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Suárez E, Pérez CM, Guzmán J. [Alternative methods of statistical analysis in epidemiology: frequency, likelihood, and Bayesian]. PUERTO RICO HEALTH SCIENCES JOURNAL 2000; 19:153-6. [PMID: 10909711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
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López-Ortiz MI, Pérez CM, Suárez E, Ríos-Dávila R. Variations in the survival probabilities of the PVC-protected red mangrove propagules: testing the encased replanting technique. PUERTO RICO HEALTH SCIENCES JOURNAL 1999; 18:387-95. [PMID: 10730307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
The EcoEléctrica Mangrove Planting Project, a five-year voluntary effort, has the purpose of testing a recently developed mangrove planting technique at the EcoEléctrica site in Peñuelas, Puerto Rico. The goal of the project is to provide empirical validation to promote or improve the technique to be used in recovering mangrove ecosystems in Puerto Rico and United States. The research presented herein analyzed the information collected on the first two years of the project. The proportions of remaining casings and seeds per study zone were compared using the chi-square distribution. Zone 1 had the least pipes lost while Zone 4 had the most (p < 0.05). Forty-three percent of the seeds in Zone 1 remained in the casing, while 26% remained in Zone 2 (p = 0.03). Median growth rates of seeds per study zone showed that Zone 1 had the highest median growth rates. Survival analysis described the survival experience of the seeds, and differences in survival probabilities were compared with the log-rank test. Zone 1 seeds had a better survival experience compared to Zones 2, 3 and 4 (p < 0.0001). Survival probabilities for being free of spots were over 60% during the whole study period. No significant differences were observed in the survival experience with the use-or-no use of casing extensions (p = 0.40), and the use-or-no use of nursed seeds (p = 0.26). Differences in survival probabilities might be attributed to variations in wave energy, depth or substrate conditions. This hypothesis will be evaluated in the second phase of the study.
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Disdier OM, Pérez CM, Suárez E. [A comparative study of indinavir versus ritonavir for assessing the development of opportunistic diseases in adult AIDS patients]. BOLETIN DE LA ASOCIACION MEDICA DE PUERTO RICO 1999; 91:85-90. [PMID: 10842439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
This observational study compared the probability of developing the first opportunistic infection among AIDS adult patients attending the "Programa SIDA de San Juan" who received either indinavir plus zidovudine and lamivudine (n = 45) or ritonavir plus zidovudine and lamivudine (n = 16) between August 1, 1996 and July 31, 1997. No significant differences were observed with respect to appearance of an opportunistic infection, increase in CD4 levels and decrease in viral load between both groups during the study period. However, an increased probability of being free of opportunistic infection after 10 months was observed for the indinavir group (p > 0.05). In addition, the probability of changing or interrupting prescribed therapy was 2 times higher for patients under ritonavir (p < 0.05). These results suggest the need to confirm these findings in a larger group of patients in a controlled clinical trial and to assess the short-term and long-term effects of both therapies among Puerto Rican AIDS patients.
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Suárez E, Pérez CM. [Methodological aspects of biostatistics and epidemiology in a clinical trial]. PUERTO RICO HEALTH SCIENCES JOURNAL 1999; 18:23-30. [PMID: 10343983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Various methodological issues in biostatistics and epidemiology which are relevant for the development of a clinical trial are discussed. A brief set of definitions regarding clinical trials and methods for the assignment of treatments is presented. In addition, methods to reduce the possibility of bias that may be introduced into a clinical trial are summarized. The different elements that must be included in the informed consent form are defined. General considerations for data analysis and for sample size required to obtain an adequate statistical power are illustrated. Finally, critical questions that can be used for the review of the literature on clinical trials are suggested.
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Arredondo G, Suárez E, Calvo R, Vazquez JA, García-Sanchez J, Martinez-Jordá R. Serum protein binding of itraconazole and fluconazole in patients with diabetes mellitus. J Antimicrob Chemother 1999; 43:305-7. [PMID: 11252341 DOI: 10.1093/jac/43.2.305] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The protein binding of itraconazole and fluconazole in the serum of patients with insulin-dependent (IDDM) and non-insulin-dependent (NIDDM) diabetes mellitus was investigated in vitro. The unbound percentage of itraconazole in patients with IDDM and NIDDM was significantly higher than that in healthy volunteers. In contrast, there were no significant differences in fluconazole protein binding. A negative correlation was established between itraconazole protein binding and albumin concentration, and a positive correlation with free fatty acid concentration. The existence of a larger percentage of unbound itraconazole in diabetes patients could imply a change in drug disposition and an alteration in the effect of the drug. This should be taken into consideration in long duration treatment, especially in view of the non-linear kinetics of itraconazole.
