Extending Neoadjuvant Care through Multi-Disciplinary Collaboration: Proceedings from the Fourth Annual Meeting of the Canadian Consortium for Locally Advanced Breast Cancer

The use of systemic therapy before surgery (“neoadjuvant therapy”) is the standard of care for the treatment of locally advanced and nonoperable breast cancer. The advantages of neoadjuvant therapy include improved rates of breast-conserving surgery, the possibility of early measurement of response, and potentially improved outcomes for certain subgroups of high-risk patients. The use of neoadjuvant therapy in operable breast cancer is increasing, although there are no clear guidelines in Canada to help guide patient selection and management. Multidisciplinary experts in the diagnosis and treatment of locally advanced breast cancer (labc) converged at the fourth annual meeting of the Canadian Consortium for LABC (colab) to further their goals of improved standards for neoadjuvant care and clinical research through education and collaboration. Canadian clinical researchers were joined by Dr. Michael Untch of the Helios Hospital Berlin–Buch—representing the German neoadjuvant treatment groups German Gynecologic Oncology Working Group (Arbeitsgemeinschaft Gynakologische Onkologie) and German Breast Group—to discuss the advancement of research in the neoadjuvant setting and important issues of clinical care and investigator-led research. The group reached a consensus on the importance of multidisciplinary collaboration, the use of clips to mark tumour location, and core biopsy testing for the estrogen and progesterone receptors and the human epidermal growth factor receptor 2 at the time of diagnosis. Other initiatives—including creation of a prospective database, inception of the colab Neoadjuvant Network, and development of a clinical survey to evaluate current practice—continue to further the colab mandate of transforming the neoadjuvant treatment landscape in Canada.

P5-08-04: Mammographic Microcalcifications and Breast Cancer Tumorigenesis: A Radiologic-Pathologic Analysis

Background

Microcalcifications (MCs) are tiny deposits of calcium in breast soft tissue. They serve as key diagnostic radiological features for localization of malignancy. Approximately 30% of early invasive breast cancers have fine, granular MCs detectable on mammography; however, their role in breast cancer tumorigenesis is currently unknown. The purpose of this study was to investigate the relationship between mammographic MCs and breast cancer pathology.

Methods: A retrospective chart review was performed for 882 women treated for breast cancer between 2000–2010 at St. Michael's Hospital. Demographic information (age and menopausal status), tumor pathology (size, histology, grade, nodal status and lymphovascular invasion), hormonal status (ER and PR), HER-2 overexpression and presence of MCs were collected for breast cancer patients. Chi-square tests were performed for categorical variables and t-tests were performed for continuous variables. All tests were two-sided and p-values less than 0.05 were considered statistically significant.

Results: A total of 826 patient charts were included; 56 (6.4%) patients had metastatic carcinoma and were excluded from analysis. Only 37.0% (326/882) of the patients presented with mammographic MCs. Patients were more likely to have MCs if they were HER-2 positive (51%) as opposed to being HER-2 negative (33.4%) (p=0.001). There was a significant association between MCs and being perimenopausal with a mean age of 50 (65.2%) (p=0.012). Patients with invasive ductal carcinomas (39.7%) were more likely to present with MCs than were patients with other tumor histology (p=0.001). There was a positive correlation between MCs and tumor grade (p=0.051), with grade III tumors (41.85%) presenting with the most MCs, followed by grade II (37.95%) and grade I (29.8%). There was no significant association between mean age, mean tumor size, ER and PR status with the presence of MCs.

Conclusion: This is the largest study that suggests the appearance of MCs on mammograms is strongly associated with HER-2 overexpression, invasive ductal carcinoma and perimenopausal status. Since HER-2 is implicated in mediating aggressive tumor growth and metastasis, future studies should investigate the molecular pathways underlying HER-2 overexpression and MC development. This would help better understand the role of MCs in breast cancer tumorigenesis.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-08-04.

Assessment of health-related quality of life with the European Organization for Research and Treatment of Cancer QLQ-C15-PAL after palliative radiotherapy of bone metastases

AIMS

To assess health-related quality of life (HRQOL) after palliative radiotherapy for painful bone metastases using a palliative questionnaire (European Organization for Research and Treatment of Cancer QLQ-C15-PAL).

MATERIALS AND METHODS

Patients scheduled to receive palliative radiotherapy for painful bone metastases (n=178) completed the QLQ-C15-PAL questionnaire before treatment and at week 1, week 2, month 1 and month 2 after the first day of radiotherapy. A partial response (PR) or a complete response (CR) to radiotherapy was defined according to the International Consensus criteria. General linear regression was used to analyse changes in QOL in the entire cohort and within responders and non-responders to radiotherapy at all follow-up periods.

RESULTS

The overall radiotherapy response was 45% at week 1 (n=21) (41% PR, 4% CR), 62% at week 2 (n=28) (58% PR, 4% CR), 62% at month 1 (n=58) (60% PR, 2% CR) and 65% at month 2 (n=38) (60% PR, 5% CR). In general, a significant decrease in pain (P<0.0001), insomnia (P<0.0001) and constipation (P=0.004) was seen by month 1 after radiotherapy. In patients who responded to radiotherapy, overall QOL significantly improved by month 2 after radiotherapy (P=0.002). Radiotherapy responders also reported an improvement in emotional functioning together with a decrease in symptoms such as insomnia and constipation at month 1. No improvements were seen in any of the QLQ-C15-PAL scores for patients whose pain did not respond to radiotherapy.

CONCLUSION

Radiotherapy responders showed not only an improvement in pain, but also in HRQOL as assessed by QLQ-C15-PAL. As early as 1 week after radiotherapy for bone metastases, a pain relief response was reported by patients.

A primer of bone metastases management in breast cancer patients

Bone is the most common site for distant spread of breast cancer. Following a diagnosis of metastatic bone disease, patients can suffer from significant morbidity because of pain and skeletal related events (SRES). Bisphosphonates are potent inhibitors of osteoclastic function and the mainstay of bone-directed therapy for bone metastases. The aims of bisphosphonates are to prevent and delay SRES, to reduce bone pain, and to improve quality of life. Bisphosphonate therapy appears to have revolutionized treatment of bone metastases, but bisphosphonate use has several limitations. Those limitations include the high cost of the agents and the need for return trips to the clinic for intravenous treatment. Moreover, many uncertainties surround bisphosphonate use-for example, the timing of bisphosphonate initiation, the choice of bisphosphonate to use, the optimal duration of treatment, and the appropriate means to identify patients who will and will not benefit. In addition, potentially serious adverse effects have been associated with bisphosphonate use-for example, renal toxicity, gastrointestinal side effects, and osteonecrosis of the jaw. The present review is intended as a primer for oncology specialists who treat patients with bone metastases secondary to breast cancer. It focuses on bisphosphonate treatment guidelines, the evidence for those guidelines, and a discussion of new therapeutic agents. It also discusses the use of biochemical markers of bone metabolism, which show promise for predicting the risk of a patient's developing a SRE and of benefiting from bisphosphonate treatment.

