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Miller AD, Townsend AK, McGowan KJ, Clark AB, Glaser AL, Patrican LA, Dobson E, Buckles EL. Non-West Nile virus-associated mortality in a population of American crows (Corvus brachyrhynchos): a gross and histopathologic study. J Vet Diagn Invest 2010; 22:289-95. [PMID: 20224095 DOI: 10.1177/104063871002200223] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The American crow (Corvus brachyrhynchos) is a common urban and rural inhabitant of the Northeast and Midwest United States that is commonly infected with West Nile virus (WNV). The current study was initiated to determine non-WNV-associated causes of mortality in the American crow. All animals (40/40) tested negative for WNV infection via polymerase chain reaction and had no evidence of infection based on immunohistochemistry. Common gross necropsy findings included external trauma (6/40), hepatosplenomegaly (6/40), poxviral dermatitis (5/40), and pneumonia (3/40). Common histologic findings included endoparasitism (32/40), multifocal hepatic and splenic necrosis (7/40), pigment accumulation in the spleen (5/40), and disseminated bacterial infection (3/40). The most significant and debilitating diseases included fungal pneumonia and poxvirus-associated lesions. The present report increases the knowledge of diseases present in the American crow population.
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Baltz AP, Clark AB. Cere Colour as a Basis for Extra-pair Preferences of Paired Male Budgerigars (Melopsittacus undulatus: Psittacidae: Aves). Ethology 2010. [DOI: 10.1111/j.1439-0310.1996.tb01108.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Gallup AC, Miller ML, Clark AB. Yawning and thermoregulation in budgerigars: science as an incremental process. Anim Behav 2009. [DOI: 10.1016/j.anbehav.2009.09.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Heiss RS, Clark AB, McGowan KJ. Growth and nutritional state of American Crow nestlings vary between urban and rural habitats. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2009; 19:829-839. [PMID: 19544727 DOI: 10.1890/08-0140.1] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In urbanized areas, many adult birds find sufficient foods to survive, but the anthropogenic foods that are abundant there may be detrimental to nestling growth. In fact, American Crow (Corvus brachyrhynchos) nestlings are smaller in suburban than rural areas, possibly because of nutrient limitation. Here, we seek to identify possible causes of size differences by comparing both size and blood chemistry measures in rural and suburban crow nestlings. We quantified land use in known crow territories and distinguished three distinct environments: suburban-residential, suburban-managed (e.g., golf courses), and rural. We measured nestlings near fledging age in each environment and bled them for determination of unbound plasma calcium, total protein, and corticosterone. We supplemented a subset of broods in suburban-residential and rural areas with a food high in protein and calcium. Rural nestlings were significantly larger than suburban-residential crows and had higher total serum protein. Nestlings in suburban-managed areas were intermediate in size and serum protein but had the lowest plasma calcium levels. Nestling corticosterone levels did not differ significantly among habitats, indicating that, although suburban nestlings may be food-limited, they were not starving. Supplemented nestlings in suburban-residential areas were significantly larger in some growth measures than their unsupplemented counterparts. Unexpectedly, supplemented rural nestlings were significantly smaller than unsupplemented rural ones, suggesting that parents use easily accessible food even when it is nutritionally suboptimal. Our results indicate that nestlings in suburban areas are nutrient restricted, rather than calorie restricted.
