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Brown S, Holtzman S, Kaufman T, Denell R. Characterization of the Tribolium Deformed ortholog and its ability to directly regulate Deformed target genes in the rescue of a Drosophila Deformed null mutant. Dev Genes Evol 1999; 209:389-98. [PMID: 10370122 DOI: 10.1007/s004270050269] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
We have analyzed the Tribolium castaneum ortholog of the Drosophila homeotic gene Deformed (Dfd) and determined its expression pattern during embryogenesis in this beetle. Tc Deformed (Tc Dfd) is expressed in the blastoderm and the condensing germ rudiment in a region that gives rise to gnathal segments. During germ band extension Tc Dfd is expressed in the mandibular and maxillary segments, their appendages, and the dorsal ridge. Comparison of insect Dfd protein sequences reveals several highly conserved regions. To determine whether common molecular features reflect conserved regulatory functions we used the Gal4 system to express the Tribolium protein in Drosophila embryos. When Tc Dfd is expressed throughout embryonic ectoderm under the control of P69B, the beetle protein autoregulates the endogenous Dfd gene. In addition, the Drosophila proboscipedia gene (a normal target of Dfd) is ectopically activated in the antennal and thoracic segments. We also compared the ability of the beetle and fly proteins to rescue defects in Dfd- mutants by expressing each throughout the embryonic during embryogenesis. Both proteins rescued Dfd- defects to the same extent in that they each restore the development of mouth hooks and cirri, as well as cause gain-of-function abnormalities of posterior mouth parts. As before, pb was ectopically activated in the antennal segment. This is the first demonstration of the ability of a heterologous homeotic selector protein to directly regulate a target gene independent of an endogenous Drosophila autoregulatory loop.
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Moawad J, Brown S, Schwartz LB. The effect of 'non-critical' (<50%) stenosis on vein graft longitudinal resistance and impedance. Eur J Vasc Endovasc Surg 1999; 17:517-20. [PMID: 10375487 DOI: 10.1053/ejvs.1999.0819] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE vein graft stenoses <50% cause minimal flow impairment, velocity elevation, or symptomatology and are therefore usually assumed to be "non-critical". The purpose of this study was to assess the effect of <50% vein graft stenosis on vein graft longitudinal impedance, as elevated impedance has been found to correlate with clinical graft failure. METHODS eight segments of non-reversed cryopreserved vein (mean length 23+/-1 cm; mean outer diameter 4.7+/-0.2 mm) were saline-perfused in vitro utilising a variable pulsatile perfusion pump, Windkessel, and clamp resistor simulating the haemodynamic conditions of arterial bypass. Proximal (Pprox) and distal (Pdist) pressure were continuously measured by fluid-filled catheter transduction, and flow (Q) by ultrasonic transit-time flowmetry. Waveforms were digitally recorded at 200 Hz at pulse rates ranging from 60-180 b.p.m. with mean flow (Q) of 154 ml/min and mean proximal pressure (Pprox) of 100 mmHg (max/min 120/90). Graded mid-graft stenoses of <50% were created using an inflatable vascular occluder and measured by the corresponding changes in mean pressure gradient (DeltaP=Pprox-Pdist) and Q (%stenosis=1-{DeltaPbaselineQstenosis/Delta PstenosisQbaseline}1/4). Vein graft longitudinal resistance (RL) was calculated as DeltaP/Q. After Fourier transformation, vein graft longitudinal impedance (ZL) was calculated as DeltaP/Q at each harmonic, with ZL determined by integration over 0-4 Hz. Results are reported as mean+/-S.E.M. RESULTS the desired levels of pressure and flow were established in all vein segments. Graded inflation of the occluder resulted in vein graft stenosis of 23+/-3% and 39+/-3%. This was accompanied by a mild reduction in Q (12% and 30%) and considerable increases in both RL (180% and 710%) and ZL (140% and 430%). CONCLUSIONS "non-critical" vein graft stenosis (<50%) causes minimal change in mean flow, but substantial elevations in longitudinal resistance and impedance. The contribution of "non-critical" stenosis to vein graft failure may be under-appreciated.
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Brown S, Steele K. Nurse-mediated serum cholesterol reduction and health locus of control--a device for targeting health promotion? Br J Gen Pract 1999; 49:467-8. [PMID: 10562749 PMCID: PMC1313447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
Varying intensities of nurse-mediated health education advice were administered to subjects over a three-month period. Mean serum total cholesterol was calculated for each group at the outset and completion of the study. A multidimensional health locus of control (MHLC) scales questionnaire was self-completed by subjects at the outset. A highly significant association between internality and reduction in serum total cholesterol in the high-intensity intervention group was observed. The completion of a MHLC scale questionnaire may assist health professionals in identifying which subjects may most benefit from high-intensity health education advice when raised serum total cholesterol is prevalent.
