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Davis G, August S, Salome RS. Nurses at risk. A call to mobilize. Am J Nurs 1999; 99:44-6. [PMID: 10333800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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Davis G, Sherman R, Wong MF, McClure G, Perez R, Hibbert M. Urinary incontinence among female soldiers. Mil Med 1999; 164:182-7. [PMID: 10091490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
A self-administered questionnaire was developed to assess the prevalence of urinary incontinence among active duty female soldiers. The questionnaire also addressed basic demographic information, including height, age, weight, and the subjects' present and past military activities. Adaptive measures that the soldiers commonly used to continue exercising and perform their duties were also explored. Seven hundred thirteen questionnaires were handed out to female soldiers at Fort Lewis (Washington), Fort Benning (Georgia), and Fitzsimons Army Medical Center (Colorado) during preparation for physical fitness tests. Of the 563 soldiers (79%) who returned completed questionnaires, 31% indicated that they commonly experienced urinary incontinence during duty and/or training to the extent that it interfered with job performance, hygiene, or was socially embarrassing. Thus, urinary incontinence is a pervasive problem among female soldiers.
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Davis G, Ellis J, Hibbert M, Perez RP, Zimbelman E. Female circumcision: the prevalence and nature of the ritual in Eritrea. Mil Med 1999; 164:11-6. [PMID: 9922637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
Abstract
This study evaluates the prevalence, complications, and attitudes concerning the practice of female circumcision among the women of Eritrea. Four hundred thirty-six Eritrean women from rural and urban environments were questioned about their perceptions and beliefs concerning female circumcision. Eighty-eight percent of those interviewed had undergone some form of female circumcision. Those who favored the continuation of the practice were more likely to be rural dwellers with little formal education, and they did so primarily out of tradition or cultural conformity. The direct and indirect consequences of this practice to the health of women and infants are considerable and as complex as the social, religious, and traditional factors that have led to its preservation.
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Davis G, McClure G, Sherman R, Hibbert M, Wong M, Perez R. Ambulatory urodynamics of female soldiers. Mil Med 1998; 163:808-12. [PMID: 9866358] [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] Open
Abstract
The purpose of this study was to assess the accuracy of ambulatory urodynamic monitoring compared with conventional urodynamic studies for the detection of exercise-induced urinary incontinence in the female soldier. Fifty active duty female soldiers with exercise-induced urinary incontinence and 10 asymptomatic control soldiers underwent conventional multichannel cystometry and then ambulatory monitoring during work or exercise. Ambulatory monitoring detected a greater number of abnormalities than conventional multichannel urodynamic studies in exercise-induced urinary incontinence. This greater sensitivity is valuable in formulating more effective treatment. Behavioral interventions were effective in treating exercise-induced urinary incontinence in this population. Test results normalized after behavioral intervention. It is neither cost-effective nor efficacious to require sophisticated urodynamic testing before instituting behavioral interventions.
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Green RJ, Potter P, Plit M, Friedman R, Hockman M, Davis G. The South African Allergic Rhinitis Working Group and allergic rhinitis. S Afr Med J 1998; 88:1366-7. [PMID: 9861936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
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Brown MA, Buddle ML, Farrell T, Davis G, Jones M. Randomised trial of management of hypertensive pregnancies by Korotkoff phase IV or phase V. Lancet 1998; 352:777-81. [PMID: 9737283 DOI: 10.1016/s0140-6736(98)03270-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND There is debate about whether diastolic blood pressure should be recorded as the fourth (muffling, K4) or fifth (disappearance, K5) Korotkoff sound in pregnancy. We compared maternal and fetal outcomes and the likelihood that episodes of severe hypertension would be recorded when hypertensive pregnancies were managed according to either K4 or K5. METHODS 220 pregnant women with diastolic hypertension (K4 > or =90 mm Hg) after the 20th week of gestation were enrolled in a prospective randomised study at two obstetric units in Australia; they were randomly assigned management with K4 (n=103) or K5 (n=117) for the remainder of the pregnancy. Clinical management was according to a uniform department protocol. Analysis was by intention to treat. All the women completed the trial. FINDINGS An episode of severe hypertension (systolic > or =170 mm Hg, diastolic > or =110 mm Hg, or both) was more likely to be recorded with use of K4 than with use of K5 (39 [38%] vs 30 [26%] women, p=0.051), mainly because of a greater likelihood that severe diastolic hypertension would be recorded (34 [33%] vs 20 [17%], p=0.006). The frequency of severe systolic hypertension and simultaneous severe systolic and diastolic hypertension did not differ between groups. Pregnancy was prolonged by an average of 2 weeks in both groups, and there were no significant differences between the groups in laboratory data, requirements for antihypertensive treatment, birthweight, fetal growth retardation, or perinatal mortality. There was no eclampsia or significant maternal morbidity in either group. INTERPRETATION A change from use of K4 to K5 would mean that one fewer case of severe diastolic hypertension would be recorded for every six hypertensive pregnancies, but all other episodes of severe hypertension would be recorded with similar frequency. Since the K4/K5 difference is smaller in hypertensive than in normotensive pregnant women and since K5 is closer to the actual intra-arterial pressure and more reliably detected, universal adoption of K5 to record diastolic blood pressure in hypertensive pregnancy should be considered.
