1
|
Waddington K, Harrison A, Rayner D, Tucker T, Glamore W. Upscaling the remediation of acidic landscapes - the coastal floodplain prioritisation method. J Environ Manage 2023; 348:119260. [PMID: 37879173 DOI: 10.1016/j.jenvman.2023.119260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/22/2023] [Accepted: 10/03/2023] [Indexed: 10/27/2023]
Abstract
Over 24 million hectares of the world's coastal floodplains are underlain by acid sulfate soils (ASS). Drainage of these sediments has led to widespread environmental degradation, raising serious health concerns. To date, onsite rehabilitation has been complicated by differing stakeholder priorities, with resources often allocated to sites with more vocal proponents rather than those exposed to more significant environmental impacts. To address this issue, this paper introduces the Coastal Floodplain Prioritisation (CFP) Method; a novel, data driven and spatially explicit multi-criteria assessment that ranks floodplain catchment areas according to their risk of transferring acidic drainage waters to an estuary. Results can be used to prioritise where remediation actions are likely to have the greatest benefit. The method was applied across six different estuaries in south-east Australia, with major field campaigns undertaken at each site. Within each estuary, the largest acid fluxes and impacts are identified with relevant mitigation measures provided. On a catchment scale, the results reflect the broader hydrogeomorphic characteristics of each estuary, including the historic acid formation conditions and recent anthropogenic drainage activities. Low-lying backswamps were identified as the highest risk zones within each estuary. These areas are also the most vulnerable to sea level rise. Reinstatement of tidal inundation to these backswamps effectively remediates acid sulfate soil discharges and provides a nature-based solution for adaptation to sea level rise with a range of co-benefits to encourage further investment.
Collapse
Affiliation(s)
- K Waddington
- Water Research Laboratory, School of Civil and Environmental Engineering, UNSW Sydney, NSW, 2093, Australia
| | - A Harrison
- Water Research Laboratory, School of Civil and Environmental Engineering, UNSW Sydney, NSW, 2093, Australia
| | - D Rayner
- Water Research Laboratory, School of Civil and Environmental Engineering, UNSW Sydney, NSW, 2093, Australia
| | - T Tucker
- Water Research Laboratory, School of Civil and Environmental Engineering, UNSW Sydney, NSW, 2093, Australia
| | - W Glamore
- Water Research Laboratory, School of Civil and Environmental Engineering, UNSW Sydney, NSW, 2093, Australia.
| |
Collapse
|
2
|
Lang Kuhs KA, Faden DL, Chen L, Smith DK, Pinheiro M, Wood CB, Davis S, Yeager M, Boland JF, Cullen M, Steinberg M, Bass S, Wang X, Liu P, Mehrad M, Tucker T, Lewis JS, Ferris RL, Mirabello L. Genetic variation within the human papillomavirus type 16 genome is associated with oropharyngeal cancer prognosis. Ann Oncol 2022; 33:638-648. [PMID: 35306154 PMCID: PMC9350957 DOI: 10.1016/j.annonc.2022.03.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/08/2022] [Accepted: 03/11/2022] [Indexed: 01/02/2023] Open
Abstract
PURPOSE A significant barrier to adoption of de-escalated treatment protocols for human papillomavirus-driven oropharyngeal cancer (HPV-OPC) is that few predictors of poor prognosis exist. We conducted the first large whole-genome sequencing (WGS) study to characterize the genetic variation of the HPV type 16 (HPV16) genome and to evaluate its association with HPV-OPC patient survival. PATIENTS AND METHODS A total of 460 OPC tumor specimens from two large United States medical centers (1980-2017) underwent HPV16 whole-genome sequencing. Site-specific variable positions [single nucleotide polymorphisms (SNPs)] across the HPV16 genome were identified. Cox proportional hazards model estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for overall survival by HPV16 SNPs. Harrell C-index and time-dependent positive predictive value (PPV) curves and areas under the PPV curves were used to evaluate the predictive accuracy of HPV16 SNPs for overall survival. RESULTS A total of 384 OPC tumor specimens (83.48%) passed quality control filters with sufficient depth and coverage of HPV16 genome sequencing to be analyzed. Some 284 HPV16 SNPs with a minor allele frequency ≥1% were identified. Eight HPV16 SNPs were significantly associated with worse survival after false discovery rate correction (individual prevalence: 1.0%-5.5%; combined prevalence: 15.10%); E1 gene position 1053 [HR for overall survival (HRos): 3.75, 95% CI 1.77-7.95; Pfdr = 0.0099]; L2 gene positions 4410 (HRos: 5.32, 95% CI 1.91-14.81; Pfdr = 0.0120), 4539 (HRos: 6.54, 95% CI 2.03-21.08; Pfdr = 0.0117); 5050 (HRos: 6.53, 95% CI 2.34-18.24; Pfdr = 0.0030), and 5254 (HRos: 7.76, 95% CI 2.41-24.98; Pfdr = 0.0030); and L1 gene positions 5962 (HRos: 4.40, 95% CI 1.88-10.31; Pfdr = 0.0110) and 6025 (HRos: 5.71, 95% CI 2.43-13.41; Pfdr = 0.0008) and position 7173 within the upstream regulatory region (HRos: 9.90, 95% CI 3.05-32.12; Pfdr = 0.0007). Median survival time for patients with ≥1 high-risk HPV16 SNPs was 3.96 years compared with 18.67 years for patients without a high-risk SNP; log-rank test P < 0.001. HPV16 SNPs significantly improved the predictive accuracy for overall survival above traditional factors (age, smoking, stage, treatment); increase in C-index was 0.069 (95% CI 0.019-0.119, P < 0.001); increase in area under the PPV curve for predicting 5-year survival was 0.068 (95% CI 0.015-0.111, P = 0.008). CONCLUSIONS HPV16 genetic variation is associated with HPV-OPC prognosis and can improve prognostic accuracy.
Collapse
Affiliation(s)
- K A Lang Kuhs
- Department of Epidemiology, College of Public Health, University of Kentucky, Lexington, USA; Department of Medicine, Vanderbilt University Medical Cancer, Nashville, USA.
| | - D L Faden
- Department of Otolaryngology, Massachusetts Eye and Ear, Massachusetts General Hospital, Harvard Medical School, Boston, USA; Broad Institute of MIT and Harvard, Cambridge, USA
| | - L Chen
- Division of Cancer Biostatistics, Department of Internal Medicine and Biostatistics and Bioinformatics Shared Resource Facility, Markey Cancer Center, University of Kentucky, Lexington, USA
| | - D K Smith
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, USA
| | - M Pinheiro
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, USA
| | - C B Wood
- Department of Otolaryngology - Head and Neck Surgery, Vanderbilt University Medical Center, Nashville, USA; Department of Otolaryngology - Head and Neck Surgery, University of Tennessee Health Science Center, Memphis, USA
| | - S Davis
- Department of Otolaryngology - Head and Neck Surgery, Vanderbilt University Medical Center, Nashville, USA
| | - M Yeager
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, USA; Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, USA
| | - J F Boland
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, USA; Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, USA
| | - M Cullen
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, USA; Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, USA
| | - M Steinberg
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, USA; Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, USA
| | - S Bass
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, USA; Cancer Genomics Research Laboratory, Leidos Biomedical Research, Inc., Frederick, USA
| | - X Wang
- Department of Pharmacology and Regenerative Medicine, The University of Illinois at Chicago, Chicago, USA
| | - P Liu
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, USA
| | - M Mehrad
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, USA
| | - T Tucker
- Department of Epidemiology, College of Public Health, University of Kentucky, Lexington, USA
| | - J S Lewis
- Department of Otolaryngology - Head and Neck Surgery, Vanderbilt University Medical Center, Nashville, USA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, USA
| | - R L Ferris
- University of Pittsburgh Medical Center Hillman Cancer Center, Pittsburgh, USA; Department of Otolaryngology-Head and Neck Surgery, University of Pittsburgh Medical Center, Pittsburgh, USA
| | - L Mirabello
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, USA
| |
Collapse
|
3
|
Pender A, Hughesman C, Law E, Kristanti A, Mcneil K, Tucker T, Bosdet I, Young S, Laskin J, Karsan A, Yip S, Ho C. P1.01-40 EGFR ctDNA Detection: The Impact of Site of Progression and Burden of Progressive Disease. J Thorac Oncol 2019. [DOI: 10.1016/j.jtho.2019.08.755] [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: 10/25/2022]
|
4
|
Myers J, Young T, Galloway M, Manyike P, Tucker T. Responding to climate change in southern Africa - the role of research. S Afr Med J 2011; 101:820-822. [PMID: 22272964] [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] [Received: 09/02/2011] [Accepted: 09/12/2011] [Indexed: 05/31/2023] Open
Abstract
Projections show that the effects of climate change in Africa will not be uniform over the region. The region is extremely vulnerable to the impact of climate change because of poverty, a high pre-existing disease burden, fragmented health services and existing water and food insecurity. Despite the consensus that locally relevant information is necessary to inform policy and practice related to climate change, very few studies assessing the association between climate change and health in southern Africa have been conducted. More complete information is therefore urgently needed for the southern African region to estimate the health risks from projected future changes in climate.
