Mechanisms of HER2-induced endothelial cell retraction

BACKGROUND

HER2 overexpression imparts a metastatic advantage in breast cancer. We have shown that HER2 signaling in breast cancer cells induces adjacent endothelial cell (EC) retraction, disrupting endothelial integrity. Because endothelial integrity is dependent on the adherens junctions, we postulated that the mechanism of tumor cell-induced EC retraction involves dissociation of catenin proteins from vascular endothelial (VE) cadherin. In this study, we report a loss of VE-cadherin in tumor-associated EC. We also tested for a change of catenin dissociation from VE-cadherin by manipulating HER2 signaling in tumor cells.

METHODS

We tested confluent monolayers of human EC for downregulation of VE cadherin and dissociation of catenins from VE cadherin after exposure to breast cancer cells or conditioned media. Using immunoprecipitation, we quantitated the remaining complexed catenins to VE-cadherin in tumor-associated EC after different treatments to manipulate HER2 signaling.

RESULTS

Treatment of EC with conditioned media from MCF-7 cells expressing HER2 induced a loss of VE-cadherin expression, and time-dependent dissociation of catenins from VE cadherin. Catenin dissociation from VE-cadherin was enhanced by Heregulin beta1 (P < .05) stimulation and decreased by trastuzumab (P < .05) blockade of HER2 signaling in cancer cells. An increase in EC phosphoSrc (Tyr 416) was seen by 8 hours.

CONCLUSIONS

Our data suggest that HER2 induction of EC retraction involves both down-regulation of VE-cadherin and dissociation of catenins. HER2 signaling appears to regulate this potential metastatic mechanism. Further, Src phosphorylation suggests that this pathway may be involved in this mechanism.

NCCN Invasive Breast Cancer Clinical Practice Guidelines in Oncology

The American Cancer Society estimates that 214,640 new cases of breast cancer will be diagnosed and 41,430 will die of the disease in the United States in 2006. Breast cancer is the most common malignancy in women in the United States and is second only to lung cancer as a cause of cancer death. The incidence of breast cancer has steadily increased in the United States over the past few decades, but breast cancer mortality appears to be declining, suggesting a benefit from early detection and more effective treatment. These guidelines discuss diagnosis, treatment, and follow up for invasive breast cancer.

For the most recent version of the guidelines, please visit NCCN.org

Human Epidermal Growth Factor Receptor 2 Regulates Angiopoietin-2 Expression in Breast Cancer via AKT and Mitogen-Activated Protein Kinase Pathways

Abnormal activation of human epidermal growth factor receptor 2 (HER2; ErbB-2) in breast tumors results in increased metastasis and angiogenesis, as well as reduced survival. Here, we show that angiopoietin-2 (Ang-2) expression correlates with HER2 activity in human breast cancer cell lines. Inhibiting HER2 activity with anti-HER2 monoclonal antibody trastuzumab (Herceptin) or HER2 short interfering RNA in tumor cells down-regulates Ang-2 expression. Consistent with the important roles of AKT and mitogen-activated protein kinase in the HER2 signaling pathway, AKT and ERK mitogen-activated protein kinase (MAPK) kinase activity is necessary for Ang-2 up-regulation by HER2. Moreover, overexpression of HER2 protein up-regulates Ang-2 expression. Heregulin-beta1-induced Ang-2 up-regulation is abrogated when AKT and ERK kinase activity are blocked. Immunohistochemical analysis of HER2 and Ang-2 proteins in human breast carcinomas shows that Ang-2 expression in breast cancer correlates with HER2 expression. These studies provide evidence that the Ang-2 gene is regulated by HER2 activity in breast cancer, and propose an additional mechanism for HER2 contributing to tumor angiogenesis and metastasis.

Paget’s disease in the era of sentinel lymph node biopsy

BACKGROUND

Paget's disease of the breast is an uncommon cancer. "Breast cancer" management has evolved to include sentinel lymph node biopsy (SLNB). Our objective is to determine utilization of SLNB in the surgical algorithm of Paget's disease.

METHODS

After institutional review board approval, a database review of patients with Paget's disease was conducted. Patient demographics, tumor characteristics, treatment including use of SLNB, and survival were reviewed. Patient characteristics and outcomes were analyzed by using contingency table chi-square, pooled t tests, and log-rank tests for comparisons.

