Abstract P2-14-19: Surgical and long-term outcomes of patients receiving neoadjuvant pertuzumab-containing regimens for HER2-positive localized breast cancer

Background: The addition of pertuzumab to trastuzumab and chemotherapy significantly improves the pathologic complete response (pCR) rate in HER2+ localized breast cancer in the preoperative setting. Although many patients are converted to breast conserving therapy (BCT) candidates by neoadjuvant HER2-directed therapy, a significant proportion opt for a mastectomy for various reasons. Among mastectomy procedures, nipple sparing mastectomy (NSM) is frequently chosen instead of non-nipple sparing mastectomy (NNSM). In this study, we evaluated the surgical and long-term outcomes of HER2+ patients receiving neoadjuvant pertuzumab-containing regimens.

Methods: We performed a retrospective review of localized breast cancer patients treated with neoadjuvant pertuzumab-containing regimens from 2011 to 2016, who underwent BCT or mastectomy at an academic institution and two community-based practices. Disease characteristics, treatment regimens, surgical outcomes, and recurrence data were extracted from the electronic medical records.

Results: Among 90 patients with stage II-III HER2+ breast cancer, 45 received AC-THP (50.0%), 26 received THP (with adjuvant AC) (29.0%), and 19 received TCHP (21.0%). The majority of patients had grade 3 tumors (61.1%), clinical stage II disease (80.0%), invasive ductal carcinoma (86.7%), and ER+ disease (65.6%). Thirty-seven (41.0%) patients underwent BCT and 53 (59.0%) patients underwent mastectomy. Among the mastectomy patients, 38 (71.7%) patients underwent bilateral mastectomies, specifically 33 (62.0%) patients underwent a NSM and 20 (38.0%) patients underwent a NNSM. The type of surgery that patients underwent stratified by type of neoadjuvant regimen is outlined in the Table 1 below. Most patients who underwent BCT and mastectomy received radiation, including 36 (97.3%) BCT, 24 (72.7%) NSM, and 18 (95.0%) NNSM. Over a median follow-up period of 33 months, 6 patients (6.7%) had recurrences with 2 (2.2%) local recurrences and 4 (4.4%) distant recurrences. The 2 local recurrences occurred in one patient who underwent BCT and one patient who underwent NNSM followed by post-mastectomy radiation.

Conclusions: Among mastectomy patients, NSM was more commonly pursued than NNSM. Rates of local recurrence following pertuzumab-containing regimens for HER2-positive localized breast cancer were low overall, regardless of the type of surgery. Data on plastic surgery approaches and complication rates will be presented at the meeting.

Table 1.Type of surgery in patients receiving neoadjuvant HER2-directed therapy. AC-THP (N = 45)TCHP (N = 19)THP (N = 26)BCT46.7%47.4%26.9%NNSM26.7%10.5%23.1%NSM26.7%42.1%50.0%

Citation Format: Haddad SA, Spring LM, Jimenez RB, Vidula N, Comander A, Shin JA, Coopey SB, Gadd MA, Hughes KS, Taghian A, Smith BL, Isakoff SJ, Moy B, Bardia A, Specht MC. Surgical and long-term outcomes of patients receiving neoadjuvant pertuzumab-containing regimens for HER2-positive localized breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-14-19.

Abstract P2-12-05: Real-time, intraoperative detection of residual breast cancer in lumpectomy cavity margins using the LUM imaging system: Results of a feasibility study

Background: Obtaining tumor-free margins is critical for local control in breast conserving surgery. Currently, 20-40% of lumpectomy patients have positive margins that require surgical re-excision. We assessed the LUM Imaging System for real-time, intraoperative detection of residual tumor in breast cancer patients. The LUM System has the particular advantage of assessing in vivo lumpectomy cavity walls rather than excised specimens, to enable more accurate excision of residual tumor.

Methods: Lumpectomy cavity walls of patients undergoing lumpectomy for invasive breast cancer or ductal carcinoma in situ (DCIS), were assessed intraoperatively using the LUM Imaging System (Lumicell Inc., Wellesley MA). LUM015, a cathepsin-activatable fluorescent agent, was given IV 4±2 hrs prior to surgery. Areas of fluorescence generated at potential sites of residual tumor in lumpectomy cavities were evaluated with a sterile hand-held device, displayed on a monitor, excised and correlated with histopathology.

Results: In vivo lumpectomy cavities were imaged with the LUM Imaging System in 60 breast cancer patients. 5 were imaged without dye. 55 received LUM015 dye preoperatively and were scanned intraoperatively. Median age was 60 years (range 44-79). Mean tumor size was 1.2cm (0.06-3.5cm) with 71% invasive cancers, 29% DCIS. The test set included 569 cavity margin surfaces assessed intraoperatively and excised. Image acquisition for each margin took approximately 1 second. The LUM Imaging System showed 100% sensitivity and 73% specificity for detection of tumor <2mm from the margin. Invasive ductal cancer (IDC), invasive lobular cancer (ILC) and areas of DCIS 1mm in size could be identified. 8 patients had positive margins on standard histopathology analysis (Table). The LUM System correctly identified all positive margins identified by standard histopathology and correctly predicted negative re-excisions in 2 of 8 patients. There were no serious adverse events. 1 patient had extravasation of LUM015 at her injection site with temporary blue skin staining but no other complication.

Conclusions: The LUM Imaging System allows real-time identification of residual tumor in the lumpectomy cavity of breast cancer patients. No sites of residual tumor were missed. Additional studies are underway to optimize this approach for reducing positive margins and second surgeries in breast cancer patients.

Table: Margin results in 8 patients with positive margins on initial lumpectomy specimenPositive lumpectomy margin histopathologyLUM cavity wall result (+/- for tumor)Tumor found at re-excisionDCIS++DCIS+-DCIS++IDC++ (Mastectomy)ILC++ (Mastectomy)DCIS+-IDC--DCIS--

Citation Format: Lanahan CR, Gadd MA, Specht MC, Ferrer J, Tang R, Rai U, Merrill AL, Biernacka A, Brachtel E, Smith BL. Real-time, intraoperative detection of residual breast cancer in lumpectomy cavity margins using the LUM imaging system: Results of a feasibility study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-12-05.

Offspring neuroimmune consequences of maternal malnutrition: Potential mechanism for behavioral impairments that underlie metabolic and neurodevelopmental disorders

Maternal malnutrition significantly increases offspring risk for both metabolic and neurodevelopmental disorders. Animal models of maternal malnutrition have identified behavioral changes in the adult offspring related to executive function and reward processing. Together, these changes in executive and reward-based behaviors likely contribute to the etiology of both metabolic and neurodevelopmental disorders associated with maternal malnutrition. Concomitant with the behavioral effects, maternal malnutrition alters offspring expression of reward-related molecules and inflammatory signals in brain pathways that control executive function and reward. Neuroimmune pathways and microglial interactions in these specific brain circuits, either in early development or later in adulthood, could directly contribute to the maternal malnutrition-induced behavioral phenotypes. Understanding these mechanisms will help advance treatment strategies for metabolic and neurodevelopmental disorders, especially noninvasive dietary supplementation interventions.

