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Labbate LA, Cardeña E, Dimitreva J, Roy M, Engel CC. Psychiatric syndromes in Persian Gulf War veterans: an association of handling dead bodies with somatoform disorders. PSYCHOTHERAPY AND PSYCHOSOMATICS 1998; 67:275-9. [PMID: 9693357 DOI: 10.1159/000012292] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Traumatic combat experience has been associated with the development of posttraumatic stress disorder, but there have been few studies about the association of military combat experience and the development of somatoform disorders. METHODS The authors evaluated 131 referred Gulf War veterans for medical and psychiatric syndromes thought related to their involvement in the Gulf War. Patients completed questionnaires regarding their traumatic experiences and were interviewed using the Structured Clinical Interview for DSM III-R. RESULTS For the sample, 69% had axis I conditions. Major depression, undifferentiated somatoform and posttraumatic stress disorders were the most common diagnoses. Reports of traumatic events were associated with both posttraumatic stress disorder (p < 0.05) and somatoform diagnoses (p < 0.05). Veterans who handled dead bodies had a 3-fold risk of receiving a somatoform diagnosis (p < 0.05). CONCLUSIONS Psychiatric syndromes may explain some medical complaints following involvement in the Persian Gulf War. The results suggest that some psychological and nonspecific somatic symptoms persisting since the Gulf War may be related to exposure to psychological trauma.
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Roy M, Stip E, Black D, Lew V, Langlois R. [Cerebellar degeneration following acute lithium intoxication]. Rev Neurol (Paris) 1998; 154:546-8. [PMID: 9773090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Lithium is a neurotoxin with a particular affinity for the cerebellum. The risk of permanent neurotoxic sequelae of lithium is increased by the concomitant use of certain conventional neuroleptics. We report two new cases of lithium neurotoxicity; one received lithium alone, not in combination with a neuroleptic. Both cases showed severe cerebellar atrophy on brain CT and MRI. Additional factors such as dehydration, systemic infection, other medications, or rapid correction of frequently-coexisting hyponatremia may contribute to the risk of lithium neurotoxicity. We discuss possible pathophysiologic mechanisms and preventive measures.
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Hoskins P, Eisenhauer E, Beare S, Roy M, Drouin P, Stuart G, Bryson P, Grimshaw R, Capstick V, Zee B. Randomized phase II study of two schedules of topotecan in previously treated patients with ovarian cancer: a National Cancer Institute of Canada Clinical Trials Group study. J Clin Oncol 1998; 16:2233-7. [PMID: 9626225 DOI: 10.1200/jco.1998.16.6.2233] [Citation(s) in RCA: 135] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE As topotecan is S-phase-specific, its efficacy is likely schedule-dependent. Therefore, a randomized study using a "pick the winner" design was undertaken to compare two schedules in patients with recurrent ovarian cancer. PATIENTS AND METHODS Patients with recurrent epithelial ovarian cancer previously treated with no more than two separate regimens of chemotherapy, one of which had to be platinum-containing, were randomized to either topotecan 1.5 mg/m2 intravenously (i.v.) over 30 minutes daily for 5 days repeated every 21 days (arm A, the standard arm), or topotecan 1.75 mg/m2 as a 24-hour infusion once a week for 4 weeks repeated every 6 weeks (arm B, the experimental arm). RESULTS Sixty-six patients were eligible and 63 were assessable for response. The response rate in arm A was 22.6% (95% confidence interval [CI], 9.6% to 41.2%), which was significantly superior to that in arm B, 3.1% (95% CI, 0.1% to 16%) (P = .026). The regimens were not equitoxic, with 94% of patients on arm A experiencing grade 3 or 4 granulocytopenia as opposed to 52% on arm B. CONCLUSION The weekly 24 hour infusion of topotecan at 1.75 mg/m2 was ineffective in relapsed ovarian cancer. The daily-times-five schedule remains the schedule of choice. As the regimens were not equitoxic, one cannot differentiate between an ineffective schedule and an ineffective dose as the reason for the differing response rates. However, the degree of myelotoxicity that already occurs will preclude any substantially higher dosing with the weekly regimen.