Collapse
Affiliation(s)
- J Myers
- Centre for Occupational and Environmental Health Research, School of Public Health and Family Medicine, University of Cape Town, South Africa
| | | | | | | | | |
Collapse
|
5
|
Myers J, Young T, Galloway M, Manyike P, Tucker T. A public health approach to the impact of climate change on health in southern Africa - identifying priority modifiable risks. S Afr Med J 2011; 101:817-820. [PMID: 22272963] [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] [Received: 09/02/2011] [Accepted: 09/12/2011] [Indexed: 05/31/2023] Open
Abstract
Anthropogenic climate change and anticipated adverse impacts on human health as outlined by the Intergovernmental Panel on Climate Change (IPCC) are taken as given. A conceptual model for thinking about the spectrum of climate-related health risks ranging from distal and infrastructural to proximal and behavioural and their relation to the burden of disease pattern typical of sub-Saharan Africa is provided. The model provides a tool for identifying modifiable risk factors with a view to future research, specifically into the performance of interventions to reduce the impact of climate change.
Collapse
Affiliation(s)
- J Myers
- Centre for Occupational and Environmental Health Research, School of Public Health and Family Medicine, University of Cape Town, South Africa
| | | | | | | | | |
Collapse
|
6
|
Abstract
We report three historical cases of severe vitamin A intoxication in anglers who had consumed reef fish liver caught in Bermuda. The subsequent analyses of 35 fish livers from seven different fish species revealed that very high concentrations of vitamin A exist in tropical fish liver, even in noncarnivorous fish species. Large variations in concentrations were observed between specimens and between species. The angling population and (especially) pregnant women should be advised of this potential health threat.
Collapse
Affiliation(s)
- E Dewailly
- Centre de Recherche du Centre Hospitalier Universitaire de Québec, 2875 Boulevarde Laurier, Québec, Canada.
| | | | | | | | | |
Collapse
|
7
|
Flagg EW, Datta SD, Lyu C, Nagaraja J, Copeland G, Silva W, Peters E, Cole L, Tucker T, Byrne MJ, Unger ER, Saraiya M, Weinstock H. O1-S02.05 Population based surveillance for cervical intraepithelial neoplasia grade 3 and adenocarcinoma in situ in three central cancer registries, USA 2009. Br J Vener Dis 2011. [DOI: 10.1136/sextrans-2011-050109.11] [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: 11/03/2022]
|
8
|
Huang B, Tucker T, Bylund JR, Rinehart JJ, Rowland RG, Strup SE, Crispen PL. Utilization of neoadjuvant chemotherapy in stages II and III urothelial carcinoma of the bladder. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.7_suppl.292] [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: 11/20/2022] Open
Abstract
292 Background: Level 1 evidence supports the use of neoadjuvant chemotherapy (NC) prior to cystectomy in patients with stage II and III urothelial carcinoma of the bladder. However, the utilization of NC in appropriate patients prior to cystectomy is unknown. Here we examine the use of and potential predictors for the use of NC prior to cystectomy. Methods: The Kentucky Cancer Registry was reviewed from the years 2000 to 2007 for patients undergoing cystectomy for stage II and III (T2-4aN0M0) bladder cancer. Histologic subtypes of bladder cancer other than urothelial carcinoma were excluded. Multiple logistic regression was utilized to examine factors associated with the use of neoadjuvant chemotherapy prior to cystectomy. Results: A total of 223 patients undergoing cystectomy during the study period were identified. Median age was 66 years and 74% of patients were male. The majority of patients, 66%, had AJCC stage II disease. 6.3% (14/223) of patients received NC prior to cystectomy. Bivariate analysis did not reveal significant differences in age, gender, stage, geographic location, or insurance status when comparing patients receiving and not receiving NC prior to cystectomy. Year of treatment was significantly associated with the use of NC with 2.8% and 9.6% of patients receiving NC between the years 2000–2003 and 2004–2007, respectively (p = 0.034). Year of diagnosis remained significantly associated with the use of NC on multiple logistic regression (OR 4.23, CI 1.12–15.9). Conclusions: Although a significant increase in the number of patients receiving NC prior to cystectomy has been observed since 2003, the overall utilization of NC remains low despite the proven survival benefit noted in randomized trials. Further investigation of the low utilization of NC in this population is warranted. No significant financial relationships to disclose.
Collapse
Affiliation(s)
- B. Huang
- Kentucky Cancer Registry, Lexington, KY; University of Kentucky, Lexington, KY
| | - T. Tucker
- Kentucky Cancer Registry, Lexington, KY; University of Kentucky, Lexington, KY
| | - J. R. Bylund
- Kentucky Cancer Registry, Lexington, KY; University of Kentucky, Lexington, KY
| | - J. J. Rinehart
- Kentucky Cancer Registry, Lexington, KY; University of Kentucky, Lexington, KY
| | - R. G. Rowland
- Kentucky Cancer Registry, Lexington, KY; University of Kentucky, Lexington, KY
| | - S. E. Strup
- Kentucky Cancer Registry, Lexington, KY; University of Kentucky, Lexington, KY
| | - P. L. Crispen
- Kentucky Cancer Registry, Lexington, KY; University of Kentucky, Lexington, KY
| |
Collapse
|
9
|
Vanderloo L, Tucker T, Ismail A, van Zandvoort M. From crawling to running: A provincial/territorial review of physical activity legislation in childcare centres across Canada. Can J Diabetes 2011. [DOI: 10.1016/s1499-2671(11)52222-1] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
10
|
Baldwin L, Ware R, Huang B, Tucker T, Goodrich S, Podzielinski I, DeSimone CP, Vannagell J, Ueland F, Seamon LG. Ten-year relative suvival for ovarian cancer. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.5113] [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: 11/20/2022] Open
|
11
|
Ware R, Baldwin L, Huang B, Tucker T, Goodrich S, Podzielinski I, DeSimone CP, Ueland F, Vannagell J, Seamon LG. Relative conditional survival in 41,476 patients with ovarian cancer. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.5090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
12
|
Wu W, Tiesinga P, Tucker T, Heiner J, Fitzpatrick D. The dynamics of V1 population response to instantaneous changes in direction of stimulus motion. J Vis 2010. [DOI: 10.1167/8.6.814] [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: 11/24/2022] Open
|
13
|
Dewailly E, Rouja P, Dallaire R, Pereg D, Tucker T, Ward J, Weber JP, Maguire JS, Julien P. Balancing the risks and the benefits of local fish consumption in Bermuda. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2010; 25:1328-38. [PMID: 19680840 DOI: 10.1080/02652030802175285] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Fish consumption today is widely recognized as highly beneficial since it constitutes a good source of several essential nutrients, such as selenium and polyunsaturated fatty acids (n-3 PUFA). However, fish can also contain contaminants such as mercury, which make the consumer, especially pregnant women, confused about the risk-benefit balance associated with fish consumption. This is particularly true for tropical fish species for which little information is available. We have previously reported that some Bermudian neonates had elevated mercury in their umbilical blood compared with international guidelines. The objective of this study was to give precise and balanced information on the content of mercury, selenium and PUFA in the most consumed fish species in Bermuda. In 2003 and 2006, a total of 307 fish were collected from 43 fish species and 351 samples were analysed (305 flesh samples, 44 liver samples, one roe and one fat sample) by inductively coupled plasma-mass spectrometry (ICP-MS) (metals) and high-resolution gas chromatography (HRGC) (fatty acids). Results show that mercury varies among species from 0.03 to 3.3 microg g(-1) and that it is possible for at-risk groups such as pregnant women to make informed choices concerning fish consumption, e.g. maximizing fish species rich in nutrients and low in mercury.
