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Ihnat MA, Nervi AM, Anthony SP, Kaltreider RC, Warren AJ, Pesce CA, Davis SA, Lariviere JP, Hamilton JW. Effects of mitomycin C and carboplatin pretreatment on multidrug resistance-associated P-glycoprotein expression and on subsequent suppression of tumor growth by doxorubicin and paclitaxel in human metastatic breast cancer xenografted nude mice. Oncol Res 2000; 11:303-10. [PMID: 10757444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
Overexpression of P-glycoprotein (Pgp), multidrug resistance-associated protein (MRP), and several other proteins has been associated with development of multidrug resistance by cancer cells, which represents a significant obstacle to successful treatment by chemotherapy. We had previously demonstrated that a single noncytotoxic dose of mitomycin C (MMC), carboplatin, or one of several other DNA cross-linking agents suppressed mRNA expression of the mdr1 gene coding for Pgp, leading to a subsequent suppression of Pgp protein levels and a concomitant decrease in drug efflux. Pretreatment with MMC led to a 5- to 10-fold decrease in the ED50 for cell killing by a subsequent agent such as the Pgp substrate, doxorubicin, but did not affect killing by the non-Pgp substrate, cisplatin. In this study, we report that MMC and carboplatin each significantly suppressed Pgp protein levels in human MDA-MB-435 cells xenografted as solid tumors into the lateral mammary fat pads of female nude mice, with a similar time course as had previously been observed in cell culture. Pretreatment of mice with MMC or carboplatin 48-72 h prior to receiving either doxorubicin or paclitaxel caused a significantly greater reduction in tumor growth rate compared to either agent alone or the combination given simultaneously. These data suggest that a combination chemotherapy regimen consisting of a DNA cross-linking agent given to modulate the MDR phenotype, followed by a second cytotoxic agent, may be an effective treatment for human patients with de novo or late stage acquired multidrug-resistant malignancies.
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402
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Topol EJ, Easton JD, Amarenco P, Califf R, Harrington R, Graffagnino C, Davis S, Diener HC, Ferguson J, Fitzgerald D, Shuaib A, Koudstaal PJ, Theroux P, Van de Werf F, Willerson JT, Chan R, Samuels R, Ilson B, Granett J. Design of the blockade of the glycoprotein IIb/IIIa receptor to avoid vascular occlusion (BRAVO) trial. Am Heart J 2000; 139:927-33. [PMID: 10827369 DOI: 10.1067/mhj.2000.105107] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Platelets play a key role in the pathogenesis of atherosclerosis, thrombosis, and acute coronary and cerebrovascular syndromes. Inhibition of platelet function by acetylsalicylic acid (aspirin) has been shown to reduce the incidence atherothrombotic events in patients with coronary, cerebrovascular, or peripheral vascular disease. Thienopyridine agents, however, including ticlopidine and clopidogrel, inhibit the adenosine diphosphate receptor and have modestly superior effects compared with aspirin on reduction of death, myocardial infarction, and stroke among a broad group of patients with vascular disease. More effective antithrombotic agents are still required to treat patients at high risk for recurrent vascular events. METHODS Lotrafiban, a selective, nonpeptide antagonist of the human platelet fibrinogen receptor (glycoprotein [GP] IIb/IIIa [alphaIIb/beta3 integrin]), blocks the binding of fibrinogen to the GP IIb/IIIa receptor, which is the final common pathway of platelet aggregation. Lotrafiban at doses of up to 50 mg twice daily was well-tolerated in a 12-week, double-blind, placebo-controlled, dose-ranging study in patients with recent myocardial infarction, unstable angina, transient ischemic attack, or stroke when added to aspirin therapy. On the basis of these results, a dosing regimen was selected for the phase III Blockage of the Glycoprotein IIb/IIIa Receptor to Avoid Vascular Occlusion (BRAVO) trial based on pharmacodynamics and drug tolerability. In the pivotal BRAVO study, lotrafiban therapy is being evaluated in patients who have had a recent myocardial infarction, unstable angina, transient ischemic attack, or ischemic stroke, or who present at any time after a diagnosis of peripheral vascular disease combined with either cardiovascular or cerebrovascular disease. RESULTS The efficacy evaluation will be based on a composite end point of clinical events (death by any cause, myocardial infarction, stroke, recurrent ischemia requiring hospitalization, or urgent ischemia-driven revascularization). The target enrollment is 9200 patients worldwide. Approximately 700 centers will participate and will be distributed within 30 countries across North America, Europe, Australia, and Asia.