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Grewal T, Boudreau M, Roy M, Chamberland A, Lefebvre C, Lavigne J, Davignon J, Minnich A. Expression of gamma-IFN responsive genes in scavenger receptor over-expressing monocytes is associated with xanthomatosis. Atherosclerosis 1998; 138:335-45. [PMID: 9690917 DOI: 10.1016/s0021-9150(98)00048-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We have recently described an inherited over-expression of the macrophage scavenger receptor (SR) in blood monocytes from members of a kindred, only two of whom displayed extensive xanthomatosis. Using mRNA differential display we demonstrated abnormally high expression of the signal transducer and activator of transcription (STAT1alpha) in monocytes from the proband II-2. Expression of gamma-interferon inducible protein 10 (IP-10), a STAT1alpha-responsive gene and mediator of inflammatory response, was also abnormally expressed in the monocytes from II-2. Over-expression of both genes was restricted to monocytes from II-2 and was not observed in monocytes from the clinically unaffected family members, unlike that of SR. Gel retardation assays with THP-1 cell extracts identified gamma-IFN inducible DNA binding activity to three potential STATI DNA binding elements in the human IP-10 promoter region from nucleotides - 245 to - 188. Taken together these results suggest that gamma-interferon mediated cell activation is responsible for STAT1alpha-induced transcription of the IP-10 gene in THP-1 macrophages as well as in monocytes from II-2. Analysis of monocytes from familial hypercholesterolemic (FH) subjects, who frequently develop xanthomatosis, revealed a significant number of subjects with elevated STAT1alpha and IP-10 expression. Our data suggest that the inflammatory effects of gamma-IFN signaling could play a role in foam cell formation and xanthomatosis.
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Smelson DA, Roy M, Roy A, Santana S. Electroretinogram in withdrawn cocaine-dependent subjects. Relationship to cue-elicited craving. Br J Psychiatry 1998; 172:537-9. [PMID: 9828997 DOI: 10.1192/bjp.172.6.537] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND We have previously reported that people who are cocaine-dependent have reduced blue cone b-wave electroretinogram (ERG) responses. In this preliminary study, we examined the relationship between blue cone ERG amplitudes and craving response to cocaine cues. METHOD A new series of 14 recently withdrawn subjects who were cocaine-dependent completed a cocaine craving questionnaire at baseline, and again following exposure to laboratory cues; an ERG was also performed. RESULTS Cocaine-dependent subjects with a blunted ERG blue cone response (< 0.5 microV) showed significantly greater increases in craving following cue-exposure than subjects without the blunted ERG blue cone response. CONCLUSIONS Subjects with a blunted ERG response may represent a subgroup more vulnerable to cocaine craving and relapse.
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Kroenke K, Koslowe P, Roy M. Symptoms in 18,495 Persian Gulf War veterans. Latency of onset and lack of association with self-reported exposures. J Occup Environ Med 1998; 40:520-8. [PMID: 9636932 DOI: 10.1097/00043764-199806000-00004] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Toxic or environmental exposures have been suggested as a possible cause of symptoms reported by Gulf War veterans. To further explore this hypothesis, we analyzed findings in 18,495 military personnel evaluated in the Department of Defense Comprehensive Clinical Evaluation Program. The program was established in 1994 to evaluate Persian Gulf veterans eligible for Department of Defense medical care who had health concerns after service in the Persian Gulf during Operation Desert Shield/Desert Storm. The evaluation included a structured clinical assessment, a physician-administered symptom checklist, and a patient questionnaire addressing self-reported exposures, combat experiences, and work loss. Among 18,495 patients examined, the most common symptoms were joint pain, fatigue, headache, memory or concentration difficulties, sleep disturbances, and rash. Symptom onset was often delayed, with two-thirds of symptoms not developing until after individuals returned from the Gulf War and 40% of symptoms having a latency period exceeding one year. There was no association between individual symptoms and patient demographics, specific self-reported exposures, or types of combat experience. Increased symptom counts were associated with work loss, the number of self-reported exposures, the number of types of combat experience, and certain ICD-9 diagnostic categories, particularly psychological disorders. Prolonged latency of symptom onset and the lack of association with any self-reported exposures makes illness related to toxic exposure less likely.