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Townsend AK, Clark AB, McGowan KJ, Buckles EL, Miller AD, Lovette IJ. Disease-mediated inbreeding depression in a large, open population of cooperative crows. Proc Biol Sci 2009; 276:2057-64. [PMID: 19324784 DOI: 10.1098/rspb.2008.1852] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Disease-mediated inbreeding depression is a potential cost of living in groups with kin, but its general magnitude in wild populations is unclear. We examined the relationships between inbreeding, survival and disease for 312 offspring, produced by 35 parental pairs, in a large, open population of cooperatively breeding American crows (Corvus brachyrhynchos). Genetic analyses of parentage, parental relatedness coefficients and pedigree information suggested that 23 per cent of parental dyads were first- or second-order kin. Heterozygosity-heterozygosity correlations suggested that a microsatellite-based index of individual heterozygosity predicted individual genome-wide heterozygosity in this population. After excluding birds that died traumatically, survival probability was lower for relatively inbred birds during the 2-50 months after banding: the hazard rate for the most inbred birds was 170 per cent higher than that for the least inbred birds across the range of inbreeding index values. Birds that died with disease symptoms had higher inbreeding indices than birds with other fates. Our results suggest that avoidance of close inbreeding and the absence of inbreeding depression in large, open populations should not be assumed in taxa with kin-based social systems, and that microsatellite-based indices of individual heterozygosity can be an appropriate tool for examining the inbreeding depression in populations where incest and close inbreeding occur.
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Townsend AK, Clark AB, McGowan KJ, Lovette IJ. Reproductive partitioning and the assumptions of reproductive skew models in the cooperatively breeding American crow. Anim Behav 2009; 77:503-512. [PMID: 20126287 DOI: 10.1016/j.anbehav.2008.10.030] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Understanding the benefits of cooperative breeding for group members of different social and demographic classes requires knowledge of their reproductive partitioning and genetic relatedness. From 2004-2007, we examined parentage as a function of relatedness and social interactions among members of 21 American crow (Corvus brachyrhynchos) family groups. Paired female breeders monopolized maternity of all offspring in their broods, whereas paired male breeders sired 82.7% of offspring, within-group auxiliary males sired 6.9% of offspring, and extragroup males sired 10.4% of offspring. Although adult females had fewer opportunities for direct reproduction as auxiliaries than males, they appeared to have earlier opportunities for independent breeding. These different opportunities for direct reproduction probably contributed to the male biased adult auxiliary sex ratio. Patterns of reproductive partitioning and conflict among males were most consistent with a synthetic reproductive skew model, in which auxiliaries struggled with breeders for a limited reproductive share, beyond which breeders could evict them. Counter to a frequent assumption of reproductive skew models, female breeders appeared to influence paternity, although their interests might have agreed with the interests of their paired males. Unusual among cooperative breeders, close inbreeding and incest occurred in this population. Incest avoidance between potential breeders did not significantly affect reproductive skew.
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Gallup AC, Miller ML, Clark AB. Yawning and thermoregulation in budgerigars, Melopsittacus undulatus. Anim Behav 2009. [DOI: 10.1016/j.anbehav.2008.09.014] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Stephenson M, Clark AB. A Contribution to the Study of Keratomalacia among Rats. Biochem J 2006; 14:502-21. [PMID: 16742953 PMCID: PMC1263902 DOI: 10.1042/bj0140502] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Raistrick H, Clark AB. Studies on the Cycloclastic Power of Bacteria: Part II. A Quantitative Study of the Aerobic Decomposition of Tryptophan and Tyrosine by Bacteria. Biochem J 2006; 15:76-82. [PMID: 16742977 PMCID: PMC1258959 DOI: 10.1042/bj0150076] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Raistrick H, Clark AB. On the Mechanism of Oxalic Acid Formation by Aspergillus niger: Report to the Medical Research Committee. Biochem J 