the continuing increases in breast-feeding initiation.

Decrease in infant mortality in New York City after 1989

OBJECTIVES

This study identified factors contributing to the rapid decline in infant mortality in New York City from 1989 to 1992.

METHODS

Changes in birthweight distributions and in birthweight/age-, cause-, and birthweight/age/cause-specific mortality rates from 1988/89 (before the mortality reduction) to 1990/91 were identified from New York City vital statistics data.

RESULTS

Infant, neonatal, and postneonatal mortality of very-low-birthweight (< 1500 g) and normal-birthweight infants decreased significantly. The declines were almost entirely due to decreases in birthweight-specific mortality rates, rather than increased birthweights. All races experienced most of these reductions. Mortality decreased significantly for 6 causes of death. These decreases were consistent with the birthweight/age groups experiencing mortality declines.

CONCLUSIONS

Widespread, multiple perinatal and postnatal factors contributed to the decline in infant mortality.

[The use of laparoscopy in urology: report of 141 cases]

OBJECTIVE

To modify laparoscopy in urology.

METHOD

From May 1992 to Nov. 1996, 141 patients (110 males and 31 females) were subjected to laparoscopy in the treatment of urological diseases. The age of the patients ranged from 9 to 76 years (mean 39 years). Five patients had nephrectomy, 12 adrenalectomy, 48 renal cyst resection, 61 high ligation of internal spermatic vein, 5 pelvic staging lymphadenectomy, 9 orchiectomy, and 1 removal of bladder diverticulum.

RESULT

The rate of successful operation was 95.7% and that of complications was 2.22%. The mean hospitalization was 4.9 +/- 4.1 days.

CONCLUSION

Laparoscopy can be used widely in clinical practice.