Ordering an echocardiogram for evaluation of left ventricular function: level of expertise necessary for efficient use

This prospective study was performed to test the hypothesis that the yield of 2-dimensional echocardiography (2DE) would be higher when it is ordered by a cardiologist than by a noncardiologist. Patients referred for transthoracic 2DE for the evaluation of left ventricular systolic function for the 11-month period between July 10, 1995, and June 10, 1996, were included in the study. Demographic, historical, and clinical findings were recorded. Whether the patient was referred by a cardiologist versus a noncardiologist was used as the predictor variable in a binary logistic regression analysis. To address the possibility that the yield of 2DE may be higher for cardiologists because the prevalence of disease in patients referred to them may be higher (selection bias), the analysis was subjected to a propensity score adjustment. Of 2176 patients referred for 2DE during the study, 1033 were referred for the evaluation of left ventricular function. The test had a positive yield in 52% of patients for cardiologists versus 31% for noncardiologists (chi(2) = 45.5, P <.0001, odds ratio 2.4 [CI = 1. 9-3.1]). This difference remained highly significant even when propensity score risk adjustment was made (chi(2) = 54.2, P <.0001, odds ratio 2.0 [CI = 1.5-2.8]). We conclude that the yield of 2DE is higher for cardiologists compared with noncardiologists and that this result was not related to differences in patient populations examined by the two groups. Thus, more efficient use of 2DE may be achieved if patients are referred to cardiologists rather than directly sent for 2DE.

Blood glucose and platelet-dependent thrombosis in patients with coronary artery disease

OBJECTIVES

To investigate the influence of blood glucose on platelet-dependent thrombosis (PDT).

BACKGROUND

Elevated blood glucose is a predictor of adverse cardiovascular risk independent of a diagnosis of diabetes, possibly due to adverse effects promoting thrombosis. The effects of blood glucose on PDT have not been characterized.

METHODS

An ex vivo extracorporeal perfusion protocol was used to measure PDT in 42 patients with stable coronary artery disease (CAD). The Badimon chamber was perfused with unanticoagulated venous blood and PDT evaluated using computerized morphometry. Whole blood impedance aggregometry and flow cytometry evaluated platelet aggregation and P-selectin expression, respectively.

RESULTS

Using a multivariate stepwise regression model, blood glucose was the best independent predictor of PDT (R2 = 0.19, p < 0.008), followed by apolipoprotein B (R2 = 0.18, p = 0.002) and intracellular magnesium levels (R2 = 0.12, p = 0.02). Platelet-dependent thrombosis was significantly greater in patients with blood glucose >, compared with <, the median value of 4.9 mmol/l (159 +/- 141 vs. 67 +/- 69 microm2/mm, p < 0.01). Neither platelet aggregation nor P-selectin expression was significantly different between the two groups. Insulin levels correlated with blood glucose (r = 0.56, p = 0.0003), but were not independently associated with either PDT, platelet aggregation or P-selectin expression. A two-way analysis of variance demonstrated an interaction between insulin (>126 pmol/l) and blood glucose (>4.9 mmol/l) in modulating PDT (F [1,38] = 8.5, p < 0.006).

CONCLUSIONS

Blood glucose is an independent predictor of PDT in stable CAD patients. The relationship is evident even in the range of blood glucose levels considered normal, indicating that the risk associated with blood glucose may be continuous and graded. These findings suggest that the increased CAD risk associated with elevated blood glucose may be, in part, related to enhanced platelet-mediated thrombogenesis.

Genetic definition and sequence analysis of Arabidopsis centromeres

High-precision genetic mapping was used to define the regions that contain centromere functions on each natural chromosome in Arabidopsis thaliana. These regions exhibited dramatic recombinational repression and contained complex DNA surrounding large arrays of 180-base pair repeats. Unexpectedly, the DNA within the centromeres was not merely structural but also encoded several expressed genes. The regions flanking the centromeres were densely populated by repetitive elements yet experienced normal levels of recombination. The genetically defined centromeres were well conserved among Arabidopsis ecotypes but displayed limited sequence homology between different chromosomes, excluding repetitive DNA. This investigation provides a platform for dissecting the role of individual sequences in centromeres in higher eukaryotes.