2006; 13:329-44. [PMID: 16742867 PMCID: PMC1258875 DOI: 10.1042/bj0130329] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Winsor CP, Clark AB. Dark Adaptation after Varying of Light Adaptation. Proc Natl Acad Sci U S A 2006; 22:400-4. [PMID: 16588094 PMCID: PMC1076790 DOI: 10.1073/pnas.22.6.400] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Clark AB, Robinson DA, McGowan KJ. EFFECTS OF WEST NILE VIRUS MORTALITY ON SOCIAL STRUCTURE OF AN AMERICAN CROW (CORVUS BRACHYRHYNCHOS) POPULATION IN UPSTATE NEW YORK. ACTA ACUST UNITED AC 2006. [DOI: 10.1642/0078-6594(2006)60[65:eownvm]2.0.co;2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Bennett AMD, Clark AB, Bath AP, Montgomery PQ. Meta-analysis of the timing of haemorrhage after tonsillectomy: an important factor in determining the safety of performing tonsillectomy as a day case procedure. Clin Otolaryngol 2005; 30:418-23. [PMID: 16232245 DOI: 10.1111/j.1365-2273.2005.01060.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES To perform a meta-analysis of studies of the timing of primary tonsillectomy haemorrhage. In particular to compare the difference in risk between 0-8 and 8-24 h; that is whether overnight inpatient tonsillectomy is required. DESIGN Medline search of all tonsillectomy studies to perform a meta-analysis of the timing of primary haemorrhages. SETTING Literature-based study. PARTICIPANTS All adult and paediatric tonsillectomy studies giving the absolute number and timing of all primary haemorrhages. MAIN OUTCOME MEASURES The overall incidence of haemorrhage occurring between 0-8 and 8-24 h. The overall incidence of haemorrhage for each of the first 24 h after operation. Compare risk of a bleed occurring 0-8, 8-24 and >24 h where data were available. RESULTS From a 1.4% overall risk of a primary haemorrhage only one in 14 occur after 8 h, i.e. 0.1% (95% CI=0.08-0.16%). A total of 833 patients would require to be kept overnight in order to identify one case of bleeding after 8 h. CONCLUSIONS Little benefit was conferred from overnight admission from the point of view of monitoring for primary haemorrhage. A case can be made for either day-case tonsillectomy (hospital stay over the period in which 93% of primary haemorrhages would occur) or the 'belt-and-braces' approach of a 1-week stay (during which all haemorrhages would occur) but current 24-h admission appears illogical.
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Thykjaer T, Christensen M, Clark AB, Hansen LR, Kunkel TA, Ørntoft TF. Functional analysis of the mismatch repair system in bladder cancer. Br J Cancer 2001; 85:568-75. [PMID: 11506498 PMCID: PMC2364098 DOI: 10.1054/bjoc.2001.1949] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
In bladder cancer the observed microsatellite instability indicates that mismatch repair deficiency could be a frequently involved factor in bladder cancer progression. To investigate this hypothesis we analysed extracts of seven bladder cancer cell lines and, as a novel approach, five clinical cancer samples for mismatch repair activity. We found that one cell line (T24) and three of the clinical samples had a reduced repair capacity, measured to approximately 20% or less. The T24 cell extract was unable to repair a G-G mismatch and showed reduced repair of a 2-base loop, consistent with diminished function of the MSH2-MSH6 heterodimer. The functional assay was combined with measurement for mutation frequency, microsatellite analysis, sequencing, MTT assay, immunohistochemical analysis and RT-PCR analysis of the mismatch repair genes MSH2, MSH3, MSH6, PMS1, PMS2 and MLH1. A >7-fold relative increase in mutation frequency was observed for T24 compared to a bladder cancer cell line with a fully functional mismatch repair system. Neither microsatellite instability, loss of repair nor mismatch repair gene mutations were detected. However, RT-PCR analysis of mRNA levels did detect changes in the ratio of expression of the Mut S and Mut L homologues. The T24 cell line had the lowest MSH6 expression level of the cell lines tested. Identical RT-PCR analysis of seventeen clinical samples (normal urothelium, 7; pTa low stage, 5; and pT1-4 high stage, 5) indicated a significant change in the expression ratio between MSH3/MSH6 (P< 0.004), MSH2/MSH3 (P< 0.012) and PMS2/MLH1 P< 0.005, in high stage bladder tumours compared to normal urothelium and low stage tumours. Collectively, the data suggest that imbalanced expression of mismatch repair genes could lead to partial loss of mismatch repair activity that is associated with invasive bladder cancer.
