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Gonsalves KE, Li H, Perez R, Santiago P, Jose-Yacaman M. Synthesis of nanostructured metals and metal alloys from organometallics. Coord Chem Rev 2000. [DOI: 10.1016/s0010-8545(00)00301-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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152
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Casanueva V, Cid X, Molina M, Ferrada M, Perez R, Dios G. Serum lipids in newborns with intrauterine growth retardation. Atherosclerosis 2000. [DOI: 10.1016/s0021-9150(00)81413-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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153
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Yildiz F, Perez R, Redpath JL. Paclitaxel exposure time determines the nature of the interaction with radiation in HeLa cells. the role of apoptosis. Eur J Cancer 2000; 36:1426-32. [PMID: 10899657 DOI: 10.1016/s0959-8049(00)00115-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The purpose of the present study was to investigate further the mechanisms underlying subadditive and superadditive interactions of radiation and paclitaxel treatments in vitro. The protocol studied was a fixed radiation treatment (7 Gy) followed either immediately or after a 10 h delay by paclitaxel treatment. Paclitaxel treatment was exposure to either a fixed dose of paclitaxel (10 nM) for varying time intervals up to 25 h, or varying doses of paclitaxel up to 20 nM for a fixed exposure time of 24 h. The cells used were HeLa. Cell survival was assessed by colony forming ability and apoptosis was measured by flow cytometry. The results show that when the paclitaxel exposure time was 24 h superadditive interactions were observed at all paclitaxel doses. A reasonable correlation between surviving fraction as measured by colony forming ability and apoptosis in the attached cells at the end of paclitaxel treatment was observed. The nature of the interaction of radiation and subsequent paclitaxel treatment is critically dependent on the duration of the paclitaxel treatment.
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Perez R, Gumbsch P. Directional anisotropy in the cleavage fracture of silicon. PHYSICAL REVIEW LETTERS 2000; 84:5347-5350. [PMID: 10990940 DOI: 10.1103/physrevlett.84.5347] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/1999] [Indexed: 05/23/2023]
Abstract
Total-energy pseudopotential calculations are used to study the cleavage anisotropy in silicon. It is shown that cracks propagate easily on 111 and 110 planes provided crack propagation proceeds in the <1;10> direction. In contrast, if the crack is driven in a <001> direction on a 110 plane the bond breaking process is discontinuous and associated with pronounced relaxations of the surrounding atoms, which results in a large lattice trapping. The different lattice trapping for different crack propagation directions can explain the experimentally observed cleavage anisotropy in silicon single crystals.
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Sharkey J, Chovnick SD, Behar RJ, Perez R, Otheguy J, Rabinowitz R, Solc Z, Huff W, Cantor A, Steele J, Webster C, Donohue M. Evolution of techniques for ultrasound-guided palladium 103 brachytherapy in 950 patients with prostate cancer. TECHNIQUES IN UROLOGY 2000; 6:128-34. [PMID: 10798814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
PURPOSE Brachytherapy is an effective, low-morbidity, cost-effective treatment for adenocarcinoma of the prostate. Although both iodine 125 and palladium 103 have been used extensively over the last 14 years, 103Pd (Theraseed) provides a more rapid initial dose and therefore better control of higher Gleason grade tumors. We assessed a highly refined methodology for 103Pd brachytherapy in patients with prostate cancer and compared outcomes before and after making adjustments in technique. MATERIALS AND METHODS Standard brachytherapy techniques were modified to include combination of preplanning with real-time adjustment, placing all needles at once to minimize prostate movement, using monitored anesthesia control sedation during preoperative volume study and cystoscopy, and several other small but important changes. Charts were reviewed from 950 patients treated with 103Pd implants from 1991 through 1999. Prostate-specific antigen (PSA) and biopsy data before and after 1993 were compared for 733 patients whose data qualified for analysis. RESULTS At 1 and 5 years after treatment, 85-88% of patients had stable PSA <1.5 ng/mL. Biopsies were negative in 90-94% at 2 years. CONCLUSION The modification in techniques provides positive results that remain stable over time.