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Plante M, Roy M. Operative laparoscopy prior to a pelvic exenteration in patients with recurrent cervical cancer. Gynecol Oncol 1998; 69:94-9. [PMID: 9600814 DOI: 10.1006/gyno.1998.4978] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Selecting out the true candidates for a pelvic exenteration frequently poses a difficult clinical dilemma in patients with recurrent cervical cancer after radiation therapy. Despite very thorough preoperative investigation, inoperable disease is discovered at the time of laparotomy in up to 60% of cases. SUBJECTS AND METHODS In this retrospective analysis, we report the use of operative laparoscopy in 13 patients with either biopsy proven locally recurrent cervical cancer (N = 9) or with clinically suspected tumor recurrence (N = 4). All have previously received radical radiation therapy. RESULTS Patients' ages ranged from 36 to 79 years (median, 43). The median duration of the procedure was 150 min (range,50-200) and median blood loss was 50 cc (range, 50-200). The procedure was well tolerated in all patients. There was no intraoperative complication. One deep thrombophlebitis occurred postoperatively. The laparoscopic evaluation could not be completed in one case because of a large nonmobile uterine fibroid filling the whole pelvis. At laparoscopy, metastatic tumor was identified in 9 of 12 patients (75%). An unnecessary laparotomy was avoided in 8 of those 9 cases (one had a palliative exenteration). The most common site of metastasis was in the previously radiated pelvis (7/9). Three patients had a negative laparoscopy. Two had an exenteration and one had a transureteroureterostomy. At the time of laparotomy, none were found to have disease that would have been missed at laparoscopy. CONCLUSION We conclude that operative laparoscopy may be a valuable additional step in the work-up and management of patients with locally recurrent cervical cancer. With experience in retroperitoneal surgery, the procedure can be carried out safely in previously radiated patients. We believe this approach can lower the number of unnecessary laparotomies, reduce the morbidity, and shorten the length of the postoperative recovery.
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Kiremidjian-Schumacher L, Roy M. Selenium and immune function. ZEITSCHRIFT FUR ERNAHRUNGSWISSENSCHAFT 1998; 37 Suppl 1:50-6. [PMID: 9558729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Selenium (Se), an essential nutrient required for optimal growth of mammalian cells, affects the immune functions of a host in vivo. Utilizing a mouse model system and healthy human volunteers, we have shown that Se enhances the capacity of lymphocytes to respond to stimulation with mitogen or alloantigen, to proliferate, and to differentiate into cytotoxic effector cells. Supplementation with Se resulted in a significant increase in the tumor cytotoxicity of mouse cytotoxic lymphocytes, lymphokine activated killer cells and macrophages, and human cytotoxic lymphocytes and natural killer (NK) cells. Se also appears to abrogate the age-related deficiency of lymphocytes from an aged host to respond to stimulation by proliferation and differentiation into cytotoxic effector cells. These effects occurred in the absence of changes in the endogenous levels of interleukin-1, interleukin-2, or interferon-gamma, and were related to the ability of Se to enhance the expression of the alpha (p55) and/or beta (p70/75) subunits of the interleukin-2 receptor (IL-2R) on the surface of activated lymphocytes and NK cells. This resulted in a greater number of functional IL-2R/cell and in enhanced proliferation and clonal expansion of cytotoxic precursor cells. The molecular mechanism that mediates the effects of Se on immune cell function does not appear to be related to the function of Se as an antioxidant or to gene activation.
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Engel CC, Roy M, Kayanan D, Ursano R. Multidisciplinary treatment of persistent symptoms after Gulf War service. Mil Med 1998; 163:202-8. [PMID: 9575762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Research suggests that individuals commonly describe persistent symptoms or syndromes after a war. After the Persian Gulf War, the Department of Veterans Affairs and the Department of Defense initiated registries and expedited health care for those with Gulf War-related health concerns. At Walter Reed Army Medical Center, the Gulf War Health Center was created in mid-1994 to contribute a continuum of care for those with Gulf War-related health problems. The purpose of this report is to describe the Gulf War Health Center's Specialized Care Program, a 3-week intensive outpatient multidisciplinary treatment program for people with persistent, disabling Gulf War-related symptoms. The program uses an evidence-based model of multidisciplinary care employed at chronic pain centers internationally and shown to yield stable improvements in pain, mood, health care use, and return to work rates. A patient is described to illustrate how the program works. Finally, a Deployment Medicine Treatment Center is proposed, a multidisciplinary treatment center like the Specialized Care Program that would offer care to those with persistent, disabling symptoms after all future deployments.
