Elevated osteonectin/SPARC expression in primary prostate cancer predicts metastatic progression.

BACKGROUND: The majority of prostate cancers (CaP) are detected in early stages with uncertain prognosis. Therefore, an intensive effort is underway to define early predictive markers of CaP with aggressive progression characteristics. METHODS: In order to define such prognostic markers, we performed comparative analyses of transcriptomes of well- and poorly differentiated (PD) tumor cells from primary tumors of patients (N=40) with 78 months of mean follow-up after radical prostatectomy. Validation experiments were carried out at transcript level by quantitative real-time reverse transcriptase-PCR (RT-PCR) (N=110) and at protein level by immunohistochemistry (N=53) in primary tumors from an independent patient cohort. RESULTS: Association of a biochemical network of 12 genes with SPARC gene as a central node was highlighted with PD phenotype. Of note, there was remarkable enrichment of NKXH_NKXH_HOX composite regulatory elements in the promoter of the genes in this network suggesting a biological significance of this gene-expression regulatory mechanism in CaP progression. Further, quantitative expression analyses of SPARC mRNA in primary prostate tumor cells of 110 patients validated the association of SPARC expression with poor differentiation and higher Gleason score. Most significantly, higher SPARC protein expression at the time of prostatectomy was associated with the subsequent development of metastasis (P=0.0006, AUC=0.803). CONCLUSIONS: In summary, we propose that evaluation of SPARC in primary CaP has potential as a prognostic marker of metastatic progression.

Radio frequency transmyocardial revascularization enhances angiogenesis and causes myocardial denervation in canine model.

BACKGROUND AND OBJECTIVE: Transmyocardial revascularization (TMR) relieves angina and improves exercise tolerance in patients. Angiogenesis and myocardial denervation have been proposed as factors contributing to these benefits. To test whether radio frequency transmyocardial revascularization (RF-TMR) enhances angiogenesis and causes myocardial denervation. STUDY DESIGN/MATERIALS AND METHODS: RF-TMR channels were created in 12 dogs which survived up to 4 weeks. Bromodeoxyuridine was administered subcutaneously to mark proliferating cells as an assay of angiogenesis. Western blot analysis of tyrosine hydroxylase and blood pressure response to topical bradykinin were used as indices of myocardial denervation. RESULTS: RF-TMR increased local vascularity by an average of 50%, whereas the rate of vascular cell proliferation was tripled over that of the untreated region. Changes in mean arterial pressure with bradykinin and tyrosine hydroxylase content were significantly decreased in RF-TMR regions as compared with normal myocardium in the same hearts. CONCLUSION: RF-TMR enhances angiogenesis and causes myocardial denervation in canine myocardium as with laser TMR.

Histologic evidence that basic fibroblast growth factor enhances the angiogenic effects of transmyocardial laser revascularization.

OBJECTIVES: To determine whether addition of basic fibroblast growth factor (bFGF), an angiogenic growth factor, enhances the angiogenic effects of transmyocardial laser revascularization (TMR). BACKGROUND: TMR is an investigational therapy for treating patients with medically refractory angina not amenable to traditional therapies. Histologic and blood flow studies in animals have suggested that TMR enhances angiogenesis above that normally seen in ischemic myocardium. We tested the hypothesis that bFGF administered into TMR channels further enhance the angiogenic effects of TMR. METHODS: Chronic ischemia was created in 3 groups of dogs using an ameroid constrictor on the proximal LAD. In the bFGF group (n = 5) non-transmyocardial channels were created in the LAD territory and bFGF, (100 ng/ml) dissolved in pluronic gel was injected into the each channel. In the TMR group (n = 7), transmyocardial channels were created without bFGF. A control group (n = 7) had ischemia without TMR of bFGF. 5-bromo-2'-deoxyuridine (BrdU) was administered to mark proliferating cells. After 8 weeks survival, colored microspheres were injected to assess the regional myocardial blood flow. RESULTS: TMR and TMR+bFGF increased total vascular density by approximately 40% over that observed in the control group. However, the number of large vessels (internal diameter > or = 50 microm) was doubled by the addition of bFGF, and this correlated with a 50% increase in the density of proliferating vascular cells and a tripling of the total estimated vascular cross sectional area. Blood flow to the LAD territory was increased by TMR compared to controls, with no further benefit observed in the bFGF group. CONCLUSIONS: On a histologic basis, basic fibroblast growth factor further enhances angiogenesis following TMR in ischemic myocardium mainly by increasing the size but not the total number of vessels.

