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Mushonga M, Kwan JYY, Purdie TG, Chaulk G, DeRocchis J, Munhoz RP, Leong WL, Hodaie M, Liu FF. Deep Brain Stimulators and Radiation Therapy in Cancer Patients. Clin Oncol (R Coll Radiol) 2022; 34:e136-e138. [PMID: 34996683 DOI: 10.1016/j.clon.2021.12.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 12/21/2021] [Indexed: 11/17/2022]
Affiliation(s)
- M Mushonga
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada
| | - J Y Y Kwan
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - T G Purdie
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - G Chaulk
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada
| | - J DeRocchis
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - R P Munhoz
- Department of Medicine, Division of Neurology, University Health Network, Toronto, Ontario, Canada
| | - W L Leong
- Department of Surgery, Division of General Surgery, University Health Network, Toronto, Ontario, Canada
| | - M Hodaie
- Department of Surgery, Division of Neurosurgery, University Health Network, Toronto, Ontario, Canada
| | - F-F Liu
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada; Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
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Keep J, Berry T, Budden S, Chuilon B, Colling B, Flynn E, Ha S, Jackson C, Keech G, Leong W, Mathew G, Organ E, Shaw C, Wilde A. DEMO double null architectural study. Fusion Engineering and Design 2021. [DOI: 10.1016/j.fusengdes.2021.112311] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Leong WL, Battiston K, Cheung F, Fulton C, Lin A, Levin W, Done S, Santerre P. Abstract P3-13-11: The outcomes of ReFilx soft tissue filler as an immediate reconstruction technique for lumpectomy followed by radiotherapy. Cancer Res 2019. [DOI: 10.1158/1538-7445.sabcs18-p3-13-11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Introduction: Lumpectomy for breast cancer can often result in poor cosmetic outcomes which can lead to long-lasting impairment of quality of life. ReFilx is a synthetic porous degradable polyurethane scaffold that has mechanical properties comparable to that of native healthy breast tissue. It has been shown in two previous porcine studies to preserve breast shape and volume over 9 months when inserted into the cavities immediately after lumpectomy. We observed minimal foreign body reaction with good integration of the host tissue while the material degraded over time. In this study, we examined the healing process of lumpectomy treated with radiation. Radiotherapy is currently a standard adjuvant therapy after lumpectomy for breast cancers; and radiation is known to affect the healing process in general. Objective: To evaluate ReFilx, as soft tissue fillers for lumpectomy cavities in combination with standard radiotherapy. Hypothesis: ReFilx will preserve breast shape and volume by supporting tissue infiltration with minimal inflammation in the presence of clinically relevant radiotherapy. Methods: 3 female Yucatan minipigs received lumpectomies carried out using electrocautery to remove normal breast tissue of approximately 2 cm diameter, after which the cavities were filled with (case) or without ReFilx (sham control) (n=3 for each condition, each pig has 12-13 breasts). 6 weeks post-implantation, 2 of the pigs received radiation directed at the right half of their bodies (6 breasts per pig) for a total dose of 42.4 Gy delivered over 15 fractions using a clinical linear accelerator. The delivered doses to target sites and the adjacent tissue were confirmed with optically stimulated luminescent dosimeters (OSLDs). A third pig was maintained as a non-irradiated control. Ultrasound examinations were performed every 3 weeks post-implantation. At week 24 and 36, samples consisted of n=3 for irradiated and non-irradiated ReFilx and sham sites for the half-irradiated pigs, and n=3 for non-irradiated ReFilx and sham sites for the non-irradiated control pig were excised by mastecomy, the tissue samples were fixed in 10% buffered formalin for subsequent histological (H&E, Masson's Trichrome) studies. Potential side effects were monitored by vital signs, pain control, wound checks, ultrasound and blood tests. Necropsies were performed at the conclusion of the study. Results: Ultrasound examination indicated no difference between ReFilx's ability to maintain breast shape and volume with or without the presence of radiation treatment, in contrast to the collapse of the sham sites by 24 weeks. Similarly, the histology of irradiated and non-irradiated ReFilx samples showed similar levels of tissue infiltration, inflammatory changes and degradation of ReFilx. There was no significant side effects observed. Conclusions: ReFilx's ability to act as a soft tissue filler for breast volume restoration post-lumpectomy does not appear to be significantly impacted by the presence of clinically relevant radiation treatment. Longer-term follow-up is currently in progress for this study. Acknowledgements: Connaught Innovation Award (University of Toronto) and Joule Innovation Fund (Canadian Medical Association).
Citation Format: Leong WL, Battiston K, Cheung F, Fulton C, Lin A, Levin W, Done S, Santerre P. The outcomes of ReFilx soft tissue filler as an immediate reconstruction technique for lumpectomy followed by radiotherapy [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 P3-13-11.
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Affiliation(s)
- WL Leong
- University Health Network, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - K Battiston
- University Health Network, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - F Cheung
- University Health Network, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - C Fulton
- University Health Network, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - A Lin
- University Health Network, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - W Levin
- University Health Network, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - S Done
- University Health Network, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - P Santerre
- University Health Network, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada
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Elmi M, Tigert A, Escallon J, Zagorski B, Leong W, Vranic M, Fyles A, Vitkin A, Cil T, McCready D. Abstract P3-12-02: Intraoperative radiotherapy outcomes in early-stage breast cancer: A study in elderly Canadian women. Cancer Res 2019. [DOI: 10.1158/1538-7445.sabcs18-p3-12-02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Objective. Breast-conserving therapy with external beam radiotherapy (EBRT) is currently the standard of care for women with early breast cancer. Our aim was to determine if early-stage breast cancers treated with lumpectomy and primary intraoperative radiotherapy (IORT) have comparable local recurrence rates. This is the first study examining the Canadian experience with IORT.
Methods. Patients who underwent breast-conserving therapy with pre-pathology IORT between 2007- 2017 were retrospectively identified. The primary outcome measure was ipsilateral breast tumor recurrence (IBRT). A time to event analysis was performed; Kaplan-Meier estimates report the fraction of patients living free of recurrence. Secondary outcomes included acute and chronic wound complications.
Results. 106 patients with a median age of 70 (IQR 65-75) were included. Median follow-up was 33 months. The majority of patients had screen-detected (94.3%), estrogen-receptor positive (96.2%), HER2neu negative (93.4%), invasive ductal carcinomas (92.5%). Only 50 (47.6%) were prescribed adjuvant endocrine blockade. IBTR occurred in 5 (4.7%) patients. Five and ten-year local recurrence-free rates were 0.95 and 0.81, respectively. The superficial skin infection rate was 9.4%. Acute symptomatic seromas occurred in 23 (21.7%), while only 10 (9.4%) persisted chronically.
Conclusion. In this cohort of Canadian post-menopausal women treated with breast-conserving surgery and IORT, the IBTR approached 5%. Despite selection of low-risk patients, the local recurrence rate is higher than what is reported in the literature with EBRT. The low rates of prescribed adjuvant systemic therapy may have contributed to this outcome.
Citation Format: Elmi M, Tigert A, Escallon J, Zagorski B, Leong W, Vranic M, Fyles A, Vitkin A, Cil T, McCready D. Intraoperative radiotherapy outcomes in early-stage breast cancer: A study in elderly Canadian women [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 P3-12-02.
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Affiliation(s)
- M Elmi
- UT Texas Health San Antonio, San Antonio, TX; Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Princess Margaret Cancer Center, University Health Network, Toroto, ON, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada
| | - A Tigert
- UT Texas Health San Antonio, San Antonio, TX; Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Princess Margaret Cancer Center, University Health Network, Toroto, ON, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada
| | - J Escallon
- UT Texas Health San Antonio, San Antonio, TX; Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Princess Margaret Cancer Center, University Health Network, Toroto, ON, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada
| | - B Zagorski
- UT Texas Health San Antonio, San Antonio, TX; Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Princess Margaret Cancer Center, University Health Network, Toroto, ON, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada
| | - W Leong
- UT Texas Health San Antonio, San Antonio, TX; Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Princess Margaret Cancer Center, University Health Network, Toroto, ON, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada
| | - M Vranic
- UT Texas Health San Antonio, San Antonio, TX; Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Princess Margaret Cancer Center, University Health Network, Toroto, ON, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada
| | - A Fyles
- UT Texas Health San Antonio, San Antonio, TX; Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Princess Margaret Cancer Center, University Health Network, Toroto, ON, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada
| | - A Vitkin
- UT Texas Health San Antonio, San Antonio, TX; Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Princess Margaret Cancer Center, University Health Network, Toroto, ON, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada
| | - T Cil
- UT Texas Health San Antonio, San Antonio, TX; Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Princess Margaret Cancer Center, University Health Network, Toroto, ON, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada
| | - D McCready
- UT Texas Health San Antonio, San Antonio, TX; Faculty of Medicine, University of Toronto, Toronto, ON, Canada; Princess Margaret Cancer Center, University Health Network, Toroto, ON, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, ON, Canada
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Seet E, Leong WL, Yeo ASN, Fook-Chong S. Effectiveness of 3-in-1 Continuous Femoral Block of Differing Concentrations Compared to Patient Controlled Intravenous Morphine for Post Total Knee Arthroplasty Analgesia and Knee Rehabilitation. Anaesth Intensive Care 2019; 34:25-30. [PMID: 16494145 DOI: 10.1177/0310057x0603400110] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We assessed the effectiveness of the 3-in-l continuous femoral block as a form of postoperative pain relief for unilateral total knee arthroplasty (TKA). Sixty patients undergoing elective unilateral TKA under subarachnoid block were randomized into three groups. Postoperative analgesia was provided with a continuous 3-in-l femoral nerve catheter with 0.15% ropivacaine in group A, a continuous 3-in-l femoral nerve catheter with 0.2% ropivacaine in group B, or patient controlled intravenous morphine in group C (control group). Groups A and B received patient controlled intravenous morphine pumps for rescue analgesia. Patients in each group were followed for 72 hours postoperatively. Five patients were excluded after randomization. In the remaining 55 patients there was no statistical difference in pain score between the groups. Total morphine use was highest in group C (P< 0.05). No appreciable difference could be found with sensorimotor blockade, morphine usage and satisfaction scores when comparing groups A and B. Femoral catheter dislodgement rate was 7.9%. There was no statistical difference between the groups when comparing the day of first ambulation and the time to discharge from the hospital. Satisfaction scores were higher in group A (P = 0.028) and group B (P = 0.002) compared to group C. We conclude that a continuous 3-in-l femoral nerve block with ropivacaine 0.15% or 0.2% for elective unilateral TKA has an opioid-sparing effect.
