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Laitinen PJ, Brown KM, Piippo K, Swan H, Devaney JM, Brahmbhatt B, Donarum EA, Marino M, Tiso N, Viitasalo M, Toivonen L, Stephan DA, Kontula K. Mutations of the cardiac ryanodine receptor (RyR2) gene in familial polymorphic ventricular tachycardia. Circulation 2001; 103:485-90. [PMID: 11157710 DOI: 10.1161/01.cir.103.4.485] [Citation(s) in RCA: 436] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Familial polymorphic ventricular tachycardia is an autosomal-dominant, inherited disease with a relatively early onset and a mortality rate of approximately 30% by the age of 30 years. Phenotypically, it is characterized by salvoes of bidirectional and polymorphic ventricular tachycardias in response to vigorous exercise, with no structural evidence of myocardial disease. We previously mapped the causative gene to chromosome 1q42-q43. In the present study, we demonstrate that patients with familial polymorphic ventricular tachycardia have missense mutations in the cardiac sarcoplasmic reticulum calcium release channel (ryanodine receptor type 2 [RyR2]). METHODS AND RESULTS In 3 large families studied, 3 different RyR2 mutations (P2328S, Q4201R, V4653F) were detected and shown to fully cosegregate with the characteristic arrhythmic phenotype. These mutations were absent in the nonaffected family members and in 100 healthy controls. In addition to identifying 3 causative mutations, we identified a number of single nucleotide polymorphisms that span the genomic structure of RyR2 and will be useful for candidate-based association studies for other arrhythmic disorders. CONCLUSIONS Our data illustrate that mutations of the RyR2 gene cause at least one variety of inherited polymorphic tachycardia. These findings define a new entity of disorders of myocardial calcium signaling.
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Small KM, Forbes SL, Brown KM, Liggett SB. An asn to lys polymorphism in the third intracellular loop of the human alpha 2A-adrenergic receptor imparts enhanced agonist-promoted Gi coupling. J Biol Chem 2000; 275:38518-23. [PMID: 10948191 DOI: 10.1074/jbc.m004550200] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
alpha(2A)-Adrenergic receptors (alpha(2A)AR) are presynaptic autoinhibitory receptors of noradrenergic neurons in the central and peripheral sympathetic nervous systems, which act to dynamically regulate neurotransmitter release. Signaling through the G(i)/G(o) family of G-proteins, the receptor subserves numerous homeostatic and central nervous system functions. A single nucleotide polymorphism of this receptor, which results in an Asn to Lys substitution at amino acid 251 of the third intracellular loop, was identified in the human population. The frequency of Lys-251 was 10-fold greater in African-Americans than in Caucasians, but was not associated with essential hypertension. To determine the consequences of this substitution, wild-type and Lys-251 receptors were expressed in CHO and COS-7 cells. Expression, ligand binding, and basal receptor function were unaffected by the substitution. However, agonist-promoted [(35)S]GTPgammaS binding was approximately 40% greater with the Lys-251 receptor. This enhanced agonist function was observed with catecholamines, azepines, and imidazolines albeit to different degrees. In studies of agonist-promoted functional coupling to G(i), the polymorphic receptor displayed enhanced inhibition of adenylyl cyclase (60 +/- 4. 4 versus 46 +/- 4.1% inhibition) and markedly enhanced stimulation of MAP kinase (57 +/- 9 versus 15- +/- 2-fold increase over basal) compared with wild-type alpha(2A)AR. The potency of epinephrine in stimulating inositol phosphate accumulation was increased approximately 4 fold with the Lys-251 receptor. Unlike previously described variants of G-protein-coupled receptors, where the minor species causes either a loss of function or increased non-agonist function, Lys-251 alpha(2A)AR represents a new class of polymorphism whose phenotype is a gain of agonist-promoted function.