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Jin W, Brown S, Roche JP, Hsieh C, Celver JP, Kovoor A, Chavkin C, Mackie K. Distinct domains of the CB1 cannabinoid receptor mediate desensitization and internalization. J Neurosci 1999; 19:3773-80. [PMID: 10234009 PMCID: PMC6782730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
Desensitization of cannabinoid receptor signaling by a G-protein coupled receptor kinase (GRK) was examined using the Xenopus oocyte expression system. Application of a CB1 agonist, WIN 55,212-2, evoked a concentration-dependent increase in K+ conductance (Kir3) in oocytes coexpressing rat CB1 with the G-protein-gated, inwardly rectifying K+ channels Kir3.1 and Kir3.4. Desensitization was slight during continuous agonist application in the absence of GRK and arrestin. However, coexpression of GRK3 and beta-arrestin 2 (beta-arr2) caused profound homologous CB1 receptor desensitization, supporting the hypothesis that GRK3 and beta-arr2 effectively produce CB1 receptor desensitization. To identify the regions of the CB1 receptor responsible for GRK3- and beta-arr2-mediated desensitization, we constructed several CB1 receptor mutants. Truncation of the C-terminal tail of CB1 receptor at residue 418 (Delta418) almost completely abolished desensitization but did not affect agonist activation of Kir3. In contrast, truncation at residues 439 and 460 did not significantly affect GRK3- and beta-arr2-dependent desensitization. A deletion mutant (Delta418-439) did not desensitize, indicating that residues within this region are important for GRK3- and beta-arr2-mediated desensitization. Phosphorylation in this region was likely involved in desensitization, because mutation of either of two putative phosphorylation sites (S426A or S430A) significantly attenuated desensitization. CB1 receptors rapidly internalize after activation by agonist. Phosphorylation of S426 or S430 was not necessary for internalization, because the S426A/S430A CB1 mutant internalized when stably expressed in AtT20 cells. These studies establish that CB1 desensitization can be regulated by a GRK and that different receptor domains are involved in GRK- and beta-arrestin-dependent desensitization and CB1 internalization.
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680
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Perazza D, Herzog M, Hülskamp M, Brown S, Dorne AM, Bonneville JM. Trichome cell growth in Arabidopsis thaliana can be derepressed by mutations in at least five genes. Genetics 1999; 152:461-76. [PMID: 10224275 PMCID: PMC1460599 DOI: 10.1093/genetics/152.1.461] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Leaf trichomes in Arabidopsis are unicellular epidermal hairs with a branched morphology. They undergo successive endoreduplication rounds early during cell morphogenesis. Mutations affecting trichome nuclear DNA content, such as triptychon or glabra3, alter trichome branching. We isolated new mutants with supernumerary trichome branches, which fall into three unlinked complementation groups: KAKTUS and the novel loci, POLYCHOME and RASTAFARI. They map to chromosomes IV, II, and V, respectively. The trichomes of these mutants presented an increased DNA content, although to a variable extent. The spindly-5 mutant, which displays a constitutive gibberellin response, also produces overbranched trichomes containing more nuclear DNA. We analyzed genetic interactions using double mutants and propose that two independent pathways, defined by SPINDLY and TRIPTYCHON, act to limit trichome growth. KAKTUS and POLYCHOME might have redundant actions mediating gibberellin control via SPINDLY. The overall leaf polysomaty was not notably affected by these mutations, suggesting that they affect the control of DNA synthesis in a tissue- or cell type-specific manner. Wild-type tetraploids also produce overbranched trichomes; they displayed a shifted polysomaty in trichomes and in the whole leaf, suggesting a developmental program controlling DNA increases via the counting of endoreduplication rounds.