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403
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Kumar M, Khan AM, Davis S. Medial displacement of grommets: an unwanted sequel of grommet insertion. J Laryngol Otol 2000; 114:448-9. [PMID: 10962678 DOI: 10.1258/0022215001906039] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Grommet insertion is one of the commonest surgical procedures performed in the UK. We have come across three cases in which grommets have displaced medially in the middle ear after establishing a satisfactory post-insertion position. We suggest that an abnormally long myringotomy incision and improper placement of the grommet are responsible for this unwanted outcome.
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404
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Davis S, Meyer C. What will replace the tech economy? TIME 2000; 155:76-7. [PMID: 11765521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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405
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Yorty JS, Richards MW, Kanawati A, Davis S, House RC, Okubo SR. A simple screening test for color matching in dentistry. GENERAL DENTISTRY 2000; 48:272-6. [PMID: 11199592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
This study compared a simple and readily available shade guide color-matching test with the general industry standard test for color discrimination. This study indicates that a simple screening test for color defective vision and color discrimination skills in dentistry can be performed by matching two Vita-Lumin shade guides. Those dental office personnel who score a low number of matches in the Vita test (that is, seven or fewer correct matches) should have additional color discrimination testing and refer shade matching to other personnel with higher scores.
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406
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Costa F, Heusinkveld J, Ballog R, Davis S, Biaggioni I. Estimation of skeletal muscle interstitial adenosine during forearm dynamic exercise in humans. Hypertension 2000; 35:1124-8. [PMID: 10818075 DOI: 10.1161/01.hyp.35.5.1124] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
It has been proposed that adenosine is a metabolic signal that triggers activation of muscle afferents involved in the exercise pressor reflex. Furthermore, exogenous adenosine induces sympathetic activation that mimics the exercise pressor reflex, and blockade of adenosine receptors inhibits sympathetic activation induced by exercise. Thus, we hypothesize that adenosine is released locally by the muscle during exercise. We used microdialysis probes, placed in the flexor digitorium superficialis muscle, to estimate muscle interstitial adenosine levels in humans. We estimated resting in vivo muscle interstitial adenosine concentrations (0.292+/-0.058 micromol/L, n=4) by perfusing increasing concentrations of adenosine to determine the gradient produced in the dialysate. Muscle interstitial adenosine concentrations increased from 0.23+/-0.04 to 0.82+/-0.14 micromol/L (n=14, P<0.001) during intermittent dynamic exercise at 50% of maximal voluntary contraction. Lactate increased from 0.8+/-0.1 to 2.3+/-0.3 mmol/L (P<0.001). Lower intensity (15% maximal voluntary contraction) intermittent dynamic exercise increased adenosine concentrations from 0.104+/-0.02 to 0.42+/-0.16 micromol/L (n=7). The addition of ischemia to this low level of exercise produced a greater increase in adenosine (from 0.095+/-0.02 to 0.48+/-0.2 micromol/L) compared with nonischemic exercise (0. 095+/-0.02 to 0.25+/-0.12 micromol/L). These results indicate that microdialysis is useful in estimating adenosine concentrations and in reflecting changes in muscle interstitial adenosine during dynamic exercise in humans.