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Roy M. [Substance dependence and vaccination]. L'INFIRMIERE DU QUEBEC : REVUE OFFICIELLE DE L'ORDRE DES INFIRMIERES ET INFIRMIERS DU QUEBEC 1998; 5:50. [PMID: 9708171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Driedger M, Rippin-Sisler C, Roy M. Lessons learned. THE CANADIAN NURSE 1998; 94:51-52. [PMID: 9573901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Hardy JF, Bélisle S, Dupont C, Harel F, Robitaille D, Roy M, Gagnon L. Prophylactic tranexamic acid and epsilon-aminocaproic acid for primary myocardial revascularization. Ann Thorac Surg 1998; 65:371-6. [PMID: 9485231 DOI: 10.1016/s0003-4975(97)01016-3] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND The efficacy of prophylactic epsilon-aminocaproic acid and tranexamic acid to reduce transfusions after primary myocardial revascularization was evaluated in a teaching hospital context. METHODS Patients (n = 134) received either epsilon-aminocaproic acid (15-g bolus + infusion of 1 g/h), high-dose tranexamic acid (10-g bolus + placebo infusion), or normal saline solution in a double-blind fashion. Anticoagulation and conduct of cardiopulmonary bypass were standardized. RESULTS Tranexamic acid and epsilon-aminocaproic acid produced a significant reduction in postoperative blood loss compared with placebo (median loss, 438 mL, 538 mL, and 700 mL, respectively). Transfusion of red cells was similar in all three groups. Nonetheless, the percentage of patients receiving hemostatic blood products was significantly decreased in the epsilon-aminocaproic acid group compared with the placebo group (20% versus 43%; p = 0.03). Both tranexamic acid and epsilon-aminocaproic acid significantly decreased total exposure to allogeneic blood products compared with placebo (p = 0.01 and p = 0.05, respectively), and this reduction was clinically important (median exposure, 2, 2, and 7.5 units, respectively). Fibrinolysis was inhibited significantly in both treatment groups. CONCLUSIONS We conclude that either high-dose tranexamic acid or epsilon-aminocaproic acid effectively reduces transfusions in patients undergoing primary, elective myocardial revascularization.
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Roy M, Perrot JL, Fond L, Cuilleron M, Misery L, Michel JL, Cambazard F. Pancréatite lupique : récidive à 1 an d'intervalle. Rev Med Interne 1998. [DOI: 10.1016/s0248-8663(98)90135-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Roy M, Guy C, Cathébras P, Sauron C, Ollagnier M, Rousset H. Angio-œdème induit par les inhibiteurs de l'enzyme de conversion : à propos de 16 observations. Rev Med Interne 1998. [DOI: 10.1016/s0248-8663(98)90099-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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291
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Jennings P, Roy M, Heidary D, Gross L. Folding pathway of interleukin-1 beta. NATURE STRUCTURAL BIOLOGY 1998; 5:11. [PMID: 9437419 DOI: 10.1038/nsb0198-11a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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292
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Becquemin MH, Bouchikhi A, Croix N, Malarbet JL, Bertholon JF, Roy M. Experimental measurements of particle retention efficiency of filters used to prevent contamination in respiratory devices. Intensive Care Med 1998; 24:81-5. [PMID: 9503227 DOI: 10.1007/s001340050520] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Various types of filters have been designed to prevent cross contamination of ventilation and respiratory devices. The aim of this study was to experimentally measure the retention efficiency of four simple filters (antibacterial and antiviral and seven combined filters (antibacterial and antiviral plus heat and water exchangers). SETTING The respiratory function testing (EFR) central department of a university teaching hospital. MEASUREMENTS AND RESULTS The same aerosol test with a wide range of particle sizes (0.15 to 15 micrometers) was used to compare the retention efficiency of each filter used in various conditions. The particle sizes and the concentration of the aerosol were measured by a laser velocimeter. For all the filters studied, the retention efficiency was found to be higher than 99%. However some of them let large particles let through. CONCLUSION These data, performed in vitro, should be assessed also by further clinical studies.