RESULTS

Fifty-four patients with Paget's disease were identified and divided into 2 cohorts (18 no SLNB and 36 SLNB). The mean age was 66 years for the no-SLNB group and 60 years for the SLNB group (P = .17). Paget's disease only was present in 33%, Paget's disease + DCIS in 41%, and Paget's disease + invasive cancer in 26%. The mean invasive tumor size was 1.62 cm in the no-SLNB group and 1.59 cm in the SLNB group (P = .96). For invasive disease, ER/PR status was similar, but Her2 was more likely to be overexpressed in SLNB (P = .04). Surgery choice ranged from "no surgery" to lumpectomy to mastectomy. Axillary staging was performed in 45 of 54 patients, with 11% in both cohorts having nodal disease. A sentinel lymph node was identified in 97% of patients. Five-year overall and disease-free survival was 100% in the no-SLNB group and 88% in the SLNB group (P = .97) and 76% in the no-SLNB group and 84% in the SLNB group (P = .88), respectively.

CONCLUSIONS

Paget's disease remains rare but should be treated similar to other "breast cancer." SLNB should be performed to evaluate the axilla when invasive disease is identified or a mastectomy is planned.

Diagnostic accuracy of mammography, clinical examination, US, and MR imaging in preoperative assessment of breast cancer

PURPOSE

To prospectively assess accuracy of mammography, clinical examination, ultrasonography (US), and magnetic resonance (MR) imaging in preoperative assessment of local extent of breast cancer.

MATERIALS AND METHODS

Institutional review board approval and informed patient consent were obtained. Results of bilateral mammography, US, and contrast-enhanced MR imaging were analyzed from 111 consecutive women with known or suspected invasive breast cancer. Results were correlated with histopathologic findings.

RESULTS

Analysis included 177 malignant foci in 121 cancerous breasts, of which 89 (50%) foci were palpable. Median size of 139 invasive foci was 18 mm (range, 2-107 mm). Mammographic sensitivity decreased from 100% in fatty breasts to 45% in extremely dense breasts. Mammographic sensitivity was highest for invasive ductal carcinoma (IDC) in 89 of 110 (81%) cases versus 10 of 29 (34%) cases of invasive lobular carcinoma (ILC) (P < .001) and 21 of 38 (55%) cases of ductal carcinoma in situ (DCIS) (P < .01). US showed higher sensitivity than did mammography for IDC, depicting 104 of 110 (94%) cases, and for ILC, depicting 25 of 29 (86%) cases (P < .01 for each). US showed higher sensitivity for invasive cancer than DCIS (18 of 38 [47%], P < .001). MR showed higher sensitivity than did mammography for all tumor types (P < .01) and higher sensitivity than did US for DCIS (P < .001), depicting 105 of 110 (95%) cases of IDC, 28 of 29 (96%) cases of ILC, and 34 of 38 (89%) cases of DCIS. In anticipation of conservation or no surgery after mammography and clinical examination in 96 breasts, additional tumor (which altered surgical approach) was present in 30. Additional tumor was depicted in 17 of 96 (18%) breasts at US and in 29 of 96 (30%) at MR, though extent was now overestimated in 12 of 96 (12%) at US and 20 of 96 (21%) at MR imaging. After combined mammography, clinical examination, and US, MR depicted additional tumor in another 12 of 96 (12%) breasts and led to overestimation of extent in another six (6%); US showed no detection benefit after MR imaging. Bilateral cancer was present in 10 of 111 (9%) patients; contralateral tumor was depicted mammographically in six and with both US and MR in an additional three. One contralateral cancer was demonstrated only clinically.

CONCLUSION

In nonfatty breasts, US and MR imaging were more sensitive than mammography for invasive cancer, but both MR imaging and US involved risk of overestimation of tumor extent. Combined mammography, clinical examination, and MR imaging were more sensitive than any other individual test or combination of tests.

Parathyroid-produced angiopoietin-2 modulates angiogenic response

BACKGROUND

Upon explant, parathyroid tissue (PTH) upregulates vascular endothelial growth factor (VEGF), a potent endothelial cell mitogen, yet PTH induces a more robust angiogenic response than VEGF alone. This implies that other angiogenic factors are also produced. We tested PTH for production and function of angiopoietin-2 (Ang-2), a protein known to modulate VEGF response.