A metastasizing model of anaplastic human Wilms tumor in the nude mouse.

Reproducible animal models of Wilms tumor have been difficult to establish. We describe a model in which cells, banked from a patient with metastatic Wilms tumor, were implanted into nude mice, resulting in the development of primary renal and metastatic pulmonary lesions. Pathologically, the lesions resembled the blastemal component of anaplastic Wilms tumor. Primary tumors showed a significant propensity for growth in the kidney as opposed to other organs. Pulmonary metastases, histologically similar to the primary lesions, were regularly observed. This represents the first reproducible model of anaplastic, metastasizing human Wilms tumor. This system may prove effective for the study of factors influencing growth and angiogenesis in aggressive variants of Wilms tumor.

Angiogenesis is enhanced in ischemic canine myocardium by transmyocardial laser revascularization.

OBJECTIVES: This study sought to test whether transmyocardial laser revascularization (TMLR) stimulates angiogenesis in an animal model of chronic ischemia. BACKGROUND: TMLR relieves angina and may also improve blood flow in patients who are not candidates for traditional therapies. The mechanisms of these benefits are not fully defined. METHODS: Ischemia was created in 14 dogs by proximal left anterior descending coronary ameroid constrictors. TMLR was performed in the anterior wall (approximately 1 channel/cm2) of seven dogs; the remaining dogs served as the ischemic control group. Myocardial blood flow was measured (colored microspheres) at rest and during chemical stress (adenosine) in the acute setting and after 2 months. RESULTS: TMLR did not influence blood flow in the acute setting. After 2 months, resting blood flow increased comparably in the anterior wall in both groups to approximately 80% of normal. However, the TMLR-treated dogs demonstrated an approximately 40% increase in blood flow capacity during stress in the ischemic territory compared with untreated dogs (left anterior descending coronary artery/left circumflex coronary artery flow 0.53+/-0.16 in the control group vs. 0.73+/-0.08 in TMLR animals, p < 0.05). Vascular proliferation, assessed by bromodeoxyuridine incorporation and proliferating cell nuclear antigen positivity in endothelial and smooth muscle cells was about four times greater in the TMLR group than in the control group (p < 0.001). The density of vessels with at least one smooth muscle cell layer was approximately 1.4 times greater in the myocardium surrounding the TMLR channel remnants than in control ischemic tissue (p < 0.001). CONCLUSIONS: In this canine model of chronic ischemia, TMLR significantly enhances angiogenesis as evidenced by the increased number of vessels lined with smooth muscle cells, markedly increased vascular proliferation and increased blood flow capacity during stress.

Evidence of vascular growth associated with laser treatment of normal canine myocardium.

BACKGROUND: Transmyocardial laser revascularization is a new therapy for patients with refractory angina. Although clinical studies suggest that transmyocardial laser revascularization decreases angina and may improve regional blood flow, the underlying mechanisms are not elucidated. We hypothesized that one mechanism may relate to stimulation of vascular growth in laser-treated regions. METHODS: Transmyocardial laser revascularization channels were made with holmium:yttrium-aluminum garnet or carbon dioxide lasers in eight normal canine hearts; animals were sacrificed 2 to 3 weeks later and examined for vascular density and for evidence of smooth muscle proliferation. RESULTS: The original channels were infiltrated by granulation tissue with associated vascularity. Vascular growth was stimulated immediately surrounding the channel remnant as evidenced by an increase in the number of vessels (approximately twice that of the control region) and an increase in the number of vascular cells staining positive for markers of cellular proliferation. CONCLUSIONS: Transmyocardial laser revascularization leads to local vascular growth as early as 2 weeks after treatment. It remains to be determined whether this mechanism contributes to increased regional blood flow or to clinical benefits associated with this novel form of therapy.