Collapse
Affiliation(s)
- E Dewailly
- Public Health Research Unit, Laval University Research Centre-CHUL-CHUQ, Quebec, Canada.
| | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Donovan TA, Schrenzel MD, Tucker T, Pessier AP, Bicknese B, Busch MDM, Wise AG, Maes R, Kiupel M, McKnight C, Nordhausen RW. Meningoencephalitis in a Polar Bear Caused by Equine Herpesvirus 9 (EHV-9). Vet Pathol 2009; 46:1138-43. [DOI: 10.1354/vp.09-vp-0007-d-cr] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A 12-year-old female polar bear ( Ursus maritimus) developed a sudden onset of muscle tremors, erratic circling, increased blinking, head shaking, and ptyalism, which progressed to partial and generalized seizures. Ancillary diagnostic tests were inconclusive, and the only significant laboratory finding was nonsuppurative pleocytosis of cerebrospinal fluid. Euthanasia was elected. Microscopic evaluation demonstrated multifocal, random nonsuppurative meningoencephalitis involving most prominently the rostral cerebral cortex, as well as the thalamus, midbrain, and rostral medulla. Lesions consisted of inflammation, neuronal necrosis, gliosis, and both neuronal and glial basophilic intranuclear inclusion bodies. Immunohistochemistry with a polyclonal antibody reactive to several equine herpesviruses was positive within affected areas of the brain, and polymerase chain reaction conclusively demonstrated the presence of only equine herpesvirus 9. The clinical and morphologic features of this case resemble other fatal herpesvirus encephalitides derived from interspecies transmission and underscore the need for extreme caution when managing wild or captive equids.
Collapse
Affiliation(s)
- T. A. Donovan
- Department of Pathology, The Animal Medical Center, New York, NY
| | - M. D. Schrenzel
- Zoological Society of San Diego, Conservation and Research for Endangered Species, Wildlife Disease Laboratories, Escondido, CA
| | - T. Tucker
- Zoological Society of San Diego, Conservation and Research for Endangered Species, Wildlife Disease Laboratories, Escondido, CA
| | - A. P. Pessier
- Wildlife Disease Laboratories (pathology), Zoological Society of San Diego, San Diego, CA
| | - B. Bicknese
- Department of Veterinary Services, Zoological Society of San Diego, San Diego, CA
| | - M. D. M. Busch
- Division of IDEXX Laboratories, Vet Med Labor GmbH, Ludwigsburg, Germany
| | - A. G. Wise
- College of Veterinary Medicine, Michigan State University, Lansing, MI
| | - R. Maes
- College of Veterinary Medicine, Michigan State University, Lansing, MI
| | - M. Kiupel
- College of Veterinary Medicine, Michigan State University, Lansing, MI
| | | | - R. W. Nordhausen
- California Animal Health & Food Safety Laboratory, University of California, Davis, CA
| |
Collapse
|
15
|
Fudge JL, Tucker T. Amygdala projections to central amygdaloid nucleus subdivisions and transition zones in the primate. Neuroscience 2009; 159:819-41. [PMID: 19272304 DOI: 10.1016/j.neuroscience.2009.01.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [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] [Received: 08/01/2008] [Revised: 01/02/2009] [Accepted: 01/06/2009] [Indexed: 11/19/2022]
Abstract
In rats and primates, the central nucleus of the amygdala (CeN) is most known for its role in responses to fear stimuli. Recent evidence also shows that the CeN is required for directing attention and behaviors when the salience of competing stimuli is in flux. To examine how information flows through this key output region of the primate amygdala, we first placed small injections of retrograde tracers into the subdivisions of the central nucleus in Old world primates, and examined inputs from specific amygdaloid nuclei. The amygdalostriatal area and interstitial nucleus of the posterior limb of the anterior commissure (IPAC) were distinguished from the CeN using histochemical markers, and projections to these regions were also described. As expected, the basal nucleus and accessory basal nucleus are the main afferent connections of the central nucleus and transition zones. The medial subdivision of the central nucleus (CeM) receives a significantly stronger input from all regions compared to the lateral core subdivision (CeLcn). The corticoamygdaloid transition zone (a zone of confluence of the medial parvicellular basal nucleus, paralaminar nucleus, and the sulcal periamygdaloid cortex) provides the main input to the CeLcn. The IPAC and amygdalostriatal area can be divided in medial and lateral subregions, and receive input from the basal and accessory basal nucleus, with differential inputs according to subdivision. The piriform cortex and lateral nucleus, two important sensory interfaces, send projections to the transition zones. In sum, the CeM receives broad inputs from the entire amygdala, whereas the CeLcn receives more restricted inputs from the relatively undifferentiated corticoamygdaloid transition region. Like the CeN, the transition zones receive most of their input from the basal nucleus and accessory basal nucleus, however, inputs from the piriform cortex and lateral nucleus, and a lack of input from the parvicellular accessory basal nucleus, are distinguishing afferent features.
Collapse
Affiliation(s)
- J L Fudge
- Department of Psychiatry, University of Rochester Medical Center, Rochester, NY 14642, USA.
| | | |
Collapse
|
16
|
Tucker T, Schnabel C, Hartmann M, Friedrich RE, Frieling I, Kruse HP, Mautner VF, Friedman JM. Bone health and fracture rate in individuals with neurofibromatosis 1 (NF1). J Med Genet 2008; 46:259-65. [DOI: 10.1136/jmg.2008.061895] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
17
|
Tucker T, Friedman JM, Friedrich RE, Wenzel R, Funsterer C, Mautner VF. Longitudinal study of neurofibromatosis 1 associated plexiform neurofibromas. J Med Genet 2008; 46:81-5. [DOI: 10.1136/jmg.2008.061051] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
18
|
Siden H, Miller M, Straatman L, Omesi L, Tucker T, Collins JJ. A report on location of death in paediatric palliative care between home, hospice and hospital. Palliat Med 2008; 22:831-4. [PMID: 18718991 DOI: 10.1177/0269216308096527] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This retrospective study analysed data for 703 children who died from 2000 to 2006 to examine where children with a broad range of progressive, life-limiting illnesses actually die when families are able to access hospital, paediatric hospice facility and care at home. There was an overall even distribution for location of death in which 35.1% of children died at home, 32.1% died in a paediatric hospice facility, 31.9% in hospital and 0.9% at another location. Previous research suggests a preference for home as the location of death, but these studies have primarily focused on adults, children with cancer or settings without paediatric hospice facilities available as an option. Our results suggest that the choice of families for end-of-life care is equally divided amongst all three options. Given the increasing numbers of children's hospices worldwide, these findings are important for clinicians, care managers and researchers who plan, provide and evaluate the care of children with life-limiting illness.
Collapse
Affiliation(s)
- H Siden
- Department of Pediatrics, University of British Columbia, Vancouver, Canada.
| | | | | | | | | | | |
Collapse
|
19
|
|
20
|
Samant R, Tucker T. How should we describe the benefits of palliative radiotherapy? Curr Oncol 2006; 13:230-4. [PMID: 22792023 PMCID: PMC3394609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
The value of radiotherapy for palliation is well known to oncologists but not necessarily to other physicians. Using terms such as symptom improvement ratio (sir) and number needed to treat (nnt) rather than traditional response rates might be more appropriate in describing the benefits of palliative radiotherapy to other health care professionals.