Abstract P5-13-09: Development and implementation of a patient-centered, nurse practitioner-led survivorship intervention for breast cancer

This abstract was withdrawn by the authors.

Abstract P4-01-05: In vivo, intraoperative margin detection utilizing the Lumicell margin assessment system

This abstract was withdrawn by the authors.

Recent highlights from atomic force microscopy of DNA

Abstract Seven recent highlights are presented from atomic force microscopy (AFM) of DNA in this lab. The first two involve advances in the observation of enzymatic reactions in near-physiological solutions. E. coli RNA polymerase was observed to process along its DNA template in a series of time-lapse images [S. Kasas, et al., Biochemistry 36, 461 (1997)], and a new small-cantilever atomic force microscope (AFM) imaged DNA degradation by DNase I at rates as fast as two seconds per image. The next five highlights involve structural observations of DNA and DNA-protein complexes, including DNA condensed for gene delivery, sequence-dependent DNA condensation, an AFM assay for RNA polymerase, and AFM evidence for a yeast kinetochore complex that may be involved in holding together sister chromatids during cell division.

Shake and stew: a non-destructive PCR-ready DNA isolation method from a single preserved fish larva

A rapid non-destructive alternative to isolate DNA from an individual fish larva is presented, based on the suspension of epithelial cells through vortex forces, and the release of DNA in a heated alkaline solution. DNA from >6056 fish larvae isolated using this protocol has yielded a high PCR amplification success rate (>93%), suggesting its applicability to other taxonomic groups or sources when tissue amount is the limiting factor.

A review of the Neotyphodium lolii / Lolium perenne symbiosis and its associated effects on animal and plant health, with particular emphasis on ryegrass staggers

Ryegrass staggers is a seasonal mycotoxicosis of grazing livestock characterised by tremors, in coordination and a staggering gait almost unaccompanied by physical lesions. Deaths occur only as a consequence of accident or starvation. Outbreaks, in summer and autumn, occur only on pasture in which endophyte (Neotyphodium lolii)-infected perennial ryegrass (Lolium perenne) predominates and usually on which animals are grazed intensively. Animals recover when moved to a different type of grazing or after rain has promoted pasture growth. The disease was recognised for 80 years before its cause was discovered as a consequence of a grazing trial of sheep on three ryegrass cultivars which happened to have three different levels of endophyte infection. The endophyte was first formally described as Acremonium loliae, later corrected to Acremonium lolii, and was finally placed in the genus Neotyphodium. It produces a number of secondary metabolites of which lolitrem B is the principal one causing ryegrass staggers symptoms. Ergopeptides are also produced which cause heat stress and lack of productivity. N. lolii is symptomless in the plant, seed borne and grows intercellularly in the aerial parts, mainly in reproductive tillers and leaf sheaths but sparsely in leaf blades. It dies in stored seed and infection rates of different ryegrass cultivars have depended on seed storage times during their production. In addition, N. Lolii produces insect feeding deterrents, among them peramine, which protects infected plants from pest predation. Because of this, control of ryegrass staggers by elimination of endophyte-infected ryegrass is not feasible in areas in which insect predation is a serious pasture problem. However, N. lolii strains vary in the secondary metabolites they produce allowing the selection of strains that produce desirable metabolites. By inoculating such strains into uninfected ryegrass plants it is possible to produce cultivars which do not cause ryegrass staggers but resist insect predation. This review aims to provide a comprehensive summary of the current understanding of the N. lolii / L. perenne symbiosis, the toxins it is known to produce, their effects on animals and plants and the strategies used to control their ill effects while maximising their beneficial ones.

PL3-1: Advances in Axillary Surgery: Sentinel Nodes and beyond

Axillary node status is one of the strongest prognostic factors in breast cancer patients. The presence of tumor in axillary nodes, and number of positive nodes, predicts risk of metastatic disease and long term survival.

In the past, axillary dissection provided both accurate evaluation of nodal status and excellent local control. However, complications of axillary dissection, including lymphedema, pain, and impaired arm function, have led to keen interest in alternatives to axillary dissection for local control and assessment of prognosis.

Sentinel node biopsy provides a low-morbidity alternative to axillary dissection for patients with clinically negative nodes. It was recognized that breast lymphatics converge in the axilla, delivering fluid, travelling tumor cells and dye particles to a small number of “sentinel” nodes. Sentinel node biopsy techniques take advantage of this lymphatic anatomy using dye injection intraoperatively to permit identification and removal of only the most important axillary nodes - those most likely to contain metastases. A negative sentinel node provides accurate staging and reliably predicts a low axillary recurrence rate, eliminating the need for dissection. Sentinel node mapping also allows study of the relationship between the size of a nodal metastasis and impact on prognosis. Sentinel node mapping techniques, morbidity, and data on the reliability of sentinel node biopsy will be reviewed.

40–50% of patients with a positive sentinel node will have additional positive axillary nodes, indicating a need for additional axillary treatment for local control. Completion axillary dissection was initially used for local control and prognostic assessment in patients with a positive sentinel node. Recently, the ACOSOG Z0011 trial showed that patients with 1 or 2 positive sentinel nodes who receive standard whole breast irradiation without further axillary surgery have equivalent local control as patients having completion axillary dissection. Axillary recurrence rates in the Z0011 trial were <1% at 6.3 years follow-up in both the radiation alone and dissection arms. Changing axillary management algorithms resulting from these data will be discussed. Sentinel node biopsy can now replace axillary dissection for patients with negative nodes undergoing either lumpectomy or mastectomy. Sentinel node biopsy can also replace dissection for lumpectomy patients with 1–2 positive sentinel nodes where data on the precise number of additional positive axillary nodes is not needed for treatment decisions. At present, axillary dissection is still recommended for patients with palpable axillary nodes, 3 or more positive sentinel nodes, gross extranodal tumor, and positive sentinel nodes after neoadjuvant therapy, or for positive nodes in patients undergoing mastectomy. Trials of radiation instead of dissection in such patients are likely.

Management of the axilla will evolve further as options for assessment of tumor and host factors increase. Gene expression profiling may prove more important than primary tumor size and node status for predicting prognosis and guiding therapy - an approach already used in estrogen receptor positive tumors. Future options for incorporating axillary node status with tumor and host factors in breast cancer management will be considered.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr PL3-1.

S4-4: Clarifying the Risk of Breast Cancer in Women with Atypical Breast Lesions

Background: Women diagnosed with atypical ductal hyperplasia (ADH), atypical lobular hyperplasia (ALH), lobular carcinoma in situ (LCIS), and borderline ADH/DCIS are at increased risk for breast cancer, but the precise degree of risk varies widely in the literature. Information from prior studies is limited by grouping ADH and ALH together and by small cohort sizes.

Objectives: To identify women with a pathologic diagnosis of ADH, ALH, LCIS, and borderline ADH/DCIS using Natural Language Processing. To evaluate breast cancer risk based on atypia type.