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Clark AB, Valle F, Drotschmann K, Gary RK, Kunkel TA. Functional interaction of proliferating cell nuclear antigen with MSH2-MSH6 and MSH2-MSH3 complexes. J Biol Chem 2000; 275:36498-501. [PMID: 11005803 DOI: 10.1074/jbc.c000513200] [Citation(s) in RCA: 173] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Eukaryotic DNA mismatch repair requires the concerted action of several proteins, including proliferating cell nuclear antigen (PCNA) and heterodimers of MSH2 complexed with either MSH3 or MSH6. Here we report that MSH3 and MSH6, but not MSH2, contain N-terminal sequence motifs characteristic of proteins that bind to PCNA. MSH3 and MSH6 peptides containing these motifs bound PCNA, as did the intact Msh2-Msh6 complex. This binding was strongly reduced when alanine was substituted for conserved residues in the motif. Yeast strains containing alanine substitutions in the PCNA binding motif of Msh6 or Msh3 had elevated mutation rates, indicating that these interactions are important for genome stability. When human MSH3 or MSH6 peptides containing the PCNA binding motif were added to a human cell extract, mismatch repair activity was inhibited at a step preceding DNA resynthesis. Thus, MSH3 and MSH6 interactions with PCNA may facilitate early steps in DNA mismatch repair and may also be important for other roles of these eukaryotic MutS homologs.
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Drotschmann K, Clark AB, Kunkel TA. Mutator phenotypes of common polymorphisms and missense mutations in MSH2. Curr Biol 1999; 9:907-10. [PMID: 10469597 DOI: 10.1016/s0960-9822(99)80396-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hereditary non-polyposis colorectal cancer (HNPCC) is associated with germline mutations in the DNA mismatch repair gene hMSH2 [1], the human homologue of the Escherichia coli MutS gene. These are mostly nonsense, frameshift or deletion mutations that result in loss of intact protein and complete inactivation of DNA mismatch repair. However, cancer is also associated with hMSH2 missense mutations that are merely inferred to be deleterious because they result in non-conservative substitutions of amino acids that are highly conserved among MutS family proteins. Moreover, sequence polymorphisms exist in hMSH2 that also change conserved amino acids but whose functional consequences and relationship to cancer are uncertain. Here, we show that yeast strains harboring putative equivalents of three hMSH2 polymorphisms have elevated mutation rates. Mutator effects were also observed for yeast equivalents of hMSH2 missense mutations found in HNPCC families and in an early onset colon tumor. Several distinct phenotypes were observed, indicating that these missense mutations have differential effects on MSH2 function(s). The results suggest that cancer may be associated with even partial loss of hMSH2 function and they are consistent with the hypothesis that polymorphisms in hMSH2 might predispose humans to disease.
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Baltz AP, Clark AB. Does Conspecific Attraction Affect Nest Choice in Budgerigars (Melopsittacus undulatus: Psittacidae: Aves)? Ethology 1999. [DOI: 10.1046/j.1439-0310.1999.00440.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Drotschmann K, Clark AB, Tran HT, Resnick MA, Gordenin DA, Kunkel TA. Mutator phenotypes of yeast strains heterozygous for mutations in the MSH2 gene. Proc Natl Acad Sci U S A 1999; 96:2970-5. [PMID: 10077621 PMCID: PMC15879 DOI: 10.1073/pnas.96.6.2970] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Heterozygosity for germ-line mutations in the DNA mismatch repair gene MSH2 predisposes humans to cancer. Here we use a highly sensitive reporter to describe a spontaneous mutator phenotype in diploid yeast cells containing a deletion of only one MSH2 allele. We also identify five MSH2 missense mutations that have dominant mutator effects in heterozygous cells when expressed at normal levels from the natural MSH2 promoter. For example, a 230-fold mutator effect is observed in an MSH2/msh2 diploid strain in which Gly693, which is invariant in MutS homologs and involved in ATP hydrolysis, is changed to alanine. DNA binding data suggest that mismatch repair is suppressed by binding of a mutant Msh2-Msh6 heterodimer to a mismatch with subsequent inability to dissociate from the mismatch in the presence of ATP. A dominant mutator effect also is observed in yeast when Gly693 is changed to serine. An early onset colorectal tumor is heterozygous for the analogous Gly --> Ser mutation in hMSH2, and a second hMSH2 mutation was not found, suggesting that this missense mutation may predispose to cancer via a dominant mutator effect. The mutator effects of the deletion mutant and the Gly --> Ala missense mutant in yeast MSH2 are enhanced by heterozygosity for a missense mutation in DNA polymerase delta that reduces its proofreading activity but is not a mutator in the heterozygous state. The synergistic effects of heterozygosity for mutations in two different genes that act in series to correct replication errors may be relevant to cancer predisposition.
