Abstract PD02-03: Regulation of Mammary Stem Cell Population with Dietary Intake of Soy Protein Isolate Reveals Novel Mechanisms for Diet-Mediated Control of Mammary Tumorigenesis

Breast cancer risk is highly modified by environmental factors including diet. Previously, we showed that dietary intake of soy protein isolate (SPI) decreased mammary tumor incidence and increased mammary tumor latency in rats relative to those fed a control casein (CAS) diet, when exposed to the chemical carcinogen NMU. Mammary tumor preventive effects by SPI were associated with up-regulation of the tumor suppressor PTEN and down-regulation of the oncogenic Wnt-signaling components in mammary epithelial cells (MECs) leading to enhanced differentiation. Given that breast cancer is considered to be initiated by stem cells (SCs) with tumorigenic potential, termed cancer stem cells (CSCs), and mammary over-expression of Wnt-1 in mice causes spontaneous breast tumors due to the expansion of mammary CSCs, we hypothesized that diet may alter the mammary SC population to effect mammary tumor prevention. Here, we investigated SPI effects relative to CAS, on mammary tumor development in MMTV-Wnt 1-Transgenic (Tg) female mice and on the mammary SC population in virgin wildtype (WT) and pre-neoplastic Tg female mice. Tumor incidence at 8 months of age of Tg mice fed SPI (n=30) post-weaning was lower than in those fed CAS (48.3% vs.73.5%; P<0.05) (n=34). Interestingly, tumor latency in SPI-fed Tg mice was shorter than for the CAS-fed group (4.65 vs. 5.88 months; P<0.05). Tumor weight and growth rate was similar for the diet groups. To evaluate SPI effects relative to CAS, on mammary SC population, epithelial cells from mammary tissues were isolated from WT (PND 100) and Tg (PND75) mice. The percentage of mammary SCs was quantified by fluorescence activated cell sorting analysis of MECs based on their expression of mouse mammary SC markers (CD29 and CD24) within the Lineage negative (Lin-) population (CD45-, TER119-, CD31-). The Lin-CD29hiCD24hi subpopulation in MECs was decreased by 50% in Tg mice fed SPI post-weaning relative to those fed CAS, decreasing the likelihood of mutations that convert normal to cancer SC and could explain the protective effects of SPI on tumor incidence. Interestingly, the SC population was expanded by 2-fold in MECs of WT mice fed SPI relative to the CAS group, which could be beneficial for mammary gland development and tissue homeostasis. Our findings provide the first report of dietary effects on the SC population in MECs in vivo. The dichotomy of SPI effects on tumor outcome in mammary tissues with dysregulated Wnt signaling maybe related to the loss of the complex regulatory grid between PTEN and Wnt/β-catenin pathways, both of which control stem cell fate. The possibility that diet can influence tumor progression at the level of the SC population suggests the important contribution of nutrition to the etiology of breast cancer and to the early management of breast health. Supported by USDA-ARS and Department of Defense Breast Cancer Research Program.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD02-03.

Experience of stenting for atherosclerotic renal artery stenosis in a cardiac catheterization laboratory: technical considerations and complications

BACKGROUND

Atherosclerotic renal artery (RA) stenosis contributes to hypertension, renal insufficiency and end stage renal disease, and is independently associated with adverse cardiovascular events. Percutaneous renal intervention is efficacious in treating renovascular hypertension and may be effective in stabilizing or improving renal function, thereby reducing cardiovascular risk. However, high rates of procedural complications have been reported.

OBJECTIVES

To determine the nature and frequency of complications of percutaneous renal intervention using contemporary techniques and equipment in a high-volume cardiac catheterization laboratory.

METHODS

Consecutive patients undergoing attempted RA stenting for atherosclerotic RA stenosis in the cardiac catheterization laboratory at the Vancouver General Hospital (Vancouver, British Columbia) between June 2000 and March 2007 were enrolled in a prospective registry. Baseline clinical characteristics, procedural and technical information, and complications were recorded.

RESULTS

A total of 132 RAs were stented in 106 patients during 108 procedures. The procedural success rate was 100%, with no related death, myocardial infarction, nephrectomy or dialysis. Major complications included three pseudoaneurysms (2.8%) and acute deterioration in renal function in six patients (5.5%), although renal function returned to baseline in one patient at 12 months.

CONCLUSIONS

RA stenting can be successfully and safely performed using contemporary techniques, and the low complication rates described should be the minimum standard for contemporary trials evaluating RA stenting.

Quality of life after late invasive therapy for occluded arteries

BACKGROUND

The open-artery hypothesis postulates that late opening of an infarct-related artery after myocardial infarction will improve clinical outcomes. We evaluated the quality-of-life and economic outcomes associated with the use of this strategy.