Methods: Using Natural Language Processing, we reviewed all electronically available pathology reports from Massachusetts General Hospital, Brigham and Women's Hospital, and Newton-Wellesley Hospital (members of Partners HealthCare System) from 1987–2010. We identified all women with a diagnosis of ADH, ALH, LCIS, and borderline ADH/DCIS with no prior or concurrent diagnosis of breast cancer. We determined the incidence of subsequent invasive and noninvasive breast cancer, the side of cancer diagnosis compared to original atypia side, and the time to cancer diagnosis for each atypia type.

Results: We reviewed 76,333 path reports in 42,950 unique individuals and identified 3049 women who were diagnosed with atypical breast lesions over this 14-year period; 1233 (40.4%) had ADH, 851 (27.9%) had ALH, 595 (19.5%) had LCIS, and 370 (12.1%) had borderline ADH/DCIS. The mean age for atypia diagnosis was 51 years (range: 18–93). At a mean follow-up of 66 months, cancer occurred in 7.0% of women with ADH, 11.3% of women with ALH, 11.1% of women with LCIS, and 8.4% of women with borderline ADH/DCIS. The median time to breast cancer diagnosis was 48 months with ADH, 50 months with ALH, 47 months with LCIS, and 60 months with borderline ADH/DCIS. Significantly more ipsilateral cancers developed than contralateral cancers for all types of atypia combined (p=0.027).

Recurrence rates and long-term survival in women diagnosed with breast cancer at age 40 and younger

70

Background: Young age at diagnosis of breast cancer has been reported to be an independent risk factor for disease recurrence. However, there is little data on long term survival of young patients. We present long term follow up of a large cohort of women diagnosed with breast cancer at age 40 and younger. We determined rates of loco-regional recurrence (LRR), distant recurrence, and overall survival and adjusted for the patient and tumor characteristics which potentially predict outcomes.

Methods: Following Institutional Review Board approval, data from the medical records of 628 women diagnosed with breast cancer at age 40 or younger between 1996 and 2008 were collected. Survival curves were estimated using the Kaplan Meier method.

Results: Median age was 37 years (range: 21-40) and median follow-up was 72 months (range: 5-177). The rates of LRR as a first site of recurrence were 5.56% at 5 years and 12.11% at 10 years. In the entire population, with median follow-up of 72 months, there was no difference in the rates of loco-regional failure between patients who underwent breast conserving therapy (7.34%) compared to mastectomy (7.40%) (p=0.980). The rates of distant recurrence as a first event were 10.65% at 5 years and 14.58% at 10 years. Overall survival was 93.1% at 5 years and 87.26% at 10 years. 79.1% of patients received systemic therapy. For patients who developed disease recurrence, either LRR or distant, median time to first recurrence was 35 months (range: 3-167).

Conclusions: Women aged 40 and younger at diagnosis of breast cancer have a good prognosis, with low overall recurrence rates at 5 and 10 years. Local recurrence in our cohort is lower than in prior studies, suggesting advances in therapy have made breast conservation a safe option in young breast cancer patients.

Performance of lactating dairy cows fed corn as whole plant silage and grain produced from genetically modified corn containing event DAS-59122-7 compared to a nontransgenic, near-isogenic control

The nutritional equivalency of grain plus whole plant silage from genetically modified corn plants containing the DAS-59122-7 (59122) event expressing the Cry34Ab1 and Cry35Ab1 proteins to grain and silage from a near-isogenic corn hybrid without this trait (control) was assessed using lactating dairy cows. Corn plants with event 59122 are resistant to western corn rootworm and tolerant to the herbicide active ingredient glufosinate-ammonium. Effects on feed intake, milk production, and milk composition were determined. The 59122 grain and the control grain were produced in 2005 from isolated plots in Richland, Iowa. Whole plant corn silage for the 59122 and control treatments were grown in isolated plots at the Kansas State University Dairy Center and ensiled in Ag-Bags. Thirty lactating Holstein cows blocked by lactation number, day of lactation, and previous energy-corrected milk production were used in a switchback design. All cows were fed diets that contained 22.7% grain plus 21.3% whole plant silage from either the 59122 or the control hybrid, in addition to 21% wet corn gluten feed, 12.3% protein mix, 8.0% whole cottonseed, and 14.7% alfalfa hay. Each period of the switchback trial included 2 wk for diet adjustment followed by 4 wk for data and sample collection. Milk samples (a.m. and p.m.) collected from 2 consecutive milkings of each collection wk were analyzed for fat, protein, lactose, solids-not-fat, milk urea nitrogen, and somatic cell count. Percentages of milk fat, protein, lactose, and solids-not-fat were not affected by dietary treatment. Yields of milk, 4% fat-corrected milk, energy-corrected milk, solids-corrected milk, and the concentrations and yields of milk fat, milk protein, milk solids, and milk lactose were not significantly different between treatments. Efficiencies of milk, fat-corrected milk, energy-corrected milk, and solids-corrected milk production also were not different when cows were fed crops from 59122 than when they were fed the control hybrid. Milk production efficiency averaged 1.48 and 1.50 kg/kg of dry matter intake for cows fed diets containing the control and 59122 corn, respectively. These data indicate that the nutritional value for milk production was not different between a diet containing grain plus whole plant corn silage produced from a 59122 corn hybrid versus a diet containing grain and corn silage from its near-isogenic control corn hybrid.

Relationship between sporidesmin-induced liver injury and serum activity of gamma-glutamyltransferase in Romney lambs sired by facial eczema-resistant or control rams

AIM

To test whether long-term selection for resistance to facial eczema (FE) influences the relationship between liver injury score (LIS) and serum activity of gamma-glutamyltransferase (GGT) in sporidesmin-dosed sheep.

METHODS

Two groups of Romney lambs were generated for this study in 1999, out of an unselected group of ewes and sired by either selected FE-resistant (R) line (n=74 lambs) or unselected Control (C) line (n=119 lambs) rams from the Ruakura Research Centre long-term FE-selection experiment. The lambs were given a single oral dose of sporidesmin, sampled for determination of serum GGT activity 3 weeks later, and lambs that had serum GGT activity >55 IU/l (reactors) were humanely killed and assessed for LIS post mortem, 6 weeks after dosing. A second round of dosing was applied to the nonreactors, followed as above by analysis of serum GGT activity and assessment of LIS post mortem (both reactors and nonreactors).

RESULTS

There was a significant linear relationship between LIS and logeGGT, which did not differ between the 2 sire lines (LIS= -2.96 (SE 0.38) + 0.89 (SE 0.07) x loge GGT, R2=0.54, p<0.001).

CONCLUSIONS

Serum GGT is a valid indicator of LIS in lambs by sires selected for different levels of susceptibility to FE. The logeGGT-LIS relationship has not changed as a result of genetic selection for resistance to FE.

A zinc-containing intraruminal device for prevention of the sporidesmin-induced cholangiopathy of facial eczema in calves

AIM

To develop and evaluate a zinc-containing intraruminal controlled-release bolus for protection of calves (175-250 kg bodyweight) against facial eczema (FE).