Collapse
Affiliation(s)
- R. Samant
- The Ottawa Hospital Regional Cancer Centre and The Ottawa Hospital, Ottawa, Ontario, Canada
- Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - T. Tucker
- Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| |
Collapse
|
21
|
Abstract
The value of radiotherapy for palliation is well known to oncologists but not necessarily to other physicians. Using terms such as symptom improvement ratio (SIR) and number needed to treat (NNT) rather than traditional response rates might be more appropriate in describing the benefits of palliative radiotherapy to other health care professionals.
Collapse
|
22
|
Fehm T, Solomayer EF, Meng S, Tucker T, Lane N, Wang J, Gebauer G. Methods for isolating circulating epithelial cells and criteria for their classification as carcinoma cells. Cytotherapy 2005; 7:171-85. [PMID: 16040397 DOI: 10.1080/14653240510027082] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [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
Novel assay methods developed for the isolation and characterization of circulating tumor cells (CTC) of epithelial origin offer the potential of markers for the non-invasive gathering of clinical information relevant to the diagnosis, evolution and treatment of carcinoma. Of the numerous techniques currently used to analyze CTC, slide-based assays are perhaps the most common. While traditional combined immunocytochemical/brightfield microscopy systems continue to be the most frequently employed, fluorescence-based analysis is gaining in importance. This is partly because fluorescence microscopy analysis of slide-mounted CTC can provide simultaneously cytogenetic as well as morphologic and multiple phenotypic information. In particular, fluorescence microscopy analysis of slide-mounted CTC can accurately determine genetic changes at the chromosomal level in patients with recurrent disease. More importantly, by identifying genetic aberrations in CTC, it becomes possible to choose those patients most likely to benefit from a given treatment. The potential of this technique has already been demonstrated by employing fluorescence in situ hybridization (FISH) methods to measure expression of the HER2/neu gene in tissue from patients with breast carcinoma for the specific purpose of identifying those patients most likely to respond to Trastuzumab targeted therapy. Here, we review the major methodologies used in the preparation and analysis of the slide-based assays.
Collapse
Affiliation(s)
- T Fehm
- Department of Obstetrics and Gynecology, University of Tuebingen, Calver Street 7, 72076 Tuebingen, Germany
| | | | | | | | | | | | | |
Collapse
|
23
|
Fehm T, Meng SD, Lane N, Tucker T, Solomayer E, Uhr J. Nachweis von Tumorzellen bei Mammakarzinompatientinnen mit Langzeitüberleben. Geburtshilfe Frauenheilkd 2005. [DOI: 10.1055/s-2005-920829] [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: 10/19/2022] Open
|
24
|
Abstract
OBJECTIVE People with neurofibromatosis type 1 (NF1) have a 10% lifetime risk of developing a malignant peripheral nerve sheath tumor (MPNST). MPNSTs are often metastatic and are a frequent cause of death among people with NF1. Clinical evidence suggests that most MPNSTs in people with NF1 develop from preexisting plexiform neurofibromas. However, it is not known whether an individual's risk of developing an MPNST is associated with the burden of benign neurofibromas. The authors conducted a study to determine whether people with NF1 who have benign neurofibromas of various kinds are at greater risk of developing MPNSTs than patients with NF1 who lack these benign tumors. METHODS Clinical information on 476 NF1 probands in the Henri Mondor Database was analyzed by logistic regression to examine associations between MPNSTs and internal plexiform, superficial plexiform, subcutaneous, and cutaneous neurofibromas. RESULTS Individuals with subcutaneous neurofibromas were approximately three times more likely to have internal plexiform neurofibromas or MPNSTs than individuals without subcutaneous neurofibromas. Individuals with internal plexiform neurofibromas were 20 times more likely to have MPNSTs than individuals without internal plexiform neurofibromas. When this analysis was done with both subcutaneous and internal plexiform neurofibromas as explanatory variables, only the association of MPNSTs with internal plexiform neurofibromas remained significant. CONCLUSIONS The observation that malignant peripheral nerve sheath tumors are strongly associated with internal plexiform neurofibromas suggests that patients with neurofibromatosis type 1 with these benign tumors warrant increased surveillance for malignancy.
Collapse
Affiliation(s)
- T Tucker
- Department of Medical Genetics, University of British Columbia, Vancouver, Canada.
| | | | | | | | | |
Collapse
|
25
|
Lai TS, Tucker T, Burke JR, Strittmatter WJ, Greenberg CS. Effect of tissue transglutaminase on the solubility of proteins containing expanded polyglutamine repeats. J Neurochem 2004; 88:1253-60. [PMID: 15009681 DOI: 10.1046/j.1471-4159.2003.02249.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [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: 11/20/2022]
Abstract
The expansion of a polyglutamine (polyQ) domain in neuronal proteins is the molecular genetic cause of at least eight neurodegenerative diseases. Proteins with a polyQ domain that is greater than 40 Q (Q40) residues form insoluble intranuclear and cytoplasmic inclusions. Expanded polyQ proteins self-associate by non-covalent interactions and become insoluble. They can also be covalently cross-linked by tissue transglutaminase (TTG), a calcium-dependent enzyme present in cells throughout the nervous system. However, it remains unclear whether TTG cross-linking directly contributes to the insolubility of the expanded polyQ proteins. Using an in vitro solubility assay, we found TTG cross-linked Q62 monomers into high molecular weight soluble complexes in a calcium-dependent reaction. Inhibition of TTG cross-linking by primary amine substrates including putrescine and biotinylated pentylamine antagonized TTG's ability to form soluble complexes. In contrast, primary amines (histamine and lysine) that were less effective inhibitors of TTG cross-linking did not inhibit Q62 from becoming insoluble. In summary, TTG can increase the solubility of expanded polyQ proteins by catalyzing intermolecular cross-links. This demonstrates directly that TTG will reduce the ability of expanded polyQ proteins from becoming insoluble. Furthermore, the effectiveness of a primary amine substrate at inhibiting formation of insoluble inclusions may be related to their ability to inhibit intermolecular cross-linking by TTG.
Collapse
Affiliation(s)
- T-S Lai
- Department of Medicine (Hematology Neurology Pathology, Duke University Medical Center, Durham, North Carolina 27710, USA.
| | | | | | | | | |
Collapse
|
26
|
Affiliation(s)
- T Tucker
- South African AIDS Vaccine Initiative, PO Box 19070, Tygerberg 7505, South Africa.
| | | |
Collapse
|
27
|
|
28
|
Abstract
Knudson's 'two-hit' hypothesis has provided extremely important insights into the pathogenesis of tumors in autosomal dominant tumor predisposition syndromes, but recent evidence suggests that some such tumors may occur without a 'second hit' or require more than two mutations. Inactivation of both RB1 alleles appears to be insufficient by itself to cause malignancy in the tumors that develop in patients with hereditary retinoblastoma. On the other hand, certain tumors in patients with tuberous sclerosis complex appear to develop in haploinsufficient tissues that do not have 'second hit' mutations of a tuberous sclerosis gene. The molecular pathogenesis of certain other tumors in patients with tuberous sclerosis complex or neurofibromatosis 1 may not be fully explained by the 'two-hit' hypothesis either. Hereditary tumors, like non-hereditary tumors, may arise by a variety of molecular mechanisms, with loss of both alleles of a particular tumor suppressor gene being a frequent, but not invariably necessary or sufficient, event. Four models are presented to explain how various tumors may arise in patients with inherited tumor predisposition syndromes such as hereditary retinoblastoma, tuberous sclerosis complex or neurofibromatosis 1. Even tumors of one particular type may develop by more than one mechanism.