METHODS

We compared percutaneous coronary intervention (PCI) plus stenting with medical therapy alone in high-risk patients in stable condition who had a totally occluded infarct-related artery 3 to 28 days after myocardial infarction. In 951 patients (44% of those eligible), we assessed quality of life by means of a battery of tests that included two principal outcome measures, the Duke Activity Status Index (DASI) (which measures cardiac physical function on a scale from 0 to 58, with higher scores indicating better function) and the Medical Outcomes Study 36-Item Short-Form Mental Health Inventory 5 (which measures psychological well-being). Structured quality-of-life interviews were performed at baseline and at 4, 12, and 24 months. Costs of treatment were assessed for 458 of 469 patients in the United States (98%), and 2-year cost-effectiveness was estimated.

RESULTS

At 4 months, the medical-therapy group, as compared with the PCI group, had a clinically marginal decrease of 3.4 points in the DASI score (P=0.007). At 1 and 2 years, the differences were smaller. No significant differences in psychological well-being were observed. For the 469 patients in the United States, cumulative 2-year costs were approximately $7,000 higher in the PCI group (P<0.001), and the quality-adjusted survival was marginally longer in the medical-therapy group.

CONCLUSIONS

PCI was associated with a marginal advantage in cardiac physical function at 4 months but not thereafter. At 2 years, medical therapy remained significantly less expensive than routine PCI and was associated with marginally longer quality-adjusted survival. (ClinicalTrials.gov number, NCT00004562.)

Characterizing the spectrum of in-stent restenosis: implications for contemporary treatment

BACKGROUND

Reports addressing treatment of in-stent restenosis (ISR) are principally derived from clinical trials.

OBJECTIVES

To characterize the spectrum of ISR in an unselected population, and to explore clinical and angiographic factors determining management.

METHODS

During a prespecified six-month period before the introduction of drug-eluting stents, consecutive cases of ISR that were identified during clinically driven cardiac catheterization at five hospitals offering all approved treatment modalities for ISR were prospectively registered.

RESULTS

ISR was identified in 363 patients; 301 (84%) had one ISR lesion and 62 (16%) had multiple lesions. Unstable clinical presentations accounted for 51%, including 15% with ST-elevation myocardial infarction. The median interval (25th, 75th percentiles) from stent insertion to angiographic diagnosis of ISR was eight months (Q1,Q3: 4,15), with a median stented length of 18 mm (Q1,Q3: 15,28). The majority of lesions (60%) displayed a diffuse ISR pattern (Mehran types 2 and 3). ISR type was independent of time to re-presentation, diabetes, arterial territory and total stent length. Treatment included percutaneous coronary intervention (PCI) alone (n=139 [38%]), PCI with brachytherapy (n=105 [29%]), medical therapy (n=60 [17%]) and coronary artery bypass graft surgery (n=59 [16%]). Medical therapy was associated with small vessel size and recurrent ISR, and coronary artery bypass graft surgery was associated with multiple lesions, as well as diffuse, occlusive and recurrent ISR. For patients treated percutaneously, PCI treatment alone was more common for focal restenosis and after ST-elevation myocardial infarction, and brachytherapy was the more common treatment for diffuse and recurrent ISR, and stable angina.

CONCLUSIONS

These data provide a benchmark description of the spectrum of ISR with which the impact of drug-eluting stents may be compared and better understood.

A randomized controlled trial of intravenous N-acetylcysteine for the prevention of contrast-induced nephropathy after cardiac catheterization: lack of effect

BACKGROUND

Contrast-induced nephropathy (CIN) after cardiac catheterization is common in patients with preexisting renal dysfunction. Studies of oral acetylcysteine to prevent CIN have produced conflicting results. Intravenous N-acetylcysteine (NAC) has logistic advantages in this setting. The objective of this study was to evaluate, in a blinded, randomized, placebo-controlled fashion, whether intravenous NAC reduced CIN in the setting of cardiac catheterization in patients with preexisting renal insufficiency.

METHODS

Patients with renal dysfunction undergoing cardiac catheterization were randomly assigned to intravenous NAC 500 mg immediately before the procedure or placebo. All patients received isotonic saline (200 mL) beforehand, followed by 1.5 mL/kg per hour for 6 hours, unless contraindicated. Exclusion criteria included acute renal failure, creatinine >400 micromol/L, concurrent dialysis, unstable clinical status, and prior NAC use. Baseline creatinine was obtained immediately before the procedure and repeated 2 to 8 days later. The primary end point was the occurrence of CIN defined as a reduction in creatinine clearance from baseline of >5 mL/min (Cockcroft-Gault formula).

RESULTS

The study was terminated early because of a determination of futility by the Data Safety Monitoring Committee after enrollment of 487 patients. The median baseline creatinine clearance was 44 mL/min (interquartile range, 33, 55). Median contrast received was 120 mL (interquartile range, 80, 175). Baseline characteristics were similar in the two groups. Altogether, 98 (22.0%) subjects had the primary end point: 23.3% in the NAC group and 20.7% in the placebo arm (P =.57).