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Clark AB, Cook ME, Tran HT, Gordenin DA, Resnick MA, Kunkel TA. Functional analysis of human MutSalpha and MutSbeta complexes in yeast. Nucleic Acids Res 1999; 27:736-42. [PMID: 9889267 PMCID: PMC148241 DOI: 10.1093/nar/27.3.736] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Mismatch repair (MMR) is initiated when a heterodimer of hMSH2*hMSH6 or hMSH2*hMSH3 binds to mismatches. Here we perform functional analyses of these human protein complexes in yeast. We use a sensitive genetic system wherein the rate of single-base deletions in a homopolymeric run in the LYS2 gene is 10 000-fold higher in an msh2 mutant than in a wild-type strain. Expression of the human proteins alone or in combination does not reduce the mutation rate of the msh2 strain, and expression of the individual human proteins does not increase the low mutation rate of a wild-type strain. However, co-expression of hMSH2 and hMSH6 in wild-type yeast increases the mutation rate 4000-fold, while co-expression of hMSH2 and hMSH3 elevates the rate 5-fold. Analysis of cell extracts indicates that the proteins are expressed and bind to mismatched DNA. The results suggest that hMutSalpha and hMutSbeta complexes form, bind to and prevent correction of replication slippage errors in yeast. Expression of hMSH6 with hMSH2 containing a proline substituted for a conserved Arg524 eliminates the mutator effect and reduces mismatch binding. The analogous mutation in humans is associated with microsatellite instability, defective MMR and cancer, illustrating the utility of the yeast system for studying human disease alleles.
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Clark AB, Lee W. Red-winged blackbird females fail to increase feeding in response to begging call playbacks. Anim Behav 1998; 56:563-570. [PMID: 9784204 DOI: 10.1006/anbe.1998.0831] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The begging behaviour of nestling birds appears to be the main signal telling parents how much food is needed by the brood. Not only may the accuracy of that information be reduced through exaggeration due to competition, but it may also vary with the age of the nestling. Younger nestlings may vary more in how frequently they call than older nestlings because they cannot discriminate stimuli as well. Thus, even if 'honest', begging from younger nestlings could be a less reliable hunger signal than that from older nestlings. We tested the prediction that parents should respond less to the increased frequency of begging from very young versus older nestlings by playing back begging calls at the nests of both younger (</=5 day) and older (>/=6 days) red-winged blackbirds, Agelaius phoeniceus. In neither case did parents respond with consistent increases in feeding, nor did young gain more weight during playbacks. This lack of response is discussed in relation to two other recent studies of blackbirds that did demonstrate increased feeding with playbacks of begging calls. Copyright 1998 The Association for the Study of Animal Behaviour.