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407
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Jiang W, Gupta D, Gallagher D, Davis S, Bhavanandan VP. The central domain of bovine submaxillary mucin consists of over 50 tandem repeats of 329 amino acids. Chromosomal localization of the BSM1 gene and relations to ovine and porcine counterparts. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:2208-17. [PMID: 10759843 DOI: 10.1046/j.1432-1327.2000.01225.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We previously elucidated five distinct protein domains (I-V) for bovine submaxillary mucin, which is encoded by two genes, BSM1 and BSM2. Using Southern blot analysis, genomic cloning and sequencing of the BSM1 gene, we now show that the central domain (V) consists of approximately 55 tandem repeats of 329 amino acids and that domains III-V are encoded by a 58.4-kb exon, the largest exon known for all genes to date. The BSM1 gene was mapped by fluorescence in situ hybridization to the proximal half of chromosome 5 at bands q2. 2-q2.3. The amino-acid sequence of six tandem repeats (two full and four partial) were found to have only 92-94% identities. We propose that the variability in the amino-acid sequences of the mucin tandem repeat is important for generating the combinatorial library of saccharides that are necessary for the protective function of mucins. The deduced peptide sequences of the central domain match those determined from the purified bovine submaxillary mucin and also show 68-94% identity to published peptide sequences of ovine submaxillary mucin. This indicates that the core protein of ovine submaxillary mucin is closely related to that of bovine submaxillary mucin and contains similar tandem repeats in the central domain. In contrast, the central domain of porcine submaxillary mucin is reported to consist of 81-amino-acid tandem repeats. However, both bovine submaxillary mucin and porcine submaxillary mucin contain similar N-terminal and C-terminal domains and the corresponding genes are in the conserved linkage regions of the respective genomes.
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408
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Wolfe J, Kreitzer S, Chervinsky P, Lawrence M, Wang Y, Reilly D, Davis S, Stahl E. Comparison of powder and aerosol formulations of salmeterol in the treatment of asthma. Ann Allergy Asthma Immunol 2000; 84:334-40. [PMID: 10752919 DOI: 10.1016/s1081-1206(10)62783-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND The efficacy and safety of the aerosol metered-dose inhaler (MDI) formulation of salmeterol for asthma symptoms have been established. Recently, salmeterol has been introduced as a micronized powder formulation administered via a breath-activated multidose powder inhaler (Diskus). OBJECTIVE A multicenter, randomized, double-blind, double-dummy, parallel-group, placebo-controlled study involving 498 adolescents and adults with mild-to-moderate asthma was conducted to compare the efficacy and safety of salmeterol powder 50 microg twice daily via Diskus, salmeterol aerosol 42 microg twice daily via MDI, and placebo. METHODS Patients were randomized to one of the three treatment groups for 12 weeks. Efficacy was assessed by serial measurements of forced expiratory volume in one second (FEV1) over 12 hours, daily peak expiratory flow (PEF), self-rated asthma symptom scores, nighttime awakenings, and supplemental albuterol use. Safety of each treatment was evaluated by monitoring vital signs, electrocardiograms, Holter monitoring, and occurrence of adverse events. RESULTS As compared with placebo, both salmeterol powder and aerosol produced significant improvement in FEV1 and PEF and decreased nighttime awakenings and supplemental albuterol use. There were no significant differences in the efficacy of the two salmeterol formulations. The magnitude of improvement in pulmonary function was undiminished over the 12-week study. Both formulations of salmeterol were well tolerated, with safety profiles not significantly different from placebo. CONCLUSION Results of this study indicate that salmeterol, administered either as a powder 50 microg twice daily via Diskus or as an aerosol 42 microg twice daily via MDI, produces clinically significant and comparable improvement in pulmonary function and is well tolerated in patients with mild-to-moderate persistent asthma.
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409
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Funk JA, Troutt HF, Davis SA, Fossler CP. In vitro susceptibility of Yersinia enterocolitica isolated from the oral cavity of swine. J Food Prot 2000; 63:395-9. [PMID: 10716571 DOI: 10.4315/0362-028x-63.3.395] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Antimicrobial susceptibility of 181 (107 ail-harboring isolates and 74 non-ail-harboring) Yersinia enterocolitica isolates obtained from the oral cavity of swine was determined against 24 antimicrobial agents. All Y. enterocolitica isolates were susceptible to sulfamethoxazole/trimethoprim, enrofloxacin, aminoglycosides, and nitrofurantoin. Susceptibility to tetracycline appeared to vary by lot of origin. Isolates were resistant to sulfonamides (other than sulfamethoxazole/trimethoprim), penicillin, ampicillin, ticarcillin, cephalothin, macrolides, and tiamulin.