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MESH Headings
- Age Factors
- Aged
- Amides/administration & dosage
- Analgesia/adverse effects
- Analgesia/methods
- Analgesia, Patient-Controlled/methods
- Analgesics, Opioid/administration & dosage
- Analysis of Variance
- Arthroplasty, Replacement, Knee/adverse effects
- Arthroplasty, Replacement, Knee/methods
- Arthroplasty, Replacement, Knee/rehabilitation
- Dose-Response Relationship, Drug
- Female
- Femoral Nerve
- Follow-Up Studies
- Humans
- Male
- Middle Aged
- Morphine/administration & dosage
- Nerve Block/methods
- Pain Measurement
- Pain, Postoperative/diagnosis
- Pain, Postoperative/drug therapy
- Patient Satisfaction
- Probability
- Prospective Studies
- Risk Assessment
- Ropivacaine
- Severity of Illness Index
- Sex Factors
- Statistics, Nonparametric
- Treatment Outcome
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Affiliation(s)
- E Seet
- Singapore Health Services Pt Ltd, Singapore General Hospital, National Cancer Centre and Dover Park Hospice, Singapore
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Leong WL, Sharifpoor S, Battiston K, Charleton D, Corrigan M, McCready DR, Done SJ, Santerre JP. Abstract P2-12-15: ReFilx- synthetic biodegradable soft tissue fillers for breast conserving surgery in breast cancer. Cancer Res 2018. [DOI: 10.1158/1538-7445.sabcs17-p2-12-15] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Introduction: Breast conserving surgery (BCS) is the most common procedure performed in breast cancers, but it can often result in breast deformities that can have negative impacts on quality of life. With better treatments, more breast cancer survivors are expected to live longer, the demand for achieving optimal cosmetic outcomes has also increased accordingly. Currently, oncoplastic techniques involving local tissue rearrangement with or without contralateral balancing procedures are used in specialized centers to achieve breast symmetry in some patients. When a breast deformity occurs, corrective options include: fat grafting, autologous flap procedures and completion mastectomy with immediate reconstruction. These techniques have long operative times, longer length of hospital stay and higher complication rates. Commercially-available synthetic implants are fabricated in pre-determined sizes and thus are not suitable to reconstruct partial breast deformities of varying size and shape. We explored the use of amino-acid based biodegradable polyurethanes as tissue fillers for BCS due to their chemical versatility, superior mechanical properties and tailored biocompatibility. Objective: To evaluate novel biodegradable polymer constructs, referred to as ReFilx, as soft tissue fillers for BCS defects. Hypothesis: Implantation of ReFilx during BCS will maintain breast shape and size and promote tissue regeneration in and around the biodegradable biomaterial, in contrast to sham controls. Methods: Two ReFilx formulations with high porosity, mechanical properties (compressive modulus=45±6 kPa and 31±9 kPa) comparable to native breast tissue and a moderate degree of swelling (202±6% and 248±6%) were selected for implantation in porcine BCS defects. Three female Yucatan Minipigs (age=4 years, weight=100-120 kg, 12 breasts per pig) received BCS to remove normal breast tissue of approximately 2 cm diameter, after which the defects were filled with ReFilx Formulation A, ReFilx Formulation B, or no filler (sham control). At 6, 12, 24, and 36 weeks post-implantation (n=3 per group), ultrasound breast examinations and mastectomies of each selected group of breasts were performed. Samples were fixed in 10% buffered formalin and stained with H&E, Masson's Trichrome and immunohistomchemistry using CD31. Results: ReFilx formulations maintained breast size and shape, with similar stiffness to native breast tissue, while sham controls collapsed over 36 weeks. The ReFilx fillers supported cell and tissue infiltration and neovascularization, as indicated by Masson's Trichrome and CD31 staining, respectively, without eliciting foreign body giant cell formation, fibrosis, or chronic inflammation, commonly associated with implanted medical devices. Conclusions: ReFilx are promising soft tissue fillers for breast volume restoration, representing a simple, versatile, permanent, and aesthetically superior solution to prevent soft tissue deformities. Acknowledgements: MaRS PoP fund, grant # MI 2011-170, NSERC # SYN 430828. Haynes Connell Foundation Breast Cancer Fund.
Citation Format: Leong WL, Sharifpoor S, Battiston K, Charleton D, Corrigan M, McCready DR, Done SJ, Santerre JP. ReFilx- synthetic biodegradable soft tissue fillers for breast conserving surgery in breast cancer [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 P2-12-15.
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Affiliation(s)
- WL Leong
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Translational Biology and Engineering Progra, University of Toronto, Toronto, ON, Canada; Campbell Family Institute of Breast Cancer Research, University Health Network, Toronto, ON, Canada; Laboratory Medicine Program, University of Toronto, Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Faculty of Dentistry, University of Toronto, Toronto, ON, Canada; Cork Breast Research Centre, Cork, Munster, Ireland; Grand River Hospital, Kitchener, ON, Canada
| | - S Sharifpoor
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Translational Biology and Engineering Progra, University of Toronto, Toronto, ON, Canada; Campbell Family Institute of Breast Cancer Research, University Health Network, Toronto, ON, Canada; Laboratory Medicine Program, University of Toronto, Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Faculty of Dentistry, University of Toronto, Toronto, ON, Canada; Cork Breast Research Centre, Cork, Munster, Ireland; Grand River Hospital, Kitchener, ON, Canada
| | - K Battiston
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Translational Biology and Engineering Progra, University of Toronto, Toronto, ON, Canada; Campbell Family Institute of Breast Cancer Research, University Health Network, Toronto, ON, Canada; Laboratory Medicine Program, University of Toronto, Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Faculty of Dentistry, University of Toronto, Toronto, ON, Canada; Cork Breast Research Centre, Cork, Munster, Ireland; Grand River Hospital, Kitchener, ON, Canada
| | - D Charleton
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Translational Biology and Engineering Progra, University of Toronto, Toronto, ON, Canada; Campbell Family Institute of Breast Cancer Research, University Health Network, Toronto, ON, Canada; Laboratory Medicine Program, University of Toronto, Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Faculty of Dentistry, University of Toronto, Toronto, ON, Canada; Cork Breast Research Centre, Cork, Munster, Ireland; Grand River Hospital, Kitchener, ON, Canada
| | - M Corrigan
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Translational Biology and Engineering Progra, University of Toronto, Toronto, ON, Canada; Campbell Family Institute of Breast Cancer Research, University Health Network, Toronto, ON, Canada; Laboratory Medicine Program, University of Toronto, Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Faculty of Dentistry, University of Toronto, Toronto, ON, Canada; Cork Breast Research Centre, Cork, Munster, Ireland; Grand River Hospital, Kitchener, ON, Canada
| | - DR McCready
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Translational Biology and Engineering Progra, University of Toronto, Toronto, ON, Canada; Campbell Family Institute of Breast Cancer Research, University Health Network, Toronto, ON, Canada; Laboratory Medicine Program, University of Toronto, Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Faculty of Dentistry, University of Toronto, Toronto, ON, Canada; Cork Breast Research Centre, Cork, Munster, Ireland; Grand River Hospital, Kitchener, ON, Canada
| | - SJ Done
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Translational Biology and Engineering Progra, University of Toronto, Toronto, ON, Canada; Campbell Family Institute of Breast Cancer Research, University Health Network, Toronto, ON, Canada; Laboratory Medicine Program, University of Toronto, Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Faculty of Dentistry, University of Toronto, Toronto, ON, Canada; Cork Breast Research Centre, Cork, Munster, Ireland; Grand River Hospital, Kitchener, ON, Canada
| | - JP Santerre
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada; Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Translational Biology and Engineering Progra, University of Toronto, Toronto, ON, Canada; Campbell Family Institute of Breast Cancer Research, University Health Network, Toronto, ON, Canada; Laboratory Medicine Program, University of Toronto, Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Faculty of Dentistry, University of Toronto, Toronto, ON, Canada; Cork Breast Research Centre, Cork, Munster, Ireland; Grand River Hospital, Kitchener, ON, Canada
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Leong WL. Optimising triggers for patient-assisted remifentanil analgesia during labour - a reply. Anaesthesia 2017; 72:1156. [PMID: 28804884 DOI: 10.1111/anae.14025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- W L Leong
- KK Women's and Children's Hospital, Singapore
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Leong WL, Sng BL, Zhang Q, Han NLR, Sultana R, Sia ATH. A case series of vital signs-controlled, patient-assisted intravenous analgesia (VPIA) using remifentanil for labour and delivery. Anaesthesia 2017; 72:845-852. [PMID: 28418067 DOI: 10.1111/anae.13878] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/26/2017] [Indexed: 11/27/2022]
Abstract
Intravenous remifentanil patient-controlled analgesia can be used during labour as an alternative to epidural analgesia. Adverse effects of opioids, including hypoxia and bradycardia, may lead to maternal morbidity and mortality. We devised an interactive feedback system based on a clinical proportional algorithm, to continuously monitor for adverse effects to enhance safety and better titrate analgesia. This vital signs-controlled, patient-assisted intravenous analgesia with remifentanil used a prototype delivery system linked to a pulse oximeter that evaluated maternal oxygen saturation and heart rate continuously. With this system, we detected oxygen saturation < 95% for more than 60 s in 15 of 29 subjects (52%); and heart rate < 60 min-1 for more than 60 s in 7 of 29 subjects (24%) during use. The system automatically responded appropriately by reducing the dosages and temporarily halting remifentanil administration, thus averting further hypoxia and bradycardia.