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Wald A, Stern JO, Skinner EP, Beutner K, Conant MA, Tyring SK, Reitano MV, Davis G. Can a multimedia educational computer-based program on genital herpes teach patients about their disease? PRIMARY CARE UPDATE FOR OB/GYNS 1998; 5:151. [PMID: 10838278 DOI: 10.1016/s1068-607x(98)00033-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Objective: Education of patients with genital herpes about their disease is time consuming. To evaluate the effectiveness of an educational computer program, we developed a multimedia interactive presentation to teach patients about genital herpes. Such programs can supplement clinician visits for patients with genital herpes, or those at risk for HSV acquisition.Methods: Patients seeking care for genital herpes, or those at risk for HSV acquisition, were asked to participate in the program during routine clinic visits at 5 physician's offices nationwide. A self-administered 7 item herpes knowledge questionnaire was given before and after participation. An additional questionnaire evaluating the satisfaction with the program was also self-administered at completion.Results: 428 patients were enrolled and completed the pre- and post-knowledge questionnaire and 332 patients completed the satisfaction survey. On the pre-test, 20.1% of patients answered all questions correctly, 65.4% answered correctly 4 to 6 questions, and 14.5% 3 or less. On the post-test, 32.9% of patients answered all questions correctly, 61.5% answered correctly 4 to 6 questions, and 5.6% 3 or less (P <.001 for pre- and post-test comparison). A positive change in knowledge between pre- and post-test was seen on 6 of 7 items (P <.001 for all 6). The overall satisfaction with the program was high: the mean rating was 6.2 on a scale 1 (poor) to 7 (excellent).Conclusion: Computer-based education programs about genital herpes may provide a useful adjunct to teaching in physician offices and result in knowledge gain about the disease, at least short-term. Such programs may assist in management of chronic sexually transmitted infections.
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Davis G, Driver J. A functional role for illusory colour spreading in the control of focused visual attention. Perception 1998; 26:1397-411. [PMID: 9616469 DOI: 10.1068/p261397] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In cases of modal completion, illusory colour spreading fills in the surface of a subjectively completed shape. In amodal completion, shapes are likewise completed, but now behind a partial occluder, so that filling in of illusory colour to the completed region no longer arises. We consider the possible functional effects that illusory colour spreading may exert on later stages of vision, and argue that comparisons of modal with amodal completion may be particularly revealing in this regard. It is hypothesised that cueing the inducers of a modally completed object should attract attention to the entire object, including the completed region, owing to the colour spreading there. By contrast, changes to the inducers of a comparable amodally completed object should only attract attention to the inducing regions themselves. This prediction is supported by findings in two experiments with stereoscopic displays, with control conditions ruling out nonattentional accounts, or explanations in terms of stereo disparity alone rather than the presence versus absence of illusory colour. We argue that illusory colours get filled in at quite early stages during modal completion, precisely so that later stages of vision, such as focused attention, can then be driven by the completed regions in the same way as for uniform regions that are physically present in the image.