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DeVito M, Biegel L, Brouwer A, Brown S, Brucker-Davis F, Cheek AO, Christensen R, Colborn T, Cooke P, Crissman J, Crofton K, Doerge D, Gray E, Hauser P, Hurley P, Kohn M, Lazar J, McMaster S, McClain M, McConnell E, Meier C, Miller R, Tietge J, Tyl R. Screening methods for thyroid hormone disruptors. ENVIRONMENTAL HEALTH PERSPECTIVES 1999; 107:407-15. [PMID: 10210697 PMCID: PMC1566416 DOI: 10.1289/ehp.99107407] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The U.S. Congress has passed legislation requiring the EPA to implement screening tests for identifying endocrine-disrupting chemicals. A series of workshops was sponsored by the EPA, the Chemical Manufacturers Association, and the World Wildlife Fund; one workshop focused on screens for chemicals that alter thyroid hormone function and homeostasis. Participants at this meeting identified and examined methods to detect alterations in thyroid hormone synthesis, transport, and catabolism. In addition, some methods to detect chemicals that bind to the thyroid hormone receptors acting as either agonists or antagonists were also identified. Screening methods used in mammals as well as other vertebrate classes were examined. There was a general consensus that all known chemicals which interfere with thyroid hormone function and homeostasis act by either inhibiting synthesis, altering serum transport proteins, or by increasing catabolism of thyroid hormones. There are no direct data to support the assertion that certain environmental chemicals bind and activate the thyroid hormone receptors; further research is indicated. In light of this, screening methods should reflect known mechanisms of action. Most methods examined, albeit useful for mechanistic studies, were thought to be too specific and therefore would not be applicable for broad-based screening. Determination of serum thyroid hormone concentrations following chemical exposure in rodents was thought to be a reasonable initial screen. Concurrent histologic evaluation of the thyroid would strengthen this screen. Similar methods in teleosts may be useful as screens, but would require indicators of tissue production of thyroid hormones. The use of tadpole metamorphosis as a screen may also be useful; however, this method requires validation and standardization prior to use as a broad-based screen.
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Abstract
BACKGROUND Schizophrenia has a high natural mortality of a largely environmental aetiology. There is, however, little research about possible risk factors. This study measured the diet, cigarette and alcohol use, exercise and obesity of a cohort of people with schizophrenia and compared results to general population rates. METHODS Semi-structured interview using validated research instruments on 102 middle-aged subjects with a diagnosis of schizophrenia, living in the community. Results were compared to general population norms using standard statistical tests. RESULTS The subjects ate a diet higher in fat and lower in fibre than the general population. They look little exercise but were not significantly more obese. They smoked heavily but drank less alcohol. Most differences remained significant after controlling for social class. CONCLUSIONS People with schizophrenia have an unhealthy lifestyle, which probably contributes to the excess mortality of the disease. They are therefore an appropriate target group for health promotion interventions.
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Brown S. Medical tattooing. TODAY'S SURGICAL NURSE 1999; 21:20-3. [PMID: 10808957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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684
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Brown S, Day S, Donnelly A. Indirect evidence of human skeletal muscle damage and collagen breakdown after eccentric muscle actions. J Sports Sci 1999; 17:397-402. [PMID: 10413267 DOI: 10.1080/026404199365911] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Indirect markers of muscle damage and collagen breakdown were recorded for up to 9 days after a bout of concentric, followed by a bout of eccentric, muscle actions. Nine untrained participants performed two bouts of 50 maximum effort repetitions on an isokinetic dynamometer (angular velocity 1.05 rad x s(-1), range of motion 1.75 rad). An initial concentric bout of muscle actions was followed by an eccentric bout 21 days later, using the same knee extensors. Concentric actions induced no changes in maximum voluntary isometric contraction force (MVC), nor induced any changes in the serum enzyme activities of creatine kinase, a lactate dehydrogenase isoenzyme (LDH-1), or alkaline phosphatase. Similarly, concentric actions induced no change in markers of collagen breakdown, namely plasma hydroxyproline and serum type 1 collagen concentration. In contrast, eccentric actions induced a 23.5+/-19.0% (mean+/-s) decrease in MVC immediately post-exercise (P < 0.05), and increased the serum enzyme activities of creatine kinase and LDH-1 to 486+/-792 and 90+/-11 IU.l(-1) respectively on day 3 post-exercise, and to 189+/-159 and 96+/-13 IU x l(-1) respectively on day 7 post-exercise (all P< 0.05). Eccentric actions induced no significant changes in plasma hydroxyproline, but increased collagen concentration on days 1 and 9 post-exercise (48.6% and 44.3% increases above pre-exercise on days 1 and 9 respectively; both P < 0.05). We conclude that eccentric but not concentric actions may result in temporary muscle damage, and that collagen breakdown may also be affected by eccentric actions. With caution, indices of collagen breakdown may be used to identify exercise-induced damage to connective tissue.