CONCLUSIONS

In this large, randomized trial, enrolling a high-risk group of patients with impaired renal function, intravenous NAC was ineffective in preventing CIN.

The profile of cardiac patients with renal artery stenosis

OBJECTIVES

We examined the prevalence and severity of renal artery stenosis (RAS) in patients undergoing cardiac catheterization who were deemed at risk for RAS based on clinical or laboratory criteria for study entry, but who had not previously been suspected of having RAS.

BACKGROUND

The diagnosis of atherosclerotic RAS remains problematic because its clinical manifestations are nonspecific.

METHODS

Consecutive patients undergoing non-emergent cardiac catheterization at a single institution during a 12-month period were evaluated using standardized clinical, laboratory, and angiographic criteria. Patients exhibiting at least one of four predefined selection criteria (severe hypertension, unexplained renal dysfunction, acute pulmonary edema with hypertension, or severe atherosclerosis) were prospectively registered and underwent coincident diagnostic renal angiography.

RESULTS

Renal angiography was performed in 851 patients and was diagnostic in 837. Angiographically evident renal atherosclerosis was present in 39% of the population, with RAS > or =50% in 120 (14.3%) and severe stenosis (> or =70%) in 61 (7.3%). Severe stenosis was present in 48 (7%) patients with severe atherosclerosis, 38 (16%) with renal dysfunction, 25 (9%) with hypertension, and 2 (22%) with acute pulmonary edema with hypertension. The prevalence was higher in those exhibiting multiple selection criteria. In a multivariate model, severe RAS was associated with age, female gender, reduced creatinine clearance, increased systolic blood pressure, and peripheral or carotid artery disease.

CONCLUSIONS

In a population at risk of, but not previously suspected of having RAS, severe RAS is associated with simple and readily determined clinical and laboratory patient characteristics. These data facilitate focused application of diagnostic renal angiography.

Primary stenting versus balloon angioplasty in occluded coronary arteries: the Total Occlusion Study of Canada (TOSCA)

BACKGROUND

Balloon angioplasty (PTCA) of occluded coronary arteries is limited by high rates of restenosis and reocclusion. Although stenting improves results in anatomically simple occlusions, its effect on patency and clinical outcome in a broadly selected population with occluded coronary arteries is unknown.

METHODS AND RESULTS

Eighteen centers randomized 410 patients with nonacute native coronary occlusions to PTCA or primary stenting with the heparin-coated Palmaz-Schatz stent. The primary end point, failure of sustained patency, was determined at 6-month angiography. Repeat target-vessel revascularization, adverse cardiovascular events, and angiographic restenosis (>50% diameter stenosis) constituted secondary end points. Sixty percent of patients had occlusions of >6 weeks' duration, baseline flow was TIMI grade 0 in 64%, and median treated segment length was 30.5 mm. With 95.6% angiographic follow-up, primary stenting resulted in a 44% reduction in failed patency (10.9% versus 19.5%, P=0.024) and a 45% reduction in clinically driven target-vessel revascularization at 6 months (15.4% versus 8.4%, P=0.03). The incidence of adverse cardiovascular events was similar for both strategies (PTCA, 23.6%; stent, 23.3%; P=NS). Stenting resulted in a larger mean 6-month minimum lumen dimension (1.48 versus 1.23 mm, P<0.01) and a reduced binary restenosis rate (55% versus 70%, P<0.01).

CONCLUSIONS

Primary stenting of broadly selected nonacute coronary occlusions is superior to PTCA alone, improving late patency and reducing restenosis and target-vessel revascularization.

Peri-operative hypoxaemia in children undergoing application of a plaster jacket for scoliosis

Twenty children (six female), median age 24 months (range 12-156) who presented for application of a plaster jacket for scoliosis were studied pre-operatively with pulse oximetry overnight and on the first postoperative night. Pre-operatively the median (range) arterial oxygen saturation was 97 (95-98)%, although eight children had short episodes of desaturation to < 90%. Postoperatively the median saturation was unchanged, and nine children had short episodes of desaturation. Neither the presence of episodes of desaturation pre-operatively, nor the median or lowest saturation recorded were predictors of postoperative median saturation or the presence of episodes of desaturation. Despite the presumed reduction in chest wall compliance, the application of a plaster jacket for scoliosis in these young children was not associated with a significant change in their oxygenation.