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MESH Headings
- Adenylyl Cyclase Inhibitors
- Adrenergic alpha-2 Receptor Agonists
- Amino Acid Sequence
- Animals
- Asparagine
- Base Sequence
- Binding Sites
- CHO Cells
- Cattle
- Cell Membrane/physiology
- Cricetinae
- Epinephrine/pharmacology
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- Genetic Variation
- Guinea Pigs
- Humans
- Inositol Phosphates/metabolism
- Lysine
- Mice
- Models, Molecular
- Molecular Sequence Data
- Oxymetazoline/pharmacology
- Polymorphism, Genetic
- Protein Structure, Secondary
- Rats
- Receptors, Adrenergic, alpha-2/chemistry
- Receptors, Adrenergic, alpha-2/genetics
- Receptors, Adrenergic, alpha-2/metabolism
- Recombinant Proteins/agonists
- Recombinant Proteins/chemistry
- Recombinant Proteins/metabolism
- Swine
- Transfection
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78
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Brown KM, Perlmutter P, McDermott RJ. Youth and tattoos: what school health personnel should know. THE JOURNAL OF SCHOOL HEALTH 2000; 70:355-360. [PMID: 11126997 DOI: 10.1111/j.1746-1561.2000.tb07273.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Though tattooing has been practiced by various cultures for centuries, this art form has undergone dramatic changes the past few decades. Today, tattoos appeal to diverse populations and mainstream culture. The proliferation of tattooing prompted increased concern for safety and awareness of hazardous conditions. Transmission of infectious diseases, such as hepatitis B and C, and theoretically, HIV, can occur when proper sterilization and safety procedures are not followed. While there are many populations at risk, a critical at-risk group is adolescents. Tattooing among adolescents is a risk-taking behavior that warrants the attention of health education in assisting adolescents in becoming informed decision-makers. Teaching and advocacy strategies are suggested, and roles for school health personnel are presented.
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79
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Papaconstantinou AD, Umbreit TH, Fisher BR, Goering PL, Lappas NT, Brown KM. Bisphenol A-induced increase in uterine weight and alterations in uterine morphology in ovariectomized B6C3F1 mice: role of the estrogen receptor. Toxicol Sci 2000; 56:332-9. [PMID: 10910991 DOI: 10.1093/toxsci/56.2.332] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The ability of the environmental xenoestrogen bisphenol A (BPA) to increase uterine wet weight in the rodent remains controversial, and few studies have previously examined the effects of BPA on uterine morphology. Furthermore, it is not known whether BPA-induced uterotrophic effects are, similarly to beta-estradiol (E(2)), mediated through the estrogen receptor (ER). In this study, we compared the effects of BPA on uterine wet weight and morphology to those of E(2) in the B6C3F1 ovariectomized mouse. To examine whether these effects were mediated through the ER, the antiestrogen ICI 182, 780 (ICI) was co-administered with BPA or E(2). We report that subcutaneous administration of BPA at doses between 0.8 and 8 mg/day over 4 days significantly increased mean uterine wet weights above those of vehicle (corn oil)-treated mice. The uterine weight data suggest that BPA acts as a partial agonist with an EC(50) of 0.72 mg/day compared to 19.4 ng/day for E(2). BPA (2 mg/day) and E(2) (40 ng/day) induced a significant increase in luminal epithelial height and in the thickness of both the stromal and myometrial layers of the uterus. The effects of 40 ng E(2)/day on all endpoints studied were reversed by 20 microg ICI/day. ICI at 200, but not 20 microg/day, was able to reverse the BPA (2 mg/day)-induced increase in both uterine wet weight and luminal epithelial height. ICI alone at 200 microg/day stimulated an increase in thickness of both the stroma and myometrium and did not reverse the effects of BPA (2 mg/day) on these layers. These results suggest that the BPA-induced increase in uterine wet weight and in luminal epithelial height in the ovariectomized B6C3F1 mouse are mediated by the ER.