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Panichi V, Migliori M, De Pietro S, Metelli MR, Taccola D, Perez R, Palla R, Rindi P, Cristofani R, Tetta C. Plasma C-reactive protein in hemodialysis patients: a cross-sectional, longitudinal clinical survey. Blood Purif 2000; 18:30-6. [PMID: 10686440 DOI: 10.1159/000014405] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In hemodialysis patients, C-reactive protein (CRP), an acute-phase reactant, is a sensitive and independent marker of malnutrition, anemia, and amyloidosis. The aim of the present studies was to evaluate CRP and interleukin 6 levels in plasma samples from long-term hemodialysis patients on different extracorporeal modalities associated with or without backfiltration. Two hundred and forty-seven patients were recruited in eight hospital-based centers. All patients had been on their dialytic modality for at least 6 months. At enrollment, 46 hemodialysis patients out of 247 (18.6%) had clinical evidence of pathologies known to be associated with high CRP values. The 201 remaining patients were defined as clinically stable and were on conventional hemodialysis (34%), hemodiafiltration with infusion volumes <10 liters/session (10%), hemodiafiltration with infusion volumes <20 liters/session (32%), and double-chamber hemodiafiltration with infusion volumes <10 liters/session (22%). Analysis of CRP values in the clinically stable patients showed that an unexpectedly high proportion (47%) of the patients had CRP values higher than 5 mg/l (taken as the upper limit in normal human subjects). The values of CRP and interleukin 6 were significantly higher in hemodiafiltration with infusion volumes <10 liters/session than in hemodiafiltration with infusion volumes >20 liters/session, in hemodialysis and in double-chamber hemodiafiltration. The same pattern occurred after 6 months of follow-up in 171 out of 201 clinically stable patients. Hemodialytic conditions that expose to the risk of backfiltration such as low exchange volume hemodiafiltration may induce a chronic inflammatory state as reflected by increased plasma values of both CRP and interleukin 6, thus suggesting the need for hemodialytic strategies that reduce (hemodialysis with low-permeability membranes or hemodiafiltration with infusion volumes >20 liters) or eliminate (double-chamber hemodiafiltration) backfiltration of bacteria-derived contaminants.
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Sharkey J, Chovnick SD, Behar RJ, Perez R, Otheguy J, Rabinowitz R, Steele J, Webster C, Donohue M, Solc Z, Huff W, Cantor A. Minimally invasive treatment for localized adenocarcinoma of the prostate: review of 1048 patients treated with ultrasound-guided palladium-103 brachytherapy. J Endourol 2000; 14:343-50. [PMID: 10910150 DOI: 10.1089/end.2000.14.343] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To assess the effectiveness of palladium-103 brachytherapy in stage T1 and T2 adenocarcinoma of the prostate. PATIENTS AND METHODS The charts of 1048 patients treated between 1991 and 1999 with transperineal realtime ultrasound-guided (103)Pd (Theraseed) implants were reviewed to assess the effects on serum prostate specific antigen (PSA) values and tissue (biopsy). Of the 1048 patients, 780 had sufficient data for this report. Preoperative total androgen blockade (leuprolide and flutamide) was used selectively in patients whose prostate size was >50 cc and those whose tumors had a Gleason score of >7. RESULTS At 1 year, 86% of the evaluable 766 patients had stable PSA concentration <1.5 ng/mL; at 5 years, 86% of the 166 patients with data available had stable PSA values <1.5 ng/mL. Biopsies were negative in 92% of the patients studied at 2 years. Patients with pretreatment PSA values <10 ng/mL had the best outcomes, and those treated with (103)Pd plus hormone ablation achieved PSA reduction more rapidly than those treated with radioisotope monotherapy. There was one disease-related death; the principal morbidity was short-term bladder and bowel irritation without permanent sequelae. Impotence occurred in approximately 15% of patients, and incontinence occurred in 5% of those who had undergone prior transurethral resection of the prostate. CONCLUSION The technique used in this study proved effective in reducing PSA concentrations to <1.5 ng/mL and in producing negative biopsies 1 and 2 years postoperatively. These results are comparable to those of external-beam radiation therapy and radical prostatectomy while demonstrating a significant reduction in morbidity.