METHODS

With use of reverse transcriptase-polymerase chain reaction and SELDI (Surface Enhanced Laser Desorption/Ionization) (Ciphergen, Freemont, Calif) technology, we tested explanted PTH for Ang-2 production and determined the time sequence of Ang-2 upregulation. With use of an in vitro rat microvessel angiogenesis assay, we determined the angiogenic response to PTH-produced Ang-2.

RESULTS

Ang-2 messenger RNA was induced within 1 hour of parathyroid explant, with a maximum level detectable at 24 hours. Ang-2 protein production was maximal at 24 hours, with elimination by 48 hours. Ang-2 supplemented gels appeared to prompt earlier angiogenic induction, whereas sequestration of Ang-2 with soluble Tie2 receptor appeared to delay angiogenic induction. Soluble Tie2 treatment did not significantly decrease cumulative microvessel length, and no significant increase in neovessel length was seen with Ang-2 supplemented gels.

CONCLUSIONS

PTH upregulates Ang-2 upon explantation, with peak protein production by 24 hours. Ang-2 appears to functionally enhance initiation of PTH-induced angiogenesis, although the ultimate neovessel length appears to be dependent on other PTH-produced factors.

Patterns of chemotherapy administration in patients with intermediate-grade non-Hodgkin's lymphoma

Records from 653 patients treated between 1991 and 1998 in the Oncology Practice Patterns Study (OPPS) were analyzed to determine contemporary chemotherapy delivery patterns in patients with intermediate-grade non-Hodgkin's lymphoma (NHL). Of the 653 patient records reviewed, 90 (14%) omitted an anthracycline or mitoxantrone (Novantrone) from primary therapy. Among patients receiving CHOP (cyclophosphamide [Cytoxan, Neosar], doxorubicin HCl, vincristine [Oncovin], prednisone) or CNOP (cyclophosphamide, mitoxantrone, vincristine, prednisone), 134 (27%) of 492 received an average relative dose intensity of less than 80% of the literature-referenced dose, due either to an inadequate planned or delivered dose. Of 181 advanced-stage patients with responsive disease, 28 (15%) failed to receive at least six treatment cycles. Overall, 283 (43%) of 653 patients potentially received suboptimal chemotherapy due either to choice of regimen or chemotherapy delivered. Patient age > or = 65 years and cardiac comorbidity appeared to have the greatest influence on a physician's decision regarding chemotherapy administration. Among the 492 patients who received CHOP or CNOP, 235 (48%) experienced a delay or reduction in chemotherapy dose (usually neutropenia-related), 100 (20%) developed mucositis, and 116 (24%) were hospitalized for febrile neutropenia. Growth factor was administered to 261 patients (53%), and its primary prophylactic use was associated with a significant reduction in the incidence of hospitalizations for febrile neutropenia in all patient subgroups receiving appropriate chemotherapeutic dose intensity (P = .02). This assessment of chemotherapy delivery to patients with intermediate-grade NHL showed significant variation from current standards. Further analysis of factors influencing chemotherapy delivery might improve therapeutic outcomes.

Delivering adjuvant chemotherapy to women with early-stage breast carcinoma: current patterns of care

BACKGROUND

Variations in practice patterns are markers for the quality of patient care in general medicine, but little is known about variation in care delivered to cancer patients. This study's purpose was to describe chemotherapy use, variations in chemotherapy delivery, and the incidence of complications in community practice settings.

METHODS

Data describing adjuvant chemotherapy for patients with early-stage breast carcinoma (ESBC) were collected from an ongoing Oncology Practice Pattern Study at 13 large managed care, academic, and community practices (1111 patients). Data collection included information about diagnoses and adjuvant chemotherapy treatments, laboratory results, supportive care, complications, and treatment modifications.

RESULTS

The median patient age was 50 years, and most patients had zero to three positive lymph nodes. Chemotherapy regimens consisting of cyclophosphamide, methotrexate, and 5-fluororacil (CMF) and of doxorubicin and cyclophosphamide (AC) accounted for 76% of the adjuvant therapies used. Overall, 30% of patients had delivered average relative dose intensities </= 85% of the referenced targets. Delivered summation dose intensities (SDIs) frequently were well below targeted SDIs. Neutropenia-related dose modifications occurred for 27.6% of patients and recurred with a 60.7% rate. AC was the regimen delivered with a dose intensity closest to the referenced target. However, patients who were treated with AC regimens and with regimens consisting of cyclophosphamide, doxorubicin, and 5-fluorouracil had significantly higher rates of chemotherapy-related complications compared with patients who were treated with CMF regimens in the most recent treatment years.

