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Millikan R, Baez L, Banerjee T, Wade J, Edwards K, Winn R, Smith TL, Logothetis C. Randomized phase 2 trial of ketoconazole and ketoconazole/doxorubicin in androgen independent prostate cancer. Urol Oncol 2001; 6:111-115. [PMID: 11344001 DOI: 10.1016/s1078-1439(00)00123-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Eighty-nine patients with progressive prostate cancer despite suppression of testosterone and withdrawal of anti-androgens were studied. This was a relatively advanced population, with 63 of 89 having either osseous metastases (mets) beyond the axial skeleton or visceral mets. Patients were randomly assigned to receive either ketoconazole alone, or ketoconazole with weekly doxorubicin. All patients received replacement hydrocortisone. The primary endpoints were response and survival. Based on PSA reduction criteria (>/= 80% maintained for at least 8 weeks), 14 of 45 patients (31%) in the single-agent ketoconazole arm responded. Sixteen of 44 patients (36%) in the combination ketoconazole/doxorubicin arm responded. There were no important differences between the two treatments in any outcome measure. The median overall survival for all patients was 12.5 months; median time to progression was 3.3 months. Toxicity was significant with both regimens, and more severe in the doxorubicin arm. Fully 20% of patients in each arm discontinued therapy due to intolerable side effects.Each of these regimens is toxic, and produced responses in fewer than half of treated patients. Although the observed median survival does compare favorably with reports from similar cohorts treated in the community, the potential benefit is only modest. In our view, neither of these regimens is sufficiently promising to justify phase 3 evaluation.
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Strebel P, Nordin J, Edwards K, Hunt J, Besser J, Burns S, Amundson G, Baughman A, Wattigney W. Population-based incidence of pertussis among adolescents and adults, Minnesota, 1995-1996. J Infect Dis 2001; 183:1353-9. [PMID: 11294666 DOI: 10.1086/319853] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2000] [Revised: 02/07/2001] [Indexed: 11/03/2022] Open
Abstract
To estimate the incidence of pertussis, a prospective study was done among members of a managed care organization in Minneapolis/St. Paul, Minnesota. Of 212 patients 10-49 years old enrolled from January 1995 through December 1996, 8 were found to be culture positive, 10 were found to be positive by polymerase chain reaction assay, 13 had a > or =2-fold increase in IgG or IgA to pertussis toxin (PT), and 18 had IgG to PT in a single serum specimen > or =3 SD above the mean of an age-matched control group. At least 1 positive laboratory test result for pertussis infection was found in 27 (13%) patients, among whom the duration of cough illness was a median of 42 days (range, 27-66 days). On the basis of any positive laboratory result, the estimated annual incidence of pertussis was 507 cases per 100,000 person-years (95% confidence interval, 307-706 cases). Bordetella pertussis infection may be a more common cause of cough illness among adolescents and adults than was recognized previously.
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Juster F, Edwards K. A rotation in chronic-care pediatrics with a focus on children and their families in the community. ACADEMIC MEDICINE : JOURNAL OF THE ASSOCIATION OF AMERICAN MEDICAL COLLEGES 2001; 76:568. [PMID: 11346625 DOI: 10.1097/00001888-200105000-00118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Chen C, Edwards K, Young B, Greenberger E. Close relationships between Asian American and European American college students. THE JOURNAL OF SOCIAL PSYCHOLOGY 2001; 141:85-100. [PMID: 11294169 DOI: 10.1080/00224540109600525] [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: 10/20/2022]
Abstract
The authors examined attitudes and behaviors regarding close relationships between European and Asian Americans, with a particular emphasis on 5 major subgroups of Asian Americans (Chinese, Japanese, Korean, Vietnamese, and Filipino Americans). Participants were 218 Asian American college students and 171 European American college students attending a culturally diverse university. The European Americans did not differentiate among the various subgroups of Asian Americans. Their attitudes regarding close relationships were less positive toward Asian Americans than toward Mexican and African Americans, a finding contrary to the prediction of social exchange theory (H. Tajfel, 1975). In contrast to the European Americans' view of homogeneity among Asian Americans, the 5 major subgroups of Asian Americans expressed a distinctive hierarchy of social preference among themselves. Results are discussed in terms of their implications for future research on interethnic relations involving Asian Americans.