Collapse
Affiliation(s)
- T Tucker
- Department of Medical Genetics, University of British Columbia, Vancouver, Canada
| | | |
Collapse
|
29
|
Ren H, Nagai Y, Tucker T, Strittmatter WJ, Burke JR. Amino acid sequence requirements of peptides that inhibit polyglutamine-protein aggregation and cell death. Biochem Biophys Res Commun 2001; 288:703-10. [PMID: 11676500 DOI: 10.1006/bbrc.2001.5783] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [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: 11/22/2022]
Abstract
Proteins with expanded polyglutamine domains cause eight inherited neurodegenerative diseases including Huntington's disease. In a previous paper, we identified peptides that inhibit polyglutamine protein aggregation and cell death and now describe the amino acid sequence requirements necessary for these activities. The original 11 amino acid polyglutamine (Q) Binding Peptide 1(QBP1; SNWKWWPGIFD) can be shortened to 8 amino acids (WKWWPGIF) without loss of ability to inhibit polyglutamine aggregation. Three determinants are responsible for inhibition: a tryptophan-rich motif (WKWW), a spacer amino acid and the tripeptide GIF. GIF can be replaced by a repeat of the tryptophan-rich motif, but the spacer remains necessary. We also demonstrate concordance between peptide activity in the in vitro assay and a cellular assay of polyglutamine aggregation and cell death. Polyglutamine binding peptides targeted for intracellular delivery by fusion to TAT retain the ability to inhibit polyglutamine aggregation and cell death in transfected COS 7 cells.
Collapse
Affiliation(s)
- H Ren
- Deane Laboratory, Duke University Medical Center, Durham, North Carolina 27710, USA
| | | | | | | | | |
Collapse
|
30
|
Abstract
Three-hundred sixteen patients who underwent 405 primary knee replacements between January 1994 and June 1999 were reviewed for the incidence of local wound and systemic complications after unilateral and simultaneous bilateral total knee arthroplasties. A body mass index of 30 or greater was used to define obesity, and patients were divided into four groups based on obesity and whether they were undergoing unilateral or bilateral total knee arthroplasties. Preoperative and postoperative knee scores were not significantly different for any patient group. Local wound complication rates did not differ between any of the study groups. Patients who were not obese who underwent unilateral total knee arthroplasty had lower systemic complication rates (3%) than the other groups; however, there was no significant difference in complication rates between patients with obesity who underwent unilateral or simultaneous bilateral total knee arthroplasties. Based on these findings, obesity does not seem to be a contraindication to bilateral total knee arthroplasties under one anesthetic.
Collapse
Affiliation(s)
- J Benjamin
- Department of Orthopaedic Surgery, University of Arizona, College of Medicine, Tucson, USA
| | | | | |
Collapse
|
31
|
Ghadimi BM, Uhr J, Tucker T, Heselmeyer-Haddad K, Auer G, Ried T, Becker H. [Interphase cytogenetics with DNA-probes for chromosome 8 to detect circulating tumor cells in breast cancer patients]. Zentralbl Chir 2001; 126:922-5. [PMID: 11753805 DOI: 10.1055/s-2001-19148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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: 10/17/2022]
Abstract
The detection of micrometastases in the bone marrow or peripheral blood of cancer patients is increasingly used for a more sensitive tumor staging and prognostication. The potential value of the currently used techniques for the detection of epithelial antigens by RT-PCR or immunohistochemistry in respect of specificity is currently controversially discussed. In the present study we demonstrate a new approach which enables the direct visualization of the tumor specific alteration of chromosome 8 in circulating tumor cells. We have therefore studied breast cancer patients with various tumor stages and tried to determine the frequency of circulating tumor cells in the peripheral blood by using interphase cytogenetics for chromosome 7 and 8. Imprints of primary breast cancers and cytospins with circulating tumor cells of corresponding patients were studied in a blinded fashion. The blood samples were generated by immunomagnetic enrichment of circulating tumor cells from peripheral blood by ferrofluid and centrifugation onto cover slips. These cytospins were then hybridized with centromer probes 7 and 8. After analyzing 27 patients with benign as well as malignant breast tumors we can demonstrate that the chromosomal pattern between malignant tumor and corresponding circulating tumor cells is identical. Furthermore, the detection of circulating tumor cells directly correlates with the primary tumor stage. We did not find any cells with chromosome 8 alterations in the patients with benign disease. Surprisingly, even in early breast cancers (T1N0) interphase cytogenetics identified circulating tumor cells in 2 out of 4 patients. In conclusion, interphase cytogenetics represent a non-invasive, sensitive and specific assay for the direct visualization of circulating tumor cells in the peripheral blood. The prognostic value of these findings remains to be further evaluated in larger prospective studies.
Collapse
Affiliation(s)
- B M Ghadimi
- Klinik für Allgemeinchirurgie, Georg-August-Universität Göttingen, Germany.
| | | | | | | | | | | | | |
Collapse
|
32
|
Schifitto G, Yiannoutsos C, Simpson DM, Adornato BT, Singer EJ, Hollander H, Marra CM, Rubin M, Cohen BA, Tucker T, Koralnik IJ, Katzenstein D, Haidich B, Smith ME, Shriver S, Millar L, Clifford DB, McArthur JC. Long-term treatment with recombinant nerve growth factor for HIV-associated sensory neuropathy. Neurology 2001; 57:1313-6. [PMID: 11591856 DOI: 10.1212/wnl.57.7.1313] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.0] [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
HIV-associated distal sensory polyneuropathy (DSP) is a common complication of AIDS. No effective treatment is available. The authors investigated the long-term effect (48 weeks) of the neurotrophin nerve growth factor (NGF) in an open-label study of 200 subjects with HIV-associated DSP. Similar to their previously reported double-blind study, the authors showed that NGF was safe and well tolerated and significantly improved pain symptoms. However, there was no improvement of neuropathy severity as assessed by neurologic examination, quantitative sensory testing, and epidermal nerve fiber density.
Collapse
Affiliation(s)
- G Schifitto
- Department of Neurology, University of Rochester, NY 14642, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Koyama E, Wu C, Shimo T, Iwamoto M, Ohmori T, Kurisu K, Ookura T, Bashir MM, Abrams WR, Tucker T, Pacifici M. Development of stratum intermedium and its role as a Sonic hedgehog-signaling structure during odontogenesis. Dev Dyn 2001; 222:178-91. [PMID: 11668596 DOI: 10.1002/dvdy.1186] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [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: 11/11/2022] Open
Abstract
Stratum intermedium is a transient and subtle epithelial structure closely associated with inner dental epithelium in tooth germs. Little is known about its development and roles. To facilitate analysis, we used bovine tooth germs, predicting that they may contain a more conspicuous stratum intermedium. Indeed, early bell stage bovine tooth germs already displayed an obvious stratum intermedium with a typical multilayered organization and flanking the enamel knot. Strikingly, with further development, the cuspally located stratum intermedium underwent thinning and involution, whereas a multilayered stratum intermedium formed at successive sites along the cusp-to-cervix axis of odontogenesis. In situ hybridization and immunohistochemistry showed that stratum intermedium produces the signaling molecule Sonic hedgehog (Shh). Maximal Shh expression was invariably seen in its thickest multilayered portions. Shh was also produced by inner dental epithelium; expression was not constant but varied with development and cytodifferentiation of ameloblasts along the cusp-to-cervix axis. Interestingly, maximal Shh expression in inner dental epithelium did not coincide with that in stratum intermedium. Both stratum intermedium and inner dental epithelium expressed the Shh receptor Patched2 (Ptch2), an indication of autocrine signaling loops. Shh protein, but not RNA, was present in underlying dental mesenchyme, probably resulting from gradual diffusion from epithelial layers and reflecting paracrine loops of action. To analyze the regulation of Shh expression, epithelial and mesenchymal layers were separated and maintained in organ culture. Shh expression decreased over time, but was maintained in unoperated specimens. Our data show for the first time that stratum intermedium is a highly regulated and Shh-expressing structure. Given its dynamic and apparently interactive properties, stratum intermedium may help orchestrate progression of odontogenesis from cusp to cervix.