CONCLUSIONS

Adjuvant chemotherapy for patients with ESBC frequently is not administered as referenced in off-protocol community settings. Variation in the delivered SDI raises concerns about potential treatment outcomes and warrants strategies to identify patients who are at risk for complications early in therapy.

HER2 signaling--induced microvessel dismantling

BACKGROUND

The human epidermal growth factor receptor 2 protein (HER2) signaling in breast cancer imparts a metastatic advantage to the cell, likely by regulating gene expression. The HER2 signaling up-regulates angiopoietin-2 (Ang-2), which disrupts endothelial cell (EC) adherens junctions. We postulated that HER2 signaling may facilitate angioinvasion by disrupting microvessel integrity.

METHODS

Rat microvessels, embedded in collagen, were grown into capillary networks and cocultured with MCF-7 or HER2 overexpressing MCF-7 (HER) to test for microvessel breakdown. We quantitated this effect by determining the cumulative length of intact microvessels. Other experiments used Herceptin- or heregulin beta 1-pretreated MCF-7 cells to modulate HER2 signaling, or soluble Tie-2/Fc receptor fusion protein (sTie2) to sequester tumor-cell released Ang-2.

RESULTS

The MCF-7 cells induced a time-dependent loss of microvessel integrity. At 12 hours, HER cells induced a 90% reduction in cumulative length (P <.05). Pretreatment with Herceptin reduced whereas heregulin beta 1 augmented microvessel dismantling (P <.01). Sequestration of Ang-2 significantly, though not dramatically, reduced the MCF-7 cell induction of microvessel dismantling (P <.01).

CONCLUSIONS

We show that HER2 signaling in breast cancer cells leads to induction of microvessel dismantling, which may open a portal for angioinvasion. It appears that Ang-2 affects this mechanism, although other factors also function in microvessel dismantling.

The impact of age on delivered dose intensity and hospitalizations for febrile neutropenia in patients with intermediate-grade non-Hodgkin's lymphoma receiving initial CHOP chemotherapy: a risk factor analysis

The purpose of this historical case series study was to evaluate the association of age on delivered dose intensity of initial CHOP (cyclophosphamide/doxorubicin/ vincristine/prednisone) chemotherapy and the occurrence of hospitalizations for febrile neutropenia for patients with intermediate-grade non-Hodgkin's lymphoma (NHL). Findings are reported for 12 managed community and academic practices. Medical records of 930 NHL patients not enrolled on clinical trial protocols were reviewed. We reported on 577 of the study patients (62%) who received initial CHOP chemotherapy. Median age of the patients was 65.1 years. Older patients (age > or = 65 years) had more hospitalizations for febrile neutropenia (28% vs. 16%; P < 0.05) than younger patients (age, 18-64 years). In patients with advanced-stage NHL (stage III/IV), older patients received fewer cycles of CHOP (< 6 cycles, 35% vs. 22%; P < 0.05) than younger patients. Older patients were planned for lower average relative dose intensity (ARDI < or = 80%; P < 0.05) and had more heart disease and comorbid conditions (P < 0.05) than younger patients. Multiple logistic regression models showed that older patients were more likely to receive a lower dose intensity (ARDI < or = 80%; odds ratio = 2.46, 95% confidence interval [CI]: 1.62-3.72) during their first 3 cycles of therapy and to experience more hospitalizations for febrile neutropenia (odds ratio = 2.17, 95% CI: 1.43-3.30). We found the dose intensity of delivered CHOP chemotherapy for elderly patients to be less than standard CHOP therapy and the risk of hospitalizations for febrile neutropenia to be greater than in younger patients. Prospective clinical trials examining supportive care measures, such as colony-stimulating factor, for elderly NHL patients are recommended.