METHODS

Boluses releasing zinc, in the form of zinc oxide, at rates ranging from 1.67 to 4.25 g/day were administered to calves which were challenged 4 weeks later with the FE toxin, sporidesmin. The efficacy of the boluses in protecting against sporidesmin-induced cholangiopathy was determined by measuring serum activities of gamma-glutamyltransferase (GGT).

RESULTS

A bolus releasing zinc at approximately 4.25 g/day gave excellent protection against sporidesmin toxicity for periods of up to 5 weeks duration.

CONCLUSIONS

This zinc-containing intraruminal controlled-release bolus has the potential to markedly reduce the incidence and severity of FE in calves within a 175-250 kg bodyweight range.

Abstract P1-15-03: Eight-Year Update of a Prospective Study of Wide Excision Alone for Ductal Carcinoma In Situ (DCIS) of the Breast

Background: The need for radiation therapy (RT) in conservatively managed DCIS is a source of ongoing debate. This is an updated analysis of a phase II prospective study of wide excision alone for DCIS. The study was activated in May 1995 and closed in July 2002 following accrual of 158 patients because the number of local recurrences (LR) met the predetermined stopping rules. The objective of the analysis is to update the distribution and cumulative incidence of events (LR, contralateral breast cancer [CBC], second malignancy and death from other causes). Materials and Methods: A total of 158 patients had DCIS with predominant nuclear grade 1 or 2, a mammographic extent of ≥2.5 cm, and excision with final microscopic margins of ≥1 cm or a re-excision without residual DCIS. Tamoxifen was not permitted. The results presented are from the 8-year analysis (8-year minimum potential follow-up time). Twenty-six patients without recurrence who were followed less than 8 years were excluded from the analysis as were 7 first events (4 LR) that occurred beyond 8 years of follow-up; the analysis thus includes 132 patients and 36 first events. Cumulative incidence curves were generated to assess the rates of LR or other events. Median follow up time was 10 years. Results: Overall, 36/132 patients (27%) had a first event as of April 2010. Of these 36 events, 19 were LR, 13 were CBC, 1 was a second malignancy, and 3 were deaths from other causes. Of the 19 LR, 13 (68%) were DCIS only and 6 (32%) were invasive. Fourteen occurred in the same quadrant and 5 were elsewhere in the ipsilateral breast. The 8-year estimated cumulative incidence of LR was 14.4% (95% CI: 8.4-20.4%). For all other events, the 8-year estimated cumulative incidence was 12.9% (95% CI: 3.6-13.1%).

The estimated annual percentage rates of LR, CBC, and other events were 2.1%, 1.5% and 0.4%, respectively.

Discussion: The results of this prospective study demonstrate a substantial and ongoing risk of LR and CBC in patients with small, nuclear grade 1 or 2 DCIS treated with wide excision with margins of ≥1cm in the absence of RT. Most LRs occurred in the same quadrant, rather than elsewhere in the breast, suggesting that excision alone is inadequate even for this highly selected population. Further study is warranted to determine if there is a subgroup of DCIS patients with nuclear grade 1 or 2 disease who are at low enough risk of LR following wide excision that RT can be omitted safely.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P1-15-03.

Significance of internal mammary lymph nodes in patients after mastectomy with tissue-expander reconstruction: a case-control study

AIM

To retrospectively assess the frequency of internal mammary lymph nodes (IMNs) in patients after mastectomy and tissue-expander reconstruction.

MATERIALS AND METHODS

Statistical analysis was performed for all available data in patients with mastectomy and tissue-expander reconstruction from 2004-2007 (study group). The data were compared with that of a control population with mastectomy who did not have reconstruction (control group). Patients with recurrent breast cancers, previous breast reconstruction, surgeries performed at outside hospitals, no available pre- or postoperative computed tomography (CT) or magnetic resonance imaging (MRI) data, or inadequate imaging follow-up were excluded.

RESULTS

There were eight patients in the study group (median age 50.5 years, seven breast cancers), and eight patients in the control group (median age 52 years, seven breast cancers). No patients had IMNs on their preoperative imaging examinations. New IMNs were present in postoperative imaging in seven of eight patients (7/8, 87.5%) in the study group. All of them were stable or decreased in size on subsequent imaging examinations. None of the patients in the control group had IMNs (0/8).

CONCLUSION

IMNs are common on imaging after mastectomy and tissue-expander placement. The IMNs decreased or remained stable on follow-up imaging and may represent reactive nodes.

Nipple-sparing mastectomy

Background

Although effective local control is the primary goal of surgery for breast cancer, the long-term aesthetic outcome is also important. Nipple-sparing mastectomy aims to address this, but there is no consensus on its clinical application. Evidence relating to oncological safety, surgical technique and early data on aesthetic outcome was reviewed.

Methods

The review was based on a PubMed search using the terms ‘nipple-sparing’ or ‘subcutaneous mastectomy’ and ‘breast cancer’.

Results

Large pathological studies report occult nipple involvement with cancer in 5·6–31 per cent, reflecting variation in inclusion criteria. Recent clinical series with careful patient selection report local recurrence in less than 5 per cent of patients. The incidence of cancer in the retained nipple after risk-reducing mastectomy is less than 1 per cent. Nipple necrosis rates range up to 8 and 16 per cent for total and partial necrosis respectively. Variations in outcome result from differences in extent of resection, placement of incisions and type of breast reconstruction.

Conclusion

Nipple-sparing mastectomy is an acceptable technique for women undergoing risk-reducing mastectomy. In the therapeutic setting, it may be offered to patients with smaller tumours far from the nipple and favourable pathological features. Women should be counselled about nipple necrosis and the potential for local recurrence.

Neoadjuvant cisplatin and bevacizumab in triple negative breast cancer (TNBC): Safety and efficacy

551

Background: We have previously shown that neoadjuvant cisplatin has activity in TNBC, a subtype of breast cancer for which there is no effective targeted therapy. Bevacizumab adds to the efficacy of chemotherapy in metastatic breast cancer; however, there is limited data on the safety or efficacy of bevacizumab in combination with chemotherapy in the neoadjuvant or adjuvant setting. Thus, we sought to explore the safety and efficacy of the addition of bevacizumab to cisplatin in the treatment of TNBC. Methods: 51 patients (pts) with confirmed TNBC provided informed consent and were enrolled in a single arm phase II trial of neoadjuvant cisplatin 75 mg/m2 q 3 weeks x 4 cycles and bevacizumab 15 mg/kg q 3 weeks x 3 cycles prior to definitive surgery. Only 3 cycles of bevacizumab were delivered to allow 6 weeks between the last dose of bevacizumab and surgery. Research biopsies were obtained and breast MRI performed before treatment and at surgery. Postoperatively, pts received doxorubicin and cytoxan (AC) plus bevacizumab or AC/Taxol plus bevacizumab. Median age was 50 yrs (range 30 to 66 yrs); tumors were clinical T1 (2%), T2 (80%), T3 (18%). Results: Forty-six pts are evaluable for response and 5 pts are still receiving neoadjuvant therapy. Clinical responses to date: 12/46 (26%) clinical complete response (cCR), 24/46 (52%) clinical partial response (cPR), 5/46 (11%) stable disease (SD), and 1/46 (2%) progressive disease (PD). Non-responders included 4/46 (9%) pts who discontinued protocol therapy for toxicity. To date, 7/46 (15%) pts achieved a complete pathological response (Miller-Payne 5) and an additional 10/46 (22%) were Miller-Payne 4. Five pts did not complete neoadjuvant therapy, 2 with tinnitus/hearing loss and 3 with grade 4 toxicities consisting of refractory hypertension in 1 pt and pulmonary embolism (PE) in 2 pts. Tissue-based assays to predict platinum/bevacizumab responses, including BRCA1/2 status, are underway. Conclusions: Cisplatin and bevacizumab has some activity in TNBC as demonstrated by 37% of evaluable pts with a Miller-Payne 4 or 5 pathological response. However, toxicity, including tinnitus/hearing loss, hypertension and PE, limited completion of neoadjuvant therapy in 11% of pts.