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Abstract
Achalasia is the best described motor disorder of the esophagus. Associations with familial glucocorticoid deficiency and alacrima (triple A syndrome) have been described in the pediatric population, but no attention has been paid to the possibility of this association in adults. Tear production was assessed in 20 patients with achalasia and 20 age- and sex-matched controls. Deficient tears were found in four achalasics compared with none among the controls (P < 0.05). This suggests that some variant of the triple A Syndrome (achalasia, alacrima, and adrenocortical insufficiency) may exist in adult patients with achalasia as well.
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Vatieri G, Gopaul D, Brown S, Hostetler P. Improving quality and resource utilization through the clinical technologist. CANADIAN JOURNAL OF MEDICAL TECHNOLOGY 1999; 57:36-42. [PMID: 10141816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
This paper reports on the significant benefits realized during the implementation of a Clinical Technologist position in two wards of a major teaching hospital. In addition to efficient and effective handling of specimens and test results, the program results in significant savings and in enhanced patient care.
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687
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Atienza F, Velasco JA, Brown S, Ridocci F, Kaski JC. Assessment of quality of life in patients with chest pain and normal coronary arteriogram (syndrome X) using a specific questionnaire. Clin Cardiol 1999; 22:283-90. [PMID: 10198738 PMCID: PMC6655793 DOI: 10.1002/clc.4960220406] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/1998] [Accepted: 10/26/1998] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Prognosis in patients with syndrome X (chest pain and normal coronary arteriograms) is good; however, persistent chest pain and functional disability are common in these patients. Accurate assessment of quality of life may be useful for patient management. AIM The quality of life status in patients with syndrome X was assessed using a specific questionnaire. This questionnaire was developed and validated for the assessment of quality of life in patients with typical chest pain despite normal coronary arteriograms. METHODS Ninety consecutive patients were invited to complete both the questionnaire (on two occasions within 2 weeks) and a standardized angina dairy. Fully completed questionnaires were received from 66 (73%) patients (mean age 58 +/- 8 years, 55 women). RESULTS Answers were scored according to a grading system where higher scores indicate worse quality of life. We observed that total scores increased with severity of angina (Canadian Class I, 38 +/- 16, II: 93 +/- 29, III-IV, 119 +/- 23; p < 0.001) and correlated with both the number and the severity of chest pain episodes (r = 0.50-0.66: p < 0.001). In patients who remained clinically stable (n = 37) during the 2-week assessment, test-retest analysis showed no score differences (87 +/- 30 vs. 81 +/- 30; p = 0.1), while total score increased in patients (n = 24) whose symptoms worsened (108 +/- 31 vs. 116 +/- 31; p < 0.02) and was reduced in those (n = 5) whose symptoms improved (55 +/- 37 vs. 39 +/- 28; p < 0.04). CONCLUSION Our study shows that quality of life is significantly impaired in patients with syndrome X and that the specific questionnaire used for assessment is a reliable and sensitive tool for the evaluation of quality of life in patients with chest pain and normal coronary arteriograms.
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Brown S, Biben C, Ooms LM, Maimone M, McGrath MJ, Gurung R, Harvey RP, Mitchell CA. The cardiac expression of striated muscle LIM protein 1 (SLIM1) is restricted to the outflow tract of the developing heart. J Mol Cell Cardiol 1999; 31:837-43. [PMID: 10329211 DOI: 10.1006/jmcc.1998.0922] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
LIM proteins perform critical roles in development and tissue differentiation. The skeletal muscle LIM protein 1 (SLIM1) comprises four and a half LIM domains. Northern blot analysis demonstrated high level expression of SLIM1 mRNA in adult human skeletal muscle with intermediate expression in adult heart and lower expression in other tissues. Western blot analysis using specific affinity-purified anti-SLIM1 antipeptide antibodies demonstrated a 32 kDa polypeptide in the aorta and atria of rabbit heart, but not in vena cava, interventricular septum or ventricular muscle. SLIM1 was also demonstrated in rabbit skeletal muscle. In situ hybridization of whole mouse embryos confirmed the cardiac expression of SLIM1 was restricted to the cardiac outflow tract from embryonic day 8.5-11. No expression was seen in atrial or ventricular muscle. SLIM1 mRNA was also demonstrated in the hindbrain, neural tube and somites. The localized expression of SLIM1 to the outflow tract of the embryonic heart implies an important role for the protein in the development of this region and possibly in congenital heart anomalies involving the separation and formation of the aortic and pulmonary trunks.