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Johnsson M, Edwards K. Phase behavior and aggregate structure in mixtures of dioleoylphosphatidylethanolamine and poly(ethylene glycol)-lipids. Biophys J 2001; 80:313-23. [PMID: 11159404 PMCID: PMC1301235 DOI: 10.1016/s0006-3495(01)76016-x] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Cryo-transmission electron microscopy has been used to investigate the phase behavior and aggregate structure in dilute aqueous mixtures of dioleoylphosphatidylethanolamine (DOPE) and poly(ethylene glycol)-phospholipids (PEG-lipids). It is shown that PEG-lipids (micelle-forming lipids) induce a lamellar phase in mixtures with DOPE (inverted hexagonal forming lipid). The amount of PEG-lipid that is needed to induce a pure dispersed lamellar phase, at physiological conditions, depends on the size of the PEG headgroup. In the transition region between the inverted hexagonal phase and the lamellar phase, particles with dense inner textures are formed. It is proposed that these aggregates constitute dispersed cubic phase particles. Above bilayer saturating concentration of PEG-lipid, small disks and spherical micelles are formed. The stability of DOPE/PEG-lipid liposomes, prepared at high pH, against a rapid drop of the pH was also investigated. It is shown that the density of PEG-lipid in the membrane, sufficient to prevent liposome aggregation and subsequent phase transition, depends on the size of the PEG headgroup. Below a certain density of PEG-lipid, aggregation and phase transition occurs, but the processes involved proceed relatively slow, over the time scale of weeks. This allows detailed studies of the aggregate structure during membrane fusion.
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Schuchat A, Hillier S, Edwards K, Schrag S, Labbok M. Early opportunities for prevention: infections of pregnant women and young infants. Emerg Infect Dis 2001; 7:532. [PMID: 11485649 PMCID: PMC2631821 DOI: 10.3201/eid0707.017711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Abstract
A better understanding of the views of service users has become increasingly relevant in providing mental health services and for the role of the mental health nurse in meeting users' needs. The four key issues that this research endeavoured to address were: (1) What are the views and perceived needs of users of mental health services in the context of the role that users see nurses fulfilling? (2) How do student nurses perceive their future role given the changes in nurse prepartion? (3) To what extent do the answers to the first two questions converge and/or diverge? (4) Recommend actions on ways in which mental health nurse training could be improved, in light of the findings of this research. Methodologically, both qualitative and quantitative data gathering approaches were used, the former for stage one in setting the agenda and the latter for stage two by means of questionnaires. The findings indicate that the key concerns for users are issues of choice, individuality, information and quality of care in terms of positive interpersonal relationships with those who have responsibilities for helping them and who are sensitive to their real needs. Users are not asking for any costly or extravagant therapies but support that is relevant to their needs and provided in a compassionate manner. The context of their lives and the degree to which users feel integrated into society is a prominent concern. These findings have implications for how mental health nurses are educated and trained and how on qualifying they function in practice. The findings throw into question whether mental health nursing can adapt to the desired changes that are being called for.
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Edwards K. Human responses to pain: a global perspective. JOURNAL OF CULTURAL DIVERSITY 2000; 7:2. [PMID: 11013522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
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Eifert GH, Thompson RN, Zvolensky MJ, Edwards K, Frazer NL, Haddad JW, Davig J. The cardiac anxiety questionnaire: development and preliminary validity. Behav Res Ther 2000; 38:1039-53. [PMID: 11004742 DOI: 10.1016/s0005-7967(99)00132-1] [Citation(s) in RCA: 188] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Heart-focused anxiety (HFA) is the fear of cardiac-related stimuli and sensations because of their perceived negative consequences. Although HFA is common to a wide variety of persons who experience chest pain and distress, it often is unrecognized and misdiagnosed, particularly in cardiology and emergency room patients without and with heart disease. To address these concerns, this article reports on the development and preliminary psychometric evaluation of the Cardiac Anxiety Questionnaire (CAQ) designed to measure HFA. In Study 1, 188 cardiology patients completed the CAQ. Item and factor analyses indicated a three-factor solution pertaining to heart-related fear, avoidance, and attention. Reliability analysis of the 18-item CAQ revealed good internal consistency of the total and subscale scores. In Study 2, 42 patients completed the CAQ and several other anxiety-related questionnaires to assess its convergent and divergent properties. Although preliminary validity results are promising, further psychometric study is necessary to cross-validate the CAQ, examine its test-retest reliability, and confirm the stability of the factor structure. Taken together, the CAQ appears to assess HFA, and may therefore be a useful instrument for identifying patients with elevated HFA without and with heart disease.