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Affiliation(s)
- W L Leong
- Department of Women's Anaesthesia, KK Women's and Children's Hospital, Singapore
| | - B L Sng
- Department of Women's Anaesthesia, KK Women's and Children's Hospital, Singapore.,Duke-NUS Medical School, Singapore
| | - Q Zhang
- SingHealth Anaesthesiology Residency Program, Singapore
| | - N L R Han
- Division of Clinical Support Services, KK Women's and Children's Hospital, Singapore
| | - R Sultana
- Centre for Quantitative Medicine, Duke-NUS Medical School, Singapore
| | - A T H Sia
- Department of Women's Anaesthesia, KK Women's and Children's Hospital, Singapore.,Duke-NUS Medical School, Singapore
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Ottolino-Perry K, Medeiros P, Blackmore K, Chamma E, Kulbatski I, Panzarella T, Rosen C, Done S, Easson A, Leong W, DaCosta R. Handheld fluorescence imaging device for real-time intraoperative margin assessment of breast cancer: ALA-induced fluorescence for the detection of breast tumours. Breast 2017. [DOI: 10.1016/s0960-9776(17)30377-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Swanepoel S, Chivers D, Leong W, Laubscher M, McCollum G, Maqungo S. Intramedullary nailing of subtrochanteric femur fractures caused by low velocity gunshots. SA orthop j 2017. [DOI: 10.17159/2309-8309/2017/v16n3a6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Tien JC, Lim MJ, Leong WL, Lew E. Nine-year audit of post-dural puncture headache in a tertiary obstetric hospital in Singapore. Int J Obstet Anesth 2016; 28:34-38. [PMID: 27641087 DOI: 10.1016/j.ijoa.2016.06.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 06/04/2016] [Accepted: 06/26/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND The KK Women's and Children's Hospital is a tertiary obstetric unit with approximately 11000 deliveries per year. Epidural analgesia is used in about 40% of laboring women. We reviewed the incidence and management of post-dural puncture headache over a nine-year period. METHODS A retrospective audit of labor epidural analgesia database records from 1 June 2005 to 31 May 2014 was conducted, identifying an "event" as an accidental dural puncture, an inadvertent intrathecal catheter insertion and/or development of a post-dural puncture headache. RESULTS A total of 43434 epidural records were reviewed. Sixty-three events were identified (an incidence of 0.15%). Women had median age of 30years and median body mass index of 27.6kg/m2; 69.8% (44/63) delivered vaginally. Procedures performed by less experienced anesthesiologists and those performed outside office hours were associated with a higher incidence of accidental dural puncture. An intrathecal catheter was inserted in 52 of 58 women (89.7%). Headache developed in 24 of 38 (63.1%) women in whom there was a witnessed accidental dural puncture. Most women who developed post-dural puncture headache presented during the primary admission (36/39; 92.3%). Paracetamol and non-steroidal anti-inflammatory drugs were the most commonly prescribed medications. Six women (9.5%) received an epidural blood patch which led to resolution of headache. CONCLUSION A retrospective audit over a nine-year period at a tertiary teaching hospital found the overall incidence of post-dural puncture headache and associated events to be 0.15%, with a decreasing trend coinciding with improvement in the teaching and supervision of trainees in labor epidural procedures.
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Affiliation(s)
- J C Tien
- Department of Women's Anesthesia, KK Women's and Children's Hospital, Singapore.
| | - M J Lim
- Department of Women's Anesthesia, KK Women's and Children's Hospital, Singapore
| | - W L Leong
- Department of Women's Anesthesia, KK Women's and Children's Hospital, Singapore
| | - E Lew
- Department of Women's Anesthesia, KK Women's and Children's Hospital, Singapore
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Valic MS, Leong WL, Done SJ, Wilson BC, Kulkarni S, McCready DR, Niu CJ, Atachia Y, Munro EA, Rempel D. Abstract P4-03-05: Wide-field optical coherence tomography (WF-OCT) for near real-time, point-of-care assessment of margin status in breast-conserving surgery specimens: Results of a feasibility study at a high-volume single-centre. Cancer Res 2016. [DOI: 10.1158/1538-7445.sabcs15-p4-03-05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Wide-Field Optical Coherence Tomography (WF-OCT) is a non-destructive, non-contact light imaging modality capable of label-free visualization of the internal microscopic architecture of breast tissue specimens. Its unique combination of high-resolution imaging in near real-time with tissue penetration depths approaching 2-mm makes it a promising imaging modality for obtaining detailed surgical margin status in breast-conserving surgery (BCS) specimens. A prototype WF-OCT imaging platform developed by Perimeter Medical Imaging, Inc. (Toronto, Canada) has permitted fully-automated, dynamically-focused visualization of margin widths around the intact surfaces of freshly excised BCS specimens. Herein are reported the results of a feasibility study at a high-volume single-centre evaluating the routine use of WF-OCT for sampling of surgical margin status in BCS specimens at the point-of-care.
Methods: Women with biopsy confirmed breast cancer and scheduled for primary BCS were recruited at Princess Margaret Cancer Centre (Toronto, Canada). Standard medical care was not altered. Freshly excised BCS specimens including all lumpectomy samples were imaged by WF-OCT immediately prior to standard histological processing. The system acquired dynamically-focused, hemispherical coverage over two contra-lateral surfaces of the intact BCS specimen within the time constraints of the cold ischemic time window. High-resolution (10 μm) images of the tissue surface down to a 1 to 2-mm depth were obtained. Blinded assessments were performed on image data sets by two clinical readers (surgeon and radiologist) trained on a validated and unrelated data set correlating OCT images with histology slides. The readers were first asked to independently assess margin status using only blinded pre- and intra-operative knowledge (without OCT). Upon completion, the readers were provided OCT images of all scanned surface and similarly asked to assess the margin status with the additional OCT information. These assessments were subsequently evaluated by a breast pathologist comparing the OCT images and corresponding histopathology sections. The added utility of WF-OCT imaging information for margin prediction was studied.
Results: [Pending study completion in August 2015]. Through accurate correlation with the histopathologic gold standard, OCT demonstrated capability to differentiate tissue microstructures, including: distinctive patterns for adipose tissue, fibrous stroma, breast lobules and ducts, cysts and microcysts, as well as in-situ and invasive carcinomas.
Implications: The fully-automated WF-OCT imaging platform can integrate conveniently into standard pathological processing workflows to provide comprehensive sampling of surgical margin status in BCS specimens at the point-of-care. Clinical readers from surgical and radiological backgrounds can be trained to competently interpret WF-OCT images of BCS specimens for accurate prediction margin status. The implementation of WF-OCT at the point-of-care for routine surgical margin assessments will be further explored in future clinical trials.
Citation Format: Valic MS, Leong WL, Done SJ, Wilson BC, Kulkarni S, McCready DR, Niu CJ, Atachia Y, Munro EA, Rempel D. Wide-field optical coherence tomography (WF-OCT) for near real-time, point-of-care assessment of margin status in breast-conserving surgery specimens: Results of a feasibility study at a high-volume single-centre. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-03-05.