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Liotti M, Woldorff MG, Perez R, Mayberg HS. An ERP study of the temporal course of the Stroop color-word interference effect. Neuropsychologia 2000; 38:701-11. [PMID: 10689046 DOI: 10.1016/s0028-3932(99)00106-2] [Citation(s) in RCA: 457] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The electrophysiological correlates of the Stroop color-word interference effect were studied in eight healthy subjects using high-density Event-Related Potentials (ERPs). Three response modalities were compared: Overt Verbal, Covert Verbal, and Manual. Both Overt Verbal and Manual versions of the Stroop yielded robust Stroop color-word interference as indexed by longer RT for incongruent than congruent color words. The Incongruent vs Congruent ERP difference wave presented two effects. A first effect was a medial dorsal negativity between 350-500 ms post-stimulus (peak at 410 ms). This effect had a significantly different scalp distribution in the Verbal and Manual Stroop versions, with an anterior-medial focus for overt or covert speech, and a broader medial-dorsal distribution for the manual task. Dipole source analysis suggested two independent generators in anterior cingulate cortex. Later on in time, a prolonged positivity developed between 500-800 ms post-stimulus over left superior temporo-parietal scalp. This effect was present for all the three response modalities. A possible interpretation of these results is that Stroop color-word interference first activates anterior cingulate cortex (350-500 ms post-stimulus), followed by activation of the left temporo-parietal cortex, possibly related to the need of additional processing of word meaning.
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Pendyala L, Creaven PJ, Schwartz G, Meropol NJ, Bolanowska-Higdon W, Zdanowicz J, Murphy M, Perez R. Intravenous ifosfamide/mesna is associated with depletion of plasma thiols without depletion of leukocyte glutathione. Clin Cancer Res 2000; 6:1314-21. [PMID: 10778956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Depletion of cellular glutathione (GSH) enhances the efficacy of many anticancer agents in preclinical systems. Limited published data showing depletion of GSH in vitro and in patients by ifosfamide and/or mesna provided the rationale for a Phase I trial. Ifosfamide and mesna were infused over 24 and 36 h, respectively, at equal daily doses; carboplatin was given after ifosfamide to a target plasma area under the curve of 4 mg x min x ml(-1). Plasma and peripheral WBC thiols were quantitated by high-performance liquid chromatography. The dose of ifosfamide was escalated from 2 to 8 g/m2; the maximum tolerated dose was 6 g/m2. Significant depletion in plasma cysteine and homocysteine, precursors for GSH synthesis, was observed (maximum, 95% to >99% at 8 g/m2). Plasma mesna and cysteine/ homocysteine levels were inversely correlated; nadir levels of cysteine/homocysteine were maintained for several hours after ifosfamide infusion had stopped and while mesna infusion was continuing. In vitro coincubation experiments confirmed that mesna reduces these thiols from disulfides to sulfhydryls, which are readily cleared, as evidenced by the significantly increased rate of excretion of cysteine in urine. In contrast, ifosfamide/mesna treatment caused a moderate depletion of plasma GSH in only 60% of the patients, with a nadir at 24 h and recovery immediately after the end of ifosfamide infusion. The GSH depletion in these patients was not dose related. The profile of GSH recovery in plasma after ifosfamide and the fact that mesna could not reduce GSH disulfides in vitro suggest that the observed GSH depletion in plasma in 60% of the patients may be related to direct reactions of GSH with ifosfamide metabolites and/or mesna. Our results indicate that mesna is a modulator of GSH precursors and that a prolonged infusion of mesna may be required to achieve GSH precursor starvation and the consequent GSH depletion in cells.