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Clark AB, Holt JM. Identifying and managing patients with hyperlipidemia. THE AMERICAN JOURNAL OF MANAGED CARE 1997; 3:1211-9; quiz 1223-5. [PMID: 10170303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Cardiovascular disease related to hyperlipidemia is a significant cause of morbidity and mortality in the United States. The benefit of lowering lipid levels in patients with and without cardiovascular disease has been demonstrated in numerous clinical trials. The results of these trials prompted the National Heart, Blood, and Lung Institute to form the Nation Cholesterol Education Panel (NCEP). This panel developed guidelines for identifying and treating lipid disorders. Before starting antilipemic therapy, patients should be evaluated for secondary causes of hyperlipidemia, including disease states and medications. Risk factors for cardiovascular disease should be identified and used to determine the patient's goal low-density lipoprotein level. Regardless of the drug therapy used, the cornerstone treatment for hyperlipidemia is dietary changes. The NCEP recommendation for dietary modification follows a two-step plan to reduce intake of cholesterol and dietary fats. Other nonpharmacologic treatments for hyperlipidemia include exercise, weight reduction for obese patients, reduction of excessive alcohol use, and smoking cessation . Drug therapy should be considered in patients who do not respond to an adequate trial of dietary modifications and lifestyle changes. The principal lipid-lowering agents currently used are the bile acid sequestrants, nicotinic acid, 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors, and fibric acid derivatives. Estrogen, fish oil, and alcohol also can decrease the risk of developing heart disease. In pharmacoeconomic studies, lipid-lowering drug therapy has been shown to decrease the number of procedures, hospitalizations, and other medical interventions required by patients with cardiovascular disease.
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Clark AB, Lobo BL, Gelfand MS. Fluconazole and amphotericin B for cryptococcal meningitis. Ann Pharmacother 1996; 30:1408-10. [PMID: 8968453 DOI: 10.1177/106002809603001209] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
OBJECTIVE To describe a patient with cryptococcal meningitis treated with the combination of amphotericin B and fluconazole. CASE SUMMARY A 41-year-old woman with cryptococcal meningitis who was not infected with HIV was treated with a combination of amphotericin B and fluconazole because she did not respond to amphotericin B alone and could not tolerate amphotericin B with flucytosine. She improved clinically, but it is unclear whether the combination was beneficial. DISCUSSION Standard therapy for cryptococcal meningitis is amphotericin B with or without flucytosine. Fluconazole is an alternative therapy, but its efficacy has not been documented in the patient population not infected with HIV. Theoretically, the combination of amphotericin B and fluconazole is antagonistic, but in vitro and in vivo data suggest that antagonism may not occur. The combination of amphotericin B and fluconazole in cryptococcal meningitis has not been evaluated in clinical trials, and its use is not recommended. CONCLUSIONS A patient with cryptococcal meningitis was treated with the combination of amphotericin B and fluconazole because of a poor response to amphotericin B monotherapy and intolerance to flucytosine. It is unclear whether her clinical response was a result of the combination.
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Umar A, Buermeyer AB, Simon JA, Thomas DC, Clark AB, Liskay RM, Kunkel TA. Requirement for PCNA in DNA mismatch repair at a step preceding DNA resynthesis. Cell 1996; 87:65-73. [PMID: 8858149 DOI: 10.1016/s0092-8674(00)81323-9] [Citation(s) in RCA: 425] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A two-hybrid system was used to screen yeast and human expression libraries for proteins that interact with mismatch repair proteins. PCNA was recovered from both libraries and shown in the case of yeast to interact with both MLH1 and MSH2. A yeast strain containing a mutation in the PCNA gene had a strongly elevated mutation rate in a dinucleotide repeat, and the rate was not further elevated in a strain also containing a mutation in MLH1. Mismatch repair activity was examined in human cell extracts using an assay that does not require DNA repair synthesis. Activity was inhibited by p21WAF1 or a p21 peptide, both of which bind to PCNA, and activity was restored to inhibited reactions by addition of PCNA. The data suggest a PCNA requirement in mismatch repair at a step preceding DNA resynthesis. The ability of PCNA to bind to MLH1 and MSH2 may reflect linkage between mismatch repair and replication and may be relevant to the roles of mismatch repair proteins in other DNA transactions.
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Westneat DF, Clark AB, Rambo KC, Westneat DF. Within-brood patterns of paternity and paternal behavior in red-winged blackbirds. Behav Ecol Sociobiol 1995. [DOI: 10.1007/bf00174140] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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