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Hamilton G, Brown S, Alonzo T, Glover M, Mersereau Y, Willson P. Building community for the long-term: an intergenerational commitment. THE GERONTOLOGIST 1999; 39:235-8. [PMID: 10224720 DOI: 10.1093/geront/39.2.235] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Intergenerational visitation programs have demonstrated advantages for the young and old, but few programs last more than a year or two. Weaving long-term intergenerational programs into the fabric of both school curricula and community cultural life was the goal of a project launched in 1988 in Phoenix, Arizona. Classrooms of children visit weekly or biweekly with nearby nursing home residents, developing friendships while pursuing educational activities. Carefully planned and widespread community support through board participation, donations, and publicity has allowed the program to continue to expand, while the budget has decreased. Materials are available which facilitate program replication.
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Munday AD, Norris FA, Caldwell KK, Brown S, Majerus PW, Mitchell CA. The inositol polyphosphate 4-phosphatase forms a complex with phosphatidylinositol 3-kinase in human platelet cytosol. Proc Natl Acad Sci U S A 1999; 96:3640-5. [PMID: 10097090 PMCID: PMC22347 DOI: 10.1073/pnas.96.7.3640] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Inositol polyphosphate 4-phosphatase (4-phosphatase) is an enzyme that catalyses the hydrolysis of the 4-position phosphate from phosphatidylinositol 3,4-bisphosphate [PtdIns(3,4)P2]. In human platelets the formation of this phosphatidylinositol, by the actions of phosphatidylinositol 3-kinase (PI 3-kinase), correlates with irreversible platelet aggregation. We have shown previously that a phosphatidylinositol 3,4,5-trisphosphate 5-phosphatase forms a complex with the p85 subunit of PI 3-kinase. In this study we investigated whether PI 3-kinase also forms a complex with the 4-phosphatase in human platelets. Immunoprecipitates of the p85 subunit of PI 3-kinase from human platelet cytosol contained 4-phosphatase enzyme activity and a 104-kDa polypeptide recognized by specific 4-phosphatase antibodies. Similarly, immunoprecipitates made using 4-phosphatase-specific antibodies contained PI 3-kinase enzyme activity and an 85-kDa polypeptide recognized by antibodies to the p85 adapter subunit of PI 3-kinase. After thrombin activation, the 4-phosphatase translocated to the actin cytoskeleton along with PI 3-kinase in an integrin- and aggregation-dependent manner. The majority of the PI 3-kinase/4-phosphatase complex (75%) remained in the cytosolic fraction. We propose that the complex formed between the two enzymes serves to localize the 4-phosphatase to sites of PtdIns(3,4)P2 production.
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691
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Mark HF, Aswad B, Bassily N, Taylor W, Brown S, Sun CL, Samy M, Zolnierz K, Wong E, Bland KI, Hsu PH. HER-2/neu gene amplification in stages I-IV breast cancer detected by fluorescent in situ hybridization. Genet Med 1999; 1:98-103. [PMID: 11336460 DOI: 10.1097/00125817-199903000-00007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE Approximately 25-30% of breast and ovarian carcinomas have amplification of the HER-2/neu oncogene. The aim of the present study was to focus on HER-2/neu gene amplification in different clinical stages of breast cancer in order to (1) determine if fluorescent in situ hybridization (FISH) can be used to detect HER-2/neu gene amplification in different clinical stages of breast cancer, (2) establish whether HER-2/neu gene amplification characterizes a subset of breast cancer in each of these stages, and (3) determine whether a trend for correlation of amplification with the clinical stage of the disease can be detected using the FISH technology. METHODS A total of 40 specimens of formalin-fixed, paraffin-embedded breast cancer tissues were analyzed cytogenetically, in a blinded fashion, for HER-2/neu gene amplification using FISH and the Vysis LSI HER-2/neu Orange and CEP 17 Green DNA dual color probe. The criterion for "high amplification" was an amplification ratio of >4.0, that for "moderate amplification" a ratio between 2.1 and 4.0, and that for "low amplification" a ratio of 1.5-2.0. RESULTS Using a cutoff point of > or =1.5, the overall frequency of HER-2/neu gene amplification among stage I tumors was 30% (3 out of 10). Of these, one-third (1 out of 3) showed low amplification, one-third (1 out of 3) were moderately amplified, and one-third (1 out of 3) were highly amplified. The overall frequency of HER-2/neu gene amplification among stage II tumors was 0% (0 out of 10). The overall frequency of HER-2/neu gene amplification among stage III tumors was 10% (1 out of 10). The sole tumor found positive was classified as moderately amplified by our criteria. The overall frequency of HER-2/neu gene amplification among stage IV tumors was 50% (5 out of 10). Four of the 5 tumors found positive were highly amplified. The overall frequency of gene amplification in the 40 cases studied was 22.5% (9 out of 40 tumors studied). CONCLUSION Although a linear correlation between HER-2/neu amplification and clinical stage cannot be established at this time, it is interesting to note that when stages I and II, and when stages III and IV are combined, respectively, the latter category has a higher amplification frequency than the former. Furthermore, stage IV has the highest frequency (5 out of 10) of HER-2/neu gene amplification than all three lower stages combined (4 out of 30). This is no doubt due to the high frequency of gene amplification observed in stage IV tumors, which, interestingly, also demonstrate high level amplification of HER-2/neu gene copy numbers. Although the biologic and clinical basis for gene amplification is not clear, given the observation that the most aggressive disease stage is associated with the highest frequency of gene amplification and the most high level amplification, further exploration of HER-2/neu as a prognostic marker of poor outcome using FISH is warranted.