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Affiliation(s)
- MS Valic
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; The Princess Margaret Cancer Centre, University Health Network (UHN), Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Perimeter Medical Imaging, Inc., Toronto, ON, Canada; University Health Network, Toronto, ON, Canada
| | - WL Leong
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; The Princess Margaret Cancer Centre, University Health Network (UHN), Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Perimeter Medical Imaging, Inc., Toronto, ON, Canada; University Health Network, Toronto, ON, Canada
| | - SJ Done
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; The Princess Margaret Cancer Centre, University Health Network (UHN), Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Perimeter Medical Imaging, Inc., Toronto, ON, Canada; University Health Network, Toronto, ON, Canada
| | - BC Wilson
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; The Princess Margaret Cancer Centre, University Health Network (UHN), Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Perimeter Medical Imaging, Inc., Toronto, ON, Canada; University Health Network, Toronto, ON, Canada
| | - S Kulkarni
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; The Princess Margaret Cancer Centre, University Health Network (UHN), Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Perimeter Medical Imaging, Inc., Toronto, ON, Canada; University Health Network, Toronto, ON, Canada
| | - DR McCready
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; The Princess Margaret Cancer Centre, University Health Network (UHN), Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Perimeter Medical Imaging, Inc., Toronto, ON, Canada; University Health Network, Toronto, ON, Canada
| | - CJ Niu
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; The Princess Margaret Cancer Centre, University Health Network (UHN), Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Perimeter Medical Imaging, Inc., Toronto, ON, Canada; University Health Network, Toronto, ON, Canada
| | - Y Atachia
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; The Princess Margaret Cancer Centre, University Health Network (UHN), Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Perimeter Medical Imaging, Inc., Toronto, ON, Canada; University Health Network, Toronto, ON, Canada
| | - EA Munro
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; The Princess Margaret Cancer Centre, University Health Network (UHN), Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Perimeter Medical Imaging, Inc., Toronto, ON, Canada; University Health Network, Toronto, ON, Canada
| | - D Rempel
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada; The Princess Margaret Cancer Centre, University Health Network (UHN), Toronto, ON, Canada; University of Toronto, Toronto, ON, Canada; Perimeter Medical Imaging, Inc., Toronto, ON, Canada; University Health Network, Toronto, ON, Canada
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Leong W, Lim T, Ismail A, Choong Y. Salmonella Typhi TolC protein: A molecular dynamics investigation. Asian Pacific Journal of Tropical Disease 2014. [DOI: 10.1016/s2222-1808(14)60546-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Foley BR, Rose CG, Rundle DE, Leong W, Edmands S. Postzygotic isolation involves strong mitochondrial and sex-specific effects in Tigriopus californicus, a species lacking heteromorphic sex chromosomes. Heredity (Edinb) 2013; 111:391-401. [PMID: 23860232 DOI: 10.1038/hdy.2013.61] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 05/08/2013] [Accepted: 05/13/2013] [Indexed: 11/09/2022] Open
Abstract
Detailed studies of the genetics of speciation have focused on a few model systems, particularly Drosophila. The copepod Tigriopus californicus offers an alternative that differs from standard animal models in that it lacks heteromorphic chromosomes (instead, sex determination is polygenic) and has reduced opportunities for sexual conflict, because females mate only once. Quantitative trait loci (QTL) mapping was conducted on reciprocal F2 hybrids between two strongly differentiated populations, using a saturated linkage map spanning all 12 autosomes and the mitochondrion. By comparing sexes, a possible sex ratio distorter was found but no sex chromosomes. Although studies of standard models often find an excess of hybrid male sterility factors, we found no QTL for sterility and multiple QTL for hybrid viability (indicated by non-Mendelian adult ratios) and other characters. Viability problems were found to be stronger in males, but the usual explanations for weaker hybrid males (sex chromosomes, sensitivity of spermatogenesis, sexual selection) cannot fully account for these male viability problems. Instead, higher metabolic rates may amplify deleterious effects in males. Although many studies of standard speciation models find the strongest genetic incompatibilities to be nuclear-nuclear (specifically X chromosome-autosome), we found the strongest deleterious interaction in this system was mito-nuclear. Consistent with the snowball theory of incompatibility accumulation, we found that trigenic interactions in this highly divergent cross were substantially more frequent (>6×) than digenic interactions. This alternative system thus allows important comparisons to studies of the genetics of reproductive isolation in more standard model systems.
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Affiliation(s)
- B R Foley
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
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Dowling RJO, Niraula S, Chang MC, Done SJ, Ennis M, Hood N, McCready DR, Leong W, Escallon JM, Reedijk M, Goodwin PJ, Stambolic V. Abstract PD03-05: Analysis of tumour cell signaling in response to neoadjuvant metformin in women with early stage breast cancer. Cancer Res 2012. [DOI: 10.1158/0008-5472.sabcs12-pd03-05] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: The anti-diabetic drug metformin, commonly used to treat type 2 diabetes due to its ability to reduce circulating glucose and insulin, has emerged as a potential anti-cancer agent. Observational studies have reported decreased cancer incidence and mortality in diabetics receiving metformin. Metformin's ability to reduce insulin may be particularly important for breast cancer (BC) because hyperinsulinemia is an adverse prognostic factor and most cells express the insulin receptor (IR). The anti-cancer effects of metformin are associated with both direct (insulin-independent) and indirect (insulin-dependent) actions. Direct effects are linked to activation of AMPK and an inhibition of mTOR signalling, while indirect effects are mediated by reductions in circulating insulin levels, leading to reduced IR-activated PI3K signalling. We conducted a neoadjuvant, single arm, “window of opportunity” trial examining the clinical and biological effects of metformin on thirty-nine locoregional BC patients awaiting definitive surgery.
Methods: Non-diabetic women with newly diagnosed, untreated BC were given metformin 500 mg tid for ≥2 weeks post diagnostic core biopsy until surgery. Fasting blood and tumour samples were collected at diagnosis and surgery. Blood glucose and insulin were assayed to assess the physiologic effects of metformin, while IHC analysis of tumours was used to characterize cellular markers before and after metformin. Specifically, IR levels and the phosphorylation status of proteins involved in AMPK and PI3K/AKT/mTOR signalling, including AMPK (T172) and AKT (S473), were examined.
Results: 39 patients with a mean age of 51 years received metformin for a median of 18 days (range 13–40) with minor GI toxicities. The clinical effects (previously reported) included significant (p < 0.05) decreases in body mass index (−0.5 kg/m2), weight (−1.2 kg), glucose (−0.14 mM) and HOMA (an estimate of insulin resistance, −0.21), and a decrease in insulin (−4.7 pmol/L) that approached significance (p = 0.0686). Ki67 staining in tumour tissue decreased significantly and TUNEL increased significantly. Levels of IR expression decreased significantly (from 4.39 to 3.82, p = 0.0375) as did the phosphorylation status of AKT (S473) and AMPK (T172) (from 9.82 to 7.08, p = <0.0001; from 6.2 to 5.1, p = 0.0034, respectively).
Conclusions: Metformin impact was consistent with beneficial anti-cancer effects. Reduced AKT phosphorylation, coupled with decreased insulin and IR levels, suggest insulin-dependent effects are important in the clinical setting. Assessment of additional factors in BC cells, including OCT1 expression (required for metformin uptake), and the phosphorylation of ACC (a marker of AMPK activation), is underway and will be reported. Integrated analysis of these factors combined with the physiological and molecular data described above will further enhance understanding of metformin action in the clinical setting.
Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD03-05.
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Affiliation(s)
- RJO Dowling
- Ontario Cancer Institute, University Health Network, Toronto, ON, Canada; University Health Network, Toronto, ON, Canada; Mt. Sinai Hospital, Toronto, ON, Canada; Campbell Family Institute for Breast Cancer Research and Laboratory Medicine Program, University Health Network, Toronto, ON, Canada; Applied Statistician, Markham, ON, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Hospital, Toronto, ON, Canada
| | - S Niraula
- Ontario Cancer Institute, University Health Network, Toronto, ON, Canada; University Health Network, Toronto, ON, Canada; Mt. Sinai Hospital, Toronto, ON, Canada; Campbell Family Institute for Breast Cancer Research and Laboratory Medicine Program, University Health Network, Toronto, ON, Canada; Applied Statistician, Markham, ON, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Hospital, Toronto, ON, Canada
| | - MC Chang
- Ontario Cancer Institute, University Health Network, Toronto, ON, Canada; University Health Network, Toronto, ON, Canada; Mt. Sinai Hospital, Toronto, ON, Canada; Campbell Family Institute for Breast Cancer Research and Laboratory Medicine Program, University Health Network, Toronto, ON, Canada; Applied Statistician, Markham, ON, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Hospital, Toronto, ON, Canada
| | - SJ Done
- Ontario Cancer Institute, University Health Network, Toronto, ON, Canada; University Health Network, Toronto, ON, Canada; Mt. Sinai Hospital, Toronto, ON, Canada; Campbell Family Institute for Breast Cancer Research and Laboratory Medicine Program, University Health Network, Toronto, ON, Canada; Applied Statistician, Markham, ON, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Hospital, Toronto, ON, Canada
| | - M Ennis
- Ontario Cancer Institute, University Health Network, Toronto, ON, Canada; University Health Network, Toronto, ON, Canada; Mt. Sinai Hospital, Toronto, ON, Canada; Campbell Family Institute for Breast Cancer Research and Laboratory Medicine Program, University Health Network, Toronto, ON, Canada; Applied Statistician, Markham, ON, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Hospital, Toronto, ON, Canada
| | - N Hood
- Ontario Cancer Institute, University Health Network, Toronto, ON, Canada; University Health Network, Toronto, ON, Canada; Mt. Sinai Hospital, Toronto, ON, Canada; Campbell Family Institute for Breast Cancer Research and Laboratory Medicine Program, University Health Network, Toronto, ON, Canada; Applied Statistician, Markham, ON, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Hospital, Toronto, ON, Canada
| | - DR McCready
- Ontario Cancer Institute, University Health Network, Toronto, ON, Canada; University Health Network, Toronto, ON, Canada; Mt. Sinai Hospital, Toronto, ON, Canada; Campbell Family Institute for Breast Cancer Research and Laboratory Medicine Program, University Health Network, Toronto, ON, Canada; Applied Statistician, Markham, ON, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Hospital, Toronto, ON, Canada
| | - W Leong
- Ontario Cancer Institute, University Health Network, Toronto, ON, Canada; University Health Network, Toronto, ON, Canada; Mt. Sinai Hospital, Toronto, ON, Canada; Campbell Family Institute for Breast Cancer Research and Laboratory Medicine Program, University Health Network, Toronto, ON, Canada; Applied Statistician, Markham, ON, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Hospital, Toronto, ON, Canada
| | - JM Escallon
- Ontario Cancer Institute, University Health Network, Toronto, ON, Canada; University Health Network, Toronto, ON, Canada; Mt. Sinai Hospital, Toronto, ON, Canada; Campbell Family Institute for Breast Cancer Research and Laboratory Medicine Program, University Health Network, Toronto, ON, Canada; Applied Statistician, Markham, ON, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Hospital, Toronto, ON, Canada
| | - M Reedijk
- Ontario Cancer Institute, University Health Network, Toronto, ON, Canada; University Health Network, Toronto, ON, Canada; Mt. Sinai Hospital, Toronto, ON, Canada; Campbell Family Institute for Breast Cancer Research and Laboratory Medicine Program, University Health Network, Toronto, ON, Canada; Applied Statistician, Markham, ON, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Hospital, Toronto, ON, Canada
| | - PJ Goodwin
- Ontario Cancer Institute, University Health Network, Toronto, ON, Canada; University Health Network, Toronto, ON, Canada; Mt. Sinai Hospital, Toronto, ON, Canada; Campbell Family Institute for Breast Cancer Research and Laboratory Medicine Program, University Health Network, Toronto, ON, Canada; Applied Statistician, Markham, ON, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Hospital, Toronto, ON, Canada
| | - V Stambolic
- Ontario Cancer Institute, University Health Network, Toronto, ON, Canada; University Health Network, Toronto, ON, Canada; Mt. Sinai Hospital, Toronto, ON, Canada; Campbell Family Institute for Breast Cancer Research and Laboratory Medicine Program, University Health Network, Toronto, ON, Canada; Applied Statistician, Markham, ON, Canada; Campbell Family Institute for Breast Cancer Research, Princess Margaret Hospital, Toronto, ON, Canada
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Leong WL, Wang DY, Done S, McCready D. Abstract P2-10-34: Development and validation of ClinicoMolecular Triad Classification (CMTC), a platform for breast cancer (BC) prognostic and predictive gene signature portfolios. Cancer Res 2012. [DOI: 10.1158/0008-5472.sabcs12-p2-10-34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Numerous gene signatures have claimed prognostic significance in BCs. Each of these gene signatures was designed to answer a specific clinical or biological question, often by dichotomizing the targeted populations into a good and a bad risk group. None of these gene signatures on its own has sufficient degree of complexity to fully characterize this very heterogenous group of diseases, and hence lacks the flexibility to personalize treatments. To exploit the full potential of the genomic approach, we developed an 803-gene molecular classification, termed ClinicoMolecular Triad Classification (CMTC) that categorized BCs into 3 clinical treatment groups (triad) that can serve as a basic framework to guide management. CMTC also provide a detailed “portfolio” of 14 other gene signatures and 19 oncogenic pathways to allow further customization of the treatments. The ability to get CMTC portfolio results at the time of initial diagnosis offers the unique advantage of early treatment planning, including the use of pre-operative chemotherapy to improve breast conservation in selected patients. This study aimed to validate the CMTC classification using an independent BC cohort.