The U.S. federal framework for research on endocrine disruptors and an analysis of research programs supported during fiscal year 1996.

The potential health and ecological effects of endocrine disrupting chemicals has become a high visibility environmental issue. The 1990s have witnessed a growing concern, both on the part of the scientific community and the public, that environmental chemicals may be causing widespread effects in humans and in a variety of fish and wildlife species. This growing concern led the Committee on the Environment and Natural Resources (CENR) of the National Science and Technology Council to identify the endocrine disruptor issue as a major research initiative in early 1995 and subsequently establish an ad hoc Working Group on Endocrine Disruptors. The objectives of the working group are to 1) develop a planning framework for federal research related to human and ecological health effects of endocrine disrupting chemicals; 2) conduct an inventory of ongoing federal research programs; and 3) identify research gaps and develop a coordinated interagency plan to address priority research needs. This communication summarizes the activities of the federal government in defining a common framework for planning an endocrine disruptor research program and in assessing the status of the current effort. After developing the research framework and compiling an inventory of active research projects supported by the federal government in fiscal year 1996, the CENR working group evaluated the current federal effort by comparing the ongoing activities with the research needs identified in the framework. The analysis showed that the federal government supports considerable research on human health effects, ecological effects, and exposure assessment, with a predominance of activity occurring under human health effects. The analysis also indicates that studies on reproductive development and carcinogenesis are more prevalent than studies on neurotoxicity and immunotoxicity, that mammals (mostly laboratory animals) are the main species under study, and that chlorinated dibenzodioxins and polychlorinated biphenyls are the most commonly studied chemical classes. Comparison of the inventory with the research needs should allow identification of underrepresented research areas in need of attention.

Liver metastases are enhanced in homozygous deletionally mutant ICAM-1 or LFA-1 mice.

BACKGROUND: Adhesion molecules play an integral role in tumor growth, invasion, and metastasis and have been shown to influence the immune response to malignant cells. The interaction of intercellular adhesion molecule-1 (ICAM-1) with lymphocyte function antigen-1 (LFA-1) is important for the adhesion of leukocytes, monocytes and lymphocytes to endothelial cells in vitro and in vivo. In order to explore the role of the ICAM-1/LFA-1 interaction in liver metastases, we utilized homozygous deletionally mutant (gene knockout) mice for ICAM-1 or LFA-1 which had been derived from the C57BL6/J background. MATERIALS AND METHODS: Wild-type C57BL6/J mice were used as controls. Animals were anesthetized and underwent a 1-cm midline lower abdominal incision. The ileocolic vein was identified and B16 melanoma cells (10(4)) were injected. The incisions were closed with skin clips. Two weeks following surgery, mice were sacrificed and their livers resected for gross and histological analysis. RESULTS: LFA-1 deficient mice developed 13 times the number of metastases compared to wild-type controls and ICAM-1 deficient mice developed 7 times that number [13.5 (n = 17) vs 1.0 (n = 19) and 36 (n = 10) vs 5.0 (n = 16), P values of 0.0003 and 0.0002 by Wilcoxon Rank Sum Test, respectively]: Histologically, multiple areas of inflammatory cells consisting of T-cells and macrophages were noted in wild-type mice. Only sparse inflammatory cells were noted surrounding the metastases in the null mice. CONCLUSIONS: Liver metastases of the B16 melanoma are markedly enhanced in ICAM-1 null and LFA-1 null mice. The ICAM-1/LFA-1 interaction is crucial to the immune response to liver metastases.

Histologic analysis of transmyocardial channels: comparison of CO2 and holmium:YAG lasers.