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Edwards K. Continuous wear contact lenses: have we been here before? HOSPITAL MEDICINE (LONDON, ENGLAND : 1998) 2000; 61:483-8. [PMID: 11091804 DOI: 10.12968/hosp.2000.61.7.2407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
New developments in contact lens materials have led to the introduction of new lenses designed for up to 30 days of continuous wear. Will these lenses lead to safer and healthier overnight use of lenses?
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Gibbons CP, Ferguson CJ, Edwards K, Roberts DE, Osman H. Use of superficial femoropopliteal vein for suprainguinal arterial reconstruction in the presence of infection. Br J Surg 2000; 87:771-6. [PMID: 10848857 DOI: 10.1046/j.1365-2168.2000.01468.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Conventional treatment of mycotic aneurysms or graft infections of the aortoiliac segment by in situ or extra-anatomic prosthetic reconstruction has a high mortality and morbidity rate, with a substantial risk of persistent graft infection. The use of autologous vein may reduce this. METHODS Eleven patients with suprainguinal arterial infections including two with mycotic aortic aneurysms, four with aortic graft infections, four infected femorofemoral grafts and an infected axillofemoral graft were treated by debridement and in situ reconstruction with autologous superficial femoropopliteal vein. All patients received appropriate antibiotic therapy and were followed by regular postoperative duplex imaging. Preoperative femoral vein duplex imaging was performed in eight of the 11 patients. RESULTS Ten of the 11 patients survived with a functioning graft and without limb loss or evidence of infection at 4-33 months. One patient died from myocardial infarction after operation. Three patients had minor swelling of one leg. Four patients required subsequent angioplasty of anastomotic stenoses detected by duplex surveillance. CONCLUSION Superficial femoropopliteal vein is an excellent conduit for suprainguinal reconstruction in the presence of infection. Duplex imaging is useful for confirming the suitability of deep veins for use as a graft and for postoperative surveillance.
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Bergstrand N, Bohl R, Carlsson J, Edwards K, Ghaneolhosseini H, Gedda L, Johnsson M, Silvander M, Sjöberg S. Stabilised liposomes with double targeting for use in BNCT. CONTEMPORARY BORON CHEMISTRY 2000. [DOI: 10.1039/9781847550644-00131] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Waites K, Johnson C, Gray B, Edwards K, Crain M, Benjamin W. Use of clindamycin disks To detect macrolide resistance mediated by ermB and mefE in Streptococcus pneumoniae isolates from adults and children. J Clin Microbiol 2000; 38:1731-4. [PMID: 10790089 PMCID: PMC86572 DOI: 10.1128/jcm.38.5.1731-1734.2000] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We studied 198 macrolide-resistant S. pneumoniae isolates obtained from adults and children to evaluate whether 2-microgram clindamycin disks can distinguish between isolates manifesting ermB- versus mefE-mediated resistance to clarithromycin and to determine the relative frequency with which each resistance mechanism occurred in these populations. The mefE gene was predominant among 109 isolates from children, occurring in 73.4% versus 50.6% of 89 isolates from adults. Three isolates (1.5%) did not amplify either gene. Among 125 mefE(+) isolates, the MIC of clarithromycin at which 90% of the isolates tested were inhibited, determined by Etest, was 32 microgram/ml versus >256 microgram/ml in 70 ermB(+) isolates. All ermB(+) isolates were highly resistant to clindamycin (MICs >256 microgram/ml), whereas all mefE(+) isolates were susceptible to clindamycin using the 2-microgram disk. Testing S. pneumoniae from the respiratory tract for susceptibility to clindamycin by agar disk diffusion is an easy and inexpensive method to estimate the frequency of resistance mediated by ermB in specific patient populations. Macrolide resistance mediated by ermB is usually of greater magnitude than that due to mefE. Clinical studies are needed to determine the significance of high- versus low-level macrolide resistance in S. pneumoniae.