HER2/neu over-expression induces endothelial cell retraction

Over-expression of the HER2/neu (HER2) proto-oncogene in breast carcinoma imparts an enhanced metastatic potential. Metastasis requires escape of the tumor cell from the vasculature into subjacent tissue, a transmigration event across an endothelial cell (EC) monolayer. EC retraction has been reported to precede transmigration in several tumor metastatic models. Using intact human iliac vein EC monolayers, we tested the abilities of MCF-7 breast cancer cells and HER cells, a transfected MCF-7 line over-expressing HER2, to induce EC retraction. We further analyzed whether HER2 signaling influenced cancer cell-induced EC retraction. MCF-7 or HER cells were co-cultured onto mature EC monolayers. More HER than MCF-7 cells induced EC retraction (76 +/- 19% vs. 17 +/- 12%, p < 0.001) with resultant exposure of subendothelial matrix (6.80 +/- 2.86% vs. 0.85 +/- 0.39%, p < 0.001). Blockade of HER2 signaling using Herceptin nearly eliminated EC retraction (p < 0.01), while stimulation of HER2 using heregulin-beta1-augmented EC retraction (p < 0.05). Further, there was no difference between cell lines in either the number of cells adhered or the strength of adherence to EC under shear stress. These data suggest that HER2 signaling enhances metastasis in breast cancer cells by inducing EC retraction, a process that appears to precede endothelial transmigration.

HER2/neu over-expression induces endothelial cell retraction

Over-expression of the HER2/neu (HER2) proto-oncogene in breast carcinoma imparts an enhanced metastatic potential. Metastasis requires escape of the tumor cell from the vasculature into subjacent tissue, a transmigration event across an endothelial cell (EC) monolayer. EC retraction has been reported to precede transmigration in several tumor metastatic models. Using intact human iliac vein EC monolayers, we tested the abilities of MCF-7 breast cancer cells and HER cells, a transfected MCF-7 line over-expressing HER2, to induce EC retraction. We further analyzed whether HER2 signaling influenced cancer cell-induced EC retraction. MCF-7 or HER cells were co-cultured onto mature EC monolayers. More HER than MCF-7 cells induced EC retraction (76 +/- 19% vs. 17 +/- 12%, p < 0.001) with resultant exposure of subendothelial matrix (6.80 +/- 2.86% vs. 0.85 +/- 0.39%, p < 0.001). Blockade of HER2 signaling using Herceptin nearly eliminated EC retraction (p < 0.01), while stimulation of HER2 using heregulin-beta1-augmented EC retraction (p < 0.05). Further, there was no difference between cell lines in either the number of cells adhered or the strength of adherence to EC under shear stress. These data suggest that HER2 signaling enhances metastasis in breast cancer cells by inducing EC retraction, a process that appears to precede endothelial transmigration.

HER2/neu over-expression induces endothelial cell retraction

Over-expression of the HER2/neu (HER2) proto-oncogene in breast carcinoma imparts an enhanced metastatic potential. Metastasis requires escape of the tumor cell from the vasculature into subjacent tissue, a transmigration event across an endothelial cell (EC) monolayer. EC retraction has been reported to precede transmigration in several tumor metastatic models. Using intact human iliac vein EC monolayers, we tested the abilities of MCF-7 breast cancer cells and HER cells, a transfected MCF-7 line over-expressing HER2, to induce EC retraction. We further analyzed whether HER2 signaling influenced cancer cell-induced EC retraction. MCF-7 or HER cells were co-cultured onto mature EC monolayers. More HER than MCF-7 cells induced EC retraction (76 +/- 19% vs. 17 +/- 12%, p < 0.001) with resultant exposure of subendothelial matrix (6.80 +/- 2.86% vs. 0.85 +/- 0.39%, p < 0.001). Blockade of HER2 signaling using Herceptin nearly eliminated EC retraction (p < 0.01), while stimulation of HER2 using heregulin-beta1-augmented EC retraction (p < 0.05). Further, there was no difference between cell lines in either the number of cells adhered or the strength of adherence to EC under shear stress. These data suggest that HER2 signaling enhances metastasis in breast cancer cells by inducing EC retraction, a process that appears to precede endothelial transmigration.

Multiple ectopic parathyroid glands

Parathyroid surgery to correct primary hyperparathyroidism is successful in 80 to 97 per cent of initial explorations. Failures are often linked to inability to locate ectopic parathyroid glands. Although ectopic parathyroid glands are relatively common (15%) multiple ectopic glands are rarely reported. We describe a case of multiple ectopic parathyroid glands and the intraoperative approach to their localization and review the anatomy and embryology of ectopic parathyroid glands. A 39-year-old woman presented with fatigue, lethargy, and depression. On biochemical evaluation she was noted to be hypercalcemic and hyperparathyroid. Preoperative parathyroid localization failed to identify abnormal parathyroid glands. At exploration three of four parathyroid glands, including an adenoma, were located in ectopic positions by a meticulous and systematic dissection. A careful exploration coupled with a thorough knowledge of parathyroid anatomy and embryology will produce successful surgical correction of primary hyperparathyroidism in greater than 95 per cent of patients even in the few patients with multiple ectopic parathyroid glands.