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Brown S, Taylor NL. Could mitochondrial dysfunction play a role in manganese toxicity? ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 1999; 7:49-57. [PMID: 21781909 DOI: 10.1016/s1382-6689(98)00054-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/1998] [Revised: 12/02/1998] [Accepted: 12/07/1998] [Indexed: 05/31/2023]
Abstract
Individuals suffering from manganese toxicity exhibit several symptoms, including mitochondrial dysfunction, which are similar to those frequently observed in cases of Parkinson's disease. We review the literature concerning manganese toxicity and mitochondrial function, and propose a simple conceptual model of the aetiology of manganese toxicity which involves an interaction between inhibition of mitochondrial energy transduction, generation of free radicals and mutations of the mitochondrial genome. This conceptual model prompts a number of relatively simple experiments which would provide a test of the model.
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Mahmoud A, Keita B, Nadjo L, Oung O, Contant R, Brown S, de Kouchkovsky Y. Coupled electron and proton transfers: compared behaviour of oxometalates in aqueous solution or after entrapment in polymer matrices. J Electroanal Chem (Lausanne) 1999. [DOI: 10.1016/s0022-0728(98)00408-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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694
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Mark HF, Brown S, Taylor W, Bassily N, Sun CL, Samy M, Bland KI. Study of chromosome 12 copy number in breast cancer using fluorescence in situ hybridization. CANCER GENETICS AND CYTOGENETICS 1999; 108:26-31. [PMID: 9973920 DOI: 10.1016/s0165-4608(98)00104-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Trisomy 12 is the most frequent numerical chromosomal abnormality reported in chronic lymphocytic leukemia (CLL). Its significance in other cancers, however, has not been extensively investigated until recently. Less than 20 cases of polysomy for chromosome 12 have been studied thus far. The most recent data in the literature suggest that gain of chromosome 12 may be a recurrent and sometimes early event in breast carcinogenesis. To test the hypothesis that a subset of breast cancer may be characterized by chromosome 12 trisomy, we conducted a retrospective study of 40 specimens. Of these, ten were stage I, ten were stage II, ten were stage III, and ten were stage IV. Out of the total sample, 12 cases (30%) were found to be presumably trisomic, if a conservative cutoff point of greater than or equal to 15% cells with three signals is adopted. Furthermore, some, but not all, of the 12 cases were found to be likely triploid, when data from a control chromosome 17 probe were taken into account. Thus, our data support the hypothesis that a subset of breast cancer exists which is characterized by an abnormal copy of chromosome 12, in either a diploid or a triploid background.
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695
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Mark HF, Taylor W, Brown S, Samy M, Sun CL, Santoro K, Bland KI. Abnormal chromosome 8 copy number in stage I to stage IV breast cancer studied by fluorescence in situ hybridization. CANCER GENETICS AND CYTOGENETICS 1999; 108:1-5. [PMID: 9973916 DOI: 10.1016/s0165-4608(98)00112-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
To test the hypothesis that the frequency of abnormal chromosome 8 copy number increases with the severity of the disease as defined by an increase in clinical stage, we conducted a fluorescence in situ hybridization (FISH) study of a sample of 42 breast cancer specimens utilizing a protocol that was optimized by our laboratory. Cytogenetic results, obtained from blinded analyses of archival specimens, demonstrated that the higher clinical stages (i.e., stages III and IV) yield higher frequencies of abnormal chromosome 8 copy number. Specifically, 45.45% and 50% of the stage I and stage II cases, respectively, were abnormal, whereas 63.64% and 60% of the stage III and stage IV cases, respectively, were abnormal for chromosome 8 copy number. The overall frequency of abnormal chromosome 8 copy number was 54.76% (23 of 42 tumors studied). When the results of a control probe were taken into account, 34.78% (8 of 23) of the abnormal cases were trisomic, whereas the remaining cases were likely triploid. Thus, the present data not only established that chromosome 8 trisomy is a recurrent finding in breast cancer, but also confirmed a higher frequency of occurrence of abnormal chromosome 8 copy number with the higher clinical stages. Future experiments utilizing additional specimens in this laboratory and from other laboratories are necessary to confirm and extend the findings of the present study.