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410
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Jones M, Castile R, Davis S, Kisling J, Filbrun D, Flucke R, Goldstein A, Emsley C, Ambrosius W, Tepper RS. Forced expiratory flows and volumes in infants. Normative data and lung growth. Am J Respir Crit Care Med 2000; 161:353-9. [PMID: 10673171 DOI: 10.1164/ajrccm.161.2.9903026] [Citation(s) in RCA: 208] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Forced expiratory flows (FEF) can be measured in infants from lung volumes initiated near total lung capacity. In order to establish reference values and to evaluate lung growth, we obtained measurements in 155 healthy subjects between 3 and 149 wk of age. Forced vital capacity (FVC) was highly correlated with body length; however, after accounting for length, age was also significant. When subjects were divided at the median age (40 wk) younger compared with older subjects had a significantly larger slope for length (3.7 versus 2.8; p = 0.002). The flow parameters (FEF(50), FEF(75), FEF(85), and FEF(25-75)) were highly correlated with length, and those infants whose mothers smoked had lower flows. For FEF(75), male subjects had lower flows than female subjects. The relationship between FEF and volume was assessed using FEV(0.5)/FVC, which decreased with increasing length. Smaller subjects emptied their lung volume proportionately faster. We conclude that our study provides reference values for this age group and demonstrates that smoke-exposed infants and male subjects have decreased FEF. In addition, our findings indicate that lung volume increases most rapidly during the first year of life and that airways are large relative to lung volume very early in life.
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411
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Pecelunas K, Danforth HD, Schildknecht EG, Davis S. Efficacy evaluation of lasalocid plus roxarsone combination medication with different geographic field strains of Eimeria acervulina. Avian Dis 2000; 44:1-7. [PMID: 10737638] [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
Performance of broiler chickens medicated with lasalocid alone (at 125 ppm) or in combination with roxarsone (at 50 ppm) was evaluated in battery and floorpen trials after challenge with geographically different field strains of coccidia containing predominately the upper intestinal species Eimeria acervulina. No significant difference in bird performance measured at 6 days postinfection (PI) was observed between lasalocid plus roxarsone-medicated (L+RM) or lasalocid-medicated (LM) birds challenged in separate battery trials with mixed-species inocula from Alabama or Georgia containing 92% or 88% E. acervulina, respectively. In contrast, L+RM birds challenged in another battery trial with a Louisiana mixed-species inoculum containing 92% E. acervulina showed significant reduction in average weight gain at 6 days PI compared with LM-challenged birds. A floorpen trial done with the same Louisiana inoculum showed significant reduction in average bird weight gain at 27 and 35 days of age (6 and 14 days PI) for L+RM-challenged birds compared with both unmedicated-nonchallenged (UMNC) control and LM-challenged birds. The LM+R groups were significantly lower in average bird weight at 27 days of age than the unmedicated-challenged controls. Feed conversions (FCs) for L+RM birds were significantly higher than those for the UMNC control birds during time of challenge (21-27 days of age) and for the 1-to-27-day-of-age time period. No significant difference in FC was seen between the UMNC and LM groups. Results of this study showed that performance of broiler birds medicated with lasalocid plus roxarsone could vary for geographically different mixed-species challenge inocula that contained predominately E. acervulina.