Abstract PD10-05: Do the Results of Metastatic Breast Tumour Biopsies Affect Patient Survival Outcomes? Results from a Large Prospective Trial

Background: Differences in receptor status between primary and metastatic breast cancer are well recognized. We have previous demonstrated substantial receptor discordance rates resulting in a change in management in 14% of patients. However, while retrospective studies suggest that discordance can be associated with a worse patient prognosis, there are currently no prospective data assessing the impact of such discordance on survival outcomes.

Methods: A single-center prospective biopsy study was performed. Patients with either recurrent or progressive disease underwent biopsy of their metastases. Subsequent treatment choices were modified according to the results and patients were followed up for progression or death. To account for the differing times at which patients entered the study, progression-free survival (PFS) was calculated as the duration between biopsy and either progression or death. Overall survival (OS) was defined as the duration from diagnosis of metastatic disease to death. A Cox propotional hazards model accounting for duration of metastatic disease and visceral versus non-visceral metastatic disease was utilized.

Results: 121 biopsies were completed and 38% of cases showed discordance between the primary and the recurrence. Survival data were available from 96 patients. After a median follow-up of 11 months, 76 patients (79%) had progressed and 38 (40%) had died. There was no difference in median PFS between concordant and discordance cases (5.9 vs. 6.5 months, HR 0.89, p=0.61). There was a non-significant trend towards worse OS in discordant cases (50.6 vs. 57.8 months, HR 0.77, p=0.47). When compared with the primary tumour a gain of HER2 was associated with a poor survival, while loss of HER2 was associated with improved outcome. Metastatic biopsies showed a trend towards better prediction of response to endocrine therapy with tumors losing progesterone receptor expression between primary and metastatic disease having worse DFS on endocrine therapy. Conclusion: We have previously shown that performing metastatic biopsies is associated with a substantial rate of receptor discordance between primary and metastatic disease. The current analysis demonstrates that this discordance is associated with a trend towards worse OS, but not PFS. Knowledge of the receptor status of metastatic disease allows better prognostication between HER2-postive and HER2-negative disease and also allows for improved prediction of response to endocrine therapy. Metastatic biopsies should therefore be considered in patients with recurrent breast cancer.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD10-05.

Abstract P1-10-05: The Impact of Resource Setting and Guidelines on Global Early Breast Cancer Practice

Background: We developed an international physician survey to identify variations in early breast cancer practice, use of guidelines, and key challenges facing clinicians (MDs) globally in implementing guideline-based care. Methods: The survey was administered at an international breast oncology meeting, and also online using a secure platform. Results were analyzed using descriptive statistics and the chi-squared test was used for bivariate analysis. Results: 691 respondents from 70 countries completed the survey. 38% of respondents were from low income (LIC) or middle income (MIC) countries. More respondents in LICs (89%) and MICs (74%) practice in academic centres; 34% of MDs in high income countries (HICs) practice in community settings (P&lt;0.001). More LIC physicians (74%) rely on clinical breast exam for diagnosis versus in MICs (58%) and HICs (55%) (P&lt;0.001). 87% of LIC physicians say that hormone receptor status is routinely reported on pathology, versus in MICs (91%) and HICs (95%) (p=0.011). The reporting of HER2 status also varies by income setting: 83% in LICs, 89% in MICs, and 95% in HICs (P&lt;0.001). Reporting seems to be the lowest in African nations (78% for hormone and 74% for HER2 status, p &lt;0.001 for each). 46% of LIC and 61% of MIC physicians offer sentinel lymph node dissection, versus 94% in HICs (P&lt;0.001). Adjuvant radiation is available in 93% of all surveyed practices. 99% of respondents give eligible patients endocrine treatment; tamoxifen is prescribed almost universally (&gt;96% of respondents). Aromatase inhibitors are given by 87% of LIC, 93% of MIC, and 94% of HIC physicians (p=0.042). 75% of MDs in LICs give chemotherapy to high risk patients; 81% of those in MICs and HICs do the same (NS). More LIC oncologists give classical CMF (21%, p=0.006), and 77% give anthracycline-taxane combinations, compared to 84% of MIC and 88% of HIC physicians (p=0.017). Trastuzumab is given to a majority (&gt;75%) of eligible patients by only 11% of LIC and 36% of MIC physicians, compared to 80% of HIC clinicians (P&lt;0.001). Trastuzumab use is most prominent in North America (85%) and Europe (75%), and lowest in Africa (19%) and Asia (32%) (P&lt;0.001). 94% of LIC and 63% of MIC physicians said trastuzumab use is limited by drug cost (P&lt;0.001); lack of HER2 testing was cited as an issue by only 8-9% of all respondents. 63% of LIC and 76% of MIC physicians say international guidelines impact their clinical practice, compared to 56% of HIC physicians (P&lt;0.001), who are more likely to rely on local/regional guidelines (33%, P&lt;0.001). Conclusions: Global practice patterns in early breast cancer care vary by resource setting but also by continent. More costly therapies such as trastuzumab are used less often in LICs and MICs. Surveyed physicians from LICs and MICs also rely on international guidelines to direct their practice more than HIC physicians. This may reflect that many guidelines with international influence are created in HICs. In order to improve breast cancer outcomes worldwide, global collaboration is required to create guidelines which not only recommend best practice, but are applicable in various resource and cultural settings, and are followed by implementation research efforts.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-10-05.

Abstract P5-15-05: Applicability of Breast Cancer Guidelines and Knowledge Translation in a Community Oncology Setting

Background: The quality of a guideline may impact adherence to that guideline. Cancer Care Ontario (CCO) produces guidelines to help manage all stages of disease. CCO's staging and follow-up guideline suggests patients (pts) with stage I breast cancer require no further staging investigations, bone scan for stage II disease, and for stage III disease in addition to bone scan, chest and abdominal imaging. The guideline on bisphosphonate (BP) use in metastatic breast cancer pts indicates that all pts with bone metastases should be offered a BP. We assessed the efficacy of knowledge translation of these guidelines at a community oncology centre by correlating rate of adherence with the quality of the guideline as scored using the Appraisal of Guidelines for Research and Evaluation (AGREE) Instrument.

Methods: The quality of 2 breast cancer guidelines from CCO were assessed using the AGREE instrument. Two cohort studies of breast cancer pts seen were then conducted to evaluate the adherence to these guidelines. Specifically, staging investigations ordered on pts seen in our multidisciplinary clinic between January 2009 and April 2010 were recorded and correlated to pathological stage of disease. Our second cohort study reviewed breast cancer pts with bone metastases who died between 1999 and 2009, and initiation of a BP was recorded in order to determine adherence to the second guideline.