No significant financial relationships to disclose.

Predicting risk of developing invasive breast cancer in the African American female population

11080

Background: African Americans (AA) have a lower incidence of breast cancer with a poorer prognosis than Caucasians. It is unclear whether AA women have fewer known risk factors for breast cancer or that risk factors have a lesser effect in AA. We evaluated the accuracy of the race-based modification Gail Model in predicting the risk of developing invasive breast cancer in the AA population. Methods: With IRB approval, we performed a retrospective analysis of data obtained from women (n=15,973) ages 40–79 presenting to our Breast Center(5/2003 to 7/2005) for a screening mammogram. The five-year probability of breast cancer for AA (n=702) versus Caucasians (n=15,721) was calculated for each individual using 3 methods: 1) the race specific Gail model, 2) the Gail model ignoring race (AA using the Caucasian model), and 3) age and race matched SEER projection using DevCan (v6.1.1) software. Results: There was no significant difference between the 5-year probability of breast cancer for Caucasians as calculated by the Gail model vs. the SEER prediction (p=NS), suggesting our population was representative of the larger study population from which SEER data was derived. As compared to SEER prediction, the modified Gail model underestimated the breast cancer risk for all age groups of AA (p<0.0001). When the Gail Model without the race-based modification was applied to the AA population, the projected risk was not significantly different from the SEER prediction (p=0.1049). Conclusions: This study suggests that the race-based modification of the Gail Model underestimate the risk of breast cancer in AA women. When the model is applied to AA women without incorporating the modification for race, the Gail model accurately reflects SEER 5-year projections of risk of invasive cancer in AA women. Differences in risk factor distribution among race, rather than a differential effect of those factors on risk, may have a substantial role in explaining the lower incidence in AA women as compared to Caucasian women over 40.

[Table: see text]

No significant financial relationships to disclose.

Evaluation of corn grain with the genetically modified input trait DAS-59122-7 fed to growing-finishing pigs

A growth performance experiment was conducted to assess the feeding value of a double-stacked transgenic corn grain for growing-finishing pigs. The genetically modified corn grain contained event DAS-59122-7, which expresses the Cry34/35Ab1 binary insecticidal protein for the control of corn rootworm. This modified transgenic grain is resistant to western corn rootworm and is also tolerant to herbicides containing the active ingredient glufosinate-ammonium. The modified grain (59122), a nontransgenic near-isoline grain (control corn), and a commercial corn (Pioneer brand hybrid 35P12) were grown in a 2005 production trial in individually isolated plots that were located 201 m apart. A total of 108 pigs were allotted to corn-soybean meal diets containing 1 of the 3 grains as the sole source of corn. There were 3 pigs per pen and 12 replicate pens per treatment. Pigs were fed grower diets from 37 to 60 kg, early finisher diets from 60 to 90 kg, and late finisher diets from 90 to 127 kg. Within each phase, data for ADG, ADFI, and G:F were calculated. At the conclusion of the experiment, pigs were slaughtered and data for carcass quality were collected. Differences between 59122 and the control corn were evaluated, with statistical significance at P<0.05. No differences in ADG, ADFI, or G:F between pigs fed the control corn and pigs fed the modified corn were observed during the grower, early finisher, or late finisher phases. For the entire experimental period, no difference between pigs fed the control and the 59122 corn were observed for final BW (128.9 vs. 127.1 kg), ADG (1.02 vs. 1.00 kg), ADFI (2.88 vs. 2.80 kg), or G:F (0.356 vs. 0.345 kg/kg). Likewise, no differences in dressing percentage (76.48 vs. 76.30%), LM area (49.8 vs. 50.4 cm(2)), 10th-rib back fat (2.20 vs. 2.12 cm), and carcass lean content (52.9 vs. 53.4%) were observed between pigs fed the control and the 59122 corn grain. It was concluded that the nutritional value of the modified transgenic corn grain containing event DAS-59122-7 was similar to that of the nontransgenic near-isoline control.

Development and validation of a model predictive of occult nipple involvement in women undergoing mastectomy

Background

This prospective study aimed to build a predictive model using preoperative information to aid selection for nipple-sparing mastectomy.

Methods

Two hundred consecutive skin-sparing mastectomy specimens without overt nipple involvement were evaluated. Demographic, preoperative pathology and imaging information was collected. Nipple specimens (2 × 2 × 2 cm) were sectioned at 3-mm intervals. Haematoxylin and eosin-stained slides were examined by a breast pathologist for involvement by tumour. Logistic regression analyses of 65 therapeutic procedures identified factors associated with occult involvement and created a predictive model. This was tested on specimens from a further 65 therapeutic procedures.

Results

Occult nipple involvement was noted in 32 (24·6 per cent) of 130 mastectomy specimens. In the training set, imaging diameter of the lesion and its distance from the nipple predicted nipple involvement on univariable analysis (P = 0·011 and P = 0·014 respectively). The multivariable logistic regression model was validated in the test set. The areas under the receiver–operating characteristic curve were 0·824 and 0·709 for the training and test sets respectively.

Conclusion

Three-quarters of women undergoing mastectomy did not have occult nipple involvement. A clinical tool including tumour size and distance from the nipple has been developed to improve patient selection for nipple-sparing mastectomy.