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80
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Brown KM, Papaconstantinou AD. Response. Toxicol Sci 2000; 56:252. [PMID: 10910980 DOI: 10.1093/toxsci/56.2.252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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81
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Blinkovsky AM, Byun T, Brown KM, Golightly EJ, Klotz AV. A non-specific aminopeptidase from Aspergillus. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1480:171-81. [PMID: 10899618 DOI: 10.1016/s0167-4838(00)00064-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A fermentation broth supernatant of the Aspergillus oryzae strain ATCC20386 contains aminopeptidase activity that releases a wide variety of amino acids from natural peptides. The supernatant was fractionated by anion exchange chromatography. Based on the primary amino acid sequence data obtained from proteins in certain fractions, polymerase chain reaction (PCR) primers were made and a PCR product was generated. This PCR product was used to screen an A. oryzae cDNA library from which the full length gene was then obtained. Fusarium venenatum and A. oryzae were used as hosts for gene expression. Transformed strains of both F. venenatum and A. oryzae over-expressed an active aminopeptidase (E.C. 3.4.11), named aminopeptidase II. The recombinant enzyme from both fungal hosts appeared as smears on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. After deglycosylation of the N-linked sugars, both samples were a sharp band at approximately 56 kDa and had identical N-terminal amino acid sequences. Aminopeptidase II is a metalloenzyme with, presumably, Zn in the active site. Using various natural peptides and para-nitroanilides (pNAs) of amino acids as substrates, the aminopeptidase was found to be non-specific. Only X-Pro bonds demonstrated resistance to hydrolysis catalyzed by this aminopeptidase. The optimal enzyme activity was observed at pH 9.5 and 55 degrees C. Among amino acid pNAs, Leu-pNA appears to have the highest value of bimolecular constant of 40 min(-1) mM(-1) (k(cat) = 230 min(-1); K(m) = 5.8 mM) at pH 7.5 and 21 degrees C. Among Xaa-Ala-Pro-Tyr-Lys-amide pentapeptides, the velocity of catalytic hydrolysis at pH 7.5 and 21 degrees C was in a decreasing order: Pro, Ala, Leu, Gly and Glu.
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82
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Farrell JM, Litovitz TL, Penafiel M, Montrose CJ, Doinov P, Barber M, Brown KM, Litovitz TA. The effect of pulsed and sinusoidal magnetic fields on the morphology of developing chick embryos. Bioelectromagnetics 2000; 18:431-8. [PMID: 9261540 DOI: 10.1002/(sici)1521-186x(1997)18:6<431::aid-bem5>3.0.co;2-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Several investigators have reported robust, statistically significant results that indicate that weak (approximately 1 microT) magnetic fields (MFs) increase the rate of morphological abnormalities in chick embryos. However, other investigators have reported that weak MFs do not appear to affect embryo morphology at all. We present the results of experiments conducted over five years in five distinct campaigns spanning several months each. In four of the campaigns, exposure was to a pulsed magnetic field (PMF); and in the final campaign, exposure was to a 60 Hz sinusoidal magnetic field (MF). A total of over 2500 White Leghorn chick embryos were examined. When the results of the campaigns were analyzed separately, a range of responses was observed. Four campaigns (three PMF campaigns and one 60 Hz campaign) exhibited statistically significant increases (P > or = 0.01), ranging from 2-fold to 7-fold, in the abnormality rate in MF-exposed embryos. In the remaining PMF campaign, there was only a slight (roughly 50%), statistically insignificant (P = 0.2) increase in the abnormality rate due to MF exposure. When the morphological abnormality rate of all of the PMF-exposed embryos was compared to that of all of the corresponding control embryos, a statistically significant (P > or = .001) result was obtained, indicating that PMF exposure approximately doubled the abnormality rate. Like-wise, when the abnormality rate of the sinusoid-exposed embryos was compared to the corresponding control embryos, the abnormality rate was increased (approximately tripled). This robust result indicates that weak EMFs can induce morphological abnormalities in developing chick embryos. We have attempted to analyze some of the confounding factors that may have contributed to the lack of response in one of the campaigns. The genetic composition of the breeding stock was altered by the breeder before the start of the nonresponding campaign. We hypothesize that the genetic composition of the breeding stock determines the susceptibility of any given flock to EMF-induced abnormalities and therefore could represent a confounding factor in studies of EMF-induced bioeffects in chick embryos.