Study design/ results: RNA from fine needle aspirates were collected in a prospective BC cohort (n = 340) between 2008 and 2010 at Princess Margaret Hospital and Mount Sinai Hospital, Toronto, we included all newly diagnosed BC patients going for surgery who consented to join the study. DNA microarray analyses were carried out using genome-wide Illumina Human Ref-8 version 3 Beadarrays, which contained >24K oligonucleotide probes. After excluding tumors with low RNA yield (n = 8, success rate 97%), non-invasive cancers (n = 27), insufficient follow-up data (n = 21), CMTC divided the remaining 284 BCs into 3 similar sized groups (triad). At a median follow-up of 32 months (range 6.3–52 months), the short-term recurrence was significantly worse (p = 0.0048) in the poor prognostic groups. This result was similar to using an independent external validation cohort (n = 2100) with long-term follow-up reported before, CMTC outperformed all other gene signatures in predicting prognosis and treatment response.
Discussion/conclusion: This prospective validation cohort study demonstrated reproducibility of CMTC in classifying BCs into the three major treatment groups and its prognostic significance. CMTC can be used as a platform to personalize treatments: CMTC-1 BCs (ER+, low proliferation) in general can be treated with surgery and tamoxifen alone. CMTC-2 tumours (ER+, high proliferation) will require additional treatments, including chemotherapy, in addition to tamoxifen; other biologics can be prescribed based on the activities of additional oncogenic pathways. Neo-adjuvant chemotherapy should be considered for CMTC-3 tumours (triple negative and HER2+) with addition of trastuzumab in those that show activation of the HER2 pathway. CMTC portfolio is being further developed into a genomic platform to guide personalized BC treatments..
Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-10-34.
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Affiliation(s)
- WL Leong
- University Health Network, Toronto, ON, Canada
| | - D-Y Wang
- University Health Network, Toronto, ON, Canada
| | - S Done
- University Health Network, Toronto, ON, Canada
| | - D McCready
- University Health Network, Toronto, ON, Canada
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Warburton R, Alriyees L, Wang DY, Wong SL, Leong W. P2-15-07: The Need for Additional Surgeries to Adequately Excise Early Breast Cancers May Have a Negative Impact on Local Recurrence. Cancer Res 2011. [DOI: 10.1158/0008-5472.sabcs11-p2-15-07] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Breast conservation surgery (BCS) is considered the standard of care for the treatment of early stage breast cancer (ESBC, AJCC stage 1 and 2). 20 to 50% of patients will require further surgery for positive or close margins. There is recent data suggesting that re-operation can have a negative impact on local and distant recurrences. Our aim is to examine the effects of multiple surgeries to obtain adequate margins on breast cancer recurrence, metastatic disease and survival.
Methods: We reviewed a prospectively maintained breast cancer database at the University Health Network and included all women who had BCS for their first diagnosis of ESBC between January 2004 and December 2007. Patients with neoadjuvant chemotherapy were excluded. We collected patient demographics, surgical pathology, adjuvant therapy and follow up outcome data, which included local recurrence, distant recurrence, cancer-specific survival and overall survival. Clinical and pathologic features were compared using chi-square analyses. Patients who had one lumpectomy were compared to those who had multiple surgeries by using Kaplan-Meier survival curves and log rank test.
Results: Of a total of 744 patients (8 patients had bilateral cancer) 577 (77.6%) had one lumpectomy only (Group 1). 167 (22.4%) patients required further surgery (group 2 = LR+LM+LRM): 83 (11.1%) had a re-excision (LR), 69 (9.3%) had mastectomy (LM) and 15 (2%) had a re-excision followed by a mastectomy (LRM). Thus, a total of 85 (11.4%) patients had mastectomy to achieve adequate margins. All clinicopathologic factors and adjuvant systemic treatments were similar between the two groups except for age and use of adjuvant radiotherapy, which was related to that fact that many of those in group 2 had mastectomy. We observed a difference in disease-free survival favoring patients with lumpectomy only (group 1–3.4% vs. group 2–8.1%, p= 0.01) but there was no difference in distant metastasis (4.5% vs. 5.6%, p=0.56), cancer-specific survival (97.6% vs. 95.6%, p=0.20) and overall survival (6.9% vs 6.3%, p= 0.76) at a median follow up of 4.54 years.
Conclusion: Despite having similar stage, grade, receptor status and adjuvant systemic therapies, having multiple surgeries for primary breast cancer appeared to be associated with decreased disease-free survival but had no difference in rates of distant metastatic disease, cancer-specific survival and overall survival.
Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-15-07.
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Affiliation(s)
- R Warburton
- 1University Health Network, University of Toronto, Toronto, ON, Canada
| | - L Alriyees
- 1University Health Network, University of Toronto, Toronto, ON, Canada
| | - DY Wang
- 1University Health Network, University of Toronto, Toronto, ON, Canada
| | - SL Wong
- 1University Health Network, University of Toronto, Toronto, ON, Canada
| | - W Leong
- 1University Health Network, University of Toronto, Toronto, ON, Canada
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Bordeleau L, Richter S, O'Malley F, Pinnaduwage D, Collins L, Mulligan AM, Youngson B, Glendon G, Leong W, Lipa J, McCready D, Andrulis I. Abstract P2-11-01: Molecular Profiling Identifies Differentially Expressed Genes between Normal Breast Tissue from BRCA Carriers and Women at Population Risk. Cancer Res 2010. [DOI: 10.1158/0008-5472.sabcs10-p2-11-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Women found to carry a BRCA1 or BRCA2 gene mutation are at significant risk of future breast cancer (BC). Prophylactic mastectomy (PM) remains the most effective risk reducing strategy in that setting. Thus far, there are no data available identifying changes in gene expression profiles prior to the onset of BC in these women using microarray technology.
Material and methods : In this pilot study, we prospectively collected PM specimens from BRCA1/2 mutation carriers (n=21), and reduction mammoplasty (RM) specimens from healthy controls at population risk of breast cancer (n=13). Samples were collected from all 4 quadrants (fresh frozen) and careful histological examination was conducted. Selected samples (most dense parenchymal tissue) were sent for microarray analyses (19K chip, http://www.uhnres.utoronto.ca/facilities/index.htm). We compared the molecular profiles of breast tissue obtained from these two groups using two approaches: 1) microarray analysis for a global assessment of gene expression, and 2) gene set analysis to identify differences based on cellular function and biologic themes. Results: Women in each group were of similar age (p=NS). No invasive cancer was identified. In histologically normal breast tissue, class comparison identified differential gene expression between RM and PM tissues. Gene set analysis of five collections including MSigDB C2, C4, cytobands, Stanford 5Mb chromosomal tiles and KEGG database identified 22 significant gene sets. Nine sets were overexpressed and 13 sets were underexpressed in PM tissues (FDR < 0.2; p < 0.012). We found overexpression of genes relating to proliferation and transcription specifically in the PM tissues enriched for Gene Ontology annotations. The top 200 genes ranked by SAM were also examined by pathway analysis that showed high enrichment for cancer related pathways. All three approaches implicated T cell receptor signaling and a TSG101-stathmin breast cancer related pathway as contributing to the differential molecular profiles between RM and PM tissues.
Discussion: We have shown differential expression of single genes as well as cancer related biologic pathways (using microarray and gene set analyses) between normal breast tissue from BRCA1/2 mutation carriers (at high risk of BC) and healthy controls (at population risk of BC). These differences may represent early molecular defects of genetic pathways potentially involved in the early stages of breast carcinogenesis in women at hereditary high risk or may represent the result of BRCA1/2 haploinsufficiency. These results support the hypothesis that molecular pathways leading to BC formation are unique to BRCA1/2 carriers. This information may help the development of innovative preventive strategies for BRCA carriers in the future.
Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P2-11-01.
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Affiliation(s)
- L Bordeleau
- McMaster University, Hamilton, ON, Canada; University of Toronto, ON, Canada; Cancer Care Ontario, Toronto, ON, Canada; University of California, Los Angeles; Mount Sinai Hospital, Toronto, ON, Canada
| | - S Richter
- McMaster University, Hamilton, ON, Canada; University of Toronto, ON, Canada; Cancer Care Ontario, Toronto, ON, Canada; University of California, Los Angeles; Mount Sinai Hospital, Toronto, ON, Canada
| | - F O'Malley
- McMaster University, Hamilton, ON, Canada; University of Toronto, ON, Canada; Cancer Care Ontario, Toronto, ON, Canada; University of California, Los Angeles; Mount Sinai Hospital, Toronto, ON, Canada
| | - D Pinnaduwage
- McMaster University, Hamilton, ON, Canada; University of Toronto, ON, Canada; Cancer Care Ontario, Toronto, ON, Canada; University of California, Los Angeles; Mount Sinai Hospital, Toronto, ON, Canada
| | - L Collins
- McMaster University, Hamilton, ON, Canada; University of Toronto, ON, Canada; Cancer Care Ontario, Toronto, ON, Canada; University of California, Los Angeles; Mount Sinai Hospital, Toronto, ON, Canada
| | - AM Mulligan
- McMaster University, Hamilton, ON, Canada; University of Toronto, ON, Canada; Cancer Care Ontario, Toronto, ON, Canada; University of California, Los Angeles; Mount Sinai Hospital, Toronto, ON, Canada
| | - B Youngson
- McMaster University, Hamilton, ON, Canada; University of Toronto, ON, Canada; Cancer Care Ontario, Toronto, ON, Canada; University of California, Los Angeles; Mount Sinai Hospital, Toronto, ON, Canada
| | - G Glendon
- McMaster University, Hamilton, ON, Canada; University of Toronto, ON, Canada; Cancer Care Ontario, Toronto, ON, Canada; University of California, Los Angeles; Mount Sinai Hospital, Toronto, ON, Canada
| | - W Leong
- McMaster University, Hamilton, ON, Canada; University of Toronto, ON, Canada; Cancer Care Ontario, Toronto, ON, Canada; University of California, Los Angeles; Mount Sinai Hospital, Toronto, ON, Canada
| | - J Lipa
- McMaster University, Hamilton, ON, Canada; University of Toronto, ON, Canada; Cancer Care Ontario, Toronto, ON, Canada; University of California, Los Angeles; Mount Sinai Hospital, Toronto, ON, Canada
| | - D McCready
- McMaster University, Hamilton, ON, Canada; University of Toronto, ON, Canada; Cancer Care Ontario, Toronto, ON, Canada; University of California, Los Angeles; Mount Sinai Hospital, Toronto, ON, Canada
| | - I. Andrulis
- McMaster University, Hamilton, ON, Canada; University of Toronto, ON, Canada; Cancer Care Ontario, Toronto, ON, Canada; University of California, Los Angeles; Mount Sinai Hospital, Toronto, ON, Canada
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Harewood GC, Murray F, Patchett S, Garcia L, Leong WL, Lim YT, Prabakaran S, Yeen KF, O'Flynn J, McNally E. Assessment of colorectal cancer knowledge and patient attitudes towards screening: is Ireland ready to embrace colon cancer screening? Ir J Med Sci 2008; 178:7-12. [PMID: 18584273 DOI: 10.1007/s11845-008-0163-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2007] [Accepted: 04/14/2008] [Indexed: 02/08/2023]
Abstract
INTRODUCTION The level of awareness among the Irish public regarding colorectal cancer (CRC) remains uncertain. This study aimed to characterise CRC knowledge levels among a cohort of Irish patients. METHODS A survey evaluating CRC knowledge levels was distributed among outpatients at a gastroenterology clinic in a Dublin teaching hospital. RESULTS In total, 472 surveys were distributed of which 465 (98.5%) were returned. Twenty-nine percent of respondents correctly judged CRC to be the commonest cause of cancer death among the options provided while 26% correctly judged the lifetime risk of CRC; 59% underestimated and 15% overestimated the risk. Most patients (91%) were willing to pay 300 euros for a prompt colonoscopy if recommended by their physician while 7% opted to wait 6 months for a free colonoscopy. CONCLUSIONS There is a willingness to embrace CRC screening and to shoulder some of the financial burden that this entails.
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Affiliation(s)
- G C Harewood
- Department of Gastroenterology, Beaumont Hospital Dublin, Dublin, Ireland.
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20
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Laura M, Leong W, Murray NMF, Ingle G, Miszkiel KA, Altmann DR, Miller DH, Reilly MM. Chronic inflammatory demyelinating polyradiculoneuropathy: MRI study of brain and spinal cord. Neurology 2005; 64:914-6. [PMID: 15753438 DOI: 10.1212/01.wnl.0000152842.11864.d0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
CNS demyelinating lesions have been reported in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). There are no studies of cord atrophy in CIDP. Ten patients with CIDP underwent brain and spinal cord MRI to investigate CNS demyelination and cord atrophy. No CNS demyelination was found, but the mean cervical cord area was significantly smaller in CIDP patients vs control subjects. Spinal cord atrophy may be related to degeneration secondary to axonal loss.
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Affiliation(s)
- M Laura
- Centre for Neuromuscular Diseases and Department of Molecular Neurosciences, National Hospital for Neurology, London, UK
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21
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Abstract
AIMS Sentinel lymph node biopsy (SLNB) is an important component in the staging and treatment of cutaneous melanoma (CM). The medical literature provides only limited information regarding melanoma sentinel lymph node (SLN) histology. This report details the specific histological patterns of melanoma metastases in sentinel lymph nodes (SLNs) and highlights some key factors in evaluating SLNs for melanoma. METHODS From 281 SLNB cases between June 1998 and May 2002, 79 consecutive cases of SLN biopsies positive for metastases from CM were retrospectively reviewed. The important characteristics of the SLNs and the metastatic foci are described. RESULTS The median size of positive SLNs was 17 mm (range, 5-38). SLNs had a median of two metastatic foci (range, 1-11), with the largest foci being a median of 1.1 mm in size (range, 0.05-24). S-100 and HMB-45 staining was positive in 100% and 92% of the detected metastatic foci, respectively. The metastatic melanoma cells were epithelioid, spindled, and mixed in 86%, 5%, and 9% of cases. Metastatic foci were most often (86%) found in the subcapsular region of the SLN. Benign naevic cells were found coexisting in 14% of positive SLNs. CONCLUSIONS Staining for S100 is more sensitive than HMB-45 (100% v 92%), but HMB-45 staining helped to distinguish benign naevic cells from melanoma. The subcapsular region was crucial in SLN evaluation, because it contained the metastases in 86% of cases. Evaluation of the subcapsular space should not be compromised by cautery artefacts or incomplete excision of the SLN.
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Affiliation(s)
- C A Murray
- Department of Dermatology, University of Toronto, Toronto, Ontario, Canada
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22
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Larock RC, Berrios-Pena NG, Fried CA, Yum EK, Tu C, Leong W. Palladium-catalyzed annulation of 1,4-dienes using ortho-functionally-substituted aryl halides. J Org Chem 2002. [DOI: 10.1021/jo00069a001] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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23
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Armstrong C, Leong W, Lees GJ. Comparative effects of metal chelating agents on the neuronal cytotoxicity induced by copper (Cu+2), iron (Fe+3) and zinc in the hippocampus. Brain Res 2001; 892:51-62. [PMID: 11172748 DOI: 10.1016/s0006-8993(00)03195-4] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The ability of metal chelating agents to prevent neuronal death caused by intra-hippocampal injections of cupric sulphate, ferric citrate and zinc chloride was investigated. Ammonium tetrathiomolybdate was itself toxic after injection into the hippocampus, but this toxicity was reduced by formation of a metal ion/tetrathiomolybdate complex with Cu+2. Disodium bathocuproine disulphonate (BCDS) prevented neuronal death caused by Cu+2, but not that induced by Fe+3 or Zn+2. Desferrioxamine prevented death caused by Fe+3, had no significant effect of the toxicity of Zn+2, and increased that caused by Cu+2. Even though N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) has a higher affinity for Cu+2 than for Zn+2, TPEN had no effect on the toxicity of Cu+2 while totally preventing damage caused by Fe+3 or Zn+2. Ethylenediaminetetra-acetic acid (EDTA) prevented the toxicity of all three metal ions. Motor seizure activity occurred in most rats after injections of Fe+3; or combinations of Cu+2 plus TPEN, or 4 nmol Fe+3 plus 0.1 nmol desferrioxamine. However, apart from the low dose desferrioxamine/Fe+3 combination, only the occasional brain contained seizure-induced neuronal loss in limbic regions outside the injected hippocampus, and these brains were not used for analysis. Seizure activity was found even with very low levels of Cu+2 with a fixed amount of TPEN (a ratio of Cu+2/TPEN of 1:100), but the extent of hippocampal damage in these brains was not significantly different to that caused by injections of saline. These studies demonstrate that idiosyncratic interactions can occur between metal ions and chelating agents. Thus further investigations are needed before chelating agents can be examined for their protective properties in various neurodegenerative diseases.
