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Bucşan AN, Veatch A, Singh DK, Akter S, Golden NA, Kirkpatrick M, Threeton B, Moodley C, Ahmed M, Doyle LA, Russell-Lodrigue K, Norton EB, Didier PJ, Roy CJ, Abramovitch RB, Mehra S, Khader SA, Kaushal D. Response to Hypoxia and the Ensuing Dysregulation of Inflammation Impacts Mycobacterium tuberculosis Pathogenicity. Am J Respir Crit Care Med 2022; 206:94-104. [PMID: 35412961 PMCID: PMC9718519 DOI: 10.1164/rccm.202112-2747oc] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Rationale: Different Mycobacterium tuberculosis (Mtb) strains exhibit variable degrees of virulence in humans and animal models. Differing stress response strategies used by different strains of Mtb could influence virulence. Objectives: We compared the virulence of two strains of Mtb with use in animal model research: CDC1551 and Erdman. Methods: Rhesus macaques, which develop human-like tuberculosis attributes and pathology, were infected with a high dose of either strain via aerosol, and virulence was compared by bacterial burden and pathology. Measurements and Main Results: Infection with Erdman resulted in significantly shorter times to euthanasia and higher bacterial burdens and greater systemic inflammation and lung pathology relative to those infected with CDC1551. Macaques infected with Erdman also exhibited significantly higher early inflammatory myeloid cell influx to the lung, greater macrophage and T cell activity, and higher expression of lung remodeling (extracellular matrix) genes, consistent with greater pathology. Expression of NOTCH4 (neurogenic locus notch homolog 4) signaling, which is induced in response to hypoxia and promotes undifferentiated cellular state, was also higher in Erdman-infected lungs. The granulomas generated by Erdman, and not CDC1551, infection appeared to have larger regions of necrosis, which is strongly associated with hypoxia. To better understand the mechanisms of differential hypoxia induction by these strains, we subjected both to hypoxia in vitro. Erdman induced higher concentrations of DosR regulon relative to CDC1551. The DosR regulon is the global regulator of response to hypoxia in Mtb and critical for its persistence in granulomas. Conclusions: Our results show that the response to hypoxia is a critical mediator of virulence determination in Mtb, with potential impacts on bacillary persistence, reactivation, and efficiency of therapeutics.
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Affiliation(s)
- Allison N. Bucşan
- Tulane National Primate Research Center, Tulane University Health Sciences Center, Covington, Louisiana
| | - Ashley Veatch
- Tulane National Primate Research Center, Tulane University Health Sciences Center, Covington, Louisiana
| | - Dhiraj K. Singh
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, Texas
| | - Sadia Akter
- Department of Molecular Microbiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Nadia A. Golden
- Tulane National Primate Research Center, Tulane University Health Sciences Center, Covington, Louisiana
| | - Melanie Kirkpatrick
- Tulane National Primate Research Center, Tulane University Health Sciences Center, Covington, Louisiana
| | - Breanna Threeton
- Tulane National Primate Research Center, Tulane University Health Sciences Center, Covington, Louisiana
| | - Chivonne Moodley
- Tulane National Primate Research Center, Tulane University Health Sciences Center, Covington, Louisiana
| | - Mushtaq Ahmed
- Department of Molecular Microbiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Lara A. Doyle
- Tulane National Primate Research Center, Tulane University Health Sciences Center, Covington, Louisiana
| | - Kasi Russell-Lodrigue
- Tulane National Primate Research Center, Tulane University Health Sciences Center, Covington, Louisiana
| | - Elizabeth B. Norton
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, Louisiana; and
| | - Peter J. Didier
- Tulane National Primate Research Center, Tulane University Health Sciences Center, Covington, Louisiana
| | - Chad J. Roy
- Tulane National Primate Research Center, Tulane University Health Sciences Center, Covington, Louisiana;,Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, Texas
| | - Robert B. Abramovitch
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan
| | - Smriti Mehra
- Tulane National Primate Research Center, Tulane University Health Sciences Center, Covington, Louisiana;,Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, Texas
| | - Shabaana A. Khader
- Department of Molecular Microbiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri
| | - Deepak Kaushal
- Tulane National Primate Research Center, Tulane University Health Sciences Center, Covington, Louisiana;,Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, Texas
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2
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Kirkpatrick M, Sweeney R, Kasten S, diTargiani R, Cerasoli D, Otto T. Use of V‐Agent Analogs to Probe the Active Site of Atypical Butyrylcholinesterase from
Oryzias latipes. FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.573.6] [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: 11/11/2022]
Affiliation(s)
- Melanie Kirkpatrick
- Research Division U.S. Army Medical Research Institute of Chemical DefenseAberdeen Proving GroundMDUnited States
| | - Richard Sweeney
- Research Division U.S. Army Medical Research Institute of Chemical DefenseAberdeen Proving GroundMDUnited States
| | - Shane Kasten
- Research Division U.S. Army Medical Research Institute of Chemical DefenseAberdeen Proving GroundMDUnited States
| | - Robert diTargiani
- Research Division U.S. Army Medical Research Institute of Chemical DefenseAberdeen Proving GroundMDUnited States
| | - Douglas Cerasoli
- Research Division U.S. Army Medical Research Institute of Chemical DefenseAberdeen Proving GroundMDUnited States
| | - Tamara Otto
- Research Division U.S. Army Medical Research Institute of Chemical DefenseAberdeen Proving GroundMDUnited States
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3
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Peischl S, Dupanloup I, Kirkpatrick M, Excoffier L. On the accumulation of deleterious mutations during range expansions. Mol Ecol 2013; 22:5972-82. [PMID: 24102784 DOI: 10.1111/mec.12524] [Citation(s) in RCA: 172] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 09/04/2013] [Accepted: 09/05/2013] [Indexed: 12/15/2022]
Abstract
We investigate the effect of spatial range expansions on the evolution of fitness when beneficial and deleterious mutations cosegregate. We perform individual-based simulations of 1D and 2D range expansions and complement them with analytical approximations for the evolution of mean fitness at the edge of the expansion. We find that deleterious mutations accumulate steadily on the wave front during range expansions, thus creating an expansion load. Reduced fitness due to the expansion load is not restricted to the wave front, but occurs over a large proportion of newly colonized habitats. The expansion load can persist and represent a major fraction of the total mutation load for thousands of generations after the expansion. The phenomenon of expansion load may explain growing evidence that populations that have recently expanded, including humans, show an excess of deleterious mutations. To test the predictions of our model, we analyse functional genetic diversity in humans and find patterns that are consistent with our model.