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Adkins B, Bu Y, Cepero E, Perez R. Exclusive Th2 primary effector function in spleens but mixed Th1/Th2 function in lymph nodes of murine neonates. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:2347-53. [PMID: 10679069 DOI: 10.4049/jimmunol.164.5.2347] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Recent studies have shown that neonatal mice are competent to develop mature, Ag-specific Th1 function in situ. However, under many conditions, Th2 responses dominate in the neonate, while Th1 responses are more prevalent in adults. To compare further the immune responses of neonates and adults, we used the enzyme-linked immunospot method to measure the frequencies of primary Th1/Th2 effectors generated in situ in the spleens and lymph nodes. As assessed by the detection of IFN-gamma- or IL-4-producing cells, adults developed mixed Th1/Th2 responses in both organs. Neonatal lymph nodes contained mature frequencies of IFN-gamma- and IL-4-producing cells. In striking contrast, while mature frequencies of Th2 cells developed in neonatal spleens, virtually no IFN-gamma-secreting cells were detected. Exclusive Th2 function was observed in both BALB/c and C57BL/6 neonates, strains in which the Th2 and Th1 lineages, respectively, are favored in adults. Although Th1 effectors were virtually undetectable, the addition of rIL-12 boosted the frequency of IFN-gamma-secreting cells to adult levels. Therefore, Th1 effectors apparently developed in situ, but Th1 effector function either was not promoted or was inhibited upon subsequent exposure to the Ag in culture. Together, these results indicate that the quality of a primary Th response in neonates is strongly dependent on the site of initial Ag exposure; responses initiated in the lymph nodes are mixed Th1/Th2, whereas responses occurring in the spleen are heavily Th2 biased.
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Albareda A, Perez R, Kayombo JH, Minguella E, Casals JA. Nonlinear mechanical behavior of piezocomposites for ultrasonic transducers. ULTRASONICS 2000; 38:151-155. [PMID: 10829648 DOI: 10.1016/s0041-624x(99)00179-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A comparative study is carried out between the nonlinear behavior of a composite and the piezoceramic used to obtain it. This characterization is necessary for using the composite in power transducer applications. A study of the losses and the resonator stiffness variations has also been done. Both these effects, as well as the possibility of the frequency hysteresis, show different behavior in the composites, since the increases in the ceramics are different from those in the composites. In this study two measurement methods are used: principally the motional impedance increase with the motional current measurements. The results obtained are normalized in order to make them independent of the resonator size, and thus make the comparison between the composite and the ceramic easier. The figure of the mechanical loss tangent tan delta m versus the mean strain <S> shows that the losses can be greater in the ceramic than in the composite for soft ceramics. The dependence behavior of the losses and stiffness variations versus the mean strain is studied for both resonators.
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Li Q, Zamorano L, Jiang Z, Gong JX, Pandya A, Perez R, Diaz F. Effect of optical digitizer selection on the application accuracy of a surgical localization system-a quantitative comparison between the OPTOTRAK and flashpoint tracking systems. COMPUTER AIDED SURGERY : OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY FOR COMPUTER AIDED SURGERY 2000; 4:314-21. [PMID: 10631374 DOI: 10.1002/(sici)1097-0150(1999)4:6<314::aid-igs3>3.0.co;2-g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Application accuracy is a crucial factor for stereotactic surgical localization systems, in which space digitization camera systems are one of the most critical components. In this study we compared the effect of the OPTOTRAK 3020 space digitization system and the FlashPoint Model 3000 and 5000 3D digitizer systems on the application accuracy for interactive localization of intracranial lesions. A phantom was mounted with several implantable frameless markers which were randomly distributed on its surface. The target point was digitized and the coordinates were recorded and compared with reference points. The differences from the reference points represented the deviation from the "true point." The root mean square (RMS) was calculated to show the differences, and a paired t-test was used to analyze the results. The results with the phantom showed that, for 1-mm sections of CT scans, the RMS was 0.76 +/- 0. 54 mm for the OPTOTRAK system, 1.23 +/- 0.53 mm for the FlashPoint Model 3000 3D digitizer system, and 1.00 +/- 0.42 mm for the FlashPoint Model 5000 system. These preliminary results showed that there is no significant difference between the three tracking systems, and, from the quality point of view, they can all be used for image-guided surgery procedures.