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696
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Stables J, Scott S, Brown S, Roelant C, Burns D, Lee MG, Rees S. Development of a dual glow-signal firefly and Renilla luciferase assay reagent for the analysis of G-protein coupled receptor signalling. J Recept Signal Transduct Res 1999; 19:395-410. [PMID: 10071773 DOI: 10.3109/10799899909036660] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Several reporter gene assays have been described where gene transcription is activated as a consequence of a specific signal transduction event, such as activation of adenylyl cyclase (1.2). Reporter genes typically consist of specific responsive elements placed upstream of a minimal promoter, which together control the expression of a readily detectable reporter protein, such as luciferase. We have developed a dual glow-signal firefly and Renilla luciferase assay, which allows the simultaneous measurement of two reporter genes in the same well of a 96-well plate. In this report we demonstrate the use of this assay for the simultaneous analysis of agonist activity at two G-protein coupled receptors which signal through activation of the G-protein alpha sub-unit, G alpha S. Chinese hamster ovary (CHO) cells stably transfected with a cAMP responsive firefly luciferase reporter were further transfected with the human Vasopressin V2 receptor. Similarly, CHO cells stably transfected with a cAMP responsive Renilla luciferase reporter were further transfected with the human beta 2-adrenoceptor. The two cell lines were mixed in individual wells of a 96-well plate and a number of compounds were screened to determine their activity at both receptors. Stimulation with vasopressin and beta 2-adrenoceptor agonists resulted in the activation of the firefly and Renilla luciferases respectively. Stimulation with forskolin, which directly stimulates adenylyl cyclase, caused the activation of both reporter genes, and stimulation with a range of further compounds with no activity at either receptor did not generate a reporter response. The dual luciferase assay allows the simultaneous screening of two receptors in a 96-well format resulting in significant time and cost savings.
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697
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Child R, Brown S, Day S, Donnelly A, Roper H, Saxton J. Changes in indices of antioxidant status, lipid peroxidation and inflammation in human skeletal muscle after eccentric muscle actions. Clin Sci (Lond) 1999; 96:105-15. [PMID: 9857113] [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
This study investigated the effects of chronic muscle inflammation on indices of antioxidant status and muscle injury after eccentric exercise. Eight subjects each performed 70 maximal voluntary eccentric muscle actions on an isokinetic dynamometer, using the knee extensors of a single leg. Venous blood samples were collected into serum and EDTA tubes 5 and 3 days before exercise, immediately before exercise, and then again on days 3, 4, 5, 6, 7, 10 and 12 after the bout. Needle biopsies were taken from the vastus lateralis of six subjects, a week before exercise (baseline), and again on days 4 and 7 post-exercise. The concentrations of malondialdehyde in plasma and muscle were used as markers of lipid peroxidation. Creatine kinase activity, beta-glucuronidase activity and total antioxidant capacity were determined in serum. In muscle, aqueous and bound total antioxidant capacity, the aqueous sulphydryl concentration, and beta-glucuronidase and glucose-6-phosphate dehydrogenase activity were determined. No changes were detected in serum total antioxidant capacity, serum creatine kinase and beta-glucuronidase after the baseline biopsy. After exercise serum creatine kinase and beta-glucuronidase were elevated although other serum measures were unchanged. In muscle, aqueous and bound total antioxidant capacity, sulphydryls, glucose-6-phosphate dehydrogenase and beta-glucuronidase were all elevated. Despite evidence of inflammation in this study, muscle antioxidant status was not compromised, and malondialdehyde was unaltered in muscle and plasma. Therefore, this study provides no evidence that chronic muscle inflammation compromises antioxidant status or increases lipid peroxidation.