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Affiliation(s)
- S Peischl
- Institute of Ecology and Evolution, University of Berne, 3012, Berne, Switzerland; Section of Integrative Biology, University of Texas, Austin, TX, 78712, USA; Swiss Institute of Bioinformatics, 1015, Lausanne, Switzerland
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4
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Guerrero RF, Kirkpatrick M, Perrin N. Cryptic recombination in the ever‐young sex chromosomes of
H
ylid frogs. J Evol Biol 2012; 25:1947-1954. [DOI: 10.1111/j.1420-9101.2012.02591.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2012] [Revised: 06/22/2012] [Accepted: 07/09/2012] [Indexed: 11/29/2022]
Affiliation(s)
- R. F. Guerrero
- Section of Integrative Biology The University of Texas at Austin Austin TX USA
| | - M. Kirkpatrick
- Section of Integrative Biology The University of Texas at Austin Austin TX USA
| | - N. Perrin
- Department of Ecology and Evolution University of Lausanne Lausanne Switzerland
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5
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Affiliation(s)
- K D Behrman
- Section of Integrative Biology, University of Texas at Austin, Austin, TX, USA.
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6
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Bisdas S, Kirkpatrick M, Giglio P, Welsh C, Spampinato MV, Rumboldt Z. Cerebral blood volume measurements by perfusion-weighted MR imaging in gliomas: ready for prime time in predicting short-term outcome and recurrent disease? AJNR Am J Neuroradiol 2009; 30:681-8. [PMID: 19179427 DOI: 10.3174/ajnr.a1465] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [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: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Current classification and grading of primary brain tumors has significant limitations. Our aim was to determine whether the relative cerebral volume (rCBV) measurements in gliomas may serve as an adjunct to histopathologic grading, with a hypothesis that rCBV values are more accurate in predicting 1-year survival and recurrence. MATERIALS AND METHODS Thirty-four patients with gliomas (WHO grade I-IV, 27 astrocytomas, 7 tumors with oligodendroglial components) underwent contrast-enhanced MR rCBV measurements before treatment. The region of interest and the single pixel with the maximum CBV value within the tumors were normalized relative to the contralateral normal tissue (rCBV(mean) and rCBV(max), respectively). Karnofsky performance score and progression-free survival (PFS) were recorded. Receiver operating characteristic curves and Kaplan-Meier survival analysis were conducted for CBV and histologic grade (WHO grade). RESULTS Significant correlations were detected only when patients with oligodendrogliomas and oligoastrocytomas were excluded. The rCBV(mean) and rCBV(max) in the astrocytomas were 3.5 +/- 2.9 and 3.7 +/- 2.7. PFS correlated with rCBV parameters (r = -0.54 to -0.56, P < or = .009). WHO grade correlated with rCBV values (r = 0.65, P < or = .0002). rCBV(max) > 4.2 was found to be a significant cutoff value for recurrence prediction with 77.8% sensitivity and 94.4% specificity (P = .0001). rCBV(max) < or = 3.8 was a significant predictor for 1-year survival (93.7% sensitivity, 72.7% specificity, P = .0002). The relative risk for shorter PFS was 11.1 times higher for rCBV(max) > 4.2 (P = .0006) and 6.7 times higher for WHO grade > II (P = .05). The combined CBV-WHO grade classification enhanced the predictive value for recurrence/progression (P < .0001). CONCLUSIONS rCBV values in astrocytomas but not tumors with oligodendroglial components are predictive for recurrence and 1-year survival and may be more accurate than histopathologic grading.
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Affiliation(s)
- S Bisdas
- Department of Radiology and Radiological Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
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7
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Abstract
Focal intracranial infections such as brain abscess, subdural empyema, or epidural abscess are unusual manifestations of salmonellosis found almost solely in immuno-compromised patients. We describe an unusual case of an 11-month old immuno-competent girl with a Salmonella Infantis subdural empyema. The case responded well to surgical drainage and long course of antibiotic treatment.