Collapse
Affiliation(s)
- E Koyama
- Department of Anatomy and Histology, University of Pennsylvania School of Dental Medicine, Philadelphia, PA 19104-6003, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Holcomb K, Gabbur N, Tucker T, Matthews RP, Lee YC, Abulafia O. 60Cobalt vs. linear accelerator in the treatment of locally advanced cervix carcinoma: a comparison of survival and recurrence patterns. EUR J GYNAECOL ONCOL 2001; 22:16-9. [PMID: 11321486] [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
OBJECTIVE To compare the survival and recurrence patterns of patients with locally advanced cervical carcinoma treated with 60cobalt radiotherapy units and linear accelerators. METHODS Two hundred and forty-eight patients with cervical carcinoma stages IIB-IVA who were treated with primary irradiation between the years 1985 and 1988 comprised the study group. The median survival of patients treated with 60cobalt units and linear accelerators was calculated using the method of Kaplan and Meier and compared using the log-rank test. Recurrence patterns were compared using chi-square analysis; p < .05 was considered significant for all tests. RESULTS One hundred and ninety-five patients were treated with 60cobalt units (Group 1) and 53 patients were treated with a linear accelerator (Group 2). Group 1 and 2 were similar with regard to mean age and weight, stage distribution, and mean dose to point A. The rate of recurrence was comparable between Group 1 and 2 (65.6% vs. 64.2%) and no significant difference was found in overall survival between the groups (20 months vs. 21 months. p = 81). There was a trend toward increasing pelvic recurrence in Group 1 (50.8%) compared to Group 2 (35.8%, p = .08). CONCLUSIONS 60Cobalt units and linear accelerators offer comparable rates of overall survival in patients with locally advanced cervix carcinoma.
Collapse
Affiliation(s)
- K Holcomb
- Department of Obstetrics and Gynecology, Kings County Hospital and State University of New York-Health Science Center at Brooklyn, USA
| | | | | | | | | | | |
Collapse
|
35
|
Tucker T, Yeats J. Laboratory monitoring of HIV--after access to antiretroviral drugs, the next challenge for the developing world. S Afr Med J 2001; 91:615. [PMID: 11584766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
|
36
|
Ghadimi B, Uhr J, Tucker T, Heselmeyer-Haddad K, Ried T, Becker H. Interphase cytogenetics with DNA-probes for chromosome 8 to detect circulating tumor cells in breast cancer patients. Eur J Cancer 2001. [DOI: 10.1016/s0959-8049(01)81097-2] [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: 11/15/2022]
|
37
|
Bashir MM, Abrams WR, Tucker T, Sellinger B, Budarf M, Emanuel B, Rosenbloom J. Molecular cloning and characterization of the bovine and human tuftelin genes. Connect Tissue Res 2001; 39:13-24; discussion 63-7. [PMID: 11062985 DOI: 10.3109/03008209809023908] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The bovine tuftelin gene was cloned and its structure determined by DNA sequence analysis and comparison to bovine tuftelin cDNA. The analyses demonstrated that the cDNA contains a 1014 bp open reading frame encoding a protein of 338 residues with a calculated molecular weight of 38,630 kDa and an isoelectric point of 5.85. Although similar, these results differ from those previously published [Deutsch et al. (1991) J. Biol. Chem. 266, 16021-16028] which contained a different conceptual amino acid sequence for the carboxy terminal region and identification of a different termination codon because of the absence of a single guanine residue in the published sequence. The protein does not appear to share homology or domain motifs with any other known protein. The bovine gene consists of 13 exons ranging in size from 66 to 1531 bp, the latter containing the encoded carboxy terminal and 3' untranslated regions. These exons are embedded in greater than 28 kbp of genomic DNA and codons are generally not divided at exon/intron borders. Sequence analysis of the cDNA and products produced by reverse transcriptase/polymerase chain reaction demonstrated that exons 2, 5 and 6 are alternatively spliced. The 3' portion of the human gene was also isolated and characterized by DNA sequencing, which demonstrated agreement between the bovine and human sequences in the segment in question. The difference between the presently reported sequence and that of the previously published one suggests the possibility of an unusual type of polymorphism which would result in markedly different amino acid sequences at the carboxy terminal region of the protein. The human tuftelin gene was localized to chromosome 1q21 by in situ hybridization.
Collapse
Affiliation(s)
- M M Bashir
- Research Center in Oral Biology and Department of Anatomy and Histology, University of Pennsylvania School of Dental Medicine, Philadelphia 19104, USA
| | | | | | | | | | | | | |
Collapse
|
38
|
Abstract
BACKGROUND This study was performed to assess radiotherapy education among family physicians. METHODS A questionnaire evaluating radiotherapy training and knowledge was given to participants of a palliative care conference. RESULTS Thirty-four physicians completed the survey (71% response rate). Major deficiencies in radiotherapy education were identified and 88% of respondents stated that they did not have adequate knowledge. Only 33% had received formal training in radiotherapy and the majority (77%) thought that they would benefit considerably from continuing medical education. CONCLUSIONS Better education about radiotherapy is required for family physicians and could lead to increased patient referral for such treatment.
Collapse
Affiliation(s)
- R Samant
- Northeastern Ontario RegionaL Cancer Centre, Sudbury, Ontario, Canada.
| | | | | | | |
Collapse
|
39
|
Pathman DE, Taylor DH, Konrad TR, King TS, Harris T, Henderson TM, Bernstein JD, Tucker T, Crook KD, Spaulding C, Koch GG. State scholarship, loan forgiveness, and related programs: the unheralded safety net. JAMA 2000; 284:2084-92. [PMID: 11042757 DOI: 10.1001/jama.284.16.2084] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT In the mid-1980s, states expanded their initiatives of scholarships, loan repayment programs, and similar incentives to recruit primary care practitioners into underserved areas. With no national coordination or mandate to publicize these efforts, little is known about these state programs and their recent growth. OBJECTIVES To identify and describe state programs that provide financial support to physicians and midlevel practitioners in exchange for a period of service in underserved areas, and to begin to assess the magnitude of the contributions of these programs to the US health care safety net. DESIGN Cross-sectional, descriptive study of data collected by telephone, mail questionnaires, and through other available documents, (eg, program brochures, Web sites). SETTING AND PARTICIPANTS All state programs operating in 1996 that provided financial support in exchange for service in defined underserved areas to student, resident, and practicing physicians; nurse practitioners; physician assistants; and nurse midwives. We excluded local community initiatives and programs that received federal support, including that from the National Health Service Corps. MAIN OUTCOME MEASURES Number and types of state support-for-service programs in 1996; trends in program types and numbers since 1990; distribution of programs across states; numbers of participating physicians and other practitioners in 1996; numbers in state programs relative to federal programs; and basic features of state programs. RESULTS In 1996, there were 82 eligible programs operating in 41 states, including 29 loan repayment programs, 29 scholarship programs, 11 loan programs, 8 direct financial incentive programs, and 5 resident support programs. Programs more than doubled in number between 1990 (n = 39) and 1996 (n = 82). In 1996, an estimated 1306 physicians and 370 midlevel practitioners were serving obligations to these state programs, a number comparable with those in federal programs. Common features of state programs were a mission to influence the distribution of the health care workforce within their states' borders, an emphasis on primary care, and reliance on annual state appropriations and other public funding mechanisms. CONCLUSIONS In 1996, states fielded an obligated primary care workforce comparable in size to the better-known federal programs. These state programs constitute a major portion of the US health care safety net, and their activities should be monitored, coordinated, and evaluated. State programs should not be omitted from listings of safety-net initiatives or overlooked in future plans to further improve health care access. JAMA. 2000;284:2084-2092.