Sequence and analysis of chromosome 2 of the plant Arabidopsis thaliana

Arabidopsis thaliana (Arabidopsis) is unique among plant model organisms in having a small genome (130-140 Mb), excellent physical and genetic maps, and little repetitive DNA. Here we report the sequence of chromosome 2 from the Columbia ecotype in two gap-free assemblies (contigs) of 3.6 and 16 megabases (Mb). The latter represents the longest published stretch of uninterrupted DNA sequence assembled from any organism to date. Chromosome 2 represents 15% of the genome and encodes 4,037 genes, 49% of which have no predicted function. Roughly 250 tandem gene duplications were found in addition to large-scale duplications of about 0.5 and 4.5 Mb between chromosomes 2 and 1 and between chromosomes 2 and 4, respectively. Sequencing of nearly 2 Mb within the genetically defined centromere revealed a low density of recognizable genes, and a high density and diverse range of vestigial and presumably inactive mobile elements. More unexpected is what appears to be a recent insertion of a continuous stretch of 75% of the mitochondrial genome into chromosome 2.

Decreased neointimal thickening after arterial wall injury in inducible nitric oxide synthase knockout mice

Mechanical injury in vivo results in the expression of the inducible form of nitric oxide synthase (iNOS) in vascular smooth muscle cells. However, the role of iNOS in modulating neointima formation after arterial wall injury is not clear. To determine whether the induction of iNOS gene expression promotes or attenuates the neointimal response to injury, we used a murine model of perivascular injury induced by placing a periadventitial collar around the carotid arteries in both wild-type and iNOS knockout mice (iNOS-KO mice). Periadventitial injury induced iNOS expression in the wild-type but not the iNOS-KO mice. Neointimal area and the intima/media ratio were significantly less in the iNOS-KO mice compared with the wild-type mice at 21 days. Injury-induced proliferation of medial cells and vascular cell adhesion molecule-1 expression were also attenuated in iNOS-KO mice compared with wild-type mice. The induction of iNOS and the activation of the nuclear factor-kappaB-mediated pathway were also demonstrated in an in vitro injury model. We conclude that mechanical injury in vivo and in vitro induces iNOS expression and that lack of iNOS expression attenuates neointima formation after perivascular arterial injury. Taken together, these findings suggest that iNOS expression after vascular injury may promote neointima formation.

Acute transverse myelitis: MR characteristics

Magnetic resonance imaging findings in 13 patients with acute transverse myelitis are reviewed. In 12 cases centrally located high intensity signal extending over few spinal segments was noted. The lesion occupied more than two thirds of the cord's cross-sectional area in 8 patients. Central dot sign was noted in 7 patients. Variable cord enlargement was seen in 5 patients. Contrast study in one patient showed peripheral enhancement. The MR characteristics that help in differentiating transverse myelitis from spinal form of multiple sclerosis are discussed.

Pyomyositis - clinical and MRI characteristics report of three cases

We report three patients with pyomyositis due to Staphylococcus aureus. Magnetic resonance imaging aided in the accurate diagnosis of the infection and of the extent of involvement. Incision, drainage and antibiotic therapy eradicated the infection in all the patients. We suggest clinical or subclinical bacteraemic seeding of the diseased muscle, as the most likely mechanism for pyomyositis.

Role of capillaries in determining CBF reserve: new insights using myocardial contrast echocardiography

To define the role of capillaries in the control of coronary blood flow (CBF) reserve, we developed a model of the coronary circulation and evaluated experimental data in its context. Our model comprised three compartments connected in series (arterial, capillary, and venous), each with its own resistance. The resistance in each vascular compartment was derived from the model based on hemodynamic data obtained in nine dogs during baseline and stenosis, both at rest and during hyperemia. The capillary hydrostatic pressure was assumed to be constant in all stages. Although in the absence of stenosis, the contribution of capillaries to total myocardial vascular resistance was only 25 +/- 5% at rest, it increased to 75 +/- 14% during hyperemia, despite the total myocardial vascular resistance decreasing by 51 +/- 13%. In the presence of a noncritical stenosis, total myocardial vascular resistance decreased by 22 +/- 10% at rest, with no change in capillary resistance. During hyperemia, total myocardial vascular resistance increased by 58 +/- 50% in the presence of the noncritical stenosis. In this situation, because arteriolar and venular resistances were already minimal, the increase in myocardial vascular resistance was due to increased capillary resistance, making it the predominant source (84 +/- 8%) of total myocardial vascular resistance. Myocardial video intensity (VI) on myocardial contrast echocardiography (MCE), which reflects capillary blood volume, decreased distal to the stenosis during hyperemia. In the presence of a flow-limiting stenosis at rest, myocardial VI also decreased, indicating that decrease in CBF was associated with an increase in capillary resistance. Our findings also provide an alternative explanation for the critical coronary closing pressure. Thus, contrary to previously held notions, capillaries play a vital role in the regulation of CBF.