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Affiliation(s)
- R.S. Soliman
- Department of Medical MicrobiologyNinewells Hospital Dundee, UK
| | - L. Clerihew
- Department of Paediatrics Ninewells Hospital
| | - A. Jollands
- Department of Paediatrics Ninewells Hospital
| | | | - D Mowle
- Department of Neurosurgery Ninewells Hospital
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Affiliation(s)
- M A R de Cara
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom.
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Abstract
The [PSI(+)] prion in yeast has been shown to improve short-term growth in some environments, but its effects on rates of adaptation have not been assessed before now. We adapted three yeast genotypes to three novel environments in the presence and the absence of the prion. There were significant differences in adaptation rates between lines with different combinations of genotype, environment, and prion status. We saw no consistent effect, however, of the prion on the rate of adaptation to new environments. A major factor affecting the rate of adaptation was initial fitness in the new environment: lines with low initial fitness evolved faster than lines with high initial fitness.
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Affiliation(s)
- S B Joseph
- Section of Integrative Biology, University of Texas, Austin, TX, USA.
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10
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Fertleman CR, Ferrie CD, Aicardi J, Bednarek NAF, Eeg-Olofsson O, Elmslie FV, Griesemer DA, Goutières F, Kirkpatrick M, Malmros INO, Pollitzer M, Rossiter M, Roulet-Perez E, Schubert R, Smith VV, Testard H, Wong V, Stephenson JBP. Paroxysmal extreme pain disorder (previously familial rectal pain syndrome). Neurology 2007; 69:586-95. [PMID: 17679678 DOI: 10.1212/01.wnl.0000268065.16865.5f] [Citation(s) in RCA: 112] [Impact Index Per Article: 6.6] [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: 11/15/2022] Open
Abstract
OBJECTIVE To describe the clinical phenotype of paroxysmal extreme pain disorder (previously called familial rectal pain syndrome), an autosomal dominant condition recently shown to be a sodium channelopathy involving SCN9A. METHODS An international consortium of clinicians, scientists, and affected families was formed. Clinical details of all accessible families worldwide were collected, including age at onset, features of attacks, problems between attacks, investigational results, treatments tried, and evolution over time. A validated pain questionnaire was completed by 14 affected individuals. RESULTS Seventy-seven individuals from 15 families were identified. The onset of the disorder is in the neonatal period or infancy and persists throughout life. Autonomic manifestations predominate initially, with skin flushing in all and harlequin color change and tonic attacks in most. Dramatic syncopes with bradycardia and sometimes asystole are common. Later, the disorder is characterized by attacks of excruciating deep burning pain often in the rectal, ocular, or jaw areas, but also diffuse. Attacks are triggered by factors such as defecation, cold wind, eating, and emotion. Carbamazepine is effective in almost all who try it, but the response is often incomplete. CONCLUSIONS Paroxysmal extreme pain disorder is a highly distinctive sodium channelopathy with incompletely carbamazepine-sensitive bouts of pain and sympathetic nervous system dysfunction. It is most likely to be misdiagnosed as epilepsy and, particularly in infancy, as hyperekplexia and reflex anoxic seizures.
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Affiliation(s)
- C R Fertleman
- Royal Free and University College Medical School, London, UK
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11
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Nosil P, Crespi BJ, Sandoval CP, Kirkpatrick M. Migration and the Genetic Covariance between Habitat Preference and Performance. Am Nat 2006; 167:E66-78. [PMID: 16673338 DOI: 10.1086/499383] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2005] [Accepted: 10/17/2005] [Indexed: 11/03/2022]
Abstract
Studies of the genetic covariance between habitat preference and performance have reported conflicting outcomes ranging from no covariance to strong covariance. The causes of this variability remain unclear. Here we show that variation in the magnitude of genetic covariance can result from variability in migration regimes. Using data from walking stick insects and a mathematical model, we find that genetic covariance within populations between host plant preference and a trait affecting performance on different hosts (cryptic color pattern) varies in magnitude predictably among populations according to migration regimes. Specifically, genetic covariance within populations is high in heterogeneous habitats where migration between populations locally adapted to different host plants generates nonrandom associations (i.e., linkage disequilibrium) between alleles at color pattern and host preference loci. Conversely, genetic covariance is low in homogeneous habitats where a single host exists and migration between hosts does not occur. Our results show that habitat structure and patterns of migration can strongly affect the evolution and variability of genetic covariance within populations.
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Affiliation(s)
- P Nosil
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada.
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12
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Affiliation(s)
- M Kirkpatrick
- Section of Integrative Biology, University of Texas, Austin, TX 78712, USA.