BACKGROUND: Transmyocardial laser revascularization using different lasers is being tested in the treatment of refractory angina. We conducted comparative analysis of the acute and chronic myocardial effects of these different lasers. METHODS: Transmyocardial channels were made in normal dog hearts with either a holmium:yttrium-aluminum garnet or a CO2 laser. Channels were examined histologically 6 to 24 hours, 2 to 3 weeks, and 6 weeks after creation. RESULTS: Regardless of the laser source, the channels were occluded by thrombus within 6 to 24 hours. Subsequently, organization and neovascularization of the channel region occurred. Thermoacoustic damage was initially greater with the holmium:yttrium-aluminum garnet laser, but the channel appearances were indistinguishable from those made with the CO2 laser by 6 weeks. CONCLUSIONS: Histologically, the myocardial effects of the CO2 and holmium:yttrium-aluminum garnet lasers are similar and differ predominantly in the amount of acute thermoacoustic injury. Channels are rapidly occluded by thrombus and are replaced by neovascularized collagen. This suggests that the physiologic effects of these two lasers may be similar and that mechanisms other than blood flow through chronic patent channels should be considered as contributing to the clinical benefits observed with this procedure.

Physiology, histology, and 2-week morphology of acute transmyocardial channels made with a CO2 laser.

BACKGROUND: Transmyocardial revascularization with a CO2 laser appears to improve symptoms in patients with refractory angina. However, it remains controversial as to whether blood flow through the channels is the mechanism of benefit, especially in the acute setting. METHODS AND RESULTS: Three protocols were used to test whether blood flows through transmyocardial CO2 laser revascularization channels. First, channels were made in excised, cross-perfused dog hearts (n = 5) using a CO2 laser (The Heart Laser; PLC Systems Inc, Milford, MA; 40 J/pulse) followed by ligation of the proximal left anterior descending coronary artery. Colored microspheres injected into the left ventricular chamber failed to detect any significant transmyocardial blood flow. In the second protocol (n = 4), laser channels were created in the left anterior descending artery territory, the left anterior descending artery was ligated, and the hearts were excised after 24 hours. Triphenyltetrazolium chloride staining revealed that no viable myocardium was detected around the laser channels in the ischemic myocardium. Finally, channels examined 2 weeks after creation in normal (n = 6) or ischemic (n = 4) myocardium did not maintain their original caliber but were invaded by granulation tissue, which included a large amount of smaller vascular spaces and vessels of various sizes. CONCLUSIONS: Transmyocardial laser revascularization channels made with this CO2 laser did not provide acute myocardial perfusion or preserve myocardial viability in the face of acute ischemia. Channel morphology changes dramatically within the first 2 weeks. To the degree that these findings pertain to human myocardium, the results suggest that transmyocardial blood flow may not be the mechanism of benefit of this procedure, particularly in the acute setting.

Is aprotinin indicated for reoperative valvular surgery?

BACKGROUND AND AIMS OF THE STUDY: While the hemostatic effect of aprotinin for patients undergoing reoperative coronary bypass is well established, it remains unclear whether these effects extend to patients undergoing reoperative valvular surgery. METHODS: We examined our experience with 85 consecutive patients undergoing isolated reoperative valvular surgery with and without use of perioperative aprotinin in order to investigate differences in perioperative blood use, blood loss, bleeding complications, mortality and incidence of myocardial injury. RESULTS: Aprotinin recipients benefited from a significant reduction in bleeding complications, and a decrease in perioperative and in-hospital mortalities as compared with untreated patients. Anaphylactic reactions and clinically significant thromboembolic events were not observed. There was no difference in the incidence of renal dysfunction or myocardial injury among aprotinin-treated and untreated groups. CONCLUSIONS: Our results indicate that aprotinin therapy can be safely administered to patients undergoing reoperative valvular surgery. No increased incidence of anaphylactic reactions, renal dysfunction or perioperative myocardial injury was noted. The observed reductions in bleeding complications and perioperative and in-hospital mortality strongly warrant the evaluation of aprotinin for reoperative valvular surgery in a prospective fashion.

The toxicologic hazard of superfund hazardous-waste sites.