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Edwards K, Edgar T, Manousiouthakis V. Reaction mechanism simplification using mixed-integer nonlinear programming. Comput Chem Eng 2000. [DOI: 10.1016/s0098-1354(00)00311-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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140
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Kulp MT, Edwards K. Repeatability of the Visual Manipulation Test. Optom Vis Sci 2000; 77:194-7. [PMID: 10795802 DOI: 10.1097/00006324-200004000-00011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND The Getman-Henderson-Marcus Visual Manipulation Test (VMT) is a commonly used test of visualization with an objective scoring procedure. However, its repeatability has not been studied. PURPOSE The purpose of this investigation was to assess the repeatability of the VMT in children in the second through fourth grades. METHOD The VMT was administered to the children (n = 193; mean age, 8.72 years) from a middle class elementary school near Columbus, Ohio. One class from each grade (n = 56) was retested by the same optometrist within 1 month. Repeatability analysis included plotting the difference vs. the mean of the scores obtained at the initial test and retest. RESULTS All the children were able to complete the test. Means and SD's were found to be 5.23+/-1.98 for second graders, 5.76+/-2.10 for third graders, and 6.95+/-2.30 for fourth graders. The mean difference between test and retest scores was close to zero. The 95% limits of agreement were found to be -4.5 to 5.2. CONCLUSION No consistent learning effect seemed to be present upon retest. However, analysis revealed poor repeatability for the VMT. Therefore, the VMT should not be used to monitor progress with therapy.
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Black S, Shinefield H, Fireman B, Lewis E, Ray P, Hansen JR, Elvin L, Ensor KM, Hackell J, Siber G, Malinoski F, Madore D, Chang I, Kohberger R, Watson W, Austrian R, Edwards K. Efficacy, safety and immunogenicity of heptavalent pneumococcal conjugate vaccine in children. Northern California Kaiser Permanente Vaccine Study Center Group. Pediatr Infect Dis J 2000; 19:187-95. [PMID: 10749457 DOI: 10.1097/00006454-200003000-00003] [Citation(s) in RCA: 1513] [Impact Index Per Article: 63.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To determine the efficacy, safety and immunogenicity of the heptavalent CRM197 pneumococcal conjugate vaccine against invasive disease caused by vaccine serotypes and to determine the effectiveness of this vaccine against clinical episodes of otitis media. METHODS The Wyeth Lederle Heptavalent CRM197 (PCV) was given to infants at 2, 4, 6 and 12 to 15 months of age in a double blind trial; 37,868 children were randomly assigned 1:1 to receive either the pneumococcal conjugate vaccine or meningococcus type C CRM197 conjugate. The primary study outcome was invasive disease caused by vaccine serotype. Other outcomes included overall impact on invasive disease regardless of serotype, effectiveness against clinical otitis media visits and episodes, impact against frequent and severe otitis media and ventilatory tube placement. In addition the serotype-specific efficacy against otitis media was estimated in an analysis of spontaneously draining ears. RESULTS In the interim analysis in August, 1998, 17 of the 17 cases of invasive disease caused by vaccine serotype in fully vaccinated children and 5 of 5 of partially vaccinated cases occurred in the control group for a vaccine efficacy of 100%. Blinded case ascertainment was continued until April, 1999. As of that time 40 fully vaccinated cases of invasive disease caused by vaccine serotype had been identified, all but 1 in controls for an efficacy of 97.4% (95% confidence interval, 82.7 to 99.9%), and 52 cases, all but 3 in controls in the intent-to-treat analysis for an efficacy of 93.9% (95% confidence interval, 79.6 to 98.5%). There was no evidence of any increase of disease caused by nonvaccine serotypes. Efficacy for otitis media against visits, episodes, frequent otitis and ventilatory tube placement was 8.9, 7.0, 9.3 and 20.1% with P < 0.04 for all. In the analysis of spontaneously draining ears, serotype-specific effectiveness was 66.7%. CONCLUSION This heptavalent pneumococcal conjugate appears to be highly effective in preventing invasive disease in young children and to have a significant impact on otitis media.