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13
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Murphy NF, Simpson CR, McAlister FA, Stewart S, MacIntyre K, Kirkpatrick M, Chalmers J, Redpath A, Capewell S, McMurray JJV. National survey of the prevalence, incidence, primary care burden, and treatment of heart failure in Scotland. Heart 2004; 90:1129-36. [PMID: 15367505 PMCID: PMC1768509 DOI: 10.1136/hrt.2003.029553] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVE To examine the epidemiology, primary care burden, and treatment of heart failure in Scotland, UK. DESIGN Cross sectional data from primary care practices participating in the Scottish continuous morbidity recording scheme between 1 April 1999 and 31 March 2000. SETTING 53 primary care practices (307,741 patients). SUBJECTS 2186 adult patients with heart failure. RESULTS The prevalence of heart failure in Scotland was 7.1 in 1000, increasing with age to 90.1 in 1000 among patients > or = 85 years. The incidence of heart failure was 2.0 in 1000, increasing with age to 22.4 in 1000 among patients > or = 85 years. For older patients, consultation rates for heart failure equalled or exceeded those for angina and hypertension. Respiratory tract infection was the most common co-morbidity leading to consultation. Among men, 23% were prescribed a beta blocker, 11% spironolactone, and 46% an angiotensin converting enzyme inhibitor. The corresponding figures for women were 20% (p = 0.29 versus men), 7% (p = 0.02), and 34% (p < 0.001). Among patients < 75 years 26% were prescribed a beta blocker, 11% spironolactone, and 50% an angiotensin converting enzyme inhibitor. The corresponding figures for patients > or = 75 years were 19% (p = 0.04 versus patients < 75), 7% (p = 0.04), and 33% (p < 0.001). CONCLUSIONS Heart failure is a common condition, especially with advancing age. In the elderly, the community burden of heart failure is at least as great as that of angina or hypertension. The high rate of concomitant respiratory tract infection emphasises the need for strategies to immunise patients with heart failure against influenza and pneumococcal infection. Drugs proven to improve survival in heart failure are used less frequently for elderly patients and women.
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Affiliation(s)
- N F Murphy
- Department of Cardiology, Western Infirmary, Glasgow, UK
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14
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McAlister FA, Murphy NF, Simpson CR, Stewart S, MacIntyre K, Kirkpatrick M, Chalmers J, Redpath A, Capewell S, McMurray JJV. Influence of socioeconomic deprivation on the primary care burden and treatment of patients with a diagnosis of heart failure in general practice in Scotland: population based study. BMJ 2004; 328:1110. [PMID: 15107312 PMCID: PMC406324 DOI: 10.1136/bmj.38043.414074.ee] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVE To examine whether there are socioeconomic gradients in the incidence, prevalence, treatment, and follow up of patients with heart failure in primary care. DESIGN Population based study. SETTING 53 general practices (307,741 patients) participating in the Scottish continuous morbidity recording project between 1 April 1999 and 31 March 2000. PARTICIPANTS 2186 adults with heart failure. MAIN OUTCOME MEASURES Comorbid diagnoses, frequency of visits to general practitioner, and prescribed drugs. RESULTS 2186 patients with heart failure were seen (prevalence 7.1 per 1000 population, incidence 2.0 per 1000 population). The age and sex standardised incidence of heart failure increased with greater socioeconomic deprivation, from 1.8 per 1000 population in the most affluent stratum to 2.6 per 1000 population in the most deprived stratum (odds ratio 1.44, P = 0.0003). On average, patients were seen 2.4 times yearly, but follow up rates were less frequent with increasing socioeconomic deprivation (from 2.6 yearly in the most affluent subgroup to 2.0 yearly in the most deprived subgroup, P = 0.00009). Overall, 812 (80.6%) patients were prescribed diuretics, 396 (39.3%) angiotensin converting enzyme inhibitors, 216 (21.4%) beta blockers, 208 (20.7%) digoxin, and 86 (8.5%) spironolactone. The wide discrepancies in prescribing between different general practices disappeared after adjustment for patient age and sex. Prescribing patterns did not vary by deprivation categories on univariate or multivariate analyses. CONCLUSIONS Compared with affluent patients, socioeconomically deprived patients were 44% more likely to develop heart failure but 23% less likely to see their general practitioner on an ongoing basis. Prescribed treatment did not differ across socioeconomic gradients.
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Affiliation(s)
- F A McAlister
- Department of Medicine, University of Alberta, Edmonton, AB, Canada T6G 2R7
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15
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Abstract
We study the form of the clines in a female mating preference and male display trait using simulations of a hybrid zone. Allopatric populations of two species are connected by demes in a stepping stone arrangement. Results show that reproductive character displacement (a pattern of increased prezygotic isolation in sympatry compared with allopatry) may or may not result when there is reinforcement (defined here as the strengthening of prezygotic isolation as a result of selection against hybrids, relative to the amount of prezygotic isolation present when hybrids are not selected against). Further, reproductive character displacement of the preference may or may not occur when it occurs in the male display. We conclude that the absence of reproductive character displacement is not evidence against the operation of reinforcement.
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Affiliation(s)
- A R Lemmon
- Section of Integrative Biology, University of Texas, Austin, TX 78712, USA.
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17
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Abstract
We consider the evolution of ecological specialization in a landscape with two discrete habitat types connected by migration, for example, a plant-insect system with two plant hosts. Using a quantitative genetic approach. we study the joint evolution of a quantitative character determining performance in each habitat together with the changes in the population density. We find that specialization on a single habitat evolves with intermediate migration rates, whereas a generalist species evolves with both very low and very large rates of movement between habitats. There is a threshold at which a small increase in the connectivity of the two habitats will result in dramatic decrease in the total population size and the nearly complete loss of use of one of the two habitats through a process of "migrational meltdown." In some situations, equilibria corresponding to a specialist and a generalist species are simultaneously stable. Analysis of our model also shows cases of hysteresis in which small transient changes in the landscape structure or accidental demographic disturbances have irreversible effects on the evolution of specialization.