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698
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Moghissi K, Dixon K, Stringer M, Freeman T, Thorpe A, Brown S. The place of bronchoscopic photodynamic therapy in advanced unresectable lung cancer: experience of 100 cases. Eur J Cardiothorac Surg 1999; 15:1-6. [PMID: 10077365 DOI: 10.1016/s1010-7940(98)00295-4] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVES The objectives of the study were: (1) to evaluate effectiveness of photodynamic therapy (PDT) for symptom palliation in patients with inoperable lung cancer; (2) to determine survival benefit in a subset of patients. METHODS One hundred patients, 68 male, 32 female, aged 44-81 years (mean 62.5) with advanced inoperable bronchogenic cancer and endobronchial luminal obstruction were prospectively studied. Eighty-two percent had previous chemo/radiotherapy. The pre-treatment protocol consisted of: clinical, radiological and bronchoscopic examination, pulmonary function testing, assessment of WHO performance status and clinical staging. Treatment protocol was: intravenous injection of 2 mg/kg body weight of photofrin/polyhaematoporphyrin and interstitial illumination using 630 nm laser light 24-72 h later. Follow-up was at 6-8 weeks for 1 year. Then every 3-6 months if applicable. Repeat PDT as necessary. RESULTS All patients were stage IIIa-IV. The histology of the tumour was: non small cell in 90 and small cell in 10. There was no treatment related mortality. Mean endoluminal obstruction fell from 85.8% to 17.5%, mean forced vital capacity (FVC) and forced expiratory volume in 1s (FEVI) improvement was 430 ml and 280 ml, respectively. Ninety patients died from 6 weeks to 37 months, mean and median survival: 9 months and 5 months, respectively. Ten patients are alive from 13 to 72 months, mean 36 months, median 29 months. Overall 2-year survival was 19%. Multivariant analysis indicated that age, sex, histology and stage of disease did not influence survival significantly but performance status did. Patients with WHO < 2 had mean and median survival of 17.8 and 14 months versus WHO > 2, 6.9 mean and 4 months median survival (log-rank P < 0.0001). CONCLUSIONS (1) PDT is effective in palliation of inoperable advanced lung cancer. (2) Subset of patients with a better performance status have added survival benefit.
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699
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Mark H, Aswad B, Taylor W, Samy M, Sun CL, Brown S, Das S, Berg J, Bland K. A retrospective FISH study of HER-2/neu oncogene amplification in relapsed and non-relapsed node-negative breast cancer. Genet Med 1999. [DOI: 10.1097/00125817-199901000-00028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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700
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Brown S, Rouse G, Hutchings P, Colgan D. Assessing the usefulness of histone H3, U2 snRNA and 28S rDNA in analyses of polychaete relationships. AUST J ZOOL 1999. [DOI: 10.1071/zo99026] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
DNA sequence data from for histone H3 (34 species), U2 snRNA (34 species) and
two segments (D1 and D9–10 expansion regions) of 28S rDNA (28 and 26
species, respectively) have been collected to investigate the relationships of
polychaetes. Representatives of all of the major morphologically identified
clades were used, as well as members of the Sipuncula, Echiura, Turbellaria,
Clitellata and Siboglinidae (formerly the phyla Pogonophora and
Vestimentifera).
Maximum parsimony analyses of the separate data sets gave conflicting results
and none conformed closely to previous results based on morphology. Instead
each data set provided corroboration of a few of the morphological groupings,
usually pairing, though inconsistently, members of the same family. Higher
groupings proposed on morphological grounds were rarely recovered.
Maximum parsimony analysis of the combined data, excluding areas of uncertain
alignment, recovered some morphological groupings such as Cirratulidae,
Terebellidae, scale worms and eunicimorphs, and did not significantly
contradict others. However, some expected groupings were not recovered.
Surprisingly, the fanworms (Sabellidae and Serpulidae) were not shown as
sister taxa, and monophyly of Phyllodocida, a morphologically well
corroborated clade, required four more steps than most parsimonious trees.
Aciculata was not seen in our analyses, although it was the most strongly
supported large clade in Rouse and Fauchald (1997, Cladistics and polychaetes.
Zoologica Scripta 26,
138–204). Trees constrained to show Aciculata as monophyletic were 18
steps longer than the most parsimonious trees. If trees are rooted on
sipunculans rather than the nematode, Aciculata is nearly recovered, being
rendered paraphyletic by the inclusion of the sister-pair of Oweniidae and
Chaetopteridae.
As suggested by some recent morphological and molecular analyses, Siboglinidae
and Clitellata may well have sister groups among polychaetes. The
morphologically aberrant Sternaspidae are closest to members of Terebellida in
the present analyses, supporting the placement of Rouse and Fauchald.
Interesting results deserving further assessment concern the placement of
Chaetopteridae, Oweniidae and Sipuncula.
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