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Molina M, Ferrada C, Perez R, Cid L, Casanueva V, Aedo C, Farias Y, Oyarzun P, Paredes P, Rosal B. Eclampsia in adolescence. Int J Gynaecol Obstet 2000. [DOI: 10.1016/s0020-7292(00)85123-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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164
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Garcia JE, Perez R, Albareda A, Minguella E. Nonlinear behavior in a piezoelectric resonator: a method of analysis. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2000; 47:921-928. [PMID: 18238626 DOI: 10.1109/58.852075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Theories used for understanding nonlinear behavior of piezoelectric resonators are usually only valid for a given range of amplitudes. Thus, important discrepancies can sometimes be observed between theory and experiment. In this work, a simplified model of the resonator is assumed in order to extend the analysis of nonlinear behavior to any kind of nonlinear function, without a significant increase of mathematical complexity. Nevertheless, nonlinearities are considered to be weak enough to be taken as perturbations. An asymptotic method is used to obtain the first and second order perturbations of the response to an harmonic excitation applied to the system, and each one is separated into Fourier series. Nonlinearity is described by two functions-Phi, (S,D,S ,D ) and Psi (S,D,S ,D )-that must be added to the constitutive equations that give T and E as functions of S and D. These functions can be split into their symmetrical and antisymmetrical parts, which have different incidence over the perturbation terms. In order to simplify the problem, no mechanical excitation is considered, the electrical one is taken as strictly harmonic, and the current rather than the e.m.f. is taken as initial data. As an application example, this method is applied in order to find the second harmonic generation for a particular kind of nonlinearity.
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Calhoun BC, Jennings BM, Peniston J, Patience T, Pulos E, Hume R, Perez R. Focused obstetrical clinic for active duty junior enlisted service women: model for improved outcomes. Mil Med 2000; 165:45-8. [PMID: 10658428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
OBJECTIVE To evaluate the utility of an interdisciplinary clinic in improving perinatal outcomes for all pregnant patients of junior enlisted rank (E4 and below) in response to previous reports that this group is at higher risk for adverse outcomes. METHODS The study population included all junior enlisted active duty patients (E4 and below) delivering between January 1, 1993, and June 30, 1996. Outcomes for patients receiving care in a focused active duty obstetrical clinic were compared with outcomes in similar cohorts of senior active duty patients (E5 and above) and non-active duty pregnant patients. Evaluation was based on perinatal outcomes, including chorioamnionitis, postpartum hemorrhage, intrauterine growth retardation, cesarean delivery, preterm delivery rates (< 37 weeks), postterm delivery rates (> 41 weeks), postpartum days, mean gestational age at delivery, mean delivery weights, Apgar scores at 1 and 5 minutes, preeclampsia, and premature labor. Variables with potential to confound perinatal outcomes were also studied. Confounding variables included tobacco use, gestational diabetes, chronic hypertension, thyroid disease, history of substance abuse, and alcohol use. Power analysis accomplished before initiation of the study showed adequate sample size (> 240 patients in each group) to demonstrate statistically different rates of preterm delivery. Statistical analysis was done using the chi 2 test for categorical variables and Student's t test for continuous variables. RESULTS There were no statistical differences between junior active duty patients, senior active duty patients, and non-active duty patients in preterm delivery and other outcome variables. CONCLUSION The focused obstetrical clinic, conducted for junior enlisted soldiers by a senior nurse practitioner, appears to provide an intervention that ensures perinatal outcomes equal to those of both the non-active duty and the senior active duty population.