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Affiliation(s)
- O Ronce
- Section of Integrative Biology, University of Texas, Austin 78712, USA.
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18
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Abstract
Reinforcement of pre-zygotic isolation can result when any of several kinds of selection act against hybrids. This paper investigates the situation where hybrids are selected against for ecological reasons, for example when there is no niche for individuals that are phenotypically intermediate between the parental species. The calculations here show how much ecological selection can lead to the reinforcement of a female mating preference or an assortative mating trait that is expressed in both sexes. The model allows for the ecological trait to be affected by any number of loci, but assumes that selection is weak and the introgression rate small. The effect of selection against hybrids increases rapidly as the difference between the mean phenotypes of the two populations increases. When genetic variation in the ecological trait is caused by many loci, stabilizing selection on it further contributes to reinforcement.
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Affiliation(s)
- M Kirkpatrick
- Section of Integrative Biology C0930, University of Texas, Austin, TX 78712, USA.
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19
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Affiliation(s)
- J Strachan
- Department of Biochemical Medicine, Tayside University Hospitals NHS Trust and University of Dundee, UK
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20
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Phillips HA, Favre I, Kirkpatrick M, Zuberi SM, Goudie D, Heron SE, Scheffer IE, Sutherland GR, Berkovic SF, Bertrand D, Mulley JC. CHRNB2 is the second acetylcholine receptor subunit associated with autosomal dominant nocturnal frontal lobe epilepsy. Am J Hum Genet 2001; 68:225-31. [PMID: 11104662 PMCID: PMC1234917 DOI: 10.1086/316946] [Citation(s) in RCA: 248] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2000] [Accepted: 11/09/2000] [Indexed: 11/03/2022] Open
Abstract
Autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) is an uncommon, idiopathic partial epilepsy characterized by clusters of motor seizures occurring in sleep. We describe a mutation of the beta2 subunit of the nicotinic acetylcholine receptor, effecting a V287M substitution within the M2 domain. The mutation, in an evolutionary conserved region of CHRNB2, is associated with ADNFLE in a Scottish family. Functional receptors with the V287M mutation are highly expressed in Xenopus oocytes and characterized by an approximately 10-fold increase in acetylcholine sensitivity. CHRNB2 is a new gene for idiopathic epilepsy, the second acetylcholine receptor subunit implicated in ADNFLE.
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Affiliation(s)
- H A Phillips
- Department of Cytogenetics and Molecular Genetics, Centre for Medical Genetics, Women's and Children's Hospital, North Adelaide, SA 5006, Australia
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Abstract
We introduce models for the runaway coevolution of female mating preferences and male display traits. The models generalize earlier results by allowing for direct natural selection on the preference, arbitrary forms of mate choice, and fairly general assumptions about the underlying genetics. Results show that a runaway is less likely when there is direct selection on the preference, but that it is still possible if there is a sufficiently large phenotypic correlation between the female's preference and the male's trait among mated pairs. Comparison of three preference functions introduced by Lande (1981) shows that open-ended preferences are particularly prone to a runaway, and that absolute preferences require very large differences between females in their preferences. We analyze the causes of the runaway seen in a model developed by Iwasa and Pomiankowski (1995).
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Affiliation(s)
- D W Hall
- Section of Integrative Biology, University of Texas, Austin 78712, USA.
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23
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Abstract
Traits that cause assortative mating such as the flowering time in plants and body size in animals can produce reproductive isolation between hybridizing populations. Can selection against unfit hybrids cause two populations to diverge in their mean values for these kinds of traits? Here I present a haploid analytical model of one population that receives gene flow from another. The partial pre-zygotic isolation between the two populations is caused by assortative mating for a trait that is influenced by any number of genes with additive effects. The post-zygotic isolation is caused by selection against genetic incompatibilities that can involve any form of selection on individual genes and gene combinations (epistasis). The analysis assumes that the introgression rate and selection coefficients are small. The results show that the assortment trait mean will not diverge from the immigrants unless there is direct selection on the trait favouring it to do so or there are genes of very large effect. The amount of divergence at equilibrium is determined by a balance between direct selection on the assortment trait and introgression from the other population. Additional selection against hybrid genetic incompatibilities reduces the effective migration rate and allows greater divergence. The role of assortment in speciation is discussed in the light of these results.
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Affiliation(s)
- M Kirkpatrick
- Section of Integrative Biology, University of Texas, Austin 78712, USA.
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24
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Abstract
We studied the effects of population size on the inbreeding depression and genetic load caused by deleterious mutations at a single locus. Analysis shows how the inbreeding depression decreases as population size becomes smaller and/or the rate of inbreeding increases. This pattern contrasts with that for the load, which increases as population size becomes smaller but decreases as inbreeding rate goes up. The depression and load both approach asymptotic limits when the population size becomes very large or very small. Numerical results show that the transition between the small and the large population regimes is quite rapid, and occurs largely over a range of population sizes that vary by a factor of 10. The effects of drift on inbreeding depression may bias some estimates of the genomic rate of deleterious mutation. These effects could also be important in the evolution of breeding systems in hermaphroditic organisms and in the conservation of endangered populations.