Evaluation of the reverse transcriptase/polymerase chain reaction for carcinoembryonic antigen for the detection of breast cancer dissemination in bone marrow and peripheral blood

This study evaluated the specificity and sensitivity of the reverse transcriptase/polymerase chain reaction (RT-PCR) for carcinoembryonic antigen (CEA) for identification of breast tumour cells in bone marrow and in peripheral blood. Using one primer set from the A2/B3 domains of CEA with five to seven mismatches to other CEA-family members allowed reproducible detection of 1 colon tumour cell and 10 breast tumour cells in 10(7) mononuclear cells. Bone marrow samples from 181 patients with breast cancer were analysed by CEA-RT-PCR; 50 of these samples were analysed in parallel by routine immunocytochemistry. CEA-mRNA-positive bone marrow cells were found in 27.6% of the patients (50/181) with breast cancer. Five immunocytochemistry-positive samples were negative when analysed by CEA-RT-PCR. Limiting factors in the detection of micrometastatic breast tumour cells by CEA-RT-PCR are the heterogeneity of the tumour cells and the deficient expression of CEA in some of these cells. However, CEA-RT-PCR using the specific primer could detect 1 colon tumour cell in 1 x 10(7) normal peripheral blood mononuclear cells.

Evaluating GA733-2 mRNA as a marker for the detection of micrometastatic breast cancer in peripheral blood and bone marrow

The GA733-2 gene encodes the epithelial glycoprotein 40, a homophilic cell-cell adhesion molecule, which is expressed on the surface of epithelial cells and associated with a variety of carcinomas, e.g. breast, colorectal and lung carcinomas. To test if it could serve as a tumor marker, we have analysed the expression of GA733-2 in bone marrow (BM) and peripheral blood (PB) from healthy donors, and of patients with haematological malignancies or breast cancer using reverse transcriptase-polymerase chain reaction (RT-PCR). The GA733-2 nested PCR was positive in 100% (8/8) of BM and 40% (16/40) of PB from healthy donors, in 100% (33/33) of BM from patients with breast cancer who had no evidence of distant metastases and also in BM and PB from patients with haematological malignancies. GA733-2 mRNA is not specific as a marker for the detection of breast cancer cells in BM and PB.

The safety profile and antiviral activity of the combination of stavudine, didanosine, and nelfinavir in patients with HIV infection

We assessed the safety profile, tolerability, and antiviral effect of 12 weeks of triple combination therapy with stavudine (d4T), didanosine (ddI), and nelfinavir in patients who had not previously received therapy with d4T, ddI, or a protease inhibitor. We also assessed the effect of the buffered tablet formulation of ddI on the pharmacokinetics of nelfinavir. The study had a single-arm, open-label design and enrolled patients aged > or =18 years who had HIV infection and > or =10,000 plasma HIV RNA copies/mL. Patients received the full recommended doses of oral d4T, ddI, and nelfinavir. Efficacy was assessed in terms of change from baseline in plasma HIV RNA and CD4+ cell counts, as well as in terms of the proportion of patients achieving HIV RNA levels <400 copies/mL. The first 10 patients enrolled in the study were included in a substudy to determine the effects of the buffered tablet formulation of ddI on the pharmacokinetic profile of nelfinavir. A dose of ddI was given 1 hour before nelfinavir, after which the maximum plasma concentration (Cmax), time to Cmax (Tmax), and area under the concentration-time curve (AUC) of nelfinavir were determined. A total of 22 patients entered the trial, of whom 1 (5%) had AIDS, 12 (55%) had symptomatic HIV infection, and 9 (41%) were asymptomatic. The median baseline CD4+ cell count was 315 cells/microL (range, 70-709 cells/microL), and the median plasma viral load was 4.8 log10 copies/mL (range, 4.0-5.6 log10 copies/mL). ddI had no clinically significant effects on the plasma pharmacokinetics of nelfinavir. At the end of 12 weeks of treatment, the mean (+/- SE) decrease in plasma viral load was 1.36+/-0.24 log10 copies/mL, and 8 of 16 patients (50%) achieved plasma HIV RNA levels <400 copies/mL; the mean (+/- SE) increase in CD4+ cell count was 111.4+/-31.7 cells/microL. Patients who were judged to be compliant with antiretroviral therapy (ie, who missed <7 days of all 3 study drugs during 12 weeks of treatment) experienced mean decreases in viral load exceeding 2.0 log10 copies/mL, and 6 of 7 patients achieved HIV RNA levels <400 copies/mL after 12 weeks of therapy. Although 95% of patients reported an adverse event of grade 1 or higher, only 1 patient experienced a grade 3 or 4 adverse event (maculopapular rash) related to nelfinavir. As reflected in the Cmax, Tmax, and AUC, administration of ddI 1 hour before nelfinavir did not influence the pharmacokinetic profile of the protease inhibitor. Triple drug therapy with d4T, ddI, and nelfinavir was well tolerated and associated with few clinically significant toxicities. This treatment resulted in substantial reductions in viral load and improvements in CD4+ cell count over 12 weeks.