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Edwards K. Trial contact lenses and vCJD. Cont Lens Anterior Eye 2000; 23:32-3. [PMID: 16303428 DOI: 10.1016/s1367-0484(00)80041-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Edwards K. A review of rigid lens design. Cont Lens Anterior Eye 2000; 23:106-11. [PMID: 16303440 DOI: 10.1016/s1367-0484(00)80002-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Edwards K. The open approach. Nurs Stand 1999; 14:61. [PMID: 11209377 DOI: 10.7748/ns1999.12.14.13.61.c2729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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145
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Wasan EK, Harvie P, Edwards K, Karlsson G, Bally MB. A multi-step lipid mixing assay to model structural changes in cationic lipoplexes used for in vitro transfection. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1461:27-46. [PMID: 10556486 DOI: 10.1016/s0005-2736(99)00144-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Formation of liposome/polynucleotide complexes (lipoplexes) involves electrostatic interactions, which induce changes in liposome structure. The ability of these complexes to transfer DNA into cells is dependent on the physicochemical attributes of the complexes, therefore characterization of binding-induced changes in liposomes is critical for the development of lipid-based DNA delivery systems. To clarify the apparent lack of correlation between membrane fusion and in vitro transfection previously observed, we performed a multi-step lipid mixing assay to model the sequential steps involved in transfection. The roles of anion charge density, charge ratio and presence of salt on lipid mixing and liposome aggregation were investigated. The resonance-energy transfer method was used to monitor lipid mixing as cationic liposomes (DODAC/DOPE and DODAC/DOPC; 1:1 mole ratio) were combined with plasmid, oligonucleotides or Na(2)HPO(4). Cryo-transmission electron microscopy was performed to assess morphology. As plasmid or oligonucleotide concentration increased, lipid mixing and aggregation increased, but with Na(2)HPO(4) only aggregation occurred. NaCl (150 mM) reduced the extent of lipid mixing. Transfection studies suggest that the presence of salt during complexation had minimal effects on in vitro transfection. These data give new information about the effects of polynucleotide binding to cationic liposomes, illustrating the complicated nature of anion induced changes in liposome morphology and membrane behavior.
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Douthwaite WA, Hough T, Edwards K, Notay H. The EyeSys videokeratoscopic assessment of apical radius and p-value in the normal human cornea. Ophthalmic Physiol Opt 1999; 19:467-74. [PMID: 10768029 DOI: 10.1046/j.1475-1313.1999.00462.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The EyeSys videokeratoscope was used to assess the corneal topography in 98 subjects. Scatterplots of distance squared versus radius squared were plotted for the near horizontal and near vertical principal meridians of the two eyes. The regression lines allowed calculation of the surface apical radius and the p-value. The group average apical radius was 7.93 mm (horizontal) and 7.78 mm (vertical). The group average p-value was 0.76 (horizontal) and 0.82 (vertical). Both apical radius and p-value were similar when comparing the two eyes for both the horizontal and the vertical meridians. The two meridians in a single eye, however, had different values for both apical radius and p-value. Male apical radii were longer than those of females but the p-values were the same. There is no apparent association between age and either apical radius or p-value for the subjects used in this study. The asphericity of the cornea does not show any apparent association with corneal curvature in this group of subjects.
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Parmar MM, Edwards K, Madden TD. Incorporation of bacterial membrane proteins into liposomes: factors influencing protein reconstitution. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1421:77-90. [PMID: 10561473 DOI: 10.1016/s0005-2736(99)00118-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Meningococcal and gonococcal outer membrane proteins were reconstituted into liposomes using detergent-mediated dialysis. The detergents octyl glucopyranoside (OGP), sodium cholate and Empigen BB were compared with respect to efficiency of detergent removal and protein incorporation. The rate of OGP removal was greater than for cholate during dialysis. Isopycnic density gradient centrifugation studies showed that liposomes were not formed and hence no protein incorporation occurred during dialysis from an Empigen BB containing reconstitution mixture. Cholate-mediated reconstitution yielded proteoliposomes with only 75% of the protein associated with the vesicles whereas all of the protein was reconstituted into the lipid bilayer during OGP-mediated reconstitution. Essentially complete protein incorporation was achieved with an initial protein-to-lipid ratio of 0.01:1 (w/w) in the reconstitution mixture; however, at higher initial protein-to-lipid ratios (0.02:1) only 75% protein incorporation was achieved. Reconstituted proteoliposomes were observed as large (>300 nm), multilamellar structures using cryo-electron microscopy. Size reduction of these proteoliposomes by extrusion did not result in significant loss of protein or lipid. Extruded proteoliposomes were unilamellar vesicles with mean diameter of about 100 nm.