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Affiliation(s)
- C Armstrong
- Department of Pharmacology and Clinical Pharmacology, University of Auckland School of Medicine, Auckland, New Zealand
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24
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Lees GJ, Leong W. In vivo, the direct and seizure-induced neuronal cytotoxicity of kainate and AMPA is modified by the non-competitive antagonist, GYKI 52466. Brain Res 2001; 890:66-77. [PMID: 11164769 DOI: 10.1016/s0006-8993(00)03080-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The 2,3-benzodiazepine GYKI 52466, administered intracerebrally or systemically, was assessed for its ability to protect against the neuronal death in the brain caused by intra-hippocampal injections of the non-N-methyl-D-aspartate (NMDA) receptor agonists, kainate and L-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA). In contrast to a previous report, a low intra-hippocampal dose of GYKI 52466 (25 nmol) did not protect against kainate toxicity. In order to achieve higher doses of GYKI 52466, solubilization in 2-hydroxypropyl-beta-cyclodextrin was used, and limited protection against AMPA, but not kainate toxicity was found. There was a commensurate reduction in seizure-related neuronal loss in the limbic regions of the brain. When diazepam was used to prevent seizures, GYKI 52466 had no effect on hippocampal neuronal loss caused by the direct toxicity of AMPA and kainate on hippocampal neurons. Systemic administration of GYKI 52466 had only a minimal effect on preventing neuronal death caused by AMPA. In vivo, GYKI 52466 is only weakly effective as a neuroprotective agent.
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Affiliation(s)
- G J Lees
- Departments of Psychiatry and Behavioural Science, School of Medicine, University of Auckland, Auckland, New Zealand.
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25
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Kelly H, Murphy A, Leong W, Leydon J, Tresise P, Gerrard M, Chibo D, Birch C, Andrews R, Catton M. Laboratory-supported influenza surveillance in Victorian sentinel general practices. Commun Dis Intell (2018) 2000; 24:379-83. [PMID: 11225381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
Laboratory-supported influenza surveillance is important as part of pandemic preparedness, for identifying and isolating candidate vaccine strains, for supporting trials of anti-influenza drugs and for refining the influenza surveillance case definition in practice. This study describes the implementation of laboratory-supported influenza surveillance in Victorian sentinel general practices and provides an estimate of the proportion of patients with an influenza-like illness proven to have influenza. During 1998 and 1999, 25 sentinel general practices contributed clinical surveillance data and 16 metropolitan practices participated in laboratory surveillance. Serological, virus-antigen detection, virus culture and multiplex polymerase chain reaction procedures were used to establish the diagnosis of influenza. Two laboratories at major teaching hospitals in Melbourne provided additional data on influenza virus identification. General practice sentinel surveillance and laboratory identification of influenza provided similar data on the pattern of influenza in the community between May and September. The clinical suspicion of influenza was confirmed in 49 to 54 per cent of cases seen in general practice.
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Affiliation(s)
- H Kelly
- Victorian Infectious Diseases Reference Laboratory, North Melbourne, Locked Bag 815, Carlton South, Vic., Australia 3053.
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26
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Leong WL, Dobson MJ, Logsdon JM, Abdel-Majid RM, Schalkwyk LC, Guernsey DL, Neumann PE. ETn insertion in the mouse Adcy1 gene: transcriptional and phylogenetic analyses. Mamm Genome 2000; 11:97-103. [PMID: 10656922 DOI: 10.1007/s003350010020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Early retrotransposons (ETn) are murine transposable elements, bearing some structural similarity to integrated proviruses, and can be insertional mutagens. We have recently identified the causative mutation of the barrelless (Adcy1brl) phenotype as an integration of a 5.7-kb ETn in an intron of the adenylyl cyclase type I (Adcy1) gene. In the present study, Northern blot analysis shows that the ETn insertion results in loss of the normal Adcy1 transcript, a finding consistent with the loss-of-function Adcy1brl mutation, and generation of shorter transcripts. These aberrant transcripts are the products of abnormal RNA splicing and termination owing to the inserted sequence, and transcription initiation within the 3' long terminal repeat (LTR) of the ETn. The DNA sequences of the LTRs were compared in phylogenetic analyses with LTRs from 22 other ETn-related sequences. Three distinct families of ETn sequences can be identified on the basis of their LTRs. The ETn found in Adcy1brl is a member of a family that includes all classified ETn elements known to have recently transposed. Further, of the four known solitary (solo) LTRs, we have identified two that show evidence of recombination between LTRs from different ETn families.
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Affiliation(s)
- W L Leong
- Department of Pathology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
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27
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Abstract
The ability of metal chelating agents to affect seizure-induced neuronal death caused by intra-amygdaloid injections of kainic acid was investigated. N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), diethyldithiocarbamate (DEDTC) and diphenylthiocarbazone (dithizone), administered simultaneously or within 30 min of a kainate injection, all failed to affect the amount of neuronal loss in the ipsilateral hippocampus. This failure was not due to an inability to complex endogenous zinc as all these chelating agents quenched staining for endogenous zinc by the Timm method. However, the period for which this quenching occurred was short for DEDTC and dithizone (a maximum of 1.5 h) although it lasted for 8 h with TPEN. TPEN, but not DEDTC or dithizone prevented the neuronal loss caused by intra-hippocampal injections of zinc chloride. In the presence of diazepam to prevent seizures, co-injection of TPEN and kainate into the hippocampus also failed to prevent the direct cytotoxicity of kainate. Endogenous zinc, released from mossy fibres in the hippocampus by seizure activity, does not appear to modify seizure activity sufficiently to alter the extent of the resulting neuronal death.
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Affiliation(s)
- G J Lees
- Department of Pharmacology and Clinical Pharmacology, University of Auckland School of Medicine, Auckland, New Zealand.
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28
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Abdel-Majid RM, Leong WL, Schalkwyk LC, Smallman DS, Wong ST, Storm DR, Fine A, Dobson MJ, Guernsey DL, Neumann PE. Loss of adenylyl cyclase I activity disrupts patterning of mouse somatosensory cortex. Nat Genet 1998; 19:289-91. [PMID: 9662407 DOI: 10.1038/980] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The somatosensory (SI) cortex of mice displays a patterned, nonuniform distribution of neurons in layer IV called the 'barrelfield' (ref. 1). Thalamocortical afferents (TCAs) that terminate in layer IV are segregated such that each barrel, a readily visible cylindrical array of neurons surrounding a cell-sparse center, represents a distinct receptive field. TCA arbors are confined to the barrel hollow and synapse on barrel-wall neurons whose dendrites are oriented toward the center of the barrel. Mice homozygous for the barrelless (brl) mutation, which occurred spontaneously in ICR stock at Université de Lausanne (Switzerland), fail to develop this patterned distribution of neurons, but still display normal topological organization of the SI cortex. Despite the absence of barrels and the overlapping zones of TCA arborization, the size of individual whisker representations, as judged by 2-deoxyglucose uptake, is similar to that of wild-type mice. We identified adenylyl cyclase type I (Adcy1) as the gene disrupted in brl mutant mice by fine mapping of proximal chromosome 11, enzyme assay, mutation analysis and examination of mice homozygous for a targeted disruption of Adcy1. These results provide the first evidence for involvement of cAMP signalling pathways in pattern formation of the brain.
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Affiliation(s)
- R M Abdel-Majid
- Department of Anatomy & Neurobiology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
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29
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Abstract
D-myo-Inositol hexakisphosphate (InsP6, phytate), a normal cellular constituent, was found to be toxic to neuronal perikarya when injected into the rat hippocampus. However, the extrinsic cholinergic innervation of the hippocampus (as estimated by staining for acetylcholinesterase) was unaffected. Its potency as a toxin was approximately equal to that of the excitotoxin quinolinate. Other highly charged derivatives of inositol (inositol hexakissulphate, inositol monophosphate) were not toxic. The cytotoxicity of InsP6 was not due to a high osmolality, or to seizure-induced lesions, but was reduced by calcium. Nevertheless, the toxicity was not due to chelation of brain calcium by InsP6, as another calcium chelator with a higher affinity for calcium, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA), produced only a very mild lesion. Thus, abnormal metabolism of InsP6 might possibly contribute to neuronal death in neurodegenerative diseases.
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Affiliation(s)
- G J Lees
- Department of Psychiatry and Behavioural Science, School of Medicine, University of Auckland, New Zealand.
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30
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Abstract
A possible indirect role of glutamate in causing the neuronal death found after intracerebral administration of a low dose of ouabain (0.1 nmol) has been evaluated. This dose of ouabain produces a more extensive neuronal lesion than those caused by glutamate receptor agonists (kainate at an equimolar dose, or NMDA (N-methyl-D-aspartate) at a 50-fold higher dose). The selective glutamate receptor antagonists, dizocilpine (MK-801) and NBQX (2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo(F)quinoxaline), in doses which blocked the direct toxicity of glutamate receptor agonists acting on either the NMDA and non-NMDA classes of glutamate receptor, failed to provide more than a minor protection against ouabain-induced neuronal death in the rat dorsal hippocampus. In contrast, the non-selective glutamate receptor antagonist, kynurenate (100 nmol) reduced the damage by around 70%. The difference in neuroprotection found between the glutamate receptor antagonists suggests that kynurenate may protect by a non-glutamatergic mechanism. Co-administration of ouabain and glutamate receptor agonists (kainate, NMDA or glutamate) resulted in additive rather than synergistic damage to hippocampal neurons. The results suggest that in vivo, ouabain and excitotoxins probably cause neuronal death by independent mechanisms.
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Affiliation(s)
- G J Lees
- Department of Psychiatry and Behavioural Science, School of Medicine, University of Auckland, Auckland, New Zealand
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31
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Abstract
Injection of ouabain, a potent and selective inhibitor of Na+/K+ ATPase, into the rat striatum and substantia nigra caused a selective neuronal loss in up to 70% of the lesioned area. However, there was a glial cell/macrophage proliferation in the core of the lesion. Neuronal loss was demonstrated by staining in vivo with Trypan Blue, a marker for dead cells. Cholinesterase staining was also lost, but in the striatum this was revealed only after pre-existing enzyme was irreversibly inhibited in vivo.