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Affiliation(s)
- T Bataillon
- INRA-SGAP, Domaine de Melgueil, Mauguio, France.
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Abstract
Many phenotypes respond physiologically or developmentally to continuously distributed environmental variables such as temperature and nutritional quality. Information about phenotypic plasticity can be used to improve the efficiency of artificial selection. Here we show that the quantitative genetic theory for 'infinite-dimensional' traits such as reaction norms provides a natural framework to accomplish this goal. It is expected to improve selection responses by making more efficient use of information about environmental effects than do conventional methods. The approach is illustrated by deriving an index for mass selection of a phenotypically plastic trait. We suggest that the same approach could be extended directly to more general and efficient breeding schemes, such as those based on general best linear unbiased prediction. Methods for estimating genetic covariance functions are reviewed.
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Affiliation(s)
- M Kirkpatrick
- Section of Integrative Biology, University of Texas, Austin 78712, USA.
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Abstract
OBJECTIVE To determine the natural variability and symmetry of force platform parameters in normal and cerebral palsy gait. DESIGN Force platform data has been analysed using coefficient of variation, analysis of variances and symmetry index. BACKGROUND It is important to establish the natural variability of force platform data so that changes in gait due to natural variability and those due to intervention can be determined. METHODS Force platform data and walking speed were recorded in 15 normal volunteers and 11 children with cerebral palsy on 3 consecutive days. Five recordings were made of each leg on each day. RESULTS The force platform parameters in both groups showed greater asymmetry in the horizontal plane. In the cerebral palsy group significant asymmetry was found in all 3 directions. The variation of the vertical ground reaction force peaks (Fz1 and Fz3) and of the anterior-posterior negative peak (Fy3) for both groups was low. Fz3 was the most reproducible force parameter. The other force parameters showed high variability and are not considered reliable measures of gait. The temporal parameters and the walking speed were reproducible measures. CONCLUSIONS Only selected ground reaction force parameters showed acceptable stability and reproducibility. Therefore caution has to be taken in the selection of these parameters, when assessing the effects of any intervention on cerebral palsy gait.
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Affiliation(s)
- R White
- Department of Biomedical Physics and Bioengineering, University of Aberdeen/Aberdeen Royal Hospitals, Foresterhill, UK.
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27
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Abstract
We develop a haploid model for the reinforcement of female mating preferences on an island that receives migrants from a continent. We find that preferences will evolve to favor island males under a broad range of conditions: when the average male display trait on the island and continent differ, when the preference acts on that difference, and when there is standing genetic variance for the preference. A difference between the mean display trait on the continent and on the island is sufficient to drive reinforcement of preferences. Additional postzygotic isolation, caused, for example, by either epistatic incompatibility or ecological selection against hybrids, will amplify reinforcement but is not necessary. Under some conditions, the degree of preference reinforcement is a simple function of quantities that can be estimated entirely from phenotypic data. We go on to study how postzygotic isolation caused by epistatic incompatibilities affects reinforcement of the preference. With only one pair of epistatic loci, reinforcement is enhanced by tighter linkage between the preference genes and the genes causing hybrid incompatibility. Reinforcement of the preference is also affected by the number of epistatically interacting genes involved in incompatibility, independent of the overall intensity of selection against hybrids.
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Affiliation(s)
- M Kirkpatrick
- Department of Zoology, University of Texas, Austin, Texas 78712, USA.
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28
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Abstract
An important but controversial class of hypotheses concerning the evolution of female preferences for extreme male mating displays involves "indirect selection." Even in the absence of direct fitness effects, preference for males with high overall fitness can spread via a genetic correlation that develops between preference alleles and high fitness genotypes. Here we develop a quantitative expression for the force of indirect selection that (i) applies to any female mating behavior, (ii) is relatively insensitive to the underlying genetics, and (iii) is based on measurable quantities. In conjunction with the limited data now available, it suggests that the evolutionary force generated by indirect selection on preferences is weak in absolute terms. This finding raises the possibility that direct selection on preference genes may often be more important than indirect selection, but more data on the quantities identified by our model and on direct selection are needed to decide the question.
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Affiliation(s)
- M Kirkpatrick
- Department of Zoology, University of Texas, Austin 78712, USA.