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412
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Davis S, Kenyon T. A day with Dr. Malaprop (or) on burning your bridges at both ends. MEDICINE AND HEALTH, RHODE ISLAND 2000; 83:11-2. [PMID: 10695305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
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413
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Kahler RJ, Knuckey NW, Davis S. Arachnoiditis ossificans and syringomyelia: a unique case report. J Clin Neurosci 2000; 7:66-8. [PMID: 10847657 DOI: 10.1054/jocn.1998.0144] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A 62-year-old male presented with progressive quadriparesis. Magnetic resonance imaging of the spine revealed a spinal cord syrinx but failed to detect extensive arachnoiditis ossificans noted on insertion of a syringopleural shunt. A postoperative computed tomography scan clearly demonstrated the abnormality and its extent. We present a rare case of syringomyelia resulting from spinal arachnoiditis ossificans and review the relevant literature.
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414
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Cook MR, Graham C, Kavet R, Stevens RG, Davis S, Kheifets L. Morning urinary assessment of nocturnal melatonin secretion in older women. J Pineal Res 2000; 28:41-7. [PMID: 10626600 DOI: 10.1034/j.1600-079x.2000.280106.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We evaluated the feasibility of using morning urine samples in epidemiological studies aimed at clarifying the relationship between nocturnal melatonin levels and breast cancer risk. Initially, a laboratory-based study of 29 women (40- 70 yr old) was performed to examine the correlation between plasma melatonin levels in hourly nocturnal blood samples and both melatonin and its major enzymatic metabolite, 6-hydroxymelatonin-sulfate (6-OHMS) in morning urine samples. In a companion field study, morning urine samples were collected from 203 healthy women to assess similarities and differences in laboratory versus field measures. Taken together, our results indicate: 1) levels of melatonin and of creatinine-corrected 6-OHMS in the first morning void urine are strongly correlated with total nocturnal plasma melatonin output (P < 0.001) and also with peak nocturnal melatonin values (P < 0.001); 2) similar ranges for 6-OHMS were found in the laboratory and the field; and 3) neither menopausal status nor hormonal replacement therapy altered 6-OHMS values in morning void urine. The inclusion of morning urine samples in epidemiological studies of cancer could allow cost-effective, widespread testing of the role played by melatonin in human health and disease.
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415
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Sherman JM, Davis S, Albamonte-Petrick S, Chatburn RL, Fitton C, Green C, Johnston J, Lyrene RK, Myer C, Othersen HB, Wood R, Zach M, Zander J, Zinman R. Care of the child with a chronic tracheostomy. This official statement of the American Thoracic Society was adopted by the ATS Board of Directors, July 1999. Am J Respir Crit Care Med 2000; 161:297-308. [PMID: 10619835 DOI: 10.1164/ajrccm.161.1.ats1-00] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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416
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Davis S, Tress B, Barber PA, Darby D, Parsons M, Gerraty R, Yang Q, Donnan G, Desmond P. Echoplanar magnetic resonance imaging in acute stroke. J Clin Neurosci 2000; 7:3-8. [PMID: 10847641 DOI: 10.1054/jocn.1999.0142] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Echoplanar magnetic resonance imaging (EPI) enables rapid, non-invasive imaging and analysis of cerebral pathophysiology in acute stroke. It represents an important clinical advance over computed tomography (CT) and conventional magnetic resonance (MR) scanning. It can rapidly delineate infarcted cerebral tissue and distinguish acute from chronic stroke. In addition, EPI has the potential to quickly determine the presence and degree of potentially viable brain tissue in the ischaemic penumbra. Thrombolysis is thought to reperfuse the penumbra and hence reduce infarct size. The thrombolytic agent tissue plasminogen activator (t-PA) improves outcome in ischaemic stroke when administered within the first 3 hours of onset. However, there is a significant risk of haemorrhage, and the time window for benefit may well exceed 3 hours in some patients. Hence, by facilitating diagnosis of 'at-risk' tissue in the ischaemic penumbra, a major clinical role of EPI may well become the rational selection of patients for acute interventional stroke therapy.