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Affiliation(s)
- G J Lees
- Department of Psychiatry and Behavioural Science, School of Medicine, University of Auckland, New Zealand
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32
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Abstract
The non-N-methyl-D-aspartate (NMDA) glutamate agonists are potent convulsants, and cause neuronal loss in many regions of the limbic system in the brain. Kainate or L-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) and the non-NMDA antagonist 2,3-dihydroxy-6-nitro-7-sulphamoyl-benzo(F)quinoxaline (NBQX) were concomitantly injected unilaterally into the rat dorsal hippocampus. Kainate with low doses of NBQX (12.5-25 nmol) almost completely prevented damage to the contralateral but not ipsilateral limbic areas (distal toxicity). In most animals, damage was still found in the contralateral midline thalamic nuclei. In contrast, high doses of NBQX (95-190 nmol) gave no protection to either side. AMPA showed a trend for a reduction in limbic damage to both sides with increasing dose of NBQX. At the highest doses, NBQX prevented damage to both sides.
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Affiliation(s)
- G J Lees
- Department of Psychiatry and Behavioural Science, School of Medicine, University of Auckland, New Zealand
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33
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Abstract
The non-N-methyl-D-aspartate (NMDA) glutamate receptor agonists kainate and L-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA), when injected into the rat dorsal hippocampus, cause neuronal death directly by activating non-NMDA receptors and as a consequence of initiating seizure activity. Co-injection of the non-NMDA antagonist 2,3-dihydroxy-6-nitro-7-sulphamoyl-benzo(F)quinoxaline (NBQX; 12.5-95 nmol) was partially effective in preventing up to about 60% of the direct excitotoxicity. On the other hand, diazepam (6 x 5 mg kg-1, i.p.) had only a minor protective effect against the direct neuronal damage, but was effective in preventing almost all the extra-hippocampal loss of neurones caused by seizure activity. The combination of intracerebral NBQX and systemic diazepam reduced the toxicity of kainate or AMPA to a greater extent than that found in the presence of either protectant alone. At optimum doses the neuronal cytotoxicity caused by non-NMDA agonists in the hippocampus was completely prevented.
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Affiliation(s)
- G J Lees
- Department of Psychiatry and Behavioural Science, School of Medicine, University of Auckland, New Zealand
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34
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Abstract
The cytotoxicity in the brain of potent selective and non-selective inhibitors of Na+/K+ ATPase has been assessed. Following injection of cardiac glycosides into the dorsal hippocampus of rats, the extent of neuronal loss roughly paralleled their potencies as inhibitors of the enzyme. Dihydroouabain was less potent than ouabain as a cytotoxin by an order of magnitude, similar to their relative affinities for Na+/K+ ATPase. The non-specific inhibitors, melittin, erythrosin B and zinc (chloride) were less neurocytotoxic than the selective inhibitors having equivalent potencies. The toxicity of a low dose of ouabain appeared to be selective for neuronal perikarya as staining for acetylcholinesterase (present on the nerve terminals of the afferent cholinergic innervation) was unaffected. A higher dose of ouabain caused a non-specific necrosis including damage to the neuropil and a loss of cholinesterase staining. Concurrently, there was an invasion of the tissue by cells resembling foaming macrophages. Other inhibitors of the enzyme caused a mixed pathology with both types of responses evident. It is suggested that the pathological response may depend on the relative degrees to which the glial and neuronal activities of the enzyme are affected.
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Affiliation(s)
- G J Lees
- Department of Psychiatry and Behavioural Science, School of Medicine, University of Auckland, New Zealand
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35
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Abstract
The ability of the non-NMDA glutamate antagonist NBQX (2,3-dihydroxy-6-nitro-7-sulphamoyl-benzo(F)quinoxaline) to protect the brain against the neuronal death caused by glutamate agonists was examined. Glutamate agonists and NBQX were co-injected into the dorsal region of the rat hippocampus and 4 days later the brain was examined histochemically for the loss of neurons. 95 nmol NBQX prevented the toxicity of glutamate agonists acting on the AMPA receptor (quisqualate and AMPA [L-alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate]), except for the higher dose of AMPA where toxicity was only partially reduced. This dose of NBQX also prevented about 50% of the toxicity of kainate, but produced a slight increase in the size of the lesions caused by NMDA (N-methyl-D-aspartate). With 190 nmol NBQX, a variable degree of non-specific damage resulted, but was mainly confined to the dentate region. Allowing for this damage, almost complete protection against the toxicity of non-NMDA glutamate agonists was obtained, with a partial protection against NMDA toxicity. Kainate, and a high dose of AMPA (2 nmol), consistently caused neuronal death in other limbic regions of the brain in addition to the hippocampal damage. About 50% of rats treated with 15 nmol quisqualate also showed damage to limbic regions. Both doses of NBQX prevented this distal damage caused by quisqualate, but not that caused by kainate. With AMPA, only the high dose of NBQX blocked the distal toxicity. Diazepam also blocked the distal toxicity of AMPA, but had only a minor effect on the hippocampal damage.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- G J Lees
- Department of Psychiatry and Behavioural Science, School of Medicine, University of Auckland, New Zealand
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36
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Lees GJ, Leong W. The non-NMDA glutamate antagonist NBQX blocks the local hippocampal toxicity of kainic acid, but not the diffuse extrahippocampal damage. Neurosci Lett 1992; 143:39-42. [PMID: 1331904 DOI: 10.1016/0304-3940(92)90228-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The neuronal lesion caused locally by the injection of 0.47 nmol kainic acid into the dorsal hippocampus was greatly reduced by the co-administration of 190 nmol 2,3-dihydro-6-nitro-7-sulphamoyl-benzo(F)quinoxaline (NBQX). Protection was particularly marked for the neurons present in the CA3 and dentate hilar regions which are the neurons most vulnerable to kainic acid. On the other hand, systemic administration of NBQX (3 doses of 30 mg/kg i.p.) was completely ineffective in blocking neuronal loss in the CA3 and hilar regions. Furthermore, neither hippocampal nor systemic NBQX could prevent the diffuse neuronal damage to other regions in the limbic system outside of the dorsal hippocampus.
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Affiliation(s)
- G J Lees
- Department of Psychiatry and Behavioural Science, School of Medicine, University of Auckland, New Zealand
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Skiadopoulos MH, Salvino R, Leong WL, Faust EA. Characterization of linker insertion and point mutations in the NS-1 gene of minute virus of mice: effects on DNA replication and transcriptional activation functions of NS-1. Virology 1992; 188:122-34. [PMID: 1533078 DOI: 10.1016/0042-6822(92)90741-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The NS-1 gene of minute virus of mice encodes a multifunctional protein required for replication of the viral genome and for transcriptional regulation of the two MVM promoters. To study the localization of activities required for DNA replication and transactivation of the capsid gene promoter, insertion and point mutations were introduced into the NS-1 gene. The mutant NS-1 genes were expressed in COS-7 cells by using an SV 40 promoter driven NS-1 expression vector. The ability of the mutant proteins to complement a replication defective NS-1 mutant of the infectious MVM plasmid pMM984 and to activate transcription from the capsid gene promoter in chloramphenicol acetyl transferase expression assays was determined. Two point mutations Ser-249 to Ala and Lys-250 to Gln and a one amino acid insertion between Asp-606 and Leu-607 had no effect on viral DNA replication and transactivation activities. Six independent insertions of between 2 and 12 amino acids inhibited the DNA replication activity of NS-1 between 20- and at least 100-fold. There was no apparent correlation between the extent of inhibition of parvoviral DNA replication and the location of the mutations. The transcriptional activation function of NS-1 was inhibited between 1.5- and at least 20-fold and was therefore overall relatively less sensitive to mutagenesis than was its DNA replication function. An exception to this was a 5 amino acid insertion between Tyr-543 and Gln-544 that abolished transactivation as well as the ability of NS-1 to complement viral DNA replication.
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Affiliation(s)
- M H Skiadopoulos
- Department of Biochemistry, Dalhousie University, Halifax, Nova Scotia
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38
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deCastro FJ, Biesbroeck R, Erikson C, Farrell P, Leong W, Murphy D, Green R. Hypertension in adolescents. A significantly high prevalence among students attending an inner city school. Clin Pediatr (Phila) 1976; 15:24-6. [PMID: 1245078 DOI: 10.1177/000992287601500104] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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deCastro FI, Biebroeck R, Erikson C, Farrell P, Leong W, Murphy D, Green R. Hypertension in adolescents. Pediatr Nurs 1975; 1:30-1. [PMID: 1041337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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40
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Abstract
A previous study of the
effect of univalent cations on the intensity of symmetrical stretching
frequency in nitrate melts has been extended. The use of divalent cations Mg2+, Ca2+,
Pb2-, and Cd2+
has confirmed that for systems in which covalent bonding is not important the
intensity of the symmetrical stretching frequency decreases linearly with the
strength of the cationic field. In systems for which covalent interactions are
important the change in intensity is probably related to the electronic structure
of the cation. The low frequency vibrational modes for the melts studied also
showed great variation in intensity. This has been correlated with the
variation in the anisotropy of the anionic polarizability and substitution in
the pseudo lattice of the melt.
The effect of the anisotropy of the polarizability was further studied by
replacing the nitrate ion by perchlorate, chlorate, and nitrite. The measurements showed
that the greater the anisotropy the higher the intensity of the lattice modes.
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