Results: Inadequate adherence was identified and correlated with low applicability scores for these two guidelines (58% and 33% respectively). Only 68 pts (61%) with bone metastases received BP for treatment between 1999 to 2009. 129 pts (56%) underwent unnecessary staging investigations.

Discussions: Non-chemotherapy breast cancer guidelines by CCO scored low in the field of applicability; this was confirmed by two retrospective cohort studies. Improvement in knowledge translation strategies are needed to improve adherence to practice guidelines set out by this national organization.

The emerging role of Krüppel-like factors in endocrine-responsive cancers of female reproductive tissues

Krüppel-like factors (KLFs), of which there are currently 17 known protein members, belong to the specificity protein (Sp) family of transcription factors and are characterized by the presence of Cys(2)/His(2) zinc finger motifs in their carboxy-terminal domains that confer preferential binding to GC/GT-rich sequences in gene promoter and enhancer regions. While previously regarded to simply function as silencers of Sp1 transactivity, many KLFs are now shown to be relevant to human cancers by their newly identified abilities to mediate crosstalk with signaling pathways involved in the control of cell proliferation, apoptosis, migration, and differentiation. Several KLFs act as tumor suppressors and/or oncogenes under distinct cellular contexts, underscoring their prognostic potential for cancer survival and outcome. Recent studies suggest that a number of KLFs can influence steroid hormone signaling through transcriptional networks involving steroid hormone receptors and members of the nuclear receptor family of transcription factors. Since inappropriate sensitivity or resistance to steroid hormone actions underlies endocrine-related malignancies, we consider the intriguing possibility that dysregulation of expression and/or activity of KLF members is linked to the pathogenesis of endometrial and breast cancers. In this review, we focus on recently described mechanisms of actions of several KLFs (KLF4, KLF5, KLF6, and KLF9) in cancers of the mammary gland and uterus. We suggest that understanding the mode of actions of KLFs and their functional networks may lead to the development of novel therapeutics to improve current prospects for cancer prevention and cure.

Change in Receptor Status in Locally Advanced Breast Cancer Patients after Treatment with Neoadjuvant Therapy (NAT)

Background: Systemic treatment decisions for locally advanced breast cancer (LABC) are made upfront, prior to surgery. ER, PR and Her2 status is often assessed on the initial core biopsy, and used to guide systemic therapy options. Hormone receptor and Her2 status may or may not be repeated after definitive surgery. Studies completed in the metastatic setting indicate that hormone receptor status may change between primary and metastatic lesion in up to 40% of cases after adjuvant treatment1. There is limited data with regards to any change occurring in the neoadjuvant setting. This study aimed to determine if a change in receptor status occurs after NAT by reassessing the ER, PR and Her2 status of locally advanced breast cancer specimens after definitive surgery, and to quantify any change observed.Methods: Patients with LABC (stage 2B or stage 3) who were entered into the prospective LABC database at the Sunnybrook Odette Cancer Centre between January 2002 and January 2008 were included. ER and PR status by IHC and Her2 status by IHC and FISH was evaluated in both the pre-treatment core biopsy specimen and in the post-treatment mastectomy specimen using the same technique. ER and PR status was also quantified and reported as percentage postivity.Results: One hundred and fifty (150) patients were enrolled in the LABC database between January 2002 and January 2008. Of these, 9 had mastectomy at a different centre, 15 had a pathological complete response, 13 did not undergo surgery for various reasons post NAT (refusal, progression, comorbidities), and 7 had missing data. The remaining 106 patients had ER and PR status reassessed post mastectomy, and 93 had Her2 status available from both pre and post-treatment specimens. Only 6 patients had a change in ER status, (5.6%, P = NS), but 25 had a change in PR status (23.6%, p = 0.0007). The majority of cases involved a loss in hormone receptor status, with only 4 patients experiencing a gain in PR status. Seven patients had a change in Her2 status (7.5%, P=NS). There was significant discordance in the quantitative analysis of PR but not ER status between specimens pre- and post-treatment, (p = 0.84 for ER, p &lt; 0.0001 for PR). There was no correlation with change in ER or PR and response to NAT.Conclusions: This study has demonstrated a significant discordance of 24% in hormone receptor status between core biopsy and final definitive surgery, primarily as a loss of PR status. Further follow up of these cases may help to determine if loss of PR or significant change in quantization confers predictive or prognostic information.Change in ER status Biopsy ER-Biopsy ER+Mastectomy ER-392Mastectomy ER+461 Change in PR status Biopsy PR-Biopsy PR+Mastectomy PR-514Mastectomy PR+2129 1. Simmons C, Miller N, Geddie W, Gianfelice D, Oldfield M, Dranitsaris G, Clemons M. “Changes in breast tumour receptor status with time – does performing a confirmatory tissue biopsy at the time of metastatic recurrence alter patient management? The results of a prospective study.” Annals of Oncology, March 18, 2009.Change in Her2 status Biopsy Her2-Biopsy Her2+Mastectomy Her2-683Mastectomy Her2+418 

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1083.

Biopsy Confirmation of Metastatic Disease in Breast Cancer: Results from a Large Prospective Study

Purpose: Decisions about systemic treatment of women with metastatic breast cancer are often based on estrogen receptor (ER), progesterone receptor (PgR), and HER2/neu status of the primary tumour. This study prospectively investigated concordance in receptor status between primary tumour and distant metastases at various stages of progression and assessed the impact of any discordance on patient management.Methods: Biopsies of suspected metastatic lesions were obtained from patients and analyzed for ER/PgR and HER2/neu. Receptor status of metastases was compared to the primary tumour. The treating physician completed questionnaires before and after biopsy to determine whether the biopsy result lead to a change in treatment plan.Results: One hundred and sixteen women were enrolled and 102 underwent biopsy. Of these 52 (51%) were newly diagnosed with metastatic disease, 17 (17%) had received one line of metastatic treatment and 35 (34%) had received 2 or more lines of treatment in the metastatic setting. 86/102 (84%) of samples were sufficient analysis; of these 5/86 biopsies (6%) showed benign disease and one biopsy (1%) confirmed a different malignancy (indolent lymphoma). Changes in hormone receptor status were observed in 33%. Among these, ER discordance was seen in 11%, PgR discordance in 27% and discordance in both ER and PgR in 5%. Loss of PgR was the most common change in hormone receptor status (25%). HER2/neu showed 4% discordance. Three patients (3%) gained and one patient (1%) lost HER2/neu expression. Biopsy results led to a change of management in 12% of patients. Patients with newly diagnosed metastatic disease were more likely to show discordance than those previously treated in the metastatic setting. Among triple negative primary tumours, no changes in receptor expression of metastases were seen.Conclusions: This is the largest prospective biopsy study we are aware of. Results demonstrate the presence of substantial discordance in receptor status between primary tumour and metastases. The number needed to biopsy to alter immediate management was 8.5, although biopsy information could also be useful in planning subsequent treatments. Tissue confirmation should therefore, be considered in all patients with suspicion of metastatic recurrence or progression.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2023.