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Santoro A, Panzetta G, Tessitore N, Atti M, Mancini E, Esteban J, London G, Ara JM, Miguel JL, Neumann KH, Opatrny K, Perez R, Perrone B, Wizemann V, Zucchelli P. A prospective randomised European multicentre study of medium-long run mortality and morbidity comparing acetate-free biofiltration and bicarbonate dialysis. J Nephrol 1999; 12:375-82. [PMID: 10626827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
In recent years, the progressive increase in the mean age of the population entering chronic dialysis treatment has been responsible, on the one hand, for the growing number of patients undergoing regular dialysis, and on the other, for the high number of "critical" patients, both as a result of their age and the presence of concomitant morbidity. Thus, dialysis treatment today is not only aimed at waste removal and water-electrolyte homeostasis, but also at a reduction in morbidity and mortality, and at improving the patients' quality of life, thanks to the use of biocompatible materials and the achievement of good cardiovascular tolerance to treatment. Consequently, diffusive-convective dialysis procedures have been on the increase, since they combine better depuration with the use of biocompatible high-flux membranes. Acetate-free biofiltration (AFB) is a diffusive-convective dialysis procedure which utilises a high-flux membrane, AN69, post-dilution infusion of a sodium bicarbonate solution (NaHCO3), and a dialysate which is completely free of any buffer, and thus also free of acetate, which may have various negative effects on the patient. A number of studies have already shown the better hemodynamic stability and the reduction of intradialytic side-effects during AFB. All these, however, were short-term studies. To verify the beneficial effects of AFB in the long run, a three year multicentre randomised European trial has been proposed to compare bicarbonate hemodialysis (BD), a technique used in nearly 80% of the world's dialysis population, and AFB. The specific aim of the investigation is to verify, in a large number of patients, the results of hemodialysis treatment in terms of morbidity, mortality and quality of life. The study involves 80 hemodialysis units across Italy, France, Germany, Spain, Slovenia and Croatia, with enrollment of about 400 patients considered "critical" for at least one of the following reasons: age, diabetes, dialysis cardiovascular instability. Fifty percent of the patients are to undergo AFB with the AN69 membrane and bicarbonate solution infusion (NaHCO3 145 or 167 mEq/lt), and the other fifty percent are to be treated by BD, with any membrane except the nonmodified cellulosic one. Biochemical, cardiological, and nutritional parameters will be considered throughout the study. Mortality, morbidity both in terms of intra- and interdialysis symptoms - and hospitalisation rate, as well as the patients' quality of life, evaluated by the SF36 questionnaire, will be analysed.
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Montero E, Falcon L, Morera Y, Delgado J, Amador JF, Perez R. CD6 molecule may be important in the pathological mechanisms of lymphocytes adhesion to human skin in psoriasis and ior t1 MAb a possible new approach to treat this disease. Autoimmunity 1999; 29:155-6. [PMID: 10433078 DOI: 10.3109/08916939908995386] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Perez R, Gonzalez F, Justo MS, Ulibarrena C. Interocular temporal delay sensitivity in the visual cortex of the awake monkey. Eur J Neurosci 1999; 11:2593-5. [PMID: 10383650 DOI: 10.1046/j.1460-9568.1999.00700.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Due to the separation of the eyes, temporal retinal disparities are created during binocular stimulation and they have been proposed to be the basis of several stereo-visual effects. This paper studies the sensitivity of cortical neurons from area V1 to interocular temporal delay in the awake monkey (Macaca mulatta). Forty-four cells were included in this study. Temporal delay sensitivity was observed in 59% of them. About half of these temporal-delay-sensitive cells were also sensitive to the stimulation sequence of the eyes. The cells that preferred one eye to be stimulated first were termed asymmetrical (46%); those which were not sensitive to the eye sequence of stimulation were termed symmetrical (54%). No clear differences were observed in the distribution of delay-sensitive cells according to their eye dominance. Fifty-six percent of balanced cells and 65% of unbalanced cells were sensitive to interocular delay. These data underline the importance of temporal cues for depth perception.
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Mir NA, Perez R, Schwallier P, Beaudry R. Relationship between ethylene response manipulation and volatile production in Jonagold variety apples. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 1999; 47:2653-2659. [PMID: 10552540 DOI: 10.1021/jf981150k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The ripening of Jonagored Jonagold apple fruit (Malus x domestica Borkh.) during development was manipulated with preharvest applications of ReTain or a combination of ReTain plus Ethrel. The fruits, harvested preclimacteric at approximately the same stages of maturity, were stored in refrigerated air (RA) for 45 days or in controlled atmosphere (CA) for 180 days at 0 degrees C. Volatile evolution, ethylene production, and respiration of stored fruit were studied during poststorage holding at 22 degrees C. ReTain reduced volatile production by 19%, but application of Ethrel to ReTain-treated fruit increased production to control levels. The inhibition of volatile production by ReTain appears to be independent of respiration but may be related to the ethylene-producing capacity of the fruit. Although ReTain reduced flavor-related volatile esters, it did not affect levels of the compound responsible for the typical spicy flavor in Jonagored Jonagold fruit, 4-methoxy-2-propenylbenzene. The CA-stored fruit had a much reduced production of volatile compounds compared to RA-stored fruit, with more discernible effects in ReTain-treated fruit. Ethrel application to ReTain-treated fruit improved the volatile production intermediate between the ReTain alone and control in CA-stored fruit. The data collectively suggest that ReTain may have some promise for better scheduling of harvest of apples with no appreciable loss in RA-stored fruit quality. Reduction in production of alpha-farnesene by ReTain may also reduce the potential for scald development in CA-stored fruit.