Multiple Ectopic Parathyroid Glands

Parathyroid surgery to correct primary hyperparathyroidism is successful in 80 to 97 per cent of initial explorations. Failures are often linked to inability to locate ectopic parathyroid glands. Although ectopic parathyroid glands are relatively common (15%) multiple ectopic glands are rarely reported. We describe a case of multiple ectopic parathyroid glands and the intraoperative approach to their localization and review the anatomy and embryology of ectopic parathyroid glands. A 39-year-old woman presented with fatigue, lethargy, and depression. On biochemical evaluation she was noted to be hypercalcemic and hyperparathyroid. Preoperative parathyroid localization failed to identify abnormal parathyroid glands. At exploration three of four parathyroid glands, including an adenoma, were located in ectopic positions by a meticulous and systematic dissection. A careful exploration coupled with a thorough knowledge of parathyroid anatomy and embryology will produce successful surgical correction of primary hyperparathyroidism in greater than 95 per cent of patients even in the few patients with multiple ectopic parathyroid glands.

Parathyroid-induced angiogenesis is VEGF-dependent

BACKGROUND

Autotransplantation of parathyroid tissue after parathyroidectomy is successful at salvaging parathyroid function. The relatively high success of parathyroid transplantation is thought to be due, in part, to the ability of parathyroid tissue to induce angiogenesis and thus recruit a new vasculature. Vascular endothelial growth factor (VEGF) is a potent angiogenic factor produced by a number of tumors and hypoxic tissues. Using a 3-dimensional intact microvessel angiogenesis system, we evaluated the role of VEGF in the stimulation of angiogenesis by human parathyroid cells.

METHODS

Freshly isolated rat microvessels embedded in a 3-dimensional collagen I matrix were treated with healthy 1-mm(3) fragments of human parathyroid tissue or isolated parathyroid cells. Other gels were supplemented with VEGF(165) or FLT-1 soluble receptor fusion protein to bind VEGF. After 11 days in culture, the gels were stained with Gs-1 lectin, a marker for rat endothelium, and linear growth of the microvessels was determined by using image analysis. Parathyroid production of VEGF was determined with reverse transcriptase-polymerase chain reaction.

RESULTS

A significant increase in microvessel growth was seen in parathyroid coculture (8.4 +/- 1.0 mm) versus VEGF(165) supplemented gels (6.2 +/- 0.3 mm, P <.01). VEGF(165) significantly augmented parathyroid-stimulated angiogenesis (13.7 +/- 2.4 mm, P <.05 vs parathyroid alone). Using quantitative reverse transcriptase-polymerase chain reaction, we identified VEGF messenger RNA (mRNA) induction within 1 hour of parathyroid explant, with a 12-fold increase by 24 hours. Treatment of parathyroid cocultures with 0.2 microg/mL FLT-1 soluble receptor protein completely eliminated the parathyroid induction of angiogenesis.

CONCLUSIONS

Parathyroid tissue expresses low levels of VEGF mRNA, which is significantly upregulated on explantation. Furthermore, the increased VEGF expression is essential to drive parathyroid-induced angiogenesis in our model. However, our data suggests that other parathyroid-produced factors are involved in mediating parathyroid-induced angiogenesis.

Development of subscales from the symptoms/problems and effects of kidney disease scales of the kidney disease quality of life instrument

BACKGROUND

The Kidney Disease Quality of Life Instrument (KDQOL) was developed to provide clinicians with a comprehensive assessment of the important domains of health-related quality of life (HRQOL) for patients with end-stage renal disease who are undergoing hemodialysis.

OBJECTIVE

The purpose of this study was to develop subscales from the 55 items comprising the Symptoms/Problems and Effects of Kidney Disease scales of the KDQOL and to measure the internal consistency reliability of these subscales.