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417
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Pecelunas K, Danforth HD, Schildknecht EG, Davis S. Efficacy Evaluation of Lasalocid Plus Roxarsone Combination Medication with Different Geographic Field Strains of Eimeria acervulina. Avian Dis 2000. [DOI: 10.2307/1592501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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418
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Mazolewski PJ, Barber A, Williams S, Simoni J, Davis S, Shires GT. Attenuating tumor necrosis factor alpha does not ameliorate other cytokine and peroxidase products during sepsis. Am J Surg 1999; 178:556-9. [PMID: 10670871 DOI: 10.1016/s0002-9610(99)00216-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Recent trials utilizing single anticytokine agents have shown no consistent survival benefit in improving the outcome of sepsis. Since an entire cascade of mediators contributes to the underlying pathophysiology, it is not surprising that monotherapy has proven unsuccessful. The purpose of this study was to measure the effects of attenuating tumor necrosis factor (TNF)alpha early in sepsis. METHODS Three groups of Sprague-Dawley rats were studied. All animals were infused with live Escherichia coli, with group I and group II rats additionally receiving a matrix metalloproteinase inhibitor. Serum levels of TNFalpha, interleukin (IL)-6, malondialdehyde (MDA), and lipid hydroperoxide (LOOH) were compared. RESULTS TNFalpha showed a significant decrease, yet IL-6, MDA, and LOOH (markers of sepsis) levels remained abnormally elevated. CONCLUSION Despite significantly attenuating TNFalpha, the septic response continued. This supports the concept that in sepsis, monotherapy directed at attenuating a single cytokine cannot overcome the tissue-damaging effects of an entire cascade of mediators.
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419
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Gittelsohn J, McCormick LK, Allen P, Grieser M, Crawford M, Davis S. Inter-ethnic differences in youth tobacco language and cigarette brand preferences. ETHNICITY & HEALTH 1999; 4:285-303. [PMID: 10705565 DOI: 10.1080/13557859998065] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
OBJECTIVE To describe and understand variations in cigarette brand preferences between adolescents from varying ethnic and gender groups around the US. DESIGN A qualitative study where adolescents, both smokers and nonsmokers, were interviewed individually in depth. SETTING Schools and recreation centers in four sites: urban Maryland (Baltimore), urban Texas (Houston), rural Alabama and rural New Mexico. PARTICIPANTS 121 adolescent volunteers 13-19 years of age, representing African American, white, American Indian and Hispanic ethnic groups, from both genders. RESULTS Considerable geographic and ethnic variation exists in terminology used by youth to refer to cigarettes and to their use. Clear patterns in brand preference by ethnic group were found that follow patterns of targeted marketing by ethnicity. White teens preferred Marlboro brand cigarettes, while African-American teens who smoke preferred Newports. Hispanic and American Indian teens were more likely to smoke Marlboro or Camel cigarettes. Hispanic teens were most likely to mention low price as a reason for choosing a particular brand or to state that the brand does not matter. Tobacco advertisements targeting ethnic groups and the use of promotional items to encourage teen smoking were also recognized as factors influencing brand preferences. CONCLUSIONS These findings have implications for the design of intervention programs aimed at curbing teen smoking. When working with teens who already smoke, using youth language to target messages at perceived characteristics of commonly used brands may be more effective and meaningful than talking about cigarette use in general. Another implication of this work is to shed light on what impact an advertising ban would have on teen brand preferences, brand loyalty, and prevalence of smoking.
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420
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Davis S, Jones M, Kisling J, Castile R, Tepper RS. Density dependence of forced expiratory flows in healthy infants and toddlers. J Appl Physiol (1985) 1999; 87:1796-801. [PMID: 10562624 DOI: 10.1152/jappl.1999.87.5.1796] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In older children and adults, density dependence (DD) of forced expiratory flow is present over the majority of the full flow-volume curve. In healthy subjects, DD occurs because the pressure drop from peripheral to central airways is primarily dependent on turbulence and convective acceleration rather than laminar resistance; however, an increase in peripheral resistance reduces DD. We measured DD of forced expiratory flow in 22 healthy infants to evaluate whether infants have low DD. Full forced expiratory maneuvers were obtained while the subjects breathed room air and then a mixture of 80% helium-20% oxygen. Flows at 50 and 75% of expired forced vital capacity (FVC) were measured, and the ratio of helium-oxygen to air flow was calculated (DD at 50 and 75% FVC). The mean (range) of DD at 50 and 75% FVC was 1.37 (1.22-1.54) and 1.23 (1.02-1.65), respectively, values similar to those reported in older children and adults. There were no significant relationships between DD and age. Our results suggest that infants, compared with older children and adults, have similar DD, a finding that suggests that infants do not have a greater ratio of peripheral-to-central airway resistance.