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Sprenger E, Schwarzmann P, Kirkpatrick M, Fox W, Heinzerling RH, Geyer JW, Knesel EA. The false negative rate in cervical cytology. Comparison of monolayers to conventional smears. Acta Cytol 1996; 40:81-9. [PMID: 8604579 DOI: 10.1159/000333588] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [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: 01/31/2023]
Abstract
OBJECTIVE To compare cervical monolayers prepared by a density gradient technique to conventional smears. STUDY DESIGN The study evaluated 2,863 patient samples. After conventional smears were prepared, the residual samples (collected in preservative fluid) were processed by the monolayer preparation system, which disaggregates the cells, removes nonclinical debris and layers the diagnostic material onto a microscopic slide. Slides were screened in Germany and the United States in masked studies. RESULTS In the U.S. study, the false negative rate for the conventional smears was 9.4% when endocervical components were present and 16.7% when absent. The false negative rate for the monolayer preparation was 4.0% when endocervical components were present and 5.7% when absent. A comparison of the diagnostic results showed that the monolayer made possible the detection of 48 cases of low grade disease or higher that were not found on the conventional smear. The German study was independent but used the same samples. The results, although based upon the Papanicolaou classification, were similar. CONCLUSION Cervical samples that are preserved in a liquid suspension and prepared using the density gradient monolayer technology have many advantages over conventional cervical cytologic smear preparations. The quality of cell preservation and presentation is superior. Elimination of obscuring material, homogeneity of the sample and standardized quality work together to produce preparations that can be effectively and reliably screened by cytotechnologists. These preparations should greatly enhance the reliability of machine-based screening in the future.
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Affiliation(s)
- E Sprenger
- Institute for Cytopathology, Clinics of the University of Kiel, Germany
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31
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Kirkpatrick M, Eunson P. Reconciliation for Rwanda's children. Lancet 1994; 344:1641. [PMID: 7984019 DOI: 10.1016/s0140-6736(94)90438-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 01/28/2023]
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33
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Abstract
It is important to determine the reproducibility of objective measures of gait in children with motor disorders in order that the effect of interventions to improve gait can be monitored. Data for walking velocity and vertical ground reaction force expressed as a percentage of body weight were collected from 15 normal children and 11 with spastic cerebral palsy. Five recordings were obtained for each foot of each child on 3 consecutive days, and calculations of variability made for each set of five recordings. Children with cerebral palsy had slower walking velocities and greater ground reaction force values, and both these parameters had low intraindividual variation for both normal children and those with cerebral palsy (coefficients of variation < 12.5%). This good reproducibility applied to intrasubject and intraday variability; no learning effect was seen over 3 days' recordings. There was no significant difference in variability whether the first three recordings or all five were used. These techniques of gait measurement in children have good reproducibility and a potential role in the objective assessment of medical and surgical interventions.
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Affiliation(s)
- M Kirkpatrick
- Department of Child Health, Medical School, University of Aberdeen, Scotland
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34
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Affiliation(s)
- D A Pittman
- School of Nursing Graduate Program at East Carolina University, Greenville, North Carolina
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35
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Kirkpatrick M, Hill WG, Thompson R. Estimating the covariance structure of traits during growth and ageing, illustrated with lactation in dairy cattle. Genet Res (Camb) 1994; 64:57-69. [PMID: 7958832 DOI: 10.1017/s0016672300032559] [Citation(s) in RCA: 140] [Impact Index Per Article: 4.7] [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: 01/28/2023] Open
Abstract
Quantitative variation in traits that change with age is important to both evolutionary biologists and breeders. We present three new methods for estimating the phenotypic and additive genetic covariance functions of a trait that changes with age, and illustrate them using data on daily lactation records from British Holstein-Friesian dairy cattle. First, a new technique is developed to fit a continuous covariance function to a covariance matrix. Secondly, this technique is used to estimate and correct for a bias that inflates estimates of phenotypic variances. Thirdly, we offer a numerical method for estimating the eigenvalues and eigenfunctions of covariance functions. Although the algorithms are moderately complex, they have been implemented in a software package that is made freely available. Analysis of lactation shows the advantages of the new methods over earlier ones. Results suggest that phenotypic variances are inflated by as much as 39% above the underlying covariance structure by measurement error and short term environmental effects. Analysis of additive genetic variation indicates that about 90% of the additive genetic variation for lactation during the first 10 months is associated with an eigen-function that corresponds to increased (or decreased) production at all ages. Genetic tradeoffs between early and late milk yield are seen in the second eigen-function, but it accounts for less than 8% of the additive variance. This illustrates that selection is expected to increase production throughout lactation.
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Affiliation(s)
- M Kirkpatrick
- Department of Zoology, University of Texas, Austin 78712
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36
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Abstract
A 3-week-old infant with meningococcal meningitis is described whose clinical course was complicated by paraparesis and urinary retention. This rare complication of meningococcal meningitis has not previously been reported in the neonatal age group.
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Affiliation(s)
- M Kirkpatrick
- Department of Community Child Health, Stirling Royal Infirmary, UK
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37
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Abstract
A new cervical cytology monolayer preparation system called Cyto-Rich was evaluated. Using samples from 557 patients, Cyto-Rich monolayers were compared to matched conventional smears. After conventional smears were prepared and spray fixed, residual exfoliated cells were transferred to preservative fluid. The cell suspensions were gently disaggregated and the epithelial component enriched with gradient centrifugal sedimentation. The batched samples were then placed on the Cyto-Rich work station where slides are automatically prepared and stained. The results demonstrate that Cyto-Rich prepared monolayers are vastly superior to the conventional smears for cell presentation. While the study showed 99% overall concordance. Cyto-Rich improved the detection of low-grade cervical intraepithelial lesions.