Collapse
Affiliation(s)
- D E Pathman
- Cecil G. Sheps Center for Health Services Research, University of North Carolina, CB7590, Chapel Hill, NC 27599, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Wyatt S, Tucker T, Ross F, Carloss H. The burden of cancer in Kentucky. The 1998 Kentucky cancer incidence report. J Ky Med Assoc 2000; 98:445-9. [PMID: 11059216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
The purpose of collecting this important disease burden information is just for reports like this. The real value lies in use of data for cancer control research, program planning, resource allocation, program design, and evaluation. Data in the annual KCR report and on the website should be a valuable resource for health agencies, clinicians, policymakers, voluntary organizations, etc in their assessment of health problems in their area and as critical decisions are made about how to utilize limited intervention resources. The Kentucky Cancer Registry will continue to work very closely with the Kentucky Cancer Program, Kentucky Medical Association, and programs and research efforts at the University of Kentucky Cancer Control Program (Mid South Cancer Information Service, Appalachia Cancer Network, Kentucky Prevention Research Center) and the Brown Cancer Center at the University of Louisville to make these data available to partners throughout the Commonwealth to help guide their assessment and planning processes. If you have questions about this data you are encouraged to contact Regional Coordinators for the Kentucky Cancer Program in your Area Development District. The contact information is shown in Appendix I.
Collapse
|
41
|
Nagai Y, Tucker T, Ren H, Kenan DJ, Henderson BS, Keene JD, Strittmatter WJ, Burke JR. Inhibition of polyglutamine protein aggregation and cell death by novel peptides identified by phage display screening. J Biol Chem 2000; 275:10437-42. [PMID: 10744733 DOI: 10.1074/jbc.275.14.10437] [Citation(s) in RCA: 141] [Impact Index Per Article: 5.9] [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: 11/06/2022] Open
Abstract
Proteins with expanded polyglutamine domains cause eight inherited neurodegenerative diseases, including Huntington's, but the molecular mechanism(s) responsible for neuronal degeneration are not yet established. Expanded polyglutamine domain proteins possess properties that distinguish them from the same proteins with shorter glutamine repeats. Unlike proteins with short polyglutamine domains, proteins with expanded polyglutamine domains display unique protein interactions, form intracellular aggregates, and adopt a novel conformation that can be recognized by monoclonal antibodies. Any of these polyglutamine length-dependent properties could be responsible for the pathogenic effects of expanded polyglutamine proteins. To identify peptides that interfere with pathogenic polyglutamine interactions, we screened a combinatorial peptide library expressed on M13 phage pIII protein to identify peptides that preferentially bind pathologic-length polyglutamine domains. We identified six tryptophan-rich peptides that preferentially bind pathologic-length polyglutamine domain proteins. Polyglutamine-binding peptide 1 (QBP1) potently inhibits polyglutamine protein aggregation in an in vitro assay, while a scrambled sequence has no effect on aggregation. QBP1 and a tandem repeat of QBP1 also inhibit aggregation of polyglutamine-yellow fluorescent fusion protein in transfected COS-7 cells. Expression of QBP1 potently inhibits polyglutamine-induced cell death. Selective inhibition of pathologic interactions of expanded polyglutamine domains with themselves or other proteins may be a useful strategy for preventing disease onset or for slowing progression of the polyglutamine repeat diseases.
Collapse
Affiliation(s)
- Y Nagai
- Deane Laboratory, Duke University Medical Center, Durham, North Carolina 27710, USA
| | | | | | | | | | | | | | | |
Collapse
|
42
|
Wyatt S, Tucker T, Ross F, Carloss HW. The burden of cancer in Kentucky: the 1997 Kentucky cancer incidence report. J Ky Med Assoc 2000; 98:166-9. [PMID: 10816986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The purpose of collecting this important disease burden information is of course not simply for reports like this one. The real value lies in use of data for program planning, resource allocation, program design, and evaluation. Data in the annual KCR report and on the website should be a valuable resource for district and county health departments in their assessment of health problems in their area and as critical decisions are made about how to utilize limited intervention resources. The Kentucky Cancer Registry will continue to work very closely with the Community Outreach Division of the Kentucky Cancer Program to make this data available on an annual basis to District Cancer Councils to help guide their assessment and planning process. District and local health departments are encouraged to actively participate in the District Cancer Councils and in the cancer control activities guided by the regional community outreach coordinators.
Collapse
|
43
|
McArthur JC, Yiannoutsos C, Simpson DM, Adornato BT, Singer EJ, Hollander H, Marra C, Rubin M, Cohen BA, Tucker T, Navia BA, Schifitto G, Katzenstein D, Rask C, Zaborski L, Smith ME, Shriver S, Millar L, Clifford DB, Karalnik IJ. A phase II trial of nerve growth factor for sensory neuropathy associated with HIV infection. AIDS Clinical Trials Group Team 291. Neurology 2000; 54:1080-8. [PMID: 10720278 DOI: 10.1212/wnl.54.5.1080] [Citation(s) in RCA: 205] [Impact Index Per Article: 8.5] [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
OBJECTIVE To evaluate the safety and efficacy of recombinant human nerve growth factor (rhNGF) in HIV-associated sensory neuropathy (SN) within a multicenter, placebo-controlled, randomized trial (ACTG 291). BACKGROUND SN affects 30% of individuals with AIDS, is worsened by neurotoxic antiretrovirals, and its treatment is often ineffective. NGF is trophic for small sensory neurons and stimulates the regeneration of damaged nerve fibers. METHODS A total of 270 patients with HIV-associated SN were randomized to receive placebo, 0.1 microg/kg rhNGF, or 0.3 microg/kg rhNGF by double-blinded subcutaneous injection twice weekly for 18 weeks. The primary outcome was change in self-reported neuropathic pain intensity (Gracely Pain Scale). Secondary outcomes included an assessment of global improvement in neuropathy by patients and investigators, neurologic examination, use of prescription analgesics, and quantitative sensory testing. In a subset, epidermal nerve fiber densities were determined in punch skin biopsies. RESULTS Both doses of NGF produced significant improvements in average and maximum daily pain compared with placebo. Positive treatment effects were also observed for global pain assessments (p = 0.001) and for pin sensitivity (p = 0.019). No treatment differences were found with respect to mood, analgesic use, or epidermal nerve fiber densities. Injection site pain was the most frequent adverse event, and resulted in unblinding in 39% of subjects. Severe transient myalgic pain occurred in eight patients, usually from accidental overdosing. There were no changes in HIV RNA levels or other laboratory indices. CONCLUSIONS We found a positive effect of recombinant human nerve growth factor on neuropathic pain and pin sensitivity in HIV-associated sensory neuropathy. rhNGF was safe and well tolerated, but injection site pain was frequent.
Collapse
Affiliation(s)
- J C McArthur
- Department of Neurology, Johns Hopkins University, Baltimore, MD, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
|
45
|
Kieburtz K, Simpson D, Yiannoutsos C, Max MB, Hall CD, Ellis RJ, Marra CM, McKendall R, Singer E, Dal Pan GJ, Clifford DB, Tucker T, Cohen B. A randomized trial of amitriptyline and mexiletine for painful neuropathy in HIV infection. AIDS Clinical Trial Group 242 Protocol Team. Neurology 1998; 51:1682-8. [PMID: 9855523 DOI: 10.1212/wnl.51.6.1682] [Citation(s) in RCA: 154] [Impact Index Per Article: 5.9] [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
BACKGROUND Painful sensory neuropathy is a common complication of HIV infection. Based on prior uncontrolled observations, we hypothesized that amitriptyline or mexiletine would improve the pain symptoms. METHOD A randomized, double-blind, 10-week trial of 145 patients assigned equally to amitriptyline, mexiletine, or matching placebo. The primary outcome measure was the change in pain intensity between baseline and the final visit. RESULTS The improvement in amitriptyline group (0.31+/-0.31 units [mean+/-SD]) and mexiletine group (0.23+/-0.41) was not significantly different from placebo (0.20+/-0.30). Both interventions were generally well tolerated. CONCLUSIONS Neither amitriptyline nor mexiletine provide significant pain relief in patients with HIV-associated painful sensory neuropathy.