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El Jastimi R, Edwards K, Lafleur M. Characterization of permeability and morphological perturbations induced by nisin on phosphatidylcholine membranes. Biophys J 1999; 77:842-52. [PMID: 10423430 PMCID: PMC1300376 DOI: 10.1016/s0006-3495(99)76936-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Nisin is an antimicrobial peptide used as food preservative. To gain some insights into the hypothesis that its bactericidal activity is due to the perturbation of the lipid fraction of the bacterial plasmic membrane, we have investigated the effect of nisin on model phosphatidylcholine (PC) membranes. We show that nisin affects the PC membrane permeability, and this perturbation is modulated by the lipid composition. Nisin-induced leakage from PC vesicles is inhibited by the presence of cholesterol. This inhibition is associated with the formation of a liquid ordered phase in the presence of cholesterol, which most likely reduces nisin affinity for the membrane. Conversely, phosphatidylglycerol (PG), an anionic lipid, promotes nisin-induced leakage, and this promotion is associated with an increased affinity of the peptide for the bilayer because nisin is a cationic peptide. When the electrostatic interactions are encouraged by the presence of 70 mol% PG in PC, the inhibitory effect of cholesterol is not observed anymore. Nisin drastically modifies the morphology of the dipalmitoyl-sn-glycero-3-phosphatidylcholine (DPPC) multilamellar dispersion without causing a significant change in the gel-to-liquid crystalline phase transition of the lipid. The morphological changes are observed from (31)P and (2)H NMR and cryo-electron microscopy. From the NMR point of view, the interactions giving rise to a broad signal (quadrupolar interactions and chemical shift anisotropy for (2)H NMR and (31)P NMR, respectively) are partly averaged out in the presence of nisin. This phenomenon is interpreted by the formation of curved lipid planes that lead to the lipid lateral diffusion occurring in the intermediate motional regime. By cryo-electron microscopy, large amorphous aggregates containing small dense globular particles are observed for samples quenched from 25 and 50 degrees C. Long thread-like structures are also observed in the fluid phase. A structural description of DPPC/nisin complex, consistent with the experimental observation, is proposed. The presence of 30 mol% cholesterol in DPPC completely inhibits the morphological changes induced by nisin. Therefore, it is concluded that nisin can significantly perturb PC bilayers from both the permeability and the structural points of view, and these perturbations are modulated by the lipidic species in the bilayer.
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Ravandi F, Rytting ME, Osmon C, Braud EL, Roach RW, Edwards K, Winn R, Abbruzzese JL, Pazdur R. Phase II trial of 5-fluorouracil, folinic acid and recombinant alpha-2a-interferon in patients with advanced colorectal cancer. Anticancer Drugs 1999; 10:519-24. [PMID: 10885898 DOI: 10.1097/00001813-199907000-00002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A clinical trial regimen modulating 5-fluorouracil (5-FU) with both folinic acid (FA) and recombinant alpha-2a-interferon (ralpha-2a-IFN) was noted to have a response rate of 54% and median survival of 16.3 months (Grem et al., J Clin Oncol 1993, 11: 1737-45). Reported herein is a phase II trial performed to further examine this regimen in metastatic colorectal cancer. Fifty-one patients with histologically proven, measurable advanced colorectal cancer with no prior therapy for metastatic disease were enrolled. ralpha-2a-IFN, 5 MIU/m2/day was given s.c. on days 1-7. FA, 500 mg/m2/day, and 5-FU, 370 mg/m2/day, were given i.v. on days 2-6. Cycles were repeated at 3 week intervals. Three complete and 12 partial responses were observed for an overall response rate of 29% (95% confidence interval: 18-45%). The median time to treatment failure and median survival were 4.6 and 15.5 months, respectively. Dose-limiting toxicities encountered were gastrointestinal, and included diarrhea, stomatitis, nausea and vomiting. These results do not support the concept of using concurrent ralpha-2a-IFN and FA as biochemical modulators of 5-FU. We observed increased toxicity and similar efficacy compared to using either modulator separately with 5-FU.
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Engebretson TO, Sirota AD, Niaura RS, Edwards K, Brown WA. A simple laboratory method for inducing anger: a preliminary investigation. J Psychosom Res 1999; 47:13-26. [PMID: 10511418 DOI: 10.1016/s0022-3999(99)00012-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
To facilitate the experimental study of anger, we developed a simple laboratory method to induce anger. This anger induction (AI) is similar in format to the Velten Mood Induction Procedure for depression (VMIP-D), and involves reading descriptors of anger experience, recalling relevant personal memories, and evoking the mood suggested by the sentence/memory. We administered the AI and VMIP-D to 81 undergraduate men and women and collected mood ratings before, during, and after each mood induction. The AI exhibited good sensitivity and specificity in that it induced moderate to greater increases in anger (>1 SD change) in 68% of the sample, significant decreases in happiness, and minimal changes in other emotions. Mood responses to the AI and VMIP-D were influenced by gender and order of presentation. Uses and limitations of this method are discussed.
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