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Davis G, Ortloff S, Reed A, Worthington G, Roberts D. Evaluation of technician supervised treadmill exercise testing in a cardiac chest pain clinic. HEART (BRITISH CARDIAC SOCIETY) 1998; 79:613-5. [PMID: 10078092 PMCID: PMC1728737 DOI: 10.1136/hrt.79.6.613] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To determine the efficacy and safety of trained cardiac technicians independently performing treadmill exercise stress tests as part of the assessment of patients with suspected angina pectoris. DESIGN Retrospective comparison of 250 exercise tests performed by cardiac technicians and 225 tests performed by experienced cardiology clinical assistants (general practitioners who perform regular NHS cardiology duties), and consultant cardiologists over the same time period. SETTING Regional cardiac centre with a dedicated cardiac chest pain clinic. PATIENTS All patients were referred by their general practitioners with a history of recent onset of chest pain, which was suspected to be angina pectoris. OUTCOME MEASURES Peak workload achieved, symptoms, indications for termination, complications. RESULTS The diagnostic yield of technician supervised tests (percentage positive or negative) was similar to that of medically supervised tests (76% v 69%, NS). The average peak workload achieved by patients was less by 1.2 mets (p < 0.005). This was probably due to more tests being terminated earlier due to chest pain and ST segment depression in the technician group compared with doctors (10% and 16% v 5% and 11% respectively, p = 0.06 and 0.07). One patient in the technician supervised group developed a supraventricular tachycardia during the recovery phase of the exercise test. CONCLUSIONS Technician supervised stress testing is associated with a high diagnostic rate and low complication rate in patients with suspected ischaemic heart disease. Its efficacy is comparable to tests supervised by experienced doctors and its use should be encouraged.
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Claridge KG, Ghabrial R, Davis G, Tomlinson M, Goodman S, Harrad RA, Potts MJ. Combined radiotherapy and medical immunosuppression in the management of thyroid eye disease. Eye (Lond) 1998; 11 ( Pt 5):717-22. [PMID: 9474324 DOI: 10.1038/eye.1997.183] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Although systemic steroids or orbital radiotherapy are effective in limiting the inflammatory response in thyroid eye disease (TED), there are reports of over 70% of treated patients requiring subsequent rehabilitative surgery: either orbital decompression or strabismus correction. This study investigated whether combined immunosuppression with primary orbital radiotherapy together with azathioprine and low-dose prednisolone, applied early in the active disease state, was more effective in treating TED. Forty consecutive patients with active TED were recruited. Orbital MRI (STIR sequence) was used to assess disease activity. Median duration of symptoms was 1.0 year. Subjects were treated with bilateral orbital radiotherapy (20 Gy in 10 fractions) and oral prednisolone and azathioprine. Pre- and post-treatment activity was measured clinically, including uniocular field of fixation, Mourits score and total eye score, until TED became inactive off all treatment. Before treatment, 15 subjects had signs of dysthyroid optic neuropathy, 35 had significant motility restriction and 38 had marked soft tissue signs. On average TED became inactive after 1.2 years (SD 0.7) of immunosuppression, and treatment was well tolerated. One patient required subsequent cosmetic orbital decompression, 6 had successful strabismus surgery and 13 required minor cosmetic lid surgery. Compared with previously reported treatment regimes we think that combined orbital radiotherapy and medical immunosuppression is far more effective than either treatment alone in the management of active TED, and led to fewer side effects of high-dose steroids. In particular there was more than a four-fold reduction in the requirement for orbital decompression and strabismus surgery.
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DeQuattro N, Hibbert M, Buller J, Larsen F, Russell S, Poore S, Davis G. Microlaparoscopic tubal ligation under local anesthesia. THE JOURNAL OF THE AMERICAN ASSOCIATION OF GYNECOLOGIC LAPAROSCOPISTS 1998; 5:55-8. [PMID: 9454878 DOI: 10.1016/s1074-3804(98)80012-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Local anesthesia to perform laparoscopic tubal ligation is of increased interest due to potential safety and cost benefits. We performed tubal ligation using microlaparoscopic techniques with local anesthesia and continuous intravenous sedation in 16 women desiring sterilization. Operating and recovery times and patient satisfaction were recorded and compared with values for 30 similar women undergoing microlaparoscopic tubal ligation under general anesthesia. Mean +/- SD operating and recovery times for local and general anesthesia were 29.3+/- 8.1 versus 33.6 +/- 11.1 minutes, and 83.9 +/- 59.4 versus 114.5 +/- 69.8 minutes, respectively. Patient satisfaction was high. The potential for cost savings when performed in an outpatient or clinic setting is significant.