LCIS and tamoxifen use: A single institution review

1527

Background: Results of the NSABP-P1 trial were published in 1998 showing a 50% reduction in breast cancer in the high- risk population with the use of tamoxifen. The use of tamoxifen is individualized, and depends on both patient and physician factors. We looked at the recommendations for and the use of tamoxifen in women with LCIS. Methods: A retrospective chart review at a single institution was performed from March 27, 1980 through September 19, 2005 for patients diagnosed with LCIS. Pathology and operative reports, as well as patient notes were reviewed for discussions about tamoxifen. Data was collected on whether a discussion took place, whether tamoxifen was or was not advised, whether the patient declined to take tamoxifen, whether they took it in the past or were currently on tamoxifen. We also examined the rate of DCIS and invasive cancer in this population. Results: There were 321 patients diagnosed with LCIS. Of those patients 193 were diagnosed after the publication of the P1 trial. Of these 193 patients we identified 104(54%) patients whose charts contained notes indicating a discussion about tamoxifen. The results of the discussion about tamoxifen are as follows: 21(20%) patients were currently taking tamoxifen, 16(15%) had taken it in the past, 37(36%) patients declined to take tamoxifen, and 17(16%) had not made a decision about taking tamoxifen. There were 13(13%) patients for whom tamoxifen was advised against. In the entire cohort of 321 patients, 15% went on to develop DCIS or invasive cancer in the first 12 years of follow up. We did not look at cancer rate Vs tamoxifen use due to the small numbers with available information. Conclusions: While the P1 trial recommends tamoxifen for breast cancer prevention in high-risk patients, in our experience, almost half of the patients did not have a documented discussion about the medication, and the majority of those who did decided not to take tamoxifen. This will likely have a large impact on the rate of DCIS and invasive breast cancer in this group.

No significant financial relationships to disclose.

Pemetrexed (Alimta, LY231514) demonstrates clinical activity in chemonaive patients with cervical cancer in a phase II single-agent trial

The objective of this study was to determine the response rate in chemonaive patients with inoperable, locally advanced, recurrent, or metastatic cervical cancer treated with pemetrexed (Alimta, LY231514), a multitargeted antifolate. The patients were treated with either 500 mg/m(2) (11 patients) or 600 mg/m(2) (24 patients) of pemetrexed, administered as a 10-min infusion on day 1 of a 21-day cycle. Patients receiving 500 mg/m(2) dose also received 5 mg/day oral folic acid supplementation beginning 2 days prior and ending on day 3 of each cycle. Of the 34 patients evaluable for efficacy, six patients (18%) had partial response, with median response duration of 3.8 months (range, 3.3-6.6 months). Twenty-four patients (71%) had stable disease, one patient (3%) had progressive disease, and three patients could not be assessed. Median overall survival was 15.2 months (range, 2.9-35.3+ months). Grade 4 hematologic toxicities consisted of neutropenia (37%), leukopenia (9%), anemia (6%), and thrombocytopenia (3%). One patient died of hypotensive shock associated with frank rectal hemorrhage that was considered to be related to the study drug. We conclude that pemetrexed therapy showed moderate activity, similar to other active agents, in the treatment of locally advanced or metastatic cervical cancer.

Mechanism of bracken fern carcinogenesis: evidence for H-ras activation via initial adenine alkylation by ptaquiloside

Bracken fern (Pteridium spp.) causes cancer of the oesophagus and the urinary bladder in cattle and sheep. Ptaquiloside (PT) is believed to be the carcinogenic principle which alkylates DNA when activated to its unstable dienone form (APT) under alkaline conditions. In this report we present evidence for the presence of PT-DNA adducts in the ileum of bracken fem-fed calves using the 32P-postlabelling assay. H-ras mutations were also observed in the ileum using single strand conformation polymorphism (SSCP) technique. Mutations corresponding to adenine to pyrimidine transversions in the codon 61 of H-ras were identified by the cycle sequencing method. In vitro DNA alkylation studies showed that APT alkylated H-ras primarily at the adenines. In addition, the rate of depurination of alkylated adenine was sequence dependent. Investigation of DNA template activity using a plasmid DNA showed that DNA synthesis by T7 DNA polymerase was terminated by the presence of all alkylated bases but certain apurinic sites allowed the DNA synthesis to continue. These results suggest that initial alkylation of adenine by PT in codon 61 followed by depurination and error in DNA synthesis lead to activation of H-ras proto-oncogene.

Pithomycotoxicosis (facial eczema) in ruminants in the Azores, Portugal

Outbreaks of pithomycotoxicosis (facial eczema), a hepatogenous photosensitisation caused by the mycotoxin sporidesmin, have affected ruminants in the Azores Islands of Portugal after warm, humid periods during late summer and autumn. Twenty-two outbreaks were recorded in cattle between 1999 and 2001, affecting 11.4 per cent of the animals in the affected herds, and in 2000 there was an outbreak in one sheep flock in which more than 20 per cent of the sheep died. The clinical signs included decreases in milk production, weight loss, photosensitisation and its sequelae, including death. The animals had high activities of gamma glutamyltransferase in their serum, and icterus and severe liver disease, including biliary hyperplasia and fibrosis, were found postmortem. The characteristic spores of the toxigenic saprophytic fungus Pithomyces chartarum were found on grass; all 381 isolates of the fungus were toxigenic for sporidesmin by elisa, and the results were confirmed by high-performance liquid chromatography analysis. Cattle from farms at greatest risk of pithomycotoxicosis were protected by supplementing their concentrate feed with zinc oxide, or using a slow-release intraruminal zinc bolus.

Pemetrexed (Alimta®, LY231514) demonstrates clinical activity in chemonaive patients with cervical cancer in a phase II single-agent trial

The objective of this study was to determine the response rate in chemonaive patients with inoperable, locally advanced, recurrent, or metastatic cervical cancer treated with pemetrexed (Alimta®, LY231514), a multitargeted antifolate. The patients were treated with either 500 mg/m2 (11 patients) or 600 mg/m2 (24 patients) of pemetrexed, administered as a 10-min infusion on day 1 of a 21-day cycle. Patients receiving 500 mg/m2 dose also received 5 mg/day oral folic acid supplementation beginning 2 days prior and ending on day 3 of each cycle. Of the 34 patients evaluable for efficacy, six patients (18%) had partial response, with median response duration of 3.8 months (range, 3.3–6.6 months). Twenty-four patients (71%) had stable disease, one patient (3%) had progressive disease, and three patients could not be assessed. Median overall survival was 15.2 months (range, 2.9–35.3+ months). Grade 4 hematologic toxicities consisted of neutropenia (37%), leukopenia (9%), anemia (6%), and thrombocytopenia (3%). One patient died of hypotensive shock associated with frank rectal hemorrhage that was considered to be related to the study drug. We conclude that pemetrexed therapy showed moderate activity, similar to other active agents, in the treatment of locally advanced or metastatic cervical cancer.

Effects of low dose rates of sporidesmin given orally to sheep

AIM

To examine clinical and subclinical effects of sporidesmin administered orally to sheep at very low daily dose rates for periods of 3 to 48 days.

METHODS

Two experiments were conducted. In Experiment A, sporidesmin-A was administered orally to groups of 16 sheep at daily dose rates of approximately 0.0042, 0.0083 and 0.0167 mg/kg bodyweight for 48 days. In Experiment B, the highest of these doses was administered orally for 3, 6, 12, 24 or 48 consecutive days. Parameters of production, clinical findings, organ weights and pathological findings were recorded.