Reduced helminth burden increases allergen skin sensitization but not clinical allergy: a randomized, double-blind, placebo-controlled trial in Vietnam

BACKGROUND

Observational evidence suggests that infection with helminths protects against allergic disease and allergen skin sensitization. It is postulated that such effects are mediated by helminth-induced cytokine responses, in particular IL-10.

OBJECTIVE

We tested this hypothesis in a rural area of central Vietnam where hookworm infection is endemic.

METHODS

One thousand five hundred and sixty-six schoolchildren aged 6-17 were randomly allocated to receive either anti-helminthic therapy or a placebo at 0, 3, 6, and 9 months. We compared changes in the prevalence of exercise-induced bronchoconstriction, allergen skin sensitization, flexural eczema on skin examination, questionnaire-reported allergic disease (wheeze and rhinitis symptoms), and immunological parameters (hookworm-induced IFN-gamma, IL-5, IL-10) between 0 and 12 months.

RESULTS

One thousand four hundred and eighty-seven children (95% of these randomized) completed the study. The most common helminth infections were hookworm (65%) and Ascaris lumbricoides (7%). There was no effect of the therapy on the primary outcome, exercise-induced bronchoconstriction (within-participant mean percent fall in peak flow from baseline after anti-helminthic treatment 2.25 (SD 7.3) vs. placebo 2.19 (SD 7.8, P=0.9), or on the prevalence of questionnaire-reported wheeze [adjusted odds ratio (OR)=1.16, 95% confidence interval (CI) 0.35-3.82, P=0.8] and rhinitis (adjusted OR=1.39, 0.89-2.15, P=0.1), or flexural dermatitis on skin examination (adjusted OR=1.15, 0.39-3.45, P=0.8). However, anti-helminthic therapy was associated with a significantly higher allergen skin sensitization risk (adjusted OR=1.31, 1.02-1.67, P=0.03). This effect was particularly strong for children infected with A. lumbricoides at baseline (adjusted OR=4.90, 1.48-16.19, P=0.009). Allergen skin sensitization was inversely related to hookworm-specific IL-10 at baseline (adjusted OR=0.76, 0.59-0.99, P=0.04). No cytokine tested, including IL-10, changed significantly after the anti-helminthic therapy compared with the placebo.

CONCLUSION

A significant reduction in worm burden over a 12-month period in helminth-infected children increases the risk of allergen skin sensitization but not of clinical allergic disease. The effect on skin sensitization could not be fully explained by any of the immunological parameters tested.

Does confirmatory tumor biopsy alter the management of breast cancer patients with distant metastases?

BACKGROUND

Decisions about systemic treatment of women with metastatic breast cancer are often based on estrogen receptor (ER), progesterone receptor (PgR), and Her2 status of the primary tumor. This study prospectively investigated concordance in receptor status between primary tumor and distant metastases and assessed the impact of any discordance on patient management.

MATERIALS AND METHODS

Biopsies of suspected metastatic lesions were obtained from patients and analyzed for ER/PgR and Her2. Receptor status was compared for metastases and primary tumors. Questionnaires were completed by the oncologist before and after biopsy to determine whether the biopsy results changed the treatment plan.

RESULTS

Forty women were enrolled; 35 of them underwent biopsy, yielding 29 samples sufficient for analysis; 3/29 biopsies (10%) showed benign disease. Changes in hormone receptor status were observed in 40% (P = 0.003) and in Her2 status in 8% of women. Biopsy results led to a change of management in 20% of patients (P = 0.002).

CONCLUSIONS

This prospective study demonstrates the presence of substantial discordance in receptor status between primary tumor and metastases, which led to altered management in 20% of cases. Tissue confirmation should be considered in patients with clinical or radiological suspicion of metastatic recurrence.

Alterations in calcium metabolism in patients on long-term bisphosphonate therapy for metastatic breast cancer (MBC): A potential therapeutic target?

1044

Background: The effect of long-term potent BP use on calcium homeostasis in MBC pts is poorly understood. These effects and the need for calcium and Vitamin D supplementation may have significant implications for pt management in both the metastatic and adjuvant settings. Methods: We evaluated serum calcium (sCa), PTH, and 25(OH)D levels and their inter-relationships in 30 MBC pts after prolonged BP use for bone metastases (BM), compared with a control group (CG) of 1484 normal women without bone or mineral disease (JCEM 2003;88:185). The MBC pts were prescribed oral calcium (1g/d) and vitamin D (400IU/d) for 1 month prior to analysis. To determine whether MBC pts differed from CG with respect to the sCa-PTH correlation, logistic regression was performed with sCa, log-transformed PTH and an interaction term (Ca × lnPTH). Results: Mean age of the two groups did not differ [MBC group (58.5 ± 2.0 yr) vs. CG (55.2 ± 0.4 yr, p >.05)]. VitD-deficiency (25vitD < 40 nM) was equally prevalent in the two groups [MBC (23%) vs. CG (25%)]. sCa was significantly higher in MBC pts (2.473 ± 0.019 mM) compared to CG (2.377 ± 0.003, p <0.001). However, PTH was not decreased in MBC pts (4.60 ± 0.36 pM), compared to CG (4.56 ± 0.06, t-test, p=0.91). Logistic regression was highly significant (p<0.0001), as were coefficients for both explanatory variables (sCa, p <0.0001 and lnPTH, p = 0.009) and their interaction (p=0.011). Conclusion: In pts with BM and prolonged BP use there appears to be a shift in the calcium set-point such that PTH release is activated by higher levels of sCa than in controls. We are currently studying whether prophylaxis for relative vit D deficiency in this population can not only correct this shift but also improve pt symptoms

No significant financial relationships to disclose.

Changes in estrogen receptor (ER), progesterone receptor (PR) and HER2/neu status with time: Discordance rates between primary and metastatic breast pathology samples

1024

Background: The occurrence of changes in tumor receptor profile (ER, PR and HER-2/neu) between primary and metastatic tissue has been recognised and may have significant treatment implications. Previous reports on receptor discordance rates have tended to be from sub-studies of clinical trials. We sought to evaluate the degree of ER, PR and HER-2/neu receptor discordance in patients treated at two Canadian cancer centres. Methods: Archival data was collected on patients for whom tissue from both primary and metastatic sites was available. Patients with recurrences in the breast or axilla were excluded. ER, PR and HER-2/neu status in the primary and metastasis were compared. Additional information including adjuvant therapy and time to metastasis biopsy was gathered. Results: To date, data is available on 80 patients. Hormone receptor (HR) status was available for 96% of primaries and 56% of metastases. HR status on both the primary and the metastasis was performed in 51% of cases. The discordance rate for ER was 21% (2-sided p=0.0096). 12% of patients changed from ER+ to ER- and 9% changed from ER- to ER+. The discordance rate for PR was 37% (2-sided p=0.0001), with all of these patients changing from PR+ to PR-. No significant HR discordance was found among different adjuvant hormone therapy subgroups. There was no correlation between HR discordance and time to rebiopsy. No discordance for HER-2/neu was found. Conclusions: Significant discordance for HR status was observed, 21% for ER and 37% for PR. HER-2/neu discordance was not observed. We are currently exploring the practical implications of these discordance rates on the management of advanced breast cancer patients in a prospective trial.