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Borchers AT, Perez R, Kaysen G, Ansari AA, Gershwin ME. Role of cytomegalovirus infection in allograft rejection: a review of possible mechanisms. Transpl Immunol 1999; 7:75-82. [PMID: 10544437 DOI: 10.1016/s0966-3274(99)80023-9] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Several lines of evidence indicate that viral infections, particularly with cytomegalovirus (CMV), play a role in the pathogenesis of solid organ allograft rejection. A diagnostic feature of acute rejection is infiltration of allograft parenchyma by lymphocytes, a process regulated by induction of adhesion molecules on vascular endothelial cells and their ligand on leucocytes. Data derived from biopsies of CMV-infected transplant recipients, as well as from experimental models of transplantation, indicate that CMV infection can result in an upregulation of such adhesion molecules, thereby facilitating the inflammatory process. Infection with CMV is also associated with an increased expression of MHC class II on multiple cell types. Since recognition of nonself MHC antigens is the major determinant of allograft rejection, an upregulation of these molecules could contribute to graft failure. Infection with CMV has also been implicated in the induction of smooth muscle proliferation and intimal thickening, both hallmarks of transplant atherosclerosis, which constitutes the most common cause of heart allograft failure. CMV can be classified into four, possibly five, different genotypes based on restriction length polymorphism of the envelope glycoprotein B gene; these genotypes may exhibit varied geographic and demographic frequency distributions and also differ in their pathogenicity and cell tropism. Further studies are needed to evaluate these issues and in particular the genetic contribution of the recipient to CMV modulation of rejection.
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Macias A, Arce S, Leon J, Mustelier G, Bombino G, Domarco A, Perez R, Lage A. Novel cross-reactive anti-idiotype antibodies with properties close to the human intravenous immunoglobulin (IVIg). Hybridoma (Larchmt) 1999; 18:263-72. [PMID: 10475241 DOI: 10.1089/027245799315925] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The most important link between the immune network theory and clinically useful therapies so far is the use of human intravenous immunoglobulin (IVIg) in the treatment of autoimmune diseases. Although still controversial, one of the main mechanisms that has been postulated for the in vivo effects of IVIg, is the selection of immune repertoires through idiotypic interactions. We describe here anti-idiotype IgG monoclonal antibodies (MAbs), which were obtained by immunization of syngeneic mice (Balb/c) with an anti-ganglioside antibody. These anti-idiotype MAbs show multiple idiotypic connections and share some of the properties of the IVIg pool. The antiidiotype (Ab2) MAbs B7 and 34B7 showed heterogeneous binding with the idiotypes of several anti-ganglioside antibodies, MAbs obtained from splenocytes of nonimmunized newborn mice, F(ab')2 fragments of IgG human myeloma proteins, and nonimmunoglobulin antigens. The recognition pattern of the B7 MAb to the idiotypes of human immunoglobulins was also studied using a phage display library obtained from the variable region genes of an asymptomatic AIDS patient and also F(ab')2 fragments obtained from an IVIg pool of healthy human donors. We also demonstrated that these MAbs produced some of the in vitro effects reported for the human IVIg pool, such as the inhibition of cell proliferation of human B and T cell lines and of normal human lymphocytes activated with different mitogens. Another striking property of the MAb B7 was its ability to induce a dose-dependent specific antibody T-cell response in vivo in syngeneic mice. Both anti-idiotype MAbs showed anti-metastatic effect in vivo when injected intravenously to mice inoculated with MB16-F10 melanoma cells. The antimetastatic effect of the antiidiotype MAbs was not observed in athymic mice inoculated with the same tumor. This kind of antibody can become an interesting tool for further exploration of the role of idiotypic network connections in the regulation of the immune system and to study the effects of interventions on network connectivity in experimental autoimmune disease, using a reagent better chemically defined than the IVIg pool.