Uncontrolled hazardous-waste sites are a major environmental and public health concern in the United States and elsewhere. The remediation of and public health responses to these sites is mandated by the federal Superfund statute. Approximately 40,000 uncontrolled waste sites have been reported to U.S. federal agencies. About 1,300 of these sites constitute the current National Priorities List (NPL) of sites for remediation. Findings from a national database on NPL sites show approximately 40% present completed exposure pathways, although this figure rose to 80% in 1996. Data from 1992 through 1996 indicate that 46% of sites are a hazard to public health. Thirty substances are found at 6% or more of sites with completed pathways. Eighteen of the substances are known human carcinogens or reasonably anticipated to be carcinogenic. Many of the 30 substances also possess systemic toxicity. The high percentage of sites with completed exposure pathways and the toxicity potential of substances in these pathways show that uncontrolled hazardous-waste sites are a major environmental threat to human health. Findings from the United States' experience in responding to uncontrolled waste sites are relevant to other countries as they address similar environmental and public health concerns.

ATSDR evaluation of health effects of chemicals. IV. Polycyclic aromatic hydrocarbons (PAHs): understanding a complex problem.

Polycyclic Aromatic Hydrocarbons (PAHs) are a group of chemicals that are formed during the incomplete burning of coal, oil, gas, wood, garbage, or other organic substances, such as tobacco and charbroiled meat. There are more than 100 PAHs. PAHs generally occur as complex mixtures (for example, as part of products such as soot), not as single compounds. PAHs are found throughout the environment in the air, water, and soil. As part of its mandate, the Agency for Toxic Substances and Disease Registry (ATSDR) prepares toxicological profiles on hazardous chemicals, including PAHs (ATSDR, 1995), found at facilities on the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) National Priorities List (NPL) and which pose the most significant potential threat to human health, as determined by ATSDR and the Environmental Protection Agency (EPA). These profiles include information on health effects of chemicals from different routes and durations of exposure, their potential for exposure, regulations and advisories, and the adequacy of the existing database. Assessing the health effects of PAHs is a major challenge because environmental exposures to these chemicals are usually to complex mixtures of PAHs with other chemicals. The biological consequences of human exposure to mixtures of PAHs depend on the toxicity, carcinogenic and noncarcinogenic, of the individual components of the mixture, the types of interactions among them, and confounding factors that are not thoroughly understood. Also identified are components of exposure and health effects research needed on PAHs that will allow estimation of realistic human health risks posed by exposures to PAHs. The exposure assessment component of research should focus on (1) development of reliable analytical methods for the determination of bioavailable PAHs following ingestion, (2) estimation of bioavailable PAHs from environmental media, particularly the determination of particle-bound PAHs, (3) data on ambient levels of PAHs metabolites in tissues/fluids of control populations, and (4) the need for a critical evaluation of current levels of PAHs found in environmental media including data from hazardous waste sites. The health effects component should focus on obtaining information on (1) the health effects of mixtures of PAHs particularly their noncarcinogenic effects in humans, and (2) their toxicokinetics. This report provides excerpts from the toxicological profile of PAHs (ATSDR, 1995) that contains more detailed information.

Research needs for the risk assessment of health and environmental effects of endocrine disruptors: a report of the U.S. EPA-sponsored workshop.

The hypothesis has been put forward that humans and wildlife species adverse suffered adverse health effects after exposure to endocrine-disrupting chemicals. Reported adverse effects include declines in populations, increases in cancers, and reduced reproductive function. The U.S. Environmental Protection Agency sponsored a workshop in April 1995 to bring together interested parties in an effort to identify research gaps related to this hypothesis and to establish priorities for future research activities. Approximately 90 invited participants were organized into work groups developed around the principal reported health effects-carcinogenesis, reproductive toxicity, neurotoxicity, and immunotoxicity-as well as along the risk assessment paradigm-hazard identification, dose-response assessment, exposure assessment, and risk characterization. Attention focused on both ecological and human health effects. In general, group felt that the hypothesis warranted a concerted research effort to evaluate its validity and that research should focus primarily on effects on development of reproductive capability, on improved exposure assessment, and on the effects of mixtures. This report summarizes the discussions of the work groups and details the recommendations for additional research.

Strategic elements of ATSDR's Great Lakes Human Health Effects Research Program.