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83
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Brown KM, Pickard K, Nicol F, Beckett GJ, Duthie GG, Arthur JR. Effects of organic and inorganic selenium supplementation on selenoenzyme activity in blood lymphocytes, granulocytes, platelets and erythrocytes. Clin Sci (Lond) 2000; 98:593-9. [PMID: 10781391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
The blood selenium (Se) concentration in the U.K. population has declined by approx. 50% between 1974 and 1991, reflecting a large decrease in dietary Se supply, with intakes only half the reference nutrient intake of 1 microg/kg body weight. Tissue levels of Se are readily influenced by dietary intake. Therefore selenoprotein activity may be sub-optimal due to low Se status, and thus compromise normal cell function. To examine the effects of changing Se intake on selenoproteins, we have determined the relative effectiveness of organic selenomethionine and inorganic sodium selenite (50 microg of Se daily for 28 days) in modulating glutathione peroxidase activities in blood cells from 45 healthy men and women, from a U.K. population. Transient and acute changes in lymphocyte, granulocyte and platelet phospholipid-hydroperoxide glutathione peroxidase (GPx4) activity occurred by day 7 or 14 of sodium selenite treatment and by day 7 in lymphocytes from selenomethionine-treated subjects compared with controls taking a placebo. In contrast, GPx4 activity in granulocytes and platelets in the selenomethionine group increased gradually over the 28 days. Cytosolic glutathione peroxidase (GPx1) activity in these blood cells from both treatment groups increased gradually over the 28 days. For each cellular selenoenzyme activity a significant inter-individual difference (P<0.001) in the extent of the response to Se supplementation was observed, but this was not related to blood Se concentrations either before or after treatments. Significant inverse correlations were evident between baseline enzyme activities and percentage change in activity after 28 days of supplementation [e.g. lymphocyte GPx4, r=-0.695 (P<0.001)], indicating that pre-treatment activity may be sub-optimal as a result of poor Se status. The different and contrasting effects that Se supplementation had on blood selenoenzyme activities may be indicative of a difference in metabolic need for Se regulated at the level of Se-dependent cell function.
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84
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Schneider P, Caspersen MB, Mondorf K, Halkier T, Skov LK, Østergaard PR, Brown KM, Brown SH, Xu F. Erratum to “Characterization of a Coprinus cinereus laccase” [Enzyme Microb. Technol. 25 (1999) 502–508]☆. Enzyme Microb Technol 2000. [DOI: 10.1016/s0141-0229(00)00142-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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85
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Lavigne JV, Brown KM, Gidding S, Evans M, Stevens VJ, von Almen TK, Ewart C, Weil C. A cholesterol-lowering diet does not produce adverse psychological effects in children: three-year results from the dietary intervention study in children. Health Psychol 2000. [PMID: 10619534 DOI: 10.1037//0278-6133.18.6.604] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The Dietary Intervention Study in Children (DISC), a 2-arm, multicenter intervention study, examined the efficacy and safety of a diet lower in total fat, saturated fatty acids, and cholesterol than the typical American child's diet. A total of 663 8- to 10-year-old children with elevated low-density lipoprotein cholesterol levels were randomly assigned to either an intervention or a usual-care group. Intervention included group and individual counseling sessions to assist participants in adopting a dietary pattern containing 28% or less of calories from total fat (<8% as saturated fat, up to 9% as polyunsaturated fat, and 11% as monounsaturated fat) and dietary cholesterol intake of less than 75 mg/1,000 kcal. The dietary intervention reduced low-density lipoprotein cholesterol levels, and 3-year results showed no adverse effects for children in the intervention group in terms of academic functioning, psychological symptoms, or family functioning.