Evidence that high-density lipoprotein cholesterol is an independent predictor of acute platelet-dependent thrombus formation

Plasma total and low-density lipoprotein (LDL) cholesterol are established risk factors for atherosclerotic vascular disease and may also contribute to a prothrombotic risk via enhanced platelet reactivity. This study examines whether high-density lipoprotein (HDL) cholesterol, which is inversely correlated with coronary artery disease, is associated with a reduced thrombogenic potential. Platelet thrombus formation was evaluated by exposing porcine aortic media placed in Badimon perfusion chambers to flowing nonanticoagulated venous blood for 5 minutes at a shear rate of 1,000 s(-1). Forty-five subjects, 23 normal (LDL 104 +/- 31, HDL 50 +/- 15 mg/dl) and 22 hypercholesterolemic (LDL 181 +/- 45, HDL 41 +/- 10 mg/dl) patients without coronary artery disease were studied. Platelet aggregation and CD62 antigen expression, and assay for circulating prothrombotic factors were also performed. In univariate analysis platelet thrombus formation correlated with weight (r = 0.33, p = 0.03), diastolic blood pressure (r = 0.39, p = 0.01), HDL cholesterol (r = -0.45, p = 0.003), total/HDL cholesterol (r = 0.43, p = 0.004) and LDL/HDL (r = 0.38, p = 0.01) ratios, and platelet CD62 expression (r = 0.41, p = 0.02). In multiple regression analysis only HDL cholesterol showed significant correlation with platelet thrombus formation (p = 0.03). Platelet aggregation and circulating prothrombotic factors did not correlate with platelet thrombus formation. A comparison between normal and hypercholesterolemic subjects revealed enhanced thrombus area (0.026 +/- 0.20 vs 0.045 +/- 0.039 mm2/mm; p = 0.04), resting CD62 expression (6 +/- 7% vs 15 +/- 10% positive platelets, p = 0.02), and platelet aggregation (16.7 +/- 5.2 vs 21.7 +/- 6.7 ohms, p = 0.04) in hypercholesterolemic subjects. Our results demonstrate that HDL cholesterol is a significant independent predictor of ex vivo platelet thrombus formation.

Inter- and intrapatient variability in etoposide kinetics with oral and intravenous drug administration

The objective of this study was to accurately determine the within- and between-patient variability in etoposide pharmacokinetics for i.v. and p.o. administered drug. Inter-and intrapatient variability in systemic etoposide exposure was measured following i.v. and p.o. drug administration using stable isotope dilution methodology. Seven patients received 50 mg of etoposide by both p.o. and i.v. routes of administration on three separate occasions 1 month apart. Etoposide plasma concentrations following p.o. and i.v. drug administration were quantitated by liquid chromatography-mass spectrometry for each route of administration. The area under the plasma etoposide concentration versus time curve, plasma etoposide clearance, and etoposide plasma half-life were calculated for each dose of drug. Kinetic measurements following i.v. and p.o. drug administration were compared. The within-patient variation in the areas under the plasma etoposide concentration versus time curves following i.v. drug administration was minimal [coefficient of variation (CV) = 9.3%]. Within-patient variability was increased 2.4-fold with oral drug administration (intrapatient CV = 22.2%). Between-patient variability was roughly three times as great as within-patient variability (interpatient i.v. CV = 28.4%; interpatient p.o. CV = 58.3%). Mean etoposide bioavailability at a dose of 50 mg was 64.6%, again with greater interpatient than intrapatient variability (34.8 versus 22.6%). Greater variation in drug toxicity is expected with p.o. compared with i.v. etoposide use. Administration of repeated doses of etoposide to the same patient should produce less variation in toxicity than between-patient dosing.

Phosphatase activity in the arterial wall after balloon injury: effect of somatostatin analog octreotide