No significant financial relationships to disclose.

A practical guide to the management of menopausal symptoms in breast cancer patients

Breast cancer is the most frequently diagnosed cancer in Canadian women. As a result of increased screening and improved treatment, more women are becoming long-term breast cancer survivors. However, due to either their treatment or prolonged survival, many of these women now have to face the consequences of premature menopause and prolonged estrogen deprivation. Hormone replacement therapy/estrogen replacement therapy (HRT/ERT) has, in the past, been recommended to healthy women at menopause not only for relief of short-term menopausal changes, particularly hot flashes, but also for its benefits on bone density, fracture reduction, and genitourinary symptoms. Recent studies have demonstrated that not only is HRT associated with an increased risk of developing breast cancer, but it also has been shown to increase the risk of recurrence in those with a breast cancer history. Until the safety of HRT/ERT in breast cancer patients can be more fully clarified, it would be wise to develop alternative strategies for the management of menopausal symptoms in these patients. This paper will discuss nonestrogen-based therapies for hot flashes, osteoporosis, and genitourinary symptoms, with emphasis on efficacy and safety in breast cancer survivors.

Bone regeneration in a rat cranial defect with delivery of PEI-condensed plasmid DNA encoding for bone morphogenetic protein-4 (BMP-4)

Gene therapy approaches to bone tissue engineering have been widely explored. While localized delivery of plasmid DNA encoding for osteogenic factors is attractive for promoting bone regeneration, the low transfection efficiency inherent with plasmid delivery may limit this approach. We hypothesized that this limitation could be overcome by condensing plasmid DNA with nonviral vectors such as poly(ethylenimine) (PEI), and delivering the plasmid DNA in a sustained and localized manner from poly(lactic-co-glycolic acid) (PLGA) scaffolds. To address this possibility, scaffolds delivering plasmid DNA encoding for bone morphogenetic protein-4 (BMP-4) were implanted into a cranial critical-sized defect for time periods up to 15 weeks. The control conditions included no scaffold (defect left empty), blank scaffolds (no delivered DNA), and scaffolds encapsulating plasmid DNA (non-condensed). Histological and microcomputed tomography analysis of the defect sites over time demonstrated that bone regeneration was significant at the defect edges and within the defect site when scaffolds encapsulating condensed DNA were placed in the defect. In contrast, bone formation was mainly confined to the defect edges within scaffolds encapsulating plasmid DNA, and when blank scaffolds were used to fill the defect. Histomorphometric analysis revealed a significant increase in total bone formation (at least 4.5-fold) within scaffolds incorporating condensed DNA, relative to blank scaffolds and scaffolds incorporating uncondensed DNA at each time point. In addition, there was a significant increase both in osteoid and mineralized tissue density within scaffolds incorporating condensed DNA, when compared with blank scaffolds and scaffolds incorporating uncondensed DNA, suggesting that delivery of condensed DNA led to more complete mineralized tissue regeneration within the defect area. This study demonstrated that the scaffold delivery system encapsulating PEI-condensed DNA encoding for BMP-4 was capable of enhancing bone formation and may find applications in other tissue types.

In vivo degradation of 14C-labeled small intestinal submucosa (SIS) when used for urinary bladder repair

The rate of in vivo degradation was determined for a naturally occurring biomaterial derived from the extracellular matrix of the small intestinal submucosa (SIS). The SIS was labeled by giving weekly intravenous injections of 10 microCi of 14C-proline to piglets from 3 weeks of age until the time of sacrifice at 26 weeks. The resultant SIS prepared from these pigs contained approximately 10(3) fold more 14C than unlabeled tissues. The labeled SIS was used to repair experimental defects in the urinary bladder of 10 dogs. The animals were sacrificed at post-operative times ranging from 3 days to 1 year and the remodeled urinary bladder tissue was harvested for evaluation of 14C by a combination of liquid scintillation counting and accelerator mass spectrometry. The remodeled tissue contained less than 10% of the 14C (disintegrations per minute/gram tissue wet weight) at 3 months post-surgery compared to the SIS biomaterial that was originally implanted. The SIS scaffold was replaced by host tissue that resembled normal bladder both in structure and function. After implantation, 14C was detected in highest concentrations in the blood and the urine. The SIS bioscaffold provides a temporary scaffold for tissue remodeling with rapid host tissue remodeling, degradation, and elimination via the urine when used as a urinary bladder repair device.

Season-of-birth bias in association football

In this longitudinal study, we assessed the frequency of birth dates for boys selected for the Football Association National School. Birthdays were divided into three periods of the year: January to April, May to August and September to December. We compared data over a 5 year period and concluded that there is indeed a bias towards selecting older children. Furthermore, analysis of separate data revealed a shift of bias when comparing two different start dates, namely September and January. Our findings show that the youngest children from the January start date (born September to December) are selected significantly more often than the youngest children from the September start date (born May to August). Interestingly, even when the influence of body mass was reduced, the selection bias towards the older players remained.

Refocusing of B-cell responses following a single amino acid substitution in an antigen

Intranasal immunization of BALB/c strain mice was carried out using baculovirus-derived human chorionic gonadotrophin (hCG) beta-chain, together with Escherichia coli heat-labile enterotoxin. Gonadotrophin-reactive immunoglobulin A (IgA) was induced in a remote mucosal site, the lung, in addition to a systemic IgG response. The extensive sequence homology with luteinizing hormone (LH) results in the production of LH cross-reactive antibodies when holo-hCG is used as an immunogen. In contrast to wild-type hCGbeta, a mutated hCGbeta-chain containing an arginine to glutamic acid substitution at position 68 did not induce the production of antibodies which cross-react with LH. Furthermore, the epitopes utilized in the B-cell response to the mutated hCGbeta shifted away from the immunodominant region of the parent wild-type molecule towards epitopes within the normally weakly immunogenic C terminus. This shift in epitope usage was also seen following intramuscular immunization of rabbits. Thus, a single amino acid change, which does not disrupt the overall structure of the molecule, refocuses the immune response away from a disadvantageous cross-reactive epitope region and towards a normally weakly immunogenic but antigen-unique area. Similar mutational strategies for epitope-refocusing may be applicable to other vaccine candidate molecules.