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86
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Xu F, Golightly EJ, Schneid P, Berka RM, Brown KM, Johnstone JA, Baker DH, Fuglsang CC, Brown SH, Svendsen A, Klotz AV. Expression and Characterization of a Recombinant Fusarium spp. Galactose Oxidase. Appl Biochem Biotechnol 2000. [DOI: 10.1385/abab:88:1-3:023] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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87
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Xu F, Brown KM, Dybdal L, Forman TM, Fuglslang CC, Wagner P. Controlled Stepwise Reduction of Disulfide Bonds and Heat-Induced Modification of Wheat Dough Proteins. Cereal Chem 1999. [DOI: 10.1094/cchem.1999.76.6.931] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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88
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Yaver DS, Overjero MD, Xu F, Nelson BA, Brown KM, Halkier T, Bernauer S, Brown SH, Kauppinen S. Molecular characterization of laccase genes from the basidiomycete Coprinus cinereus and heterologous expression of the laccase lcc1. Appl Environ Microbiol 1999; 65:4943-8. [PMID: 10543807 PMCID: PMC91665 DOI: 10.1128/aem.65.11.4943-4948.1999] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A laccase from Coprinus cinereus is active at alkaline pH, an essential property for some potential applications. We cloned and sequenced three laccase genes (lcc1, lcc2, and lcc3) from the ink cap basidiomycete C. cinereus. The lcc1 gene contained 7 introns, while both lcc2 and lcc3 contained 13 introns. The predicted mature proteins (Lcc1 to Lcc3) are 58 to 80% identical at the amino acid level. The predicted Lcc1 contains a 23-amino-acid C-terminal extension rich in arginine and lysine, suggesting that C-terminal processing may occur during its biosynthesis. We expressed the Lcc1 protein in Aspergillus oryzae and purified it. The Lcc1 protein as expressed in A. oryzae has an apparent molecular mass of 66 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and absorption maxima at 278 and 614 nm. Based on the N-terminal protein sequence of the laccase, a 4-residue propeptide was processed during the maturation of the enzyme. The dioxygen specificity of the laccase showed an apparent K(m) of 21 +/- 2 microM and a catalytic constant of 200 +/- 10 min(-1) for O(2) with 2, 2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) as the reducing substrate at pH 5.5. Lcc1 from A. oryzae may be useful in industrial applications. This is the first report of a basidiomycete laccase whose biosynthesis involves both N-terminal and C-terminal processing.
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89
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Lavigne JV, Brown KM, Gidding S, Evans M, Stevens VJ, von Almen TK, Ewart C, Weil C. A cholesterol-lowering diet does not produce adverse psychological effects in children: three-year results from the dietary intervention study in children. Health Psychol 1999; 18:604-13. [PMID: 10619534 DOI: 10.1037/0278-6133.18.6.604] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The Dietary Intervention Study in Children (DISC), a 2-arm, multicenter intervention study, examined the efficacy and safety of a diet lower in total fat, saturated fatty acids, and cholesterol than the typical American child's diet. A total of 663 8- to 10-year-old children with elevated low-density lipoprotein cholesterol levels were randomly assigned to either an intervention or a usual-care group. Intervention included group and individual counseling sessions to assist participants in adopting a dietary pattern containing 28% or less of calories from total fat (<8% as saturated fat, up to 9% as polyunsaturated fat, and 11% as monounsaturated fat) and dietary cholesterol intake of less than 75 mg/1,000 kcal. The dietary intervention reduced low-density lipoprotein cholesterol levels, and 3-year results showed no adverse effects for children in the intervention group in terms of academic functioning, psychological symptoms, or family functioning.
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90
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Xiao Z, McCallum TJ, Brown KM, Miller GG, Halls SB, Parney I, Moore RB. Characterization of a novel transplantable orthotopic rat bladder transitional cell tumour model. Br J Cancer 1999; 81:638-46. [PMID: 10574249 PMCID: PMC2362887 DOI: 10.1038/sj.bjc.6690741] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
An animal tumour model that mimics the human counterpart is essential for preclinical evaluation of new treatment modalities. The objective of this study was to develop and characterize such a model. To accomplish this, the established AY-27 rat bladder transitional cell carcinoma (TCC) cell line was transplanted orthotopically into Fischer CDF344 female rats. AY-27 TCC cells were grown in monolayer cell culture and instilled intravesically as single cell suspensions into bladders that had been conditioned with mild acid washing. Tumour growth was assessed weekly by subjecting the rats to magnetic resonance imaging (MRI). At intervals following implantation and MRI tumour detection, the animals were sacrificed for necropsy, histological examination and immunocytochemical studies. Flow cytometry was also performed for detection of Fas or Fas-ligand expression on AY-27 cells. The overall tumour establishment was 95% (97/102 rats) at 12-50 days, while in a subgroup of animals sacrificed at 16 days, 80 out of 82 animals (97%) developed TCC, the majority of which was superficial. Tumour stage was assessed by gross pathology and light microscopy. Histological examination of the tumour specimens confirmed the presence of grade II-III TCC. Immunocytochemistry confirmed that the tumour model maintained the features of TCC. The changes seen on MRI correlated well with the extent of tumour invasion identified histologically. Patchy carcinoma in situ could be detected histologically 12-13 days post-inoculation, and progressed to papillary tumour or invasive disease thereafter. Neither Fas nor Fas-ligand was expressed on AY-27 cells. The orthotopic AY-27 TCC model is highly reproducible and is ideal for preclinical studies on experimental intravesical therapies.