Phosphorylation of transcription factors fos/jun dimer activator protein (AP)-1 and nuclear factor-kappaB (NF-kappaB) plays a cardinal role in vascular smooth muscle cell (SMC) response to growth stimuli. Activity of protein tyrosine (PTP) and serine/threonine phosphatases (PP2A, B, and C) regulates in balance with the activity of protein kinases the level of transcription factor phosphorylation. Somatostatin analog octreotide stimulates phosphatase activity and inhibits cell growth. We examined in rats the activity of tissue phosphatases after arterial wall injury and treatment with octreotide and its effect on AP-1 and NF-kappaB phosphorylation and arterial response to injury. The activity of PTP did not change after balloon injury. Treatment of rats with PTP stimulator octreotide increased the PTP activity by 20% +/- 18% in uninjured arteries (p = 0.04 compared with control) and by 49% +/- 44% compared with injured untreated rats (p = 0.017). Treatment of rats with okadaic acid, a specific phosphatase inhibitor, prevented the octreotide-induced increase in PTP activity. PP2A activity of uninjured arteries was not affected significantly with treatment with octreotide (105% +/- 21%, p = 0.57 compared with control). After balloon injury PP2A activity was significantly reduced, 54% +/- 24% of control (p = 0.001). This reduction was prevented with treatment with octreotide, activity 88% +/- 25% of control. When rats were treated with octreotide and okadaic acid, the activity of PP2A in uninjured arteries was decreased to 65% +/- 12% of control (p = 0.03) and the injury-induced reduction was preserved, activity 54% +/- 8% of control (p = 0.001). There was no change in PP2B and C activity after balloon injury. Increased phosphatase activity with octreotide was associated with stabilization of the unphosphorylated form and reduction in nuclear binding of AP-1 and NF-kappaB and was associated with reduced SMC proliferation after balloon injury. Inhibition of increased phosphatase activity with okadaic acid was associated with increased nuclear binding of AP-1 and NF-kappaB. Increased nuclear binding of AP-1 and NF-kappaB after injury was associated with increased expression of fos, jun, and p105 subunit mRNA and restored the proliferative response of SMC after balloon injury. We conclude that the activity of PP2A is decreased after arterial balloon injury which leads to increased AP-1 and NF-kappaB phosphorylation and nuclear binding and is involved in regulation of SMC proliferation. Treatment with octreotide prevented the injury-induced reduction in PP2A activity and decreased transcription factor phosphorylation and SMC proliferation. Modification of phosphatase activity is a potential regulatory mechanism of arterial wall response to injury.

Oral magnesium supplementation inhibits platelet-dependent thrombosis in patients with coronary artery disease

The use of magnesium in the treatment of acute myocardial infarction remains controversial despite preliminary experimental evidence that magnesium plays a beneficial role as a regulator of thrombosis. This study examines whether oral magnesium treatment inhibits platelet-dependent thrombosis (PDT) in patients with coronary artery disease (CAD). In a randomized prospective, double-blind, crossover, and placebo-controlled study, 42 patients with CAD (37 men, 5 women, mean age 68 +/- 9 years) on aspirin received either magnesium oxide tablets (800 to 1,200 mg/day) or placebo for 3 months (phase 1) followed by a 4-week wash-out period, and the crossover treatment for 3 months (phase 2). PDT, platelet aggregation, platelet P-selectin flow cytometry, monocyte tissue factor procoagulant activity (TF-PCA), and adhesion molecule density were assessed before and after each phase. PDT was evaluated by an ex vivo perfusion model using the Badimon chamber. Median PDT was significantly reduced by 35% in patients who received magnesium versus placebo (delta change from baseline -24 vs 26 mm2/mm; p = 0.02, respectively). There was no significant effect of magnesium treatment on platelet aggregation, P-selectin expression, monocyte TF-PCA, or adhesion molecules. Oral magnesium treatment inhibited PDT in patients with stable CAD. This effect appears to be independent of platelet aggregation or P-selectin expression, and is evident despite aspirin therapy. These findings suggest a potential mechanism whereby magnesium may beneficially alter outcomes in patients with CAD.

Membrane type 1 matrix metalloproteinase expression in human atherosclerotic plaques: evidence for activation by proinflammatory mediators

BACKGROUND

Matrix metalloproteinases (MMPs) are expressed in atherosclerotic plaques, where in their active form, they may contribute to vascular remodeling and plaque disruption. In this study, we tested the hypothesis that membrane type 1 MMP (MT1-MMP), a novel transmembrane MMP that activates pro-MMP-2 (gelatinase A), is expressed in human atherosclerotic plaques and that its expression is regulated by proinflammatory molecules.

METHODS AND RESULTS

MT1-MMP expression was examined in normal and atherosclerotic human arteries by immunocytochemistry with specific antibodies. MT1-MMP expression in human saphenous vein-derived smooth muscle cells (SMCs) maintained in tissue culture was determined under basal conditions and in response to proinflammatory molecules (interleukin [IL]-1alpha, tumor necrosis factor [TNF]-alpha, and oxidized LDL [ox-LDL]) by use of Northern blot and ribonuclease protection assays for mRNA, Western blot and immunoprecipitation for protein, and gelatin zymography for catalytic activity. Medial SMCs of normal vessel wall expressed MT1-MMP. In atherosclerotic arteries, MT1-MMP expression was noted within the complex atheroma colocalizing with SMCs and macrophages (Mphi). Cultured SMCs constitutively expressed MT1-MMP mRNA and protein, which increased 2- to 4-fold over control in a time-dependent manner within 4 to 8 hours of exposure to IL-1alpha, TNF-alpha, and ox-LDL (thiobarbituric acid-reactive substances, 13.4 nmol/mg LDL protein), whereas native LDL had no effect. Flow cytometry revealed MT1-MMP expression by human monocyte-derived Mphi, which increased 3.8-fold over baseline within 6 hours after exposure to 10 ng/mL TNF-alpha.