The immune responses to bacterial antigens encountered in vivo at mucosal surfaces

Mammals have evolved a sophisticated immune system for handling antigens encountered at their mucosal surfaces. The way in which mucosally delivered antigens are handled influences our ability to design effective mucosal vaccines. Live attenuated derivatives of pathogens are one route towards the development of mucosal vaccines. However, some molecules, described as mucosal immunogens, are inherently immunogenic at mucosal surfaces. Studies on mucosal immunogens may facilitate the identification of common characteristics that contribute to mucosal immunogenicity and aid the development of novel, non-living mucosal vaccines and immunostimulators.

"Modern marriage" for African Americans, 1920-1940

Between January 1925 and June 1926 the New York Messenger ran a serialized romance story entitled “The Letters of Davy Carr.” The story, set in Washington, DC, centres on the youngest daughter of the middle-class Rhodes family. Caro­line Rhodes, a grade-school teacher and a dark and lively beauty with “all the best and worst points of the modern flapper,” alternately fascinates and horrifies the priggish narrator, Davy Carr (Anonymous, Jan. 1925 26). Carr purports to be a well-educated twenty-something man, native of a “little provincial Southern city,” sojourning in Washington, DC, in 1922 to do research for a book on the slave trade. While boarding with the Rhodeses, Carr writes letters to a his war buddy back in New York, describing “colored society” in the nation’s capital, with a focus on the fascinating Caroline (Mar. 1925 146; Apr. 1925 165). Fussed over by her “Victorian” mother and elder sister, Caroline smokes and constantly visits Carr’s room to chat. He describes how she sat in his room, swinging her silk-clad legs with the abandon of a small boy, and regaled [him] in terms piquant and interesting, if a trifle startling at times, with her very mod­ern views of the woman question, fellows, and marriage … it was decidedly refreshing, but I am not sure that it was not more shocking than anything else. (Jan. 1925 27)

Igh-6(-/-) (B-cell-deficient) mice fail to mount solid acquired resistance to oral challenge with virulent Salmonella enterica serovar typhimurium and show impaired Th1 T-cell responses to Salmonella antigens

In the present study we evaluated the role of B cells in acquired immunity to Salmonella infection by using gene-targeted B-cell-deficient innately susceptible mice on a C57BL/6 background (Igh-6(-/-)). Igh-6(-/-) mice immunized with a live, attenuated aroA Salmonella enterica serovar Typhimurium vaccine strain showed impaired long-term acquired resistance against the virulent serovar Typhimurium strain C5. Igh-6(-/-) mice were able to control a primary infection and to clear the inoculum from the reticuloendothelial system. However, Igh-6(-/-) mice, unlike Igh-6(+/+) C57BL/6 controls, did not survive an oral challenge with strain C5 at 4 months after vaccination. Transfer of immune serum did not restore resistance in Igh-6(-/-) mice. Total splenocytes and purified CD4(+) T cells obtained from Igh-6(-/-) mice 4 months after vaccination showed reduced ability to release Th1-type cytokines (interleukin 2 and gamma interferon) upon in vitro restimulation with serovar Typhimurium soluble cell extracts compared to cells obtained from Igh-6(+/+) C57BL/6 control mice. Therefore, the impaired resistance to oral challenge with virulent serovar Typhimurium observed in B-cell-deficient mice, which cannot be restored by passive transfer of Salmonella-immune serum, may be in part due to a reduced serovar Typhimurium-specific T-cell response following primary immunization.

Measuring quality in hospitals: is there a difference between for-profits and not-for-profits?

Health care professionals agree that by measuring quality, improvements can be made in care delivery. There are measurable differences between not-for-profit and for-profit hospitals, both in public perception and care outcomes. The ability by consumers, insurers and providers to easily access quality data will drive the health care industry to take a quality focus in their daily business. Quality providers with measurable results will gain a larger share of health care dollars and consumer trust. Physicians will choose to partner with the quality leaders and will refine their practices as part of the quality evolution.

A phase I and pharmacological study of protracted infusions of crisnatol mesylate in patients with solid malignancies

This Phase I and pharmacological study was performed to assess the feasibility of administering the polycyclic aromatic hydrocarbon crisnatol in increasingly prolonged continuous i.v. infusions to patients with advanced solid malignancies. The study also sought to characterize the-principal toxicities of crisnatol on this schedule, to recommend doses for subsequent disease-directed studies, and to characterize possible associations between pharmacological parameters and toxicity. Sixteen patients were treated with 40 courses of crisnatol administered as a continuous i.v. infusion. The initial dose-schedule was 750 mg/m2/day for 6 days, and the duration of the infusion was to be progressively increased by 3-day increments to 9, 12, 15, 18, and 21. Courses were to be repeated every 4 weeks. Moderate to severe central nervous system (CNS) toxicity precluded the administration of crisnatol 750 mg/m2/day for longer than 6 days, and, therefore, the dose of crisnatol was reduced to 600 mg/m2/day. At this dose, three of five patients receiving a 12-day infusion experienced dose-limiting toxicity, which consisted of pulmonary thromboembolism (two patients) and grade 4 thrombocytopenia (one patient). None of the six patients completing a 9-day infusion at 600 mg/m2/day developed dose-limiting toxicity during the first or second course of crisnatol. At this dose level, the plasma concentrations at steady state (Css) averaged 1607.8+/-261.1 ng/ml, which exceeds minimal inhibitory concentrations for most tumors in vitro (1000 ng/ml). In fact, the administration of crisnatol at a dose of 600 mg/m2/day for 9 days resulted in the longest duration that biologically relevant plasma crisnatol concentrations have been sustained. Plasma Css values were significantly higher in patients who experienced severe CNS toxicity compared with those who did not (2465.3+/-1213.5 versus 1342+/-447.3 ng/ml; P = 0.04). There were no relationships evident between the clearance of crisnatol and indices reflecting renal and hepatic functions. One patient with a glioblastoma multiforme experienced a partial response lasting 14 months. The relative lack of intolerable CNS toxicity at the recommended dose for Phase II studies of crisnatol, 600 mg/m2/day for 9 days, as well as the magnitude of the Css values achieved and the antitumor activity observed at this dose, are encouraging. However, the mechanisms for the apparently increased thrombogenicity observed in this trial are unclear and require further elucidation.