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Roy M, Bouchou K, Sauron C, Cathébras P, Bencharif L, Jaubert J, Rousset H. Hypothyroïdie suivie de maladie de Basedow sous interféron alpha. Rev Med Interne 1998. [DOI: 10.1016/s0248-8663(98)90232-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Michel JL, Rabeisen N, Roy M, Perrot JL, Godard W, Cambazard F. Une nouvelle indication de la vitamine D2: la pustulose exanthématique de la grossesse (impétigo herpétiforme). Rev Med Interne 1998. [DOI: 10.1016/s0248-8663(98)90248-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Fond L, Perrot S, Michel JL, Tardy B, Misery L, Guy C, Roy M, Cambazard F. Interactions héparine-ilomédine®. Rev Med Interne 1998. [DOI: 10.1016/s0248-8663(98)90154-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Roy M, Chen JC, Miller M, Boyaner D, Kasner O, Edelstein E. Epidemic Bacillus endophthalmitis after cataract surgery I: acute presentation and outcome. Ophthalmology 1997; 104:1768-72. [PMID: 9373105 DOI: 10.1016/s0161-6420(97)30028-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE The purpose of the study is to report the clinical outcome of acute Bacillus endophthalmitis after cataract surgery. DESIGN The study design is a cohort study. PARTICIPANTS Fourteen eyes of 14 patients with epidemic acute postoperative inflammation after exposure to bacteria-contaminated viscoelastic material were studied. INTERVENTION Three patients with milder clinical presentations were treated without vitrectomy or antibiotics. Eleven patients with more severe infection were treated with vitrectomy as well as intravitreous and topical fortified antibiotics. MAIN OUTCOME MEASURES Final visual acuities were obtained in all 14 study patients. Results of microbiologic studies of aqueous and vitreous specimens from 11 vitrectomized eyes also were analyzed. RESULTS One patient with late presentation had severe inflammation and had phthisis bulbi develop with no light perception. The remaining 13 patients had successful resolution of inflammation after treatment by 1 month of follow-up. Twelve of these 13 patients, including 1 nonvitrectomized patient, had final visual acuities of 20/100 or better at 6 months' follow-up. Six patients, including two patients with nonvitrectomized eyes, had outcomes of 20/40 or better visual acuity. Bacillus species were grown from all 11 (100%) vitreous and 7 (88%) of 8 aqueous specimens obtained from vitrectomized patients, as well as from the contaminated viscoelastic material remaining in the operating room. CONCLUSIONS Postoperative Bacillus endophthalmitis need not result in poor outcome. Results depend on factors including bacterial load, specific bacterial species, timing of treatment, and immune status of the patient.
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Smelson DA, Roy A, Roy M. Risperidone diminishes cue-elicited craving in withdrawn cocaine-dependent patients. CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 1997; 42:984. [PMID: 9429074 DOI: 10.1177/070674379704200920] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Roy M, Roy A, Smelson D, Brown S, Weinberger L. Reduced blue cone electroretinogram in withdrawn cocaine dependent patients: a replication. Biol Psychiatry 1997; 42:631-3. [PMID: 9376460 DOI: 10.1016/s0006-3223(97)00294-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Newlon MG, Roy M, Hausken ZE, Scott JD, Jennings PA. The A-kinase anchoring domain of type IIalpha cAMP-dependent protein kinase is highly helical. J Biol Chem 1997; 272:23637-44. [PMID: 9295304 DOI: 10.1074/jbc.272.38.23637] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Subcellular localization of the type II cAMP-dependent protein kinase is controlled by interaction of the regulatory subunit with A-Kinase Anchoring Proteins (AKAPs). This contribution examines the solution structure of a 44-residue region that is sufficient for high affinity binding to AKAPs. The N-terminal dimerization domain of the type IIalpha regulatory subunit of cAMP-dependent protein kinase was expressed to high levels on minimal media and uniformly isotopically enriched with 15N and 13C nuclei. Sequence-specific backbone and side chain resonance assignments have been made for greater than 95% of the amino acids in the free dimerization domain using high resolution multidimensional heteronuclear NMR techniques. Contrary to the results from secondary structure prediction algorithms, our analysis indicates that the domain is highly helical with a single 3-5-residue sequence involved in a beta-strand. The assignments and secondary structure analysis provide the basis for analyzing the structure and dynamics of the dimerization domain both free and complexed with specific anchoring proteins.
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Heidary DK, Gross LA, Roy M, Jennings PA. Evidence for an obligatory intermediate in the folding of interleukin-1 beta. NATURE STRUCTURAL BIOLOGY 1997; 4:725-31. [PMID: 9303000 DOI: 10.1038/nsb0997-725] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The folding of the beta-sheet protein, interleukin-1 beta, was examined at pH 5.0 and 25 degrees C using pulse-labelling hydrogen exchange and electrospray ionization mass spectrometric analysis, as well as stopped-flow circular dichroism and fluorescence spectroscopies. The first detectable event is the formation of a partially folded intermediate in a kinetic step with a relaxation time of 126 +/- 26 ms. There is a lag in native protein production of at least 400 ms. Optical studies indicate that the intermediate is converted to the native species in a reaction with a relaxation time of 43 +/- 5 s. The kinetic rates determined from stopped-flow fluorescence, circular dichroism and pulse-labelling experiments are similar and consistent with a simple sequential model for the folding pathway of interleukin-1 beta at pH 5.0 and 25 degrees C. Taken together, our data provide kinetic evidence that formation of the native state of interleukin-1 beta proceeds through an obligatory intermediate. We explain our results in terms of the classical and new views of protein folding.
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