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91
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Abbaszadegan MR, Struewing JP, Brown KM, Snider JV, Goodsaid F, Gore-Langton R, Hughes MR. Automated detection of prevalent mutations in BRCA1 and BRCA2 genes, using a fluorogenic PCR allelic discrimination assay. GENETIC TESTING 1999; 1:171-80. [PMID: 10464643 DOI: 10.1089/gte.1997.1.171] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Mutations in the genes BRCA1 and BRCA2 account for 5%-10% of familial early onset breast cancer. Identification of these mutations allows molecular diagnosis for breast cancer susceptibility. A high through-put automated PCR allelic discrimination assay (ADA) was developed to detect the prevalent mutations in these genes. Two allele specific oligonucleotides (ASO) are directly used in the PCR reaction, in both of which the fluorescent reporter and quencher dyes are attached to the 5' and 3' ends, respectively. During PCR, fluorescence is generated after cleavage of the annealed ASO by the 5' nuclease activity of Taq polymerase. The wild-type BRCA sequence is distinguished from the mutant sequence by the differential fluorescence emission of two different reporter dyes. The sensitivity of ADA is at the level of a single cell following a nested PCR. Eighty-six patient samples can be analyzed for each mutation in 15-min post-PCR without the need for radioactivity, gel electrophoresis, or membrane blotting/hybridization.
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92
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Blinkovsky AM, Byun T, Brown KM, Golightly EJ. Purification, characterization, and heterologous expression in Fusarium venenatum of a novel serine carboxypeptidase from Aspergillus oryzae. Appl Environ Microbiol 1999; 65:3298-303. [PMID: 10427010 PMCID: PMC91495 DOI: 10.1128/aem.65.8.3298-3303.1999] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/1999] [Accepted: 04/27/1999] [Indexed: 11/20/2022] Open
Abstract
A novel serine carboxypeptidase (EC 3.4.16.1) was found in an Aspergillus oryzae fermentation broth and was purified to homogeneity. This enzyme has a molecular weight of ca. 67,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and its specific activity is 21 U/mg for carbobenzoxy (Z)-Ala-Glu at pH 4.5 and 25 degrees C. It has a ratio of bimolecular constants for Z-Ala-Lys and Z-Ala-Phe of 3.75. Optimal enzyme activity occurs at pH 4 to 4.5 and 58 to 60 degrees C for Z-Ala-Ile. The N terminus of this carboxypeptidase is blocked. Internal fragments, obtained by cyanogen bromide digestion, were sequenced. PCR primers were then made based on the peptide sequence information, and the full-length gene sequence was obtained. An expression vector that contained the recombinant carboxypeptidase gene was used to transform a Fusarium venenatum host strain. The transformed strain of F. venenatum expressed an active recombinant carboxypeptidase. In F. venenatum, the recombinant carboxypeptidase produced two bands which had molecular weights greater than the molecular weight of the native carboxypeptidase from A. oryzae. Although the molecular weights of the native and recombinant enzymes differ, these enzymes have very similar kinetic parameters.
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93
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Berg-Smith SM, Stevens VJ, Brown KM, Van Horn L, Gernhofer N, Peters E, Greenberg R, Snetselaar L, Ahrens L, Smith K. A brief motivational intervention to improve dietary adherence in adolescents. The Dietary Intervention Study in Children (DISC) Research Group. HEALTH EDUCATION RESEARCH 1999; 14:399-410. [PMID: 10539230 DOI: 10.1093/her/14.3.399] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Motivational interviewing offers health care professionals a potentially effective strategy for increasing a patient's readiness to change health behaviors. Recently, elements of motivational interviewing and the stages of change model have been simplified and adapted for use with patients in brief clinical encounters. This paper describes in detail a brief motivational intervention model to improve and renew dietary adherence with adolescents in the Dietary Intervention Study in Children (DISC). DISC is a randomized, multi-center clinical trial assessing the efficacy and safety of lowering dietary fat to decrease low-density lipoprotein cholesterol in high-risk children. In the first 3 years of follow-up covering ages 8-13, intervention participants (n = 334) were exposed to a family-based group intervention approach to change dietary choices. To address adherence and retention obstacles as participants moved into adolescence (age 13-17), an individual-level motivational intervention was implemented. The DISC motivational intervention integrates several intervention models: stages of change, motivational interviewing, brief negotiation and behavioral self-management. A preliminary test of the intervention model suggests that it was acceptable to the participants, popular with interventionists and appeared to be an age-appropriate shift from a family-based intervention model.