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Homandberg GA, Davis G, Maniglia C, Shrikhande A. Cartilage chondrolysis by fibronectin fragments causes cleavage of aggrecan at the same site as found in osteoarthritic cartilage. Osteoarthritis Cartilage 1997; 5:450-3. [PMID: 9536293 DOI: 10.1016/s1063-4584(97)80049-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Steward DJ, Haining RL, Henne KR, Davis G, Rushmore TH, Trager WF, Rettie AE. Genetic association between sensitivity to warfarin and expression of CYP2C9*3. PHARMACOGENETICS 1997; 7:361-7. [PMID: 9352571 DOI: 10.1097/00008571-199710000-00004] [Citation(s) in RCA: 229] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Cytochrome P4502C9 (CYP2C9) is largely responsible for terminating the anticoagulant effect of racemic warfarin via hydroxylation of the pharmacologically more potent S-enantiomer to inactive metabolites. Mutations in the CYP2C9 gene result in the expression of three allelic variants, CYP2C9*1, CYP2C9*2 and CYP2C9*3. Both CYP2C9*2 and CYP2C9*3 exhibit altered catalytic properties in vitro relative to the wild-type enzyme. In the present study, a patient was genotyped who had proven unusually sensitive to warfarin therapy and could tolerate no more than 0.5 mg of the racemic drug/day. PCR-amplification of exons 3 and 7 of the CYP2C9 gene, followed by restriction digest or sequence analysis, showed that this individual was homozygous for CYP2C9*3. In addition, patient plasma warfarin enantiomer ratios and urinary 7-hydroxywarfarin enantiomer ratios were determined by chiral-phase high performance liquid chromotography in order to investigate whether either parameter might be of diagnostic value in place of a genotypic test. Control patients receiving 4-8 mg warfarin/day exhibited plasma S:R ratios of 0.50 +/- 0.25:1, whereas the patient on very low-dose warfarin exhibited an S:R ratio of 3.9:1. In contrast, the urinary 7-hydroxywarfarin S:R ratio of 4:1 showed the same stereoselectivity as that reported for control patients. Therefore, expression of CYP2C9*3 is associated with diminished clearance of S-warfarin and a dangerously exacerbated therapeutic response to normal doses of the racemic drug. Analysis of the plasma S:R warfarin ratio may serve as a useful alternative test to genotyping for this genetic defect.
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Harvill LM, Davis G. Medical students' reasons for changing answers on multiple-choice tests. ACADEMIC MEDICINE : JOURNAL OF THE ASSOCIATION OF AMERICAN MEDICAL COLLEGES 1997; 72:S97-S99. [PMID: 9347753 DOI: 10.1097/00001888-199710001-00033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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191
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Alvarez J, Slomovic B, Powers R, Davis G. R-008. Novel test kit for the determination of sperm viability in semen. Hum Reprod 1997. [DOI: 10.1093/humrep/12.suppl_2.240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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192
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Alvarez J, Slomovic B, Powers R, Davis G. R-007. High prevalence of leukocyte infiltration in sperm samples used for IVF. Hum Reprod 1997. [DOI: 10.1093/humrep/12.suppl_2.239-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Marlor CW, Delaria KA, Davis G, Muller DK, Greve JM, Tamburini PP. Identification and cloning of human placental bikunin, a novel serine protease inhibitor containing two Kunitz domains. J Biol Chem 1997; 272:12202-8. [PMID: 9115294 DOI: 10.1074/jbc.272.18.12202] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Interrogation of the public expressed sequence tag (EST) data base with the sequence of preproaprotinin identified ESTs encoding two potential new members of the Kunitz family of serine protease inhibitors. Through reiterative interrogation, an EST contig was obtained, the consensus sequence from which encoded both of the novel Kunitz domains in a single open reading frame. This consensus sequence was used to direct the isolation of a full-length cDNA clone from a placental library. The resulting cDNA sequence predicted a 252-residue protein containing a putative NH2-terminal signal peptide followed sequentially by each of the two Kunitz domains within a 170-residue ectodomain, a putative transmembrane domain, and a 31-residue hydrophilic COOH terminus. The gene for this putative novel protein was mapped by use of a radiation hybrid panel to chromosome 19q13, and Northern analysis showed that the corresponding mRNA was expressed at high levels in human placenta and pancreas and at lower levels in brain, lung, and kidney. An endogenous soluble form of this protein, which was designated as placental bikunin, was highly purified from human placenta by sequential kallikrein-Sepharose affinity, gel filtration, and C18 reverse-phase chromatography. The natural protein exhibited the same NH2 terminus as predicted from the cloned cDNA and inhibited trypsin, plasma kallikrein, and plasmin with IC50 values in the nanomolar range.
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Davis G, Millner R, Roberts D. Transesophageal echocardiographic detection of complications after Cabrol's procedure. J Am Soc Echocardiogr 1997; 10:375-6. [PMID: 9168362 DOI: 10.1016/s0894-7317(97)70077-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Cabrol's procedure represents an improvement on earlier surgical techniques used in the management of a patient with aortic insufficiency associated with an aneurysm of the ascending aorta. We report a patient in whom the diagnosis of complications after a Cabrol procedure was facilitated by transesophageal echocardiography. The role of transesophageal echocardiography in the follow-up of these patients is discussed.