CONCLUSIONS

This study demonstrates that MT1-MMP, an activator of pro-MMP-2, is expressed by SMCs and Mphi in human atherosclerotic plaques. Furthermore, proinflammatory molecules upregulate MT1-MMP expression in vascular SMCs and Mphi. Thus, activation of SMCs and Mphi by proinflammatory molecules may influence extracellular matrix remodeling in atherosclerosis by regulating MT1-MMP expression.

Analysis of sensitivity and specificity of cytokeratin 19 reverse transcriptase/polymerase chain reaction for detection of occult breast cancer in bone marrow and leukapheresis products

PURPOSE

The work aimed to evaluate the sensitivity and specificity of the cytokeratin (CK) 19 reverse transcriptase/polymerase chain reaction (RT-PCR) for the detection of occult breast cancer in bone marrow and leukapheresis products.

MATERIALS AND METHODS

Peripheral blood and bone marrow samples, obtained from 96 and 8 healthy donors respectively, served as negative controls. A total of 115 bone marrow samples and 29 leukapheresis samples from routine patients with breast cancer were analysed by CK19 RT-PCR. The PCR results were compared with those from routine immunocytology for CK8, 18, 19.

RESULTS

The CK19 RT-PCR technique with primer pairs from Datta et al. (J Clin Oncol 12: 475-482, 1994), using an annealing temperature of 72 degrees C, allowed the detection of one tumour cell in 10(7) mononuclear cells. None of the control samples (96 peripheral blood and 8 bone marrow) that were positive for beta2-microglobulin by RT-PCR showed a signal for CK19. However, expression of CK19 mRNA was observed in 40.87% (70/115) of bone marrow and in 24.13% (7/29) of leukapheresis samples of patients with breast cancer. Standard immunocytology and PCR were combined for the detection of tumour cells. Five of the 65 bone marrow samples were found to be positive by CK19 RT-PCR, but were negative with the immunocytology method.

CONCLUSION

RT-PCR using CK19-specific primers and optimal experimental conditions is a reliable and specific method for the detection of micrometastatic breast cancer cells.

Impact of some ecological factors on the occurrence of poultry soil-inhabiting keratinophiles

Investigations were conducted to assess the ecological factors governing distribution and survival of keratinophilic fungi in poultry farm soils. All the poultry farm soils were rich in humus and the keratinophilic fungi were generally found to be proportional to the soil organic matter. These soils were nearly neutral to weakly alkaline and organically rich with a high content of organic carbon, nitrogen, phosphorus, potassium, magnesium, calcium and iron.

Myocardial viability on echocardiography predicts long-term survival after revascularization in patients with ischemic congestive heart failure

OBJECTIVES

This study was conducted to evaluate the effect of revascularization on survival in patients with congestive heart failure (CHF) due to ischemic left ventricular (LV) systolic dysfunction based on the presence of myocardial viability (MV).

BACKGROUND

There are insufficient data regarding the survival benefit of revascularization in patients with CHF due to ischemic LV systolic dysfunction.

METHODS

Follow-up was obtained in 87 consecutive patients with CHF due to ischemic LV systolic dysfunction (New York Heart Association [NYHA] class II-IV; LV ejection fraction <0.35) who underwent low-dose dobutamine echocardiography (DE). MV within each of 12 myocardial segments representing the LV was defined as having either: 1) normal function or mild dyssynergy at rest; 2) severe resting dyssynergy that improved on DE, or 3) worsening of function on DE except in the case of akinesia.

RESULTS

At a mean follow-up of 40+/-17 months, 37 patients had received revascularization on the basis of clinical grounds, and there were 22 (25%) cardiac-related deaths. Multivariate Cox regression analysis revealed that when patients with at least five segments showing MV underwent revascularization, mortality was reduced by an average of 93% (confidence interval of 22% to 99%), which was associated with improvement in NYHA class as well as LV ejection fraction. Patients with less than five segments showing MV who underwent revascularization (and thus, showing mostly scar), and those with at least 5 segments demonstrating MV who were treated medically, had a much higher mortality.