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Brown KM. An unexpected benefit of the radial artery. Ann Thorac Surg 1999; 67:1827-8. [PMID: 10391317 DOI: 10.1016/s0003-4975(99)00163-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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95
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Trinh DP, Brown KM, Jeang KT. Epithelin/granulin growth factors: extracellular cofactors for HIV-1 and HIV-2 Tat proteins. Biochem Biophys Res Commun 1999; 256:299-306. [PMID: 10079180 DOI: 10.1006/bbrc.1999.0317] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Epithelin/granulin growth factor is synthesized as a 593 amino acid precursor protein that contains 7.5 imperfectly conserved repeats of approximately 57 amino acids. Processed epithelin/granulin peptides have been isolated from vertebrate/invertebrate species and are growth factors implicated in epithelial and haemic cell function. Here they are identified as Human Immunodeficiency Virus (HIV) Tat binding proteins using the yeast two-hybrid assay. Intracellularly in yeast, mutation of selected cysteines in an epithelin/granulin dimeric repeat caused loss of binding to Tat exon 1. In vitro binding of HIV-1 and HIV-2 Tat to epithelin/granulin dimeric and monomeric repeats was also observed by GST-glutathione bead "pulldown" assays. Because Tat is actively secreted from HIV-infected cells and has been shown to serve as a mitogenic factor for angiogenesis and for Kaposi-like cells, our observations suggest that epithelin/granulin growth factors may function as biologically important extracellular Tat co-factors.
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Abstract
From 1987 to 1994, the annual frequency of adoption by breeding pairs at a Lake Erie ring-billed gull, Larus delawarensis, colony ranged from 3 to 37% (average 8%/year, N=7 years) and, on average, foster parents raised 0.5 fewer of their own chicks to fledging than pairs that did not adopt. The key evolutionary question is: why do some individuals apparently suffer the costs associated with a behaviour that appears to enhance the fitness of others? From 1992 to 1995, I investigated the proximate and ultimate causes of adoption in ring-billed gulls from the perspectives of both the foster parents and adopted chicks, and tested predictions that differentiated between various competing adaptive and nonadaptive hypotheses that have been proposed to explain it. While I was able to demonstrate a breeding cost, I failed to identify any benefits to foster parents. Thus, the adaptive hypotheses that rely on the foster parents benefiting were not supported (e.g. kin selection, reciprocal altruism, acquisition of parenting experience). From the foster parent's perspective, adoption was mediated through errors in parent-offspring recognition. Under natural conditions, most fostering pairs were tending small chicks (<6 days old) at the time of adoptions; in chick-transfer experiments, resident parents did not discriminate against foreign chicks until their own chicks were 7-9 days old. Chicks (N=25) that subsequently abandoned their natal nests were lighter, and grew at a slower rate, than chicks that survived to fledging in their home broods. Thus, departing chicks were at a survival disadvantage in their home broods. Chicks that gained acceptance into foreign broods where they were older/larger than the resident chicks realized high survival at the expense of their foster siblings and parents. Based upon individual growth rates and the corresponding survival probabilities, disadvantaged chicks approximately doubled their survival chances through foster care. Why has selection not eliminated adoption? I argue that adoption is an evolutionary arms race between the two principle actor groups; disadvantaged chicks, which benefit through foster care, and host parents, which avoid providing foster care (e.g. infanticide). In ring-billed gulls, selection has failed to eliminate adoption because the long-term reproductive cost (estimated at 4%, this study) of an occasional adoption is probably offset by the relatively higher costs associated with stricter kin discrimination mechanisms (e.g. parental infanticide). (c) 1998 The Association for the Study of Animal Behaviour.