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Selleseth D, Johnson J, Davis G. The antiviral efficacy of topical ZOVIRAX® cream or VECTAVIR® cream in HSV-infected mice. Antiviral Res 1997. [DOI: 10.1016/s0166-3542(97)83277-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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196
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Greenfield EA, Howard E, Paradis T, Nguyen K, Benazzo F, McLean P, Höllsberg P, Davis G, Hafler DA, Sharpe AH, Freeman GJ, Kuchroo VK. B7.2 expressed by T cells does not induce CD28-mediated costimulatory activity but retains CTLA4 binding: implications for induction of antitumor immunity to T cell tumors. THE JOURNAL OF IMMUNOLOGY 1997. [DOI: 10.4049/jimmunol.158.5.2025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
The B7 family of costimulatory molecules provides the second signal necessary for activation of T cells. In the absence of the second signal, responding T cells become anergic. Although predominantly expressed on professional APCs, recent evidence shows that the B7 molecules are also expressed on T cells. To study the functions of B7 molecules on T cells, we transfected murine B7.1 (CD80) and B7.2 (CD86) cDNAs into the EL4 T cell thymoma cell line and examined the transfectants for their ability to costimulate T cell proliferation in vitro and to induce antitumor immunity in vivo. Here we show that although EL4-B7.1 cells costimulate T cells and induce tumor regression, EL4-B7.2 transfectants failed to costimulate T cell proliferation or induce tumor regression. To understand the cellular basis for this difference, we examined the binding of EL4-B7.1 and EL4-B7.2 to CTLA4 and CD28. Whereas EL4-B7.1 cells bound both CTLA4-Ig and CD28-Ig, EL4-B7.2 transfectants preferentially bound CTLA4-Ig, but not CD28-Ig. Similar binding data were obtained with freshly isolated murine T cells, which have been shown to constitutively express B7.2. Our data suggest, therefore, that B7.2 expressed on T cells may not costimulate but instead inhibit the T cell response by preferential binding to CTLA4.
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Greenfield EA, Howard E, Paradis T, Nguyen K, Benazzo F, McLean P, Höllsberg P, Davis G, Hafler DA, Sharpe AH, Freeman GJ, Kuchroo VK. B7.2 expressed by T cells does not induce CD28-mediated costimulatory activity but retains CTLA4 binding: implications for induction of antitumor immunity to T cell tumors. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1997; 158:2025-34. [PMID: 9036945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The B7 family of costimulatory molecules provides the second signal necessary for activation of T cells. In the absence of the second signal, responding T cells become anergic. Although predominantly expressed on professional APCs, recent evidence shows that the B7 molecules are also expressed on T cells. To study the functions of B7 molecules on T cells, we transfected murine B7.1 (CD80) and B7.2 (CD86) cDNAs into the EL4 T cell thymoma cell line and examined the transfectants for their ability to costimulate T cell proliferation in vitro and to induce antitumor immunity in vivo. Here we show that although EL4-B7.1 cells costimulate T cells and induce tumor regression, EL4-B7.2 transfectants failed to costimulate T cell proliferation or induce tumor regression. To understand the cellular basis for this difference, we examined the binding of EL4-B7.1 and EL4-B7.2 to CTLA4 and CD28. Whereas EL4-B7.1 cells bound both CTLA4-Ig and CD28-Ig, EL4-B7.2 transfectants preferentially bound CTLA4-Ig, but not CD28-Ig. Similar binding data were obtained with freshly isolated murine T cells, which have been shown to constitutively express B7.2. Our data suggest, therefore, that B7.2 expressed on T cells may not costimulate but instead inhibit the T cell response by preferential binding to CTLA4.