CONCLUSIONS

Revascularization produces a clear survival benefit in patients with CHF due to ischemic LV systolic dysfunction who have a significant region of the LV demonstrating MV. These data may have wide-ranging implications in the management of patients with coronary artery disease whose main clinical presentation is CHF.

Expression of MUC-1 epitopes on normal bone marrow: implications for the detection of micrometastatic tumor cells

PURPOSE

The expression of the carcinoma-associated mucin MUC-1 is thought to be restricted to epithelial cells and is used for micrometastatic tumor cell detection in patients with solid tumors, including those with breast cancer. Little is known, however, about the expression of MUC-1 epitopes in normal hematopoietic cells.

MATERIALS AND METHODS

MUC-1 expression was analyzed by flow cytometry and immunocytology on bone marrow (BM) mononuclear cells and purified CD34+ cells from healthy volunteers, using different anti-MUC-1-specific monoclonal antibodies. In addition, Western blotting of MUC-1 proteins was performed.

RESULTS

Surprisingly, 2% to 10% of normal human BM mononuclear cells expressed MUC-1, as defined by the anti-MUC-1 antibodies BM-2 (2E11), BM-7, 12H12, MAM-6, and HMFG-1. In contrast, two antibodies recognizing the BM-8 and the HMFG-2 epitopes of MUC-1 were not detected. MUC-1+ cells from normal BM consisted primarily of erythroblasts and normoblasts. In agreement with this, normal CD34+ cells cultured in vitro to differentiate into the erythroid lineage showed a strong MUC-1 expression on day 7 proerythroblasts. Western blotting of these cells confirmed that the reactive species is the known high molecular weight MUC-1 protein.

CONCLUSION

Our data demonstrate that some MUC-1 epitopes are expressed on normal BM cells and particularly on cells of the erythroid lineage. Hence the application of anti-MUC-1 antibodies for disseminated tumor cell detection in BM or peripheral blood progenitor cells may provide false-positive results, and only carefully evaluated anti-MUC-1 antibodies (eg, HMFG-2) might be selected. Furthermore, MUC-1-targeted immunotherapy in cancer patients might be hampered by the suppression of erythropoiesis.

Tenascin-C is expressed in macrophage-rich human coronary atherosclerotic plaque

BACKGROUND

Tenascin is a large extracellular matrix glycoprotein generally found in adult tissues undergoing active remodeling such as healing wounds and tumors. To determine the potential role of tenascin-C (TN-C) in the pathophysiology of atherosclerosis, we investigated the pattern of expression of TN-C in human coronary atherosclerotic plaques.

METHODS AND RESULTS

Immunohistochemical staining and in situ hybridization demonstrated minimal and random expression of TN-C in fibrotic but lipid-poor atherosclerotic plaques. In contrast, all plaques with an organized lipid core or ruptured intimal surface strongly expressed TN-C, which was preferentially concentrated around the lipid core, shoulder regions, and ruptured area of the plaques but not in the fibrous cap. TN-C was not detected in normal arterial tissue. To identify the cellular source of TN-C, the plaques were stained with smooth muscle cell- and macrophage-specific antibodies. TN-C expression correlated with the infiltration of macrophages. Northern blot and immunoprecipitation analysis showed that macrophages expressed 7. 0-kb TN-C mRNA and 220-kDa protein. Reverse transcription-polymerase chain reaction of total RNA derived from macrophages showed that they express the small isoform of TN-C. Zymogram analysis revealed that macrophages markedly increased MMP-9 expression.

CONCLUSIONS

This study demonstrates that the level of TN-C expression correlates with the degree of inflammation present, not with plaque size. In addition, cultured macrophages have the capacity to express the TN-C gene. These findings suggest the significance of macrophages in the remodeling of atherosclerotic plaque matrix composition.

Oxidized low-density lipoprotein regulates matrix metalloproteinase-9 and its tissue inhibitor in human monocyte-derived macrophages

BACKGROUND

Macrophages in human atherosclerotic plaques produce a family of matrix metalloproteinases (MMPs), which may influence vascular remodeling and plaque disruption. Because oxidized LDL (ox-LDL) is implicated in many proatherogenic events, we hypothesized that ox-LDL would regulate expression of MMP-9 and tissue inhibitor of metalloproteinase-1 (TIMP-1) in monocyte-derived macrophages. MWRHOSA AND RESULTS: Mononuclear cells were isolated from normal human subjects with Ficoll-Paque density gradient centrifugation, and adherent cells were allowed to differentiate into macrophages during 7 days of culture in plastic dishes. On day 7, by use of serum-free medium, the macrophages were incubated with various concentrations of native LDL (n-LDL) and copper-oxidized LDL. Exposure to ox-LDL (10 to 50 microg/mL) increased MMP-9 mRNA expression as analyzed by Northern blot, protein expression as measured by ELISA and Western blot, and gelatinolytic activity as determined by zymography. The increase in MMP-9 expression was associated with increased nuclear binding of transcription factor NF-kappaB and AP-1 complex on electromobility shift assay. In contrast, ox-LDL (10 to 50 microg/mL) decreased TIMP-1 expression. Ox-LDL-induced increase in MMP-9 expression was abrogated by HDL (100 microg/mL). n-LDL had no significant effect on MMP-9 or TIMP-1 expression.