RESULTS

In Experiment A, severe liver lesions and photosensitisation were evident as early as 18 days after commencement of daily low-dose administration of sporidesmin, and were associated with significant bodyweight loss. Significant bodyweight loss also occurred in non-photosensitised sporidesmin-treated sheep. Bodyweight reductions were associated with reduced carcass weights and skin weights in treated animals. Sporidesmin administration was also associated with reduced bodyweight gains and pathological changes of the liver, kidney, hepatic lymph nodes, thymus, adrenal gland, heart and spleen. In Experiment B, only moderate changes occurred in a few sheep in the groups dosed with sporidesmin at 0.0167 mg/kg for 3 or 6 days, but major changes were frequently recorded in animals dosed at this rate for 12 days or longer. These comprised changes in the liver and other organs, and photosensitisation typical of the disease, facial eczema. Results are discussed in relation to animal welfare and economic issues associated with this disease.

CONCLUSIONS

Sporidesmin caused significant clinical and sub-clinical disease and reduced animal production at relatively low daily dose rates. The effects of repeated daily low-dose administration of sporidesmin appear to be cumulative. There was considerable variation in susceptibility between individual animals. These results emphasise the considerable production losses and animal welfare effects associated with sporidesmin toxicity in sheep.

Urinary excretion of immunoreactive sporidesmin metabolites in sheep in relation to factors influencing susceptibility to sporidesmin intoxication

AIM

To study the urinary disposition of orally administered sporidesmins A and D in sheep and identify factors influencing their kinetics, particularly the influence of breeding for resistance and susceptibility to sporidesmin, the mycotoxin responsible for the hepatogenous photosensitisation, facial eczema.

METHODS

A competitive ELISA was used to monitor urinary output of immunoreactive metabolites after the intraruminal administration, to female Romney sheep, of either sporidesmin A or sporidesmin D, the nontoxic analogue. Preliminary characterisation of metabolites was carried out using HPLC with fractions monitored by ELISA.

RESULTS

Maximum urinary excretion rates of immunoreactive metabolites occurred 2-8 h after dosing with sporidesmin D and 15-30 h after dosing with sporidesmin A. Sporidesmin D caused no liver injury, as detected by changes in serum enzyme activity, while the liver injury caused by sporidesmin A was greatest for the sheep with the highest cumulative output of metabolite. When sporidesmin D was administered in two separate doses to sheep bred for either resistance or susceptibility to facial eczema, the variability of metabolic output between sheep within groups was much less after the second dose. The mean urinary metabolite excretion was greater for the susceptible than the resistant sheep but the difference was not significant. Potentiation (caused by pre-administration of small doses of sporidesmin A) resulted in a more severe reaction to the dosed sporidesmin A. Urinary output of metabolite was less in the potentiated than in the unpotentiated sheep. When resistant and susceptible sheep were dosed with sporidesmin A after potentiation there was no difference between them in their cumulative totals or excretion rates of immunoreactive metabolites. However, the volume of urine produced by the susceptible sheep was lower and less variable than the resistant sheep and consequently the concentration of their urinary metabolites was higher. Preliminary ELISA examination of HPLC-fractionated urine from a sheep dosed with sporidesmin A indicated the presence of several metabolites of sporidesmin.

CONCLUSION

Sporidesmin A and metabolites are rapidly excreted in urine but not as rapidly as sporidesmin D and its metabolites. Only minor differences between sheep bred for resistance and susceptibility were seen. Potentiation caused a more severe reaction to sporidesmin A and less urinary excretion of the sporidesmin and its metabolites.

CLINICAL RELEVANCE

This work is part of a programme with the aim of identifying FE-resistant animals without the need for sporidesmin dosing.

Significantly increased recovery of intestinal parasites on routine stool specimen evaluation

Three hundred thirty-six stool samples from October 2001 through October 2002 were analyzed for the presence of intestinal parasites. Fifty-six of these (16.7%) were positive for a total of 66 parasites; 65/66 (98.5%) were detected by iodine and dimethyl sulfoxide-modified acid-fast (DMSO-mAFB) stained smears of fresh and formalin-ethylacetate sedimentation concentrated samples. Saline, iodine, and DMSO-mAFB stained smears of fresh stool samples alone detected significantly fewer parasites, finding only 50/66 (75.8%) (p < 0.05). Stool samples analyzed by trichrome stained specimens preserved in Zinc sulfate polyvinyl alcohol (Zinc PVA) detected only 41/ 66 (62.2%) of the parasites. In our study population, it was necessary to perform the National Committee for Clinical Laboratory Standard (NCCLS) recommended to accurately detect intestinal parasites. The concentration technique is simple and significantly increased the detection of intestinal parasites.

Complications of breast surgery

Surgical procedures performed for diagnosis and treatment of breast disease have become progressively less invasive. As an increasing proportion of breast surgery is performed on an outpatient basis, identification and management of postoperative problems have become a collaborative effort involving the surgeon, the patient, home care services and medical office staff. Although this shift to outpatient care has created a number of challenges, complication rates are no higher when breast procedures are performed on an outpatient or short-stay basis. Perioperative, short-term and long-term complications, including wound complications, injuries to adjacent structures, lymphedema, and pain syndromes are discussed.

The efficacy of Herceptin therapies is influenced by the expression of other erbB receptors, their ligands and the activation of downstream signalling proteins

ErbB2 and EGFR are attractive oncology therapeutic targets as their overexpression in tumors predicts a poorer clinical outcome in a variety of epithelial malignancies. However, clinical results with therapeutic compounds targeting these receptors have been mixed. Therefore, there is a need for improved predictive biomarkers for these targeted therapeutics. In this study we analysed tissue microarrays of patients treated with combination chemotherapy and Herceptin for expression or phosphorylation of signalling proteins associated with erbB receptors to identify protein biomarkers that are predictive of breast cancer patient response. A comparison of expression or phosphorylation of these markers with patient outcome revealed that response to Herceptin depended not only on expression levels of erbB2 but also on expression of EGFR, expression of erbB ligands, expression of other receptors and phosphorylation of downstream proteins. Elucidating the biological effects of EGFR/erbB2 targeted therapeutics will enable patient tumor profiling to identify likely responders and the determination of biologically effective doses that allows chronic administration of these agents in order to maximise efficacy.

Inheritance of resistance to facial eczema: a review of research findings from sheep and cattle in New Zealand

Facial eczema (FE) is a costly problem to New Zealand pastoral agriculture, and has a detrimental impact on animal wellbeing. Incidence and severity of the disease can be reduced by grazing management and zinc prophylaxis. An additional strategy is to breed animals that are genetically resistant to intoxication with sporidesmin, the causative mycotoxin. This review summarises research findings on the inheritance of resistance of animals to FE, including evidence of among- and within-breed genetic variation, direct and correlated responses to selection, and identification of genetic markers and candidate genes for FE resistance.

Gene encoding the group B streptococcal protein R4, its presence in clinical reference laboratory isolates & R4 protein pepsin sensitivity

BACKGROUND & OBJECTIVES

R proteins were first identified by Lancefield in group B Streptococcus (GBS) as resistant to trypsin at pH8 and sensitive to pepsin at pH2. The R4 protein found predominantly in type III and some type II and V invasive isolates conforms to these criteria. The Rib protein, although structurally and epidemiologically similar to R4, was reported as resistant to both proteases. We report here the gene encoding the R4 protein from a type III group B streptococcal isolate (76-043) well characterized in our laboratory.