The goal of the Agency for Toxic Substances and Disease Registry's (ATSDR) Great Lakes Human Health Effects Research Program is to identify at-risk populations and to prevent potential human health effects associated with exposure to chemical contaminants in the Great Lakes basin. While this research effort is mandated by the Great Lakes Critical Programs Act of 1990, it also represents a significant opportunity to define a broader model or strategy for other regional or systems-level studies of potential health effects in at-risk populations. This article describes the strategy developed by ATSDR for this purpose in the Great Lakes Basin, as well as the program's specific research objectives and current status. It also outlines the projected implications of this research effort for greater comprehension of the potential health effects of exposure to contaminants in the Great Lakes Basin.

Histologic appearance of transmyocardial laser channels after 4 1/2 weeks.

Preliminary results of clinical studies suggest that transmyocardial laser revascularization is an effective treatment for patients with chronic angina that cannot be treated by other means. The mechanism of this effect remains controversial. We present autopsy results from a patient obtained 4 1/2 weeks after operation that show that the channels do not maintain patency. Further work is needed to determine the frequency of channel patency and its relation to clinical benefit.

Safety and efficacy of aprotinin under conditions of deep hypothermia and circulatory arrest.

Aprotinin has been successfully used to reduce blood loss and blood product requirements in patients undergoing primary and reoperative cardiac operations. Its safety and efficacy during profound hypothermia and circulatory arrest have been questioned, however. A retrospective review compared 24 patients who received aprotinin during complex aortic procedures under profound hypothermia and circulatory arrest with 24 age-matched patients undergoing similar procedures without aprotinin. Activated clotting time was maintained at longer than 500 seconds (kaolin activating agent) or longer than 750 seconds (celite). We observed no statistically significant difference in the incidence of neurologic events (p not significant) or myocardial infarctions (p not significant), and there was a trend toward reduced in-hospital mortality rate in aprotinin-treated patients. A higher incidence of postoperative renal dysfunction was encountered in aprotinin-treated patients. Aprotinin recipients had a significant reduction in requirements for postoperative homologous erythrocytes (p = 0.01). We conclude that aprotinin may be safely and effectively used in patients undergoing deep hypothermia and circulatory arrest.

Assessment of effect levels of chemicals from quantitative structure-activity relationship (QSAR) models. I. Chronic lowest-observed-adverse-effect level (LOAEL).

With the multitude of new chemicals being synthesized and the paucity of long-term test data on chemicals that could be introduced into the environment, innovative approaches must be developed to determine the health and environmental effects of chemicals. Research was conducted to employ quantitative structure-activity relationship (QSAR) techniques to study the feasibility of developing models to estimate the noncarcinogenic toxicity of chemicals that are not addressed in the literature by relevant studies. A database of lowest-observed-adverse effect level (LOAEL) was assembled by extracting toxicity information from 104 U.S. EPA documents, 124 National Cancer Institute/National Toxicology Program (NCI/NTP) reports, and 6 current reports from the literature. A regression model, based on 234 chemicals of diverse structures and chemical classes including both alicyclic and aromatic compounds, was developed to assess the chronic oral LOAELs in rats. The model was incorporated into an automated computer package. Initial testing of this model indicates it has application to a wide range of chemicals. For about 55% of the compounds in the data set, the estimated LOAELs are within a factor of 2 of the observed LOAELs. For over 93%, they are within a factor of 5. Because of the paucity or absence of long-term toxicity data, the public health and risk assessment community could utilize such QSAR models to determine initial estimates of toxicity for the ever-increasing numbers of chemicals that lack complete pertinent data. However, this and other such models should be used only by expert toxicologists who must objectively look at the estimates thus generated in light of the overall weight of evidence of the available toxicologic information of the subject chemical(s).

Public health assessment for dioxins exposure from soil.

Dioxins are among the most toxic anthropogenic chemicals in the environment. Their toxicity has been extensively studied in both humans and animals. Dioxin-contaminated soil may result in dioxins occurring in a food chain. This is especially important for the general population. It has been estimated that about 98% of exposure to dioxins is through the oral route. In the 1980s, a concentration level of 1 ppb 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in soil was specified as "a level of concern," based on cancer effects. However, recent studies indicate that end points other than cancer are also of concern. A health risk analysis scenario based on health effects of TCDD other than cancer is discussed and compared with the projected intake from 1 ppb TCDD in soil.