METHODS

The 55 items from the Symptoms/Problems and Effects of Kidney Disease scales were arranged into substantively meaningful clusters using an affinity mapping procedure. The resulting subscales were assessed for internal consistency reliability using data from a sample of 165 individuals with kidney disease who had completed the KDQOL.

RESULTS

Eleven multi-item subscales were identified: pain, psychological dependency, cognitive functioning, social functioning, dialysis-related symptoms, cardiopulmonary symptoms, sleep, energy, cramps, diet, and appetite. Four items (clotting or other problems with access site, high blood pressure, numbness in hands or feet, and blurred vision) were not included in any of these subscales. Internal consistency reliability estimates for the 11 subscales ranged from 0.66 to 0.92. These subscales correlated with the scales from the 36-Item Short-Form Health Survey as hypothesized (ie, corresponding pain, energy, and social functioning scales had the highest correlations). In addition, several subscales were significantly associated, as hypothesized, with other variables such as the number of disability days.

CONCLUSIONS

The results of this study further support the reliability and validity of the KDQOL. The 11 subscales identified yield more detailed information on the HRQOL of patients with kidney disease and provide a basis for specific improvements in the quality of care delivered to these patients.

HER2 regulatory control of angiopoietin-2 in breast cancer

BACKGROUND

HER2 overexpression is a marker of aggressive breast cancer. Tumors that overexpress HER2 induce endothelial cell retraction and endothelial destabilization. Because angiopoietin-2 (Ang-2) also destabilizes microvessels, we postulated that HER2 signaling upregulates Ang-2 as a mechanism of angioinvasion.

METHODS

We tested human breast cancers and breast cancer cell lines for coexpression of HER2 and Ang-2 with Northern blot, reverse transcriptase-polymerase chain reaction, and enzyme-linked immunosorbent assay. Further, we manipulated HER2 signaling with 100 ng/mL MAbHu HER2 (Herceptin; Genentech, San Francisco, Calif) and Heregulin beta1 (100 ng/mL; R&D Systems, Inc, Minneapolis, Minn) to test for HER2 regulation of Ang-2 production.

RESULTS

Three of 4 breast cancer cell lines expressed HER2 protein and Ang-2 mRNA. HER cells, a stably transfected cell line that overexpresses HER2 6-fold, showed a 430% increase in Ang-2 mRNA compared to parental MCF-7 cells. Heregulin beta1 stimulation of HER2 signaling in MCF-7 cells increased Ang-2 by 20% (P <.05). HER2 signaling blockade with 100 ng/mL Herceptin reduced Ang-2 mRNA 90% (P <.001). Five of 11 cancers expressed both HER2 and Ang-2; 2 cancers expressed only Ang-2.

CONCLUSIONS

We conclude that human breast cancers express Ang-2. HER2 signaling appears to regulate Ang-2 expression, although other signaling pathways may also regulate Ang-2. Ang-2 may be a therapeutic target in these cancers and may define which patients would benefit from Herceptin therapy.

Preoperative detection of sporadic parathyroid adenomas using technetium-99m-sestamibi: what role in clinical practice?

Preoperative localization of pathologic parathyroid glands remains controversial. Because experienced parathyroid surgeons can identify and cure parathyroid pathology in sporadic primary hyperparathyroidism in better than 95 per cent of first-time explorations, few consider preoperative localization studies cost effective in this population. However, the primary reason for failure at the initial exploration is the inability of the surgeon to identify an adenoma in a normal anatomical location. Recent reports have indicated that operative time can be reduced and initial success improved with preoperative localization of adenomas using the highly sensitive technetium-99m (Tc)-sestamibi scan. We evaluated 16 consecutive patients with sporadic primary hyperparathyroidism using a double-phase Tc-sestamibi scan with delayed images, hypothesizing that 90 per cent of adenomas would be accurately detected, and furthermore that a negative scan would predict multigland disease. Of the 16 scans, 13 showed a focal delayed washout of the tracer, constituting a positive scan. Eleven of 13 were true positive (85%), with two false positive scans (15%), both of which also had nodular thyroid disease. The three negative scans were indeed hyperplastic multigland disease, determined at exploration. The mean operative time for a bilateral exploration for the true positive cases was 109 minutes, compared to 148 minutes for a small cohort group without imaging (not significant). In conclusion, 85 per cent of adenomas can be successfully localized with the Tc-sestamibi delayed-image technique, and may decrease operative time. Additionally, a negative scan is a likely predictor of multigland disease, which allows for improved preoperative patient education and preparation for cryopreservation. These data suggest that preoperative Tc-sestamibi scanning may improve the success rate for the occasional parathyroid surgeon, and that an extended prospective trial is warranted.