Interferon-alpha upregulates gene expression of aquaporin-5 in human parotid glands

Aquaporins are a family of homologous membrane proteins that function as highly selective water channels. Aquaporin-5 (AQP5) is uniquely present in lacrimal and salivary glands, where it accounts for normal tear and saliva production. We tested the hypothesis that orally administered human interferon-alpha (HuIFN-alpha) benefits persons with xerostomia by augmenting the production of AQP5 protein by parotid gland epithelium. Cells from three human parotid glands were cultured with and without human lymphoblastoid IFN-alpha, and assayed for AQP5 mRNA levels by reverse transcriptase polymerase chain reaction (RT-PCR), and AQP5 protein levels by Western blot. Intracellular localization of AQP5 protein was done using confocal microscopy. The functional integrity of the glandular tissue was confirmed by RT-PCR analysis of alpha-amylase 1 and basic proline-rich protein transcripts. AQP5 was constitutively expressed in human parotid gland tissue, with AQP5 protein restricted to the plasma membranes and cytoplasmic vesicles of acinar cells. IFN-alpha augmented AQP5 transcription and protein production in a concentration-dependent manner, and increased the size of intensity of staining of AQP5-containing cytoplasmic vesicles in acinar cells. We conclude that IFN-alpha upregulates AQP5 gene expression in human parotid acinar cells in vitro. To our knowledge, this is the first demonstration that IFN-alpha regulates the gene expression of an aquaporin.

Root-growth behavior of the Arabidopsis mutant rgr1. Roles of gravitropism and circumnutation in the waving/coiling phenomenon

In this study we investigated the kinetics of the gravitropic response of the Arabidopsis mutant rgr1 (reduced root gravitropism). Although the rate of curvature in rgr1, which is allelic to axr4, was smaller than in the wild type (ecotype Wassilewskija), curvature was initiated in the same region of the root, the distal elongation zone. The time lag for the response was unaffected in the mutant; however, the gravitropic response of rgr1 contained a feature not found in the wild type: when roots growing along the surface of an agar plate were gravistimulated, there was often an upward curvature that initiated in the central elongation zone. Because this response was dependent on the tactile environment of the root, it most likely resulted from the superposition of the waving/coiling phenomenon onto the gravitropic response. We found that the frequency of the waving pattern and circumnutation, a cyclic endogenous pattern of root growth, was the same in rgr1 and in the wild type, so the waving/coiling phenomenon is likely governed by circumnutation patterns. The amplitudes of these oscillations may then be selectively amplified by tactile stimulation to provide a directional preference to the slanting.

Characterization of rice endo-beta-glucanase genes (Gns2-Gns14) defines a new subgroup within the gene family

Thirteen new beta-glucanase-encoding genes have been identified in the rice genome. These genes, together with other monocot beta-glucanases, have now been classified into four subfamilies based on the structure and function of the genes. Two tandem gene clusters, Gns2-Gns3-Gns4 and Gns5-Gns6, were classified in the defense-related Subfamily A. Growth-related 1,3;1,4-beta-glucanase Gns1 was classified in Subfamily B. Gns7 and Gns8, together with the barley genes GVI and Hv34, represent Subfamily C. Gns9 and a beta-glucanase gene from wheat were grouped in Subfamily D. Genes in Subfamilies C and D have structures that are distinct from those of the other subfamilies, but there are very little data available on the biochemical or physiological roles of these genes. Gene expression in growing tissues and lack of gene induction in response to disease-related treatments suggest that Subfamilies C and D may function in control of plant growth.

Effect of acute exposure to 3-nitropropionic acid on activities of endogenous antioxidants in the rat brain

The response of endogenous antioxidants to acute exposure of the mitochondrial inhibitor, 3-nitropropionic acid (3-NPA), was investigated in selected rat brain regions. Rats treated with 3-NPA (30 mg/kg, s.c.) were sacrificed at 30, 60, 90 and 120 min after injection to examine the alterations in reduced glutathione levels (GSH), and activities of antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) in the hippocampus (HIP), frontal cortex (FC), and caudate nucleus (CN). CAT activity increased in the HIP 90 min after 3-NPA treatment. While cytosolic copper/zinc SOD (CuZn-SOD) and mitochondrial manganese SOD (Mn-SOD) levels increased in the FC at 120 min, only the Mn-SOD increased in the CN 90 min after treatment. The activity of GPx decreased in the HIP 120 min after 3-NPA injection. When compared with the control, administration of 3-NPA led to GSH depletion in HIP within 120 min. The depletion of GSH and induction of antioxidant enzyme activities after the 3-NPA exposure suggest conditions favorable for oxidative stress.

The effect of convection on a propagating front with a liquid product: Comparison of theory and experiments

This work is devoted to the investigation of propagating polymerization fronts converting a liquid monomer into a liquid polymer. We consider a simplified mathematical model which consists of the heat equation and equation for the depth of conversion for one-step chemical reaction and of the Navier-Stokes equations under the Boussinesq approximation. We fulfill the linear stability analysis of the stationary propagating front and find conditions of convective and thermal instabilities. We show that convection can occur not only for ascending fronts but also for descending fronts. Though in the latter case the exothermic chemical reaction heats the cold monomer from above, the instability appears and can be explained by the interaction of chemical reaction with hydrodynamics. Hydrodynamics changes also conditions of the thermal instability. The front propagating upwards becomes less stable than without convection, the front propagating downwards more stable. The theoretical results are compared with experiments. The experimentally measured stability boundary for polymerization of benzyl acrylate in dimethyl formamide is well approximated by the theoretical stability boundary. (c) 1998 American Institute of Physics.

Effect of dialyzer reuse on survival of patients treated with hemodialysis

OBJECTIVE

To evaluate the impact of dialyzer reuse on the survival of US hemodialysis patients.

STUDY DESIGN AND PARTICIPANTS

Nonconcurrent cohort study of 27938 patients beginning hemodialysis in the United States in 1986 and 1987.

MAIN OUTCOME MEASURE

Patient survival.

RESULTS

Dialysis in freestanding facilities reprocessing dialyzers with the combination of peracetic and acetic acids was associated with greater mortality than treatment in facilities not reprocessing dialyzers (rate ratio [RR],1.10, 95% confidence interval [CI], 1.02-1.18; P=.02) In contrast, there was no significant difference between survival in freestanding facilities reprocessing dialyzers with either formaldehyde (RR,1.03, 95% CI, 0.96-1.10; P=.45) or glutaraldehyde (RR, 1.13, 95% CI, 0.95-1.35, P=.18) and survival in freestanding facilities not reprocessing dialyzers. Among freestanding facilities reprocessing dialyzers, use of peracetic/acetic acid was associated with a higher rate of death than use of formaldehyde (RR = 1.08, 95% CI, 1.01-1.14; P=.02). There was no statistical difference between survival in hospital-based facilities reprocessing dialyzers with either peracetic/acetic acid (RR=0.95, 95% CI, 0.85-1.06; P=.40), formaldehyde (RR=1.06, 95% CI, 0.98-1.15; P=.12), or glutaraldehyde (RR=1.09, 95% CI, 0.71-1.67; P=.70) and survival in hospital-based facilities not reprocessing dialyzers. In addition, choice of sterilant was not associated with a statistically significant difference in survival among hospital-based facilities reprocessing dialyzers.