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MESH Headings
- Animals
- Antibodies, Anti-Idiotypic/immunology
- Antibodies, Anti-Idiotypic/therapeutic use
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/therapeutic use
- Autoimmune Diseases/immunology
- Autoimmune Diseases/therapy
- B-Lymphocytes/cytology
- B-Lymphocytes/immunology
- Cell Division
- Cell Line
- Cross Reactions
- G(M2) Ganglioside/immunology
- Humans
- Immunoglobulin G/immunology
- Immunoglobulin G/therapeutic use
- Immunoglobulin Idiotypes/immunology
- Immunoglobulins, Intravenous/immunology
- In Vitro Techniques
- Melanoma, Experimental/immunology
- Melanoma, Experimental/secondary
- Melanoma, Experimental/therapy
- Mice
- Mice, Inbred C57BL
- Mice, Nude
- T-Lymphocytes/cytology
- T-Lymphocytes/immunology
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172
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Padillo FJ, Regueiro JC, Canis M, Zurera L, Perez R, Del Castillo D, Diaz C, Solorzano G, Pera-Madrazo C. Percutaneous management of a high-output duodenal fistula after pancreas transplantation using occluding coiled embolus and fibrin sealant. Transplant Proc 1999; 31:1715-6. [PMID: 10331048 DOI: 10.1016/s0041-1345(99)00074-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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173
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Martinez A, Gonzalez F, Capeans C, Perez R, Sanchez-Salorio M. Dorzolamide effect on ocular blood flow. Invest Ophthalmol Vis Sci 1999; 40:1270-5. [PMID: 10235564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
PURPOSE To evaluate the effect of dorzolamide on ocular blood flow in normal and glaucomatous eyes. METHODS Twenty-six eyes with documented open-angle glaucoma of 26 patients and 13 normal control eyes of 8 age-matched subjects were included in this study. All eyes underwent color Doppler imaging for measuring peak-systolic velocity, end-diastolic velocity, and resistance index in the ophthalmic and central retinal arteries and the maximal and minimal velocities in the central retinal vein. Eyes were grouped in control and initial and advanced glaucoma categories. Measurements were made in all groups before and after application of topical dorzolamide. Intragroup comparisons between baseline and dorzolamide conditions were made using paired Student's t-test. Intergroup comparisons under baseline conditions between normal and glaucomatous eyes were made by using the one-way ANOVA test. Statistical significance was set at P < 0.05. RESULTS The peak-systolic velocity of the central retinal artery in glaucomatous eyes and the end-diastolic velocity of the ophthalmic and central retinal arteries in all groups were significantly higher after application of dorzolamide. The minimal velocity of the central retinal vein showed significantly higher values after dorzolamide, whereas the maximal velocity remained unchanged. The peak-systolic velocity of the ophthalmic artery in all groups and the peak-systolic velocity of the central retinal artery in normal eyes also remained unchanged. The resistance index was significantly lower in the ophthalmic and central retinal arteries in all groups after dorzolamide. The intraocular pressure was significantly reduced in all groups after dorzolamide. Under baseline conditions normal control eyes and glaucomatous eyes showed differences in various measurements. Peak-systolic velocity was significantly lower in glaucomatous eyes than in normal control eyes with the exception of the ophthalmic artery in the initial glaucoma group. End-diastolic velocity was lower in glaucomatous eyes than in control eyes in both arteries. Maximal and minimal velocities of the central retinal vein were lower in glaucomatous eyes than in normal control eyes. Resistance index was higher in glaucomatous eyes than in normal control eyes in the ophthalmic artery but not in the central retinal artery. CONCLUSIONS Most hemodynamic parameters of intraocular and periocular vessels improve after application of topical dorzolamide in both normal control and glaucomatous eyes. Dorzolamide should be regarded as a useful drug for treatment of glaucoma not only because it reduces intraocular pressure but also because it improves the ocular blood supply.
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174
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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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175
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London E, Rudich S, McVicar J, Wolfe B, Perez R. Equivalent renal allograft function with laparoscopic versus open liver donor nephrectomies. Transplant Proc 1999; 31:258-60. [PMID: 10083099 DOI: 10.1016/s0041-1345(98)01526-7] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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