METHODS

Trypsin extracted GBS proteins were assayed for protease sensitivities by double-diffusion Ouchterlony using varying conditions for the enzyme pepsin. Standard haemoglobin assay was used to examine pepsin enzymatic activity. Thirty clinical isolates of varying protein profiles identified by double-diffusion from our reference strain laboratory were screened by PCR and Southern technique. SDS-PAGE gel purified R4 amino acid sequences were determined and used to design oligonucleotide primers for screening a 76-043 genomic library.

RESULTS

R4 was sensitive to pepsin at pH2 but appeared resistant at pH4, the reported pH used for Rib. By standard haemoglobin assay and trypsin extract studies of R4 protein, pepsin was shown to be active at pH2, yet easily inactivated; assays of GBS surface proteins are critical at pH2. Of the amino acids initially sequenced from R4, 88 per cent (61/69) showed identity to Rib; the r4 nucleotide sequence was identical to that of rib. All isolates with strong positive protein reactions for R4 were positive in both PCR and Southern technique, whereas isolates expressing alpha, beta, R1/R4, and R5 (BPS) protein profiles were not.

INTERPRETATION & CONCLUSION

Sequenced PCR products aligned with identity to the R4 and Rib nucleotide sequences and confirmed the identity of these proteins and their molecular sequences.

Spectrofluorometric analysis of phylloerythrin (phytoporphyrin) in plasma and tissues from sheep suffering from facial eczema

AIMS

To study the increase in phylloerythrin concentration in plasma and the disposition of phylloerythrin in skin and other tissues of sheep in which the hepatogenous photosensitisation,facial eczema, had been experimentally induced by dosing with the mycotoxin, sporidesmin. Spectroscopic differences between plasma and skin measurements of animals kept inside and outside after dosing were also studied in order to establish whether phylloerythrin undergoes photodegradation when exposed to sunlight.

METHODS

Twenty-six Romney x Polled Dorset (25-30 kg)weaned female lambs were purchased from a commercial flock in the Waikato region, New Zealand. Twenty-two of these lambs were dosed with 0.25 mg sporidesmin/kg liveweight on each of two consecutive days (Days -1 and 0); the remaining four lambs served as controls. Both sporidesmin-dosed lambs and controls were randomly divided into two penned groups, one group housed inside in a darkened room and the others outside, exposed to natural sunlight. The lambs were fed green lucerne pellets and lucerne chaff ad libitum for 10 days prior to dosing and until Day 12 after the first dose; thereafter, all the lambs were fed fresh, cut grass (mainly ryegrass) ad libitum, until the end of the experimental period on Day 26. Plasma samples collected on Days -2, 7, 10, 12, 14, 17, 20 and 25were analysed for gamma glutamyltransferase (GGT) activity, bilirubin concentration, and the fluorescence spectrum of phylloerythrin. Spectrofluorometric analysis of phylloerythrin in skin was performed in vivo on the same days, using an external fiber-optic probe.

RESULTS

Eight of 11 lambs (73%) kept outside after sporidesmin dosing became photosensitised during the experimental period. None of the sporidesmin-dosed animals kept inside showed clinical signs of photosensitisation. The GGT activity in plasma increased exponentially during the experimental period in all sporidesmin-dosed animals until it reached a plateau. All plasma obtained from sporidesmin-dosed sheep had spectral characteristics similar to those of phylloerythrin, namely a peak in the excitation spectrum at 422 nm and strong emission band at 650 (SE 1) and 709 (SE 1) nm. The fluorescence under excitation at 422 nm of phylloerythrin added to plasma from control lambs had identical peaks. Emission spectra obtained from plasma from healthy sheep without addition of phylloerythrin showed either no fluorescence or minor fluorescence at around 671 nm. Fluorescence in skin of sporidesmin-dosed animals had similar spectra to that in plasma. The appearance of the phylloerythrin-like spectra occurred 2-3 days later in the skin than in plasma, and phylloerythrin in sunlight-exposed skin did not suffer photodegradation during the course of the study.

CONCLUSION

Plasma concentrations of phylloerythrin in healthy sheep were <0.1 micromol/l, and clinical signs of photosensitisation were not evident until concentrations exceeded 0.3 micromol/l. Plasma concentrations of phylloerythrin rose as high as 4.9 micromol/l in some animals. The concentration of phylloerythrin in skin began increasing 2-3 days later than that in blood. Hepatogenous photosensitisation can be diagnosed by analysis of plasma phylloerythrin concentrations using a spectroscopic method.

Tremorgenic mycotoxins increase gastric smooth muscle activity of sheep reticulum and rumen in vitro

Reticulum and rumen strips (consisting of both muscle layers and the myenteric plexus) were superfused with Tyrode Ringer and their contractions recorded isometrically. The strips were subjected to exogenous acetylcholine and electrical field stimulation (EFS) resulting in contractions that could be blocked by atropine. Responses to the tremorgenic mycotoxin penitrem A and others thought to be involved in ryegrass staggers, paxilline and lolitrem B (10(-10)-10(-6)M), were compared with those of control vehicle (0.1% DMSO). The tremorgens were without effect on quiescent preparations. Penitrem A and paxilline enhanced spontaneously active preparations and the amplitude of contractions in response to EFS. Responses to paxilline had a shorter latency than to penitrem A. Responses of spontaneously active preparations were resistant to atropine. Penitrem A, but not paxilline, increased responses to exogenous acetylcholine. Lolitrem B (10(-6)M) increased responses to EFS, but many responses were equivocal, possibly due to the lower solubility of lolitrem B in aqueous solutions compared to the other tremorgens. The results show that these mycotoxins have peripheral excitatory effects on the reticulorumen and it is suggested that such activity in vivo may reflexly affect centrally derived cyclical contractions.

Mycotoxicoses of grazing animals in New Zealand

Mycotoxicoses are some of the most important diseases of animals grazing pastures in New Zealand, especially in northern areas where the disease, facial eczema, occurs. New Zealand scientists have led the world in research on facial eczema and endophyte-related diseases associated with tremoring. Facial eczema (pithomycotoxicosis) was one of the first mycotoxicoses to be studied systematically and successful methods for its control now exist. Toxicity is caused by the concentration of sporidesmin in the biliary system and its redox cycling which leads to the formation of toxic free-radicals. Zinc salts are capable of preventing facial eczema. Their efficacy and safety for farm use has been demonstrated and intraruminal boluses containing zinc have been developed for use in sheep and cattle. Endophyte-related diseases have received special attention over the last 15 years. It is now recognised that Neotyphodium spp and grasses (especially ryegrass and fescue) are an essential symbiosis, making control of these diseases in grazing animals difficult. New Zealand research has demonstrated inhibitory effects of zearalenone, from Fusarium spp growing on pasture litter, on sheep fertility.