CONCLUSIONS

Dialysis in freestanding facilities reprocessing dialyzers with peracetic/acetic acid may be associated with worse survival than dialysis in free-standing facilities not reprocessing dialyzers or in those reprocessing with formaldehyde. We were unable to determine whether these relationships arose from greater comorbidity among patients treated in facilities using peracetic/acetic acid, poor quality of dialysis procedures in these facilities, or direct toxicity of peracetic/acetic acid. These findings raise important concerns about potentially avoidable mortality among US hemodialysis patients treated in dialysis facilities reprocessing hemodialyzers.

Apo-dystrophins (Dp140 and Dp71) and dystrophin splicing isoforms in developing brain

PCR studies have shown that exons 71-74 are spliced out in most dystrophin mRNA transcripts in the brain. We have prepared new monoclonal antibodies against the syntrophin-binding region of dystrophin encoded by exons 73-74 and examined three protein products of the dystrophin gene in brain; the widely distributed Dp71, the recently discovered, brain-specific Dp140 and dystrophin itself. Exon 73-74 mAbs bound to all three proteins in brain and the extent of binding suggests that alternatively spliced dystrophins are less prominent at the protein level than predicted by PCR data. Dp140, unlike Dp71, was found to be present at much higher levels in foetal brain than in adult brain. If lack of functional Dp140 is the cause of the cognitive impairment in some Duchenne muscular dystrophy patients, this result suggests that the effects may occur early in development, which would reduce the options for therapeutic intervention.

The use of xenogeneic small intestinal submucosa as a biomaterial for Achilles tendon repair in a dog model

A study was conducted to evaluate the tissue response to a xenogeneic biomaterial when this material was used to repair an experimentally induced Achilles tendon defect in the dog. Twenty dogs had a 1.5 cm segmental defect of the Achilles tendon created surgically which was then repaired with acellular connective tissue derived from porcine small intestinal submucosa (SIS). The animals were sacrificed at 1, 2, 4, 8, 12, 16, 24, and 48 weeks and the neotendons examined for uniaxial longitudinal tensile strength, morphologic appearance, hydroxyproline (collagen) content, and disappearance of the originally implanted SIS material over time. The contralateral normal Achilles tendons served as controls as did four additional dogs that had a 1.5 cm segmental Achilles tendon defect created surgically without subsequent surgical repair with SIS. Results showed the SIS remodeled neotendons to be stronger than the musculotendinous origin or the boney insertion (> 1000 N) by 12 weeks after surgery and to consist of organized collagen-rich connective tissue similar to the contralateral normal tendons. The four dogs in which no SIS was implanted showed inferior strength at the comparable time points of 4, 8, 12, and 16 weeks. Immunohistochemical studies suggest that the SIS biomaterial becomes degraded within the first eight weeks and serves as a temporary scaffold around which the body deposits appropriate and organized connective tissue. SIS is a promising biomaterial worthy of further investigation for orthopedic soft tissue applications.

Three-dimensional anatomy of the cancellous structures within the proximal femur from computed tomography data

Quantitative computed tomography was used to investigate the three-dimensional architecture and the density distribution of the cancellous structures of the proximal femur. We examined 10 femora from the cadavera of 10 individuals, 47-83 years old at the time of death. Three anatomic elements could be distinguished: the epiphysis, the epiphyseal scar, and the metaphysis. Although these elements constitute a functional unit, their individual cancellous patterns revealed significant structural differences. The epiphyseal segment had a more reticulate cancellous appearance, whereas the metaphysis demonstrated a more longitudinally oriented trabecular distribution. The three-dimensional reconstruction of the densest epiphyseal trabecular groups showed two different patterns: a dumbbell type (found in eight bones) and a hemispheric type (found in two bones). The epiphyseal scar was a clearly recognizable high-density structure found in all 10 bones. The epiphyseal scar-diaphysis angle was 13-26 degrees higher than the center column-diaphysis angle. The scar appeared as a tray supporting the epiphyseal cancellous structures, supported itself by the metaphyseal intersection of the main compressive and the arcuate trabecular systems. This intersection always occurred in a relatively small band-shaped zone under the central third of the epiphyseal scar. These three discrete anatomical segments within the proximal femur may reflect developmental and functional adaptations determined by joint incongruity or eccentric muscular activity. The present data will serve as a reference for future studies in which the cancellous patterns are used to help with the early diagnosis of states of disease.

Full-length and short forms of utrophin, the dystrophin-related protein

All previous studies of the localization of utrophin (the dystrophin-related protein) in muscle and other tissues have been performed only with antibodies against the C-terminal region of the protein. Since several short forms of dystrophin, the apo-dystrophins, are produced from the 3' end of the dystrophin gene, there is a possibility that similar short forms of utrophin exist and that these could be responsible for some of the many different localizations of 'utrophin' in muscle. We have produced a new panel of 15 mAbs against the N-terminal region of utrophin and we have used it together with mAbs against the C-terminal region to show that full-length utrophin is present at neuromuscular junctions, in nerves, blood vessels and capillaries in normal muscle and in the sarcolemma of patients with muscular dystrophy and dermatomyositis. However, two of the 15 mAbs also recognised rat/mouse utrophin and both of these detected an additional 62 kDa protein on Western blots of rat C6 glioma cells. This potential 62 kDa 'apo-utrophin' was not detected in human cerebral cortex, in rat Schwannoma cells nor in any of the non-nerve cells and tissues tested.

A novel root gravitropism mutant of Arabidopsis thaliana exhibiting altered auxin physiology

A root gravitropism mutant was isolated from the DuPont Arabidopsis thaliana T-DNA insertional mutagenesis collection. This mutant has reduced root gravitropism, hence the name rgr1. Roots of rgr1 are shorter than those of wild-type, and they have reduced lateral root formation. In addition, roots of rgr1 coil clockwise on inclined agar plates, unlike wild-type roots which grow in a wavy pattern. The rgr1 mutant has increased resistance, as measured by root elongation, to exogenously applied auxins (6-fold to indole-3-acetic acid, 3-fold to 2,4-dichlorophenoxyacetic acid, and 2-fold to napthyleneacetic acid). It is also resistant to polar auxin transport inhibitors (2-fold to triiodobenzoic acid and 3- to 5-fold to napthylphthalamic acid). The rgr1 mutant does not appear to be resistant to other plant hormone classes. When grown in the presence of 10(-7) M 2,4-dichlorophenoxyacetic acid, rgr1 roots have fewer root hairs than wild type. All these rgr1 phenotypes are Mendelian recessives. Complementation tests indicate that rgr1 is not allelic to previously characterized agravitropic or auxin-resistant mutants. The rgr1 locus was mapped using visible markers to 1.4 +/- 0.6 map units from the CH1 locus at 1-65.4. The rgr1 mutation and the T-DNA cosegregate, suggesting that rgr1 was caused by insertional gene inactivation.