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421
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Tepper RS, Jones M, Davis S, Kisling J, Castile R. Rate constant for forced expiration decreases with lung growth during infancy. Am J Respir Crit Care Med 1999; 160:835-8. [PMID: 10471605 DOI: 10.1164/ajrccm.160.3.9811025] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Airway caliber and lung volume (VL) increase many fold between infancy and adulthood; however, these two components of the lung may not increase proportionately during lung growth and development. We evaluated in infants the rate of emptying during forced expiration from near total lung capacity to residual volume. From the flow-volume curves we calculated (1) a rate constant (k) as the change in flow divided by the change in volume between 50% and 75% of expired forced vital capacity (FVC), and (2) the fraction of the FVC expired in 0.5 s (FEV(0.5)/FVC). Seventeen normal healthy infants were evaluated twice; mean ages (ranges) at first and second tests were 30 (5 to 76) and 58 (28 to 98) wk. Analysis of cross-sectional and longitudinal data indicated that the rate of emptying during forced expiration measured by both parameters was greatest in the youngest infants and decreased during infancy. Our findings are consistent with the concept that younger infants have large airways relative to their VL and that VL increases more rapidly than airway caliber early in life.
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422
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Savage EB, Clark RE, Griffin WP, Davis SA, Hughson S, Conway CJ, Magovern GJ. The AB-180 circulatory support system: summary of development and plans for phase I clinical trial. Ann Thorac Surg 1999; 68:768-74. [PMID: 10475486 DOI: 10.1016/s0003-4975(99)00579-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND The AB-180 circulatory support system is a small, durable, efficient centrifugal pump with low thrombogenic potential. The device was designed to provide a fully implantable, left ventricular assist system for short-term support to address the issues of systemic anticoagulation, thrombus formation, infection, and cost. METHODS Extensive bench and animal studies were performed to validate the mechanical integrity of the device and its functionality as an implant. RESULTS These studies demonstrated anticoagulation requirements, established operating guidelines, incorporated safety systems, and demonstrated safety and efficacy. CONCLUSIONS The AB-180 fulfills the stated goals on initial evaluation. A phase I human trial is underway.
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Ball D, Bishop J, Smith J, O'Brien P, Davis S, Ryan G, Olver I, Toner G, Walker Q, Joseph D. A randomised phase III study of accelerated or standard fraction radiotherapy with or without concurrent carboplatin in inoperable non-small cell lung cancer: final report of an Australian multi-centre trial. Radiother Oncol 1999; 52:129-36. [PMID: 10577698 DOI: 10.1016/s0167-8140(99)00093-6] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE To investigate the effects separately and together of (a) shortening overall treatment time and (b) giving concurrent carboplatin in patients having radical radiotherapy for inoperable non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Between April 1989 and May 1995, 204 patients with medically inoperable or technically unresectable NSCLC localised to the primary site and regional lymph nodes were randomised to receive one of four treatments using a 2 x 2 factorial design: standard radiotherapy, 60 Gy in 30 fractions in 6 weeks (R6); accelerated radiotherapy, 60 Gy in 30 fractions in 3 weeks (R3); standard radiotherapy as in R6 with carboplatin 70 mg/m2/day for 5 days during weeks 1 and 5 of radiotherapy (R6C); accelerated radiotherapy as in R3 with carboplatin 70 mg/m2/day for 5 days during week 1 of radiotherapy (R3C). RESULTS The estimated median survival of all randomised patients was 15.7 months and estimated 2-year survival was 31%. The longest survival was seen in patients randomised to R6C (median 20.3 months, 41% surviving at 2 years) but there were no statistically significant differences between treatment arms or treatment factors (carboplatin versus no carboplatin, accelerated versus conventional radiotherapy). Haematological toxicity was significantly greater in patients treated with carboplatin and oesophageal toxicity was significantly greater and more protracted in patients treated with accelerated radiotherapy. CONCLUSIONS This study failed to show a significant survival advantage for any of the treatment arms or factors. Halving overall treatment time resulted in significantly greater oesophageal toxicity with no suggestion of a survival advantage.