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Affiliation(s)
- J W Geyer
- Roche Biomedical Laboratories, Burlington, NC 27244
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Kirkpatrick M, Poore P. Prevention vs cure in developing countries. Lancet 1992; 339:994. [PMID: 1348828] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
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42
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Abstract
We present methods for estimating the parameters of inheritance and selection that appear in a quantitative genetic model for the evolution growth trajectories and other "infinite-dimensional" traits that we recently introduced. Two methods for estimating the additive genetic covariance function are developed, a "full" model that fully fits the data and a "reduced" model that generates a smoothed estimate consistent with the sampling errors in the data. By decomposing the covariance function into its eigenvalues and eigenfunctions, it is possible to identify potential evolutionary changes in the population's mean growth trajectory for which there is (and those for which there is not) genetic variation. Algorithms for estimating these quantities, their confidence intervals, and for testing hypotheses about them are developed. These techniques are illustrated by an analysis of early growth in mice. Compatible methods for estimating the selection gradient function acting on growth trajectories in natural or domesticated populations are presented. We show how the estimates for the additive genetic covariance function and the selection gradient function can be used to predict the evolutionary change in a population's mean growth trajectory.
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Affiliation(s)
- M Kirkpatrick
- Department of Zoology, University of Texas, Austin 78712
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43
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Kirkpatrick M, Lamichhane S. Demographic patterns, attitudes and practices of women attending an antenatal clinic in rural Nepal. J Inst Med 1990; 12:37-44. [PMID: 12283775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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45
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Abstract
Infinite-dimensional characters are those in which the phenotype of an individual is described by a function, rather than by a finite set of measurements. Examples include growth trajectories, morphological shapes, and norms of reaction. Methods are presented here that allow individual phenotypes, population means, and patterns of variance and covariance to be quantified for infinite-dimensional characters. A quantitative-genetic model is developed, and the recursion equation for the evolution of the population mean phenotype of an infinite-dimensional character is derived. The infinite-dimensional method offers three advantages over conventional finite-dimensional methods when applied to this kind of trait: (1) it describes the trait at all points rather than at a finite number of landmarks, (2) it eliminates errors in predicting the evolutionary response to selection made by conventional methods because they neglect the effects of selection on some parts of the trait, and (3) it estimates parameters of interest more efficiently.
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Affiliation(s)
- M Kirkpatrick
- Department of Zoology, University of Texas, Austin 78712
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46
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Abstract
Sexual reproduction confronts evolutionary biology with a paradox: other things being equal, an asexual (all-female) population will have twice the reproductive potential of a competing sexual population and therefore should rapidly drive the sexual population to extinction. Thus, the persistence of sexual reproduction in most life forms implies a compensatory advantage to sexual reproduction. Work on this problem has emphasized the evolutionary advantages produced by the genetic recombination that accompanies sexual reproduction. Here we show that genetic segregation produces an advantage to sexual reproduction even in the absence of an advantage from recombination. Segregation in a diploid sexual population allows selection to carry a single advantageous mutation to a homozygous state, whereas two separate mutations are required in a parthenogenetic population. The complete fixation of advantageous mutations is thus delayed in a heterozygous state in asexual populations. Calculation of the selective load incurred suggests that it may offset the intrinsic twofold reproductive advantage of asexual reproduction and maintain sexual reproduction in diploid populations.
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Affiliation(s)
- M Kirkpatrick
- Department of Zoology, University of Texas, Austin 78712
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47
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48
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Abstract
Growth trajectories differ from many other quantitative characters in that they are characterized by a continuous function rather than by a finite number of discrete measurements. We review here recently developed methods for predicting the evolution of growth trajectories under the influence of natural or artificial selection. Using our method, analysis of genetic data from mice shows that the patterns of genetic variation arising from developmental processes impose constraints on evolution of growth trajectories. These constraints can be quantified to reveal the families of growth trajectories that can be produced by selection and those families that cannot. The data suggest there may be relatively few evolutionary degrees of freedom for growth trajectories despite the presence of abundant additive genetic variation to alter size and (or) growth rate at every age. The description of these constraints may be useful to both biologists who would like to determine the evolutionary options available to natural populations and to breeders who would like to alter growth trajectories to economically improve domesticated species. Our methods and conclusions can be generalized to other kinds of "infinite-dimensional" or complex characters, including morphological shapes and norms of reaction.
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Affiliation(s)
- M Kirkpatrick
- Department of Zoology, University of Texas, Austin 78712
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49
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50
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Abstract
The clinical features of 107 cases of children with hydrocephalus and measured raised intraventricular pressure were analysed retrospectively. Fifty one children had recently been diagnosed as having hydrocephalus, and the remainder had had shunts injected to direct the cerebrospinal fluid. The most common symptoms in the group were vomiting, behavioural changes, drowsiness, and headaches. The most common clinical signs were inappropriately increasing occipitofrontal head circumferences, tense anterior fontanelles, splayed sutures, and distension of the scalp veins. Half the infantile cases of hydrocephalus were without symptoms, and a quarter of the cases with cerebrospinal fluid shunts and measured raised intraventricular pressure were without signs. There were no fewer than 33 different clinical signs including several unusual ones, such as macular rash and sweating. We believe that the presentation of hydrocephalus with raised intraventricular pressure is sufficiently variable, unusual, or even absent to justify the direct measurement of intracranial pressure.
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Affiliation(s)
- M Kirkpatrick
- Department of Neurology, Royal Hospital for Sick Children, Edinburgh
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