Collapse
Affiliation(s)
- K Kieburtz
- University of Rochester Medical Center, NY 14620, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Navia BA, Dafni U, Simpson D, Tucker T, Singer E, McArthur JC, Yiannoutsos C, Zaborski L, Lipton SA. A phase I/II trial of nimodipine for HIV-related neurologic complications. Neurology 1998; 51:221-8. [PMID: 9674806 DOI: 10.1212/wnl.51.1.221] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.2] [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] Open
Abstract
BACKGROUND Few effective treatments are available for AIDS dementia complex (ADC) and HIV-associated neuropathy. However, recent in vitro studies indicate that nimodipine, a voltage-dependent calcium channel antagonist, can prevent HIV-related neuronal injury and may provide a novel form of treatment for these disorders. METHODS To determine the safety and possible efficacy of this agent, 41 patients with mild to severe ADC, including 19 patients with neuropathy, were entered into the AIDS Clinical Trial Group multicenter, phase-I and phase-II study. Nimodipine at 60 mg p.o., five times daily; 30 mg p.o., three times daily; or placebo was administered for 16 weeks as adjuvant treatment to antiretroviral therapy. RESULTS Neuropsychological performance at baseline, measured by the composite neuropsychological Z score (NPZ-8), correlated significantly with the ADC stage and with CSF levels of neopterin, a marker of immune activation. No significant differences in toxicity were observed among the three arms. Intent-to-treat analysis showed no significant change in the NPZ-8, although improvement was suggested in the high-dose arm. In addition, a trend toward stabilization in peripheral neuropathy was observed in both nimodipine arms compared with placebo. CONCLUSIONS Nimodipine and other similar nonantiretroviral agents may provide a safe and promising avenue of treatment for neurologic disorders associated with HIV infection. The results of this study indicate that further clinical trials are warranted.
Collapse
Affiliation(s)
- B A Navia
- Tufts Neurology Program and Department of Psychiatry, Tufts University School of Medicine, Beth Israel Deaconess Medical Center, Boston, MA, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Müller FO, Terblanchè J, Schall R, van Zyl Smit R, Tucker T, Marais K, Groenewoud G, Porchet HC, Weiner M, Hawarden D. Pharmacokinetics of triptorelin after intravenous bolus administration in healthy males and in males with renal or hepatic insufficiency. Br J Clin Pharmacol 1997; 44:335-41. [PMID: 9354307 PMCID: PMC2042859 DOI: 10.1046/j.1365-2125.1997.t01-1-00592.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
AIMS Triptorelin is a gonadotropin-releasing hormone (GnRH) analogue with enhanced affinity for GnRH receptors and a prolonged half-life due to its resistance to enzymatic degradation. The sustained-release formulation of this molecule is advantageous in conditions requiring chronic hormone suppression. METHODS This was an open study to determine the pharmacokinetics of a single i.v. bolus dose of 0.5 mg triptorelin acetate in four groups of six male subjects; namely in healthy subjects (Group I), in patients with varying degrees of renal insufficiency (Groups II and III), and in patients with hepatic insufficiency (Group IV). RESULTS The maximum concentrations of triptorelin were found to be similar for all four study groups (geometric mean Cmax between 41.6 mg ml(-1) and 53.9 mg ml(-1)). The total clearance of triptorelin decreased with increasing renal impairment, and was even lower in patients with hepatic insufficiency (geometric mean CLtot: 210 ml min(-1), 113 ml min(-1), 86.8 ml min(-1) and 57.3 ml min(-1) for Groups I, II, III and IV, respectively). Serum triptorelin concentrations in all four groups were adequately described by a three-compartment model. The elimination half-life for patients with hepatic impairment was similar to that of patients with renal impairment (geometric mean t(1/2, z): 6.6 h, 7.7 h and 7.6 h for Groups II, III and IV, respectively), but significantly longer than in healthy volunteers (2.8 h for Group I). The first and second distribution half-lives were similar for the four groups studied, with geometric mean distribution half-lives of about 0.1 h (6 min) and 0.75 h (45 min), respectively. CONCLUSIONS Although both renal and hepatic function are important for the clearance of triptorelin, the liver plays the predominant role in subjects suffering from some degree of renal impairment.
Collapse
Affiliation(s)
- F O Müller
- FARMOVS Research Centre for Clinical Pharmacology and Drug Development, University of the Orange Free State, Bloemfontein, South Africa
| | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Sidtis JJ, Dafni U, Slasor P, Hall C, Price RW, Kieburtz K, Tucker T, Clifford DB. Stable neurological function in subjects treated with 2'3'-dideoxyinosine. J Neurovirol 1997; 3:233-40. [PMID: 9200072 DOI: 10.3109/13550289709018299] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [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: 02/04/2023]
Abstract
AIDS Dementia Complex (ADC) is a frequent and devastating complication of HIV infection. There is evidence that zidovudine (ZDV) has an effect in alleviating the symptoms of ADC, and may have a role in its prevention. It is therefore important that new antiretroviral therapies be evaluated not only for the risk of neurologic side effects, but also for their relative efficacy to ZDV in the prevention of ADC. The present study reports the effects of 2'3'-dideoxyinosine (DDI, didanosine, Videx) therapy on neuropsychological performance in the context of several large clinical trials targeting advanced systemic HIV-1 infection. Subjects treated with DDI had stable neurologic performance in quantitative tests over a 1 year period and were similar to zidovudine treated subjects.
Collapse
Affiliation(s)
- J J Sidtis
- Department of Neurology, University of Minnesota, Minneapolis, USA
| | | | | | | | | | | | | | | |
Collapse
|
49
|
Ditkoff EC, Tucker T, Levine RU, Lindheim SR, Sauer MV, Longacre T. Bilateral serous cystadenofibromas clinically simulating hyperreactio luteinalis following controlled ovarian hyperstimulation and in vitro fertilization. J Assist Reprod Genet 1997; 14:230-3. [PMID: 9130073 PMCID: PMC3454693 DOI: 10.1007/bf02766116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [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: 02/04/2023] Open
Abstract
We report a case of bilateral serous cystadenofibromas clinically simulating hyperreactio luteinalis during a normal pregnancy resulting from controlled ovarian stimulation and in vitro fertilization. Incomplete regression at 2-year follow-up prompted surgical intervention. This case demonstrates that the clinical and sonographic features that have been associated with hyperreactio luteinalis are not specific for this condition and emphasizes the need for close clinical follow-up in all presumptive cases for which a histologic diagnosis has not been established.
Collapse
Affiliation(s)
- E C Ditkoff
- Department of Obstetrics and Gynecology, Columbia-Presbyterian Medical Center, Columbia University, New York, New York 10032, USA
| | | | | | | | | | | |
Collapse
|
50
|
Abstract
Confocal imaging has revealed microdomains of intracellular free Ca2+ in turtle hair cells evoked by depolarizing pulses and has delineated factors affecting the growth and dissipation of such domains. However, imaging experiments have limited spatial and temporal resolution. To extend the range of the results we have developed a three-dimensional model of Ca2+ diffusion in a cylindrical hair cell, allowing part of the Ca2+ influx to occur over a small circular region (radius 0.125-1.0 micron) representing a high-density array of voltage-dependent channels. The model incorporated experimental information about the number of channels, the fixed and mobile Ca2+ buffers, and the Ca2+ extrusion mechanism. A feature of the calculations was the use of a variable grid size depending on the proximity to the Ca2+ channel cluster. The results agreed qualitatively with experimental data on the localization of the Ca2+ transients, although the experimental responses were smaller and slower, which is most likely due to temporal and spatial averaging in the imaging. The model made predictions about 1) the optimal Ca2+ channel number and density within a cluster, 2) the conditions to ensure independence of neighboring clusters, and 3) the influence of the Ca2+ buffers on the kinetics and localization of the microdomains. We suggest that an increase in the mobile Ca2+ buffer concentration in high-frequency hair cells (which possess a larger number of release sites) would allow lower amplitude and faster Ca2+ responses and promote functional independence of the sites.
Collapse
Affiliation(s)
- Y C Wu
- Department of Neurophysiology, University of Wisconsin Medical School, Madison 53706, USA
| | | | | |
Collapse
|