CONCLUSIONS

These data demonstrate that unlike n-LDL, ox-LDL upregulates MMP-9 expression while reducing TIMP-1 expression in monocyte-derived macrophages. Furthermore, HDL abrogates ox-LDL-induced MMP-9 expression. Thus, ox-LDL may contribute to macrophage-mediated matrix breakdown in the atherosclerotic plaques, thereby predisposing them to plaque disruption and/or vascular remodeling.

Stage III and oestrogen receptor negativity are associated with poor prognosis after adjuvant high-dose therapy in high-risk breast cancer

We report on the efficacy and toxicity of a sequential high-dose therapy with peripheral blood stem cell (PBSC) support in 85 patients with high-risk stage II/III breast cancer. There were 71 patients with more than nine tumour-positive axillary lymph nodes. An induction therapy of two cycles of ifosfamide (total dose, 7.5 g m(-2)) and epirubicin (120 mg m(-2)) was given, and PBSC were harvested during G-CSF-supported leucocyte recovery following the second cycle. The PBSC-supported high-dose chemotherapy consisted of two cycles of ifosfamide (total dose, 12,000 mg m(-2)), carboplatin (900 mg m(-2)) and epirubicin (180 mg m(-2)). Patients were autografted with a median number of 3.7 x 10(6) CD34+ cells kg(-1) (range, 1.9-26.5 x 10(6)) resulting in haematological reconstitution within approximately 2 weeks following high-dose therapy. The toxicity was moderate in general, and there was no treatment-related toxic death. Twenty-one patients relapsed between 3 and 30 months following the last cycle of high-dose therapy (median, 11 months). The probability of disease-free and overall survival at 4 years were 60% and 83%, respectively. According to a multivariate analysis, patients with stage II disease had a significantly better probability of disease-free survival (74%) in comparison to patients with stage III disease (36%). The probability of disease-free survival was also significantly better for patients with oestrogen receptor-positive tumours (70%) compared to patients with receptor-negative ones (40%). Bone marrow samples collected from 52 patients after high-dose therapy were examined to evaluate the prognostic relevance of isolated tumour cells. The proportion of patients presenting with tumour cell-positive samples did not change in comparison to that observed before high-dose therapy (65% vs 71%), but a decrease in the incidence and concentration of tumour cells was observed over time after high-dose therapy. This finding was true for patients with relapse and for those in remission, which argues against a prognostic significance of isolated tumour cells in bone marrow. In conclusion, sequential high-dose chemotherapy with PBSC support can be safely administered to patients with high-risk stage II/III breast cancer. Further intensification of the therapy, including the addition of non-cross resistant drugs or immunological approaches such as the use of antibodies against HER-2/NEU, may be envisaged for patients with stage III disease and hormone receptor-negative tumours.

A canine model of chronic ischemic cardiomyopathy: characterization of regional flow-function relations

The controversy regarding the mechanism(s) of left ventricular (LV) dysfunction in chronic coronary artery disease is, in part, related to the lack of an appropriate animal model for this condition. We have developed such a model by placing Ameroid constrictors on proximal portions of coronary arteries in dogs who were euthanized (mean of 6 wk) after the development of severe global LV dysfunction noted on two-dimensional echocardiography. The LV end-systolic size nearly doubled (P < 0.001) over the observation period, and the percent change in LV size from end diastole to end systole decreased by >50% (P < 0.001). Regional dysfunction was noted in 23 of 24 myocardial beds analyzed within regions showing no gross evidence of infarction. In 10 of these beds, severe dysfunction was noted without a decrease in radiolabeled microsphere-derived myocardial blood flow (MBF). In 13 myocardial beds, decrease in function was associated with a decrease in MBF (P < 0.001), with close coupling noted between percent wall thickening and MBF. In the beds that exhibited an ultimate decrease in MBF, the decrease in function preceded the decrease in MBF. In conclusion, we describe chronic LV dysfunction in a canine model of multivessel stenosis that closely mimics chronic ischemic LV dysfunction in humans. Whereas regional function is severely reduced in this model, MBF is varied in different segments and at different times during the observation period. These results provide new insights regarding flow-function relations in chronic ischemic LV dysfunction.