Short-term changes in tonic accommodation

Experiments were performed to determine the diurnal variation of, as well as the influence of total darkness on, tonic accommodation. In general, under both conditions trend analysis showed that variations in tonic accommodation over time were either nonsystematic in nature or could be best described by a simple linear function. Given the relatively small range of mean tonic accommodation values over time (0.5 to 1.1 D), the results demonstrate the robustness and stability of tonic accommodation under naturally occurring viewing conditions during the course of a day. In contrast, during the 2-hr period in total darkness, tonic accommodation exhibited a three-fold increase in mean range (0.6 to 2.5 D) as well as a significant increasing linear trend in some subjects, suggesting less stability of tonic accommodation in the absence of visual stimuli.

In vitro detection of heparin-induced humoral antiplatelet activity

We investigated the etiology of thrombocytopenia, with or without platelet thrombi, occurring while patients are receiving parenteral heparin. We used two in vitro methods to detect possible humoral factors in the sera of patients who became thrombocytopenic while receiving heparin. In the presence of heparin, four of four such patients' serum caused platelet aggregation. Only serum from the patient most severely affected clinically caused release of platelet factor 3 (PF3). All control sera gave negative results by both methods. We propose that platelet aggregation studies may be a sensitive and reliable method of confirming that thrombocytopenia occurring during heparin therapy is due to a humoral factor requiring the presence of heparin.

Hand injuries: incidence and epidemiology in an emergency service

During a four-month period, 1,164 patients presented to the surgical section of our Emergency Services (ES) with chief complaints involving the hand. Patient records were analyzed for several variables including demographics, diagnosis and therapeutic procedures. Lacerations were the most frequent injury, 61.5% (n=716) with deep structure injuries present in 6.1% (n=44). Of deep structure injuries, 36.4% were tendon lacerations, 27.2% were nerve injuries, and 36.4% were compound fractures. "Bites" accounted for 5.2% (37) of all lacerations, eight of which were human bites. Fractures were the second most frequent injury, (11.4%) and involved 143 separate bones. Infections were present in 7%; over half were paronychias. There were 42 (3.6%) thermal injuries.

Locomotion of bluefish

1. Pressure previously measured on the body surface of swimming bluefish were resolved into their backward vectorial components to allow calculation of profile drag. It was 0.18 kg at a speed of 1.8 m/sec. Tangential drag was calculated as if for a thin plate of an area equal to that of the fish. It was 0.08 kg at 1.8 m/sec. Net drag, 0.26 kg, was the sum of profile and tangential drag. 2. Thrust and drag also were calculated from the changes of acceleration measured during steady swimming, assuming that thrust took place only during the acceleration phase, whereas drag occurred during both acceleration and deceleration. This drag was 0.08 kg at a speed of 1.1 m/sec. It is compatible with the drag of 0.26 at 1.8 m/sec calculated from profile and tangential drag provided drag varies as the square of velocity. 3. The force required to produced maximal acceleration was measured during a scare. It was calculated to be 6.9 kg at a peak acceleration of 3 g. 4. The compression strength of th vertebrae was found to be approximately 20 kg per cm2, or roughly three times the force encountered during maximal acceleration. This safety factor of 3 would be reduced when the back was curved, or if opposing groups of muscles were under tension. 5. The finding that a bluefish can accelerate at 3 g and that the vertebral column is strongg enough to withstand this force indicates that the muscles and body structure of a bluefish would be able to withstand the force of gravity if the fish were otherwise equipped for terrestrial life. This fish may have evolved these strengths simultaneously with land animals. It is speculated that other fish may have evolved some degree of strength to overcome inertia and drag during aquatic locomotion, and this evolution may have been a prelude to terrestrial locomotion.

Pressure Distribution on the Body Surface of Swimming Fish

1. Pressures on the body surface of bluefish, swimming at 0-6 m.p.h., compared to lateral pressure, were recorded using strain-gauge manometers.

2. While in motion, the front of the fish is subject to a head-on pressure exactly equal to that calculated using the Pitot equation. In salt water, this pressure, in cm H2O, is equal to the speed, in m.p.h., divided by 0.98, all squared.

3. On the widest diameter the pressure is negative while swimming. This is attributable to the Bernoulli effect.

4. Pressure on the base of the tail is still negative, but not so negative as on the shoulder, in live swimming fish. The body and tail motion seem to draw water away from the peduncle of the tail, thereby diminishing turbulence.

5. In a dead fish the pressure at the base of the tail is positive, suggesting the possibility of boundary-layer separation and increased drag in dead fish towed through water.

6. The hydrodynamic pressures in fish swimming are often as great as the hydrostatic pressures encountered in animals of equal length subjected to gravity. We conclude that body defences against hydrodynamic pressure would also be useful against gravitational hydrostatic pressure.

7. Body structures which appear to resist hydrodynamic pressures in water and hydrostatic pressures on land are the skull, the vertebral column, and the circulatory system.

8. Transition from aquatic to terrestrial life may have been facilitated by adaptation to the pressures encountered on the body surface while swimming.