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Young JR, Davis SA, Bown PR, Mann S. Coccolith ultrastructure and biomineralisation. J Struct Biol 1999; 126:195-215. [PMID: 10441529 DOI: 10.1006/jsbi.1999.4132] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The relationship between calcite biomineralisation and coccolith ultrastructure is analysed across the diversity of calcifying haptophytes. The emphasis is on integration of evidence from crystallographic and ultrastructural studies but additional relevant information from biochemical and phylogenetic work is reviewed. We attempt to identify aspects of ultrastructure which are most likely to be the product of self-organising processes. The principal topics reviewed are heterococcolith rim nucleation, including reassessment of the V/R model; crystal growth regulation in heterococcoliths; holococcolith biomineralisation; and the diversity of other biomineralisation modes in haptophytes. It is concluded that the diverse range of calcareous structures produced by haptophytes probably has a common phylogenetic origin and is produced via operation of a limited set of mainly shared genetic and biochemical pathways. Copyright 1999 Academic Press.
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425
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Walker PM, Romaschin AD, Davis S, Piovesan J. Lower limb ischemia: phase 1 results of salvage perfusion. J Surg Res 1999; 84:193-8. [PMID: 10357919 DOI: 10.1006/jsre.1999.5641] [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
Revascularization of an ischemic lower extremity is associated with high morbidity (20-30%) and perioperative mortality (10-20%) regardless of the mode of intervention, surgical or thrombolytic, considered to be due to polymorphonuclear (PMN) activation and mediator release. In this study, the safety and feasibility of cell-free extracorporeal perfusion of the limb with a solution designed to minimize both local and systemic injury was tested. Methods. Patients with severe limb ischemia (sensory/motor loss, rest pain/gangrene) were studied prospectively by random assignment into the treatment arm (n = 14) or control arm (n = 21). Surgical management consisted of restorative procedure, thrombectomy or embolectomy (n = 21), or reconstruction (n = 14). Reperfusion of the ischemic limb was achieved with hypertonic, hyperoncotic perfusate containing anti-oxidants delivered via the arterial tree (mean volume 1835 +/- 824 ml) with initial venous drainage (mean volume 775 +/- 263 ml) in the restorative group. Means were compared by paired t test. Results. No adverse systemic effects were detected after limb perfusion (electrolytes, coagulation, platelet function, CBC). Rapid lactate wash-out was observed within 30 min of perfusion (preperfusion 3.2 +/- 4.1 mM, 30 min postperfusion 0.7 +/- 0.71 mM, P < 0.01). Blunting of PMN activation was shown by chemiluminescence (CL) analysis (preischemic CL: 0.68 +/- 0.2; 30 min CL: 0.47 +/- 0. 2; P < 0.013). F2-isoprostanes, a marker of free radical-mediated systemic lipid peroxidation, were significantly reduced in patients treated with study perfusion method (70.55 +/- 39.54 versus control 194.38 +/- 25.24, P < 0.005). Mortality with treatment was 0/14 versus 5/21 in the control. Complication frequency: MI 0/14 vs 3/21; renal 0/14 vs 1/21; leg edema 1/14 vs 5/21; amputations 2/14 vs 1/21. Conclusion. Modification of limb perfusion in patients with severe limb ischemia, using our simple and rapid (15-20 min) method provides beneficial systemic effects.
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