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Berka RM, Rey MW, Brown KM, Byun T, Klotz AV. Molecular characterization and expression of a phytase gene from the thermophilic fungus Thermomyces lanuginosus. Appl Environ Microbiol 1998; 64:4423-7. [PMID: 9797301 PMCID: PMC106663 DOI: 10.1128/aem.64.11.4423-4427.1998] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The phyA gene encoding an extracellular phytase from the thermophilic fungus Thermomyces lanuginosus was cloned and heterologously expressed, and the recombinant gene product was biochemically characterized. The phyA gene encodes a primary translation product (PhyA) of 475 amino acids (aa) which includes a putative signal peptide (23 aa) and propeptide (10 aa). The deduced amino acid sequence of PhyA has limited sequence identity (ca. 47%) with Aspergillus niger phytase. The phyA gene was inserted into an expression vector under transcriptional control of the Fusarium oxysporum trypsin gene promoter and used to transform a Fusarium venenatum recipient strain. The secreted recombinant phytase protein was enzymatically active between pHs 3 and 7.5, with a specific activity of 110 micromol of inorganic phosphate released per min per mg of protein at pH 6 and 37 degrees C. The Thermomyces phytase retained activity at assay temperatures up to 75 degrees C and demonstrated superior catalytic efficiency to any known fungal phytase at 65 degrees C (the temperature optimum). Comparison of this new Thermomyces catalyst with the well-known Aspergillus niger phytase reveals other favorable properties for the enzyme derived from the thermophilic gene donor, including catalytic activity over an expanded pH range.
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Butler JD, Brown KM. Granular cell tumor of the extrahepatic biliary tract. Am Surg 1998; 64:1033-6. [PMID: 9798763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Granular cell tumors (GCTs) are usually benign lesions that most commonly arise in the skin, subcutaneous tissue, tongue, and oral cavity. GCT of the biliary tract is rare, but most commonly occurs in young African-American females. We report the 58th case of GCT involving the extrahepatic biliary system, and review the world literature on this tumor in this location.
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Brown KM, McMahon RP, Biro FM, Crawford P, Schreiber GB, Similo SL, Waclawiw M, Striegel-Moore R. Changes in self-esteem in black and white girls between the ages of 9 and 14 years. The NHLBI Growth and Health Study. J Adolesc Health 1998; 23:7-19. [PMID: 9648018 DOI: 10.1016/s1054-139x(97)00238-3] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PURPOSE We examined changes in self-esteem and feelings of competence with physical appearance and social acceptance over approximately 5 years in 1166 white and 1213 black girls, aged 9 and 10 years at baseline. METHODS Maturation stage and body mass index (BMI) were assessed annually. Biennially girls completed Harter's Self-Perception Profile for children. Changes were analyzed in the context of race, sexual maturation, BMI, and household income. Longitudinal regression models were used to compare trends with age in global self-worth, physical appearance, and social acceptance. RESULTS Mean global self-worth showed little change over ages 9-14 years in blacks (p = 0.09) but decreased in whites (p < 0.001). Mean physical appearance scores for both races declined between ages 9 and 14 years (blacks, p < 0.001; whites, p < 0.001). Mean social acceptance scores increased for both races between ages 9 and 14 years (blacks, p < 0.001; whites, p < 0.001). For all three scores, these changes differed between blacks and whites (all three p values, < or = 0.002). Adjustment for maturation stage, BMI, and household income did not alter the significance or direction of racial differences in the changes with age in global self-worth and physical appearance scores. Self-worth, physical appearance, and social acceptance scores decreased with increasing BMI. Decreases in physical appearance and social acceptance scores with increasing BMI were smaller in blacks than in whites (p < 0.05). After adjustment for maturation stage and household income, racial differences in social acceptance scores depended on BMI (p < 0.05) but not on age (p = 0.008). CONCLUSIONS This article reports the first data on self-esteem scores by age for a large population of black girls aged 9 and 14 years and concludes that self-esteem does not follow the same developmental pattern in black as in white girls. A reason for black girls' higher and more stable self-worth and their greater satisfaction with their physical appearance compared to white girls may be racial differences in attitudes toward physical appearance and obesity.
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