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Wald A, Corey L, Cone R, Hobson A, Davis G, Zeh J. Frequent genital herpes simplex virus 2 shedding in immunocompetent women. Effect of acyclovir treatment. J Clin Invest 1997; 99:1092-7. [PMID: 9062368 PMCID: PMC507918 DOI: 10.1172/jci119237] [Citation(s) in RCA: 266] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Reactivation of herpes simplex virus type 2 (HSV-2) occurs intermittently as perceived clinically and by viral culture. We performed a series of studies to evaluate the frequency and pattern of HSV-2 reactivation using both viral isolation and HSV PCR assay. Daily samples of genital secretions were obtained from 27 HSV-2 seropositive women; a subset of subjects obtained samples while receiving oral acyclovir 400 mg PO twice a day. HSV DNA was detected in genital swab specimens on 28% of 1,410 d compared with 8.1% of days by viral isolation. 11 of 20 women had HSV DNA detected on > 20% of days, 4 on > 50%, and 2 on > 75% of days; in contrast, none of the women shed on > 21% of days by viral isolation. The daily administration of oral acyclovir promptly reduced the frequency of HSV DNA detection by a median of 80%. Within 3-4 d of discontinuing daily acyclovir, HSV DNA again appeared in the genital area. HSV-2 shedding in the genital mucosa occurs much more frequently than previously appreciated. This frequent reactivation likely plays a role in the epidemic spread of genital herpes worldwide.
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de la Torre JC, Cada A, Nelson N, Davis G, Sutherland RJ, Gonzalez-Lima F. Reduced cytochrome oxidase and memory dysfunction after chronic brain ischemia in aged rats. Neurosci Lett 1997; 223:165-8. [PMID: 9080458 DOI: 10.1016/s0304-3940(97)13421-8] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The effects of chronic cerebrovascular ischemia on memory function and cytochrome oxidase (CO) activity were investigated. Cerebrovascular insufficiency was induced by permanent bilateral carotid artery ligation (2-VO) in 19 month old rats. Sham surgery in no-vessel occlusion (no-VO) rats were used for controls. Memory function was tested 1 week prior to surgery and then weekly for 21 days using the Morris water maze. Regional brain activity of CO was measured 4 weeks after surgery by quantitative histochemistry. Histologic examination of brain slices was used to evaluate any neuropathology present. Results showed that 2-VO rats were significantly impaired in the water maze task at each testing period with respect to no-VO controls. In addition, CO activity in 2-VO rats was markedly reduced only in the dorsal CA1 region of the hippocampus and in the posterior parietal cortex. These brain regions are involved in visuo-spatial memory mechanisms. Analysis of other brain regions in 2-VO rats did not reveal further CO activity changes. There were no damaged or loss of neurons in 2-VO or no-VO groups in any region examined, including CA1 and posterior parietal cortex. The CA1 region however, is known to undergo neuronal loss 25 weeks after chronic 2-VO suggesting that this vascular insult can induce a slowly-evolving cascade consisting of neuronal damage, atrophy and death. The present findings indicate that reduced CO activity in CA1 and posterior parietal regions can predict neural damage and atrophy prior to structural perikaryal pathology following chronic brain ischemia. In addition, the data shows that neuronal energy metabolic deficiency may initiate visuo-spatial memory impairment in this aging rat model.
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Roder HM, Fracasso RP, Hoffman FJ, Witowsky JA, Davis G, Pellegrino CB. Phosphorylation-dependent monoclonal Tau antibodies do not reliably report phosphorylation by extracellular signal-regulated kinase 2 at specific sites. J Biol Chem 1997; 272:4509-15. [PMID: 9020176 DOI: 10.1074/jbc.272.7.4509] [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: 02/03/2023] Open
Abstract
Analysis of phosphorylation of tau, the microtubule-associated proteins hyperphosphorylated in Alzheimer's disease, is often performed using phosphorylation-sensitive monoclonal antibodies thought to report the presence or absence of one or two specific phosphorylations (cognate sites). Using several such antibodies we found a much more complicated relationship between phosphorylation at specific sites, as monitored by two-dimensional phosphopeptide mapping, and antibody recognition of these sites. Multiple phosphorylation of tau in several stages by the brain extracellular signal-regulated kinase 2 isoform PK40 suggested that phosphorylation at cognate sites is sometimes necessary (but not sufficient) to induce a change of antibody reactivity and in some cases is not even necessary in the background of multiple phosphorylation at other sites. No single phosphorylation site was found to be responsible for any level of gel mobility shift associated with phosphorylation. Tau acquired its maximal gel mobility retardation and final immunochemical profile at substoichiometric phosphorylation of most sites. This suggests that many alternate phosphorylation patterns can produce the same conformational and immunochemical presentation on sodium dodecyl sulfate-gel electrophoresis. Although PK40(erk2) prefers some phosphorylation sites, most notably Ser235, followed by Ser199 or Ser202 and Thr205, the phosphorylation of multiple Ser/Thr-Pro sites is not highly sequential. Ser396 is one of the least preferred sites and seems to require prior phosphorylation at Ser404.
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