Stimulation of angiogenesis by canine parathyroid tissue

BACKGROUND

Autotransplanted parathyroid tissue is capable of inducing neovascularization in vivo, restoring calcium homeostasis with regulatory control. The mechanisms of parathyroid-induced neovascularization remain to be determined. Using an unique three-dimensional in vitro model, we tested the ability of parathyroid tissue to stimulate angiogenesis.

METHODS

Healthy 1 mm3 fragments of normal canine parathyroid tissue were cocultured with freshly isolated microvessels that were embedded in a collagen I gel. After 7 days the gels were stained with Gs-1 lectin, a specific marker for rat endothelium. With image analysis the microvessel density (as the percentage of area) was determined.

RESULTS

A significant increase in mean microvessel density (20.90% +/- 1.28 versus 16.51% +/- 1.66%) was seen with parathyroid coculture compared with control (n = 17, p < 0.05). There was no difference in microvessel density between controls and microvessels exposed to increasing concentrations of parathyroid hormone or calcium. The density of seeded microvessels influenced the effect of parathyroid stimulation of angiogenesis. The effect was apparent only at low seeding densities.

CONCLUSIONS

We conclude that parathyroid tissue intrinsically stimulates angiogenesis in vitro by a secreted product, independent of calcium or parathyroid hormone.

Using the theory of reasoned action (TRA) to understand the decision to use condoms in an STD clinic population

The theory of reasoned action (TRA) provides useful information when designing health education interventions. In this study, 703 heterosexual STD clinic clients responded to a TRA-based survey. With steady partners, social norms and attitudes toward condom use were significant predictors of intention for both men and women. The interaction of attitude and norm increased prediction for men (R = .64, p < 0.001) and women (R = .70, p < 0.001). With casual partners, attitude was a predictor for men and social norm was a predictor for women. Prior use of condoms increased prediction for men (R = .38, p < 0.001) and women (R = .47, p < 0.001). Findings suggest that, in addition to traditional TRA model variables, the relationship between sexual partners and the individual's prior experience with condom use should be incorporated into attempts to understand this complex, dyadic behavior. Examining specific outcome and normative beliefs also provides important information for intervention design.

A review of health-related quality-of-life measures used in end-stage renal disease

Health-related quality of life (HRQOL) is a critical issue in the treatment of end-stage renal disease (ESRD) patients. The variety of symptoms, comorbidities, and treatments of ESRD over the course of its chronic disease trajectory necessitate comprehensive assessment of the impact of interventions on HRQOL. A literature review of ESRD HRQOL studies was performed to provide an overview of the instruments used and to provide recommendations for HRQOL assessment in future studies. Instruments were classified based on the health domains they assess and whether they are generic or disease targeted. The instruments were judged in terms of their comprehensiveness, reliability, and validity.

Characteristics of health promotion programs in Federal worksites: findings from the Federal Employee Worksite Project

PURPOSE

To describe how well-established health promotion programs at selected federal worksites were designed, organized, and implemented and to identify factors related to employee participation.

DESIGN

This descriptive study related characteristics of the health promotion program, worksites, and workforce to employee participation and perceptions of program impacts.

SETTING

The study was conducted at 10 established federal worksite health promotion programs in various regions of the country.

SUBJECTS

A total of 3403 of 5757 federal employees (59%) sampled completed employee surveys.

MEASURES

Study data were collected from on-site observations, interviews, focus groups, and employee surveys.

RESULTS

Overall, program participation rates were high, and employees reported positive impacts on their health and attitudes toward the agency. Participation in health screening, perceived program convenience, and perceived support by management and others were important determinants of participation and of perceived work-related outcomes.

CONCLUSIONS

Although site selection and response rate limit generalizability, the sites evaluated represent a broad cross-section of different types and sizes of agencies. The findings should be relevant in many other settings. Study programs compare favorably with private sector programs. Employees viewed the programs very positively. The most cogent challenge in justifying these, and perhaps other, worksite programs is that most participants already or simultaneously engage in health promotion activities elsewhere "on their own."