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Zamacona MK, Suárez E, García E, Aguirre C, Calvo R. The significance of lipoproteins in serum binding variations of propofol. Anesth Analg 1998; 87:1147-51. [PMID: 9806699 DOI: 10.1097/00000539-199811000-00032] [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: 11/26/2022]
Abstract
UNLABELLED The protein binding of propofol was investigated in vitro in isolated lipoprotein fractions (very low-density lipoprotein [VLDL], low-density lipoprotein [LDL], and high-density lipoprotein [HDL]) and in serum samples from the following subjects: healthy normolipemic volunteers (n = 16), hyperlipidemic subjects diagnosed with familiar polygenic hypercholesterolemia (n = 26) showing high levels of cholesterol, and elderly subjects (n = 15). Protein binding was determined by using ultrafiltration, and the concentration of unbound propofol was measured by using liquid chromatography. Levels of total cholesterol, triglycerides, VLDL cholesterol, LDL cholesterol, HDL cholesterol, albumin, and alpha1-acid glycoprotein were also measured. Propofol was extensively bound to the three lipoprotein fractions (88%+/-2% to VLDL, 93%+/-1% to LDL, and 91%+/-4% to HDL). The percentage of unbound propofol was significantly decreased (P < 0.0001) in hyperlipidemic (0.88%+/-0.20%) individuals whose levels of cholesterol and triglycerides were increased versus healthy subjects (1.26%+/-0.22%), whereas no significant difference was found in the elderly group (1.12%+/-0.23%). A positive relationship was found between serum protein binding of propofol and lipid levels. Multiple regression analysis, including all subjects, showed that changes in the levels of total cholesterol and triglycerides explained approximately 62% of the variability in the serum protein binding of propofol. These results stress the importance of triglycerides and cholesterol in the serum protein binding of propofol. We therefore suggest that these variations in lipid levels, and consequently in protein binding, may influence anesthetic practice with propofol. IMPLICATIONS We investigated the effect of serum lipids in the protein binding of propofol. We found that propofol binds extensively to all lipoprotein fractions. Propofol binding showed a significant relationship with the serum levels of cholesterol and triglycerides.
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Calvo R, Jiménez RM, Trocóniz IF, Suárez E, Gonzalo A, Lucero ML, Raczka E, Orjales A. Serum protein binding of lerisetron, a novel specific 5HT3 antagonist, in patients with cancer. Cancer Chemother Pharmacol 1998; 42:418-22. [PMID: 9771958 DOI: 10.1007/s002800050839] [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: 10/28/2022]
Abstract
The aim of this study was, (1) to characterize the serum protein binding of lerisetron, a new 5-hydroxytryptamine (5-HT3) receptor antagonist under investigation as an antiemetic agent, and (2) to measure the percentage of unbound lerisetron in cancer patients. The binding parameters were determined in human serum albumin (HSA), alpha1-acid glycoprotein (AAG) and in pooled serum from six healthy volunteers. Concentrations of lerisetron ranging from 50 ng/ml to 2 microg/ml were used. The serum protein binding of 14C-lerisetron (2 microg/ml) was determined by ultrafiltration in three groups of individuals. Group I comprised healthy subjects (n = 11), group II comprised cancer patients undergoing radiotherapy (n = 9), and group III comprised cancer patients receiving chemotherapy (n = 18). The unbound concentration of lerisetron was measured in all samples by liquid scintillation counting. Concentrations of both AAG and HSA were also measured in all serum samples. The drug was extensively bound in pooled serum, involving a nonsaturated process. In HSA, lerisetron was also highly bound (4.04+/-0.8% unbound) and the protein binding was essentially unchanged within the studied concentration range of lerisetron. The extent of binding to AAG was high but significantly lower than in serum and in HSA and was also independent of lerisetron concentration. The unbound lerisetron was significantly decreased in group II cancer patients when compared with group I subjects (2.38+/-0.64% vs 3.70+/-0.70%; P < 0.001). No significant changes in lerisetron binding were observed in group III patients. HSA was diminished in both groups of patients and AAG was only significantly increased in group II. Unbound lerisetron was correlated with AAG in group II and with HSA in group III.
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Moro A, Calixto A, Suárez E, Araña MJ, Perea SE. Differential expression of the p27Kip1 mRNA in IFN-sensitive and resistant cell lines. Biochem Biophys Res Commun 1998; 245:752-6. [PMID: 9588187 DOI: 10.1006/bbrc.1998.8512] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
IFNs arrest the growth of a small cell lung cancer (SCLC) cell line NCI-H82 in the G1 phase but not the growth of the derived cell line NCI-H82R. Progression through the G1 phase is controlled by positive and negative regulatory genes. Oncoviral genes can override this control. In this study, we compared the effects of human IFN alpha 2b on the mRNA levels of the Cdk inhibitor p27Kip1 in NCI-H82, NCI-H82R and HPV 16 E7-transfected NCI-H82 cell lines. Induction of the 2-5 Oligoadenylate synthetase (2-5 OAS) gene was used as a marker of IFN-dependent signal transduction The expression of p27Kip1 mRNA increased at 48 and 72 hr after IFN alpha 2b addition in sensitive cells. In contrast, p27Kip1 mRNA had only slight variations in both the resistant and E7-transfected cells. Interestingly, the E7-transfected NCI-H82 cells became resistant to the IFN alpha 2b anti-proliferative effect. Our results suggest that p27Kip1 could be a key mediator of the IFN alpha 2b-induced growth arrest and that HPV 16 E7 might affect p27Kip1 inducibility, originating IFN alpha 2b-resistant cells.
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Zamacona MK, Suárez E, Aguilera L, Aguirre C, Calvo R. Serum protein binding of propofol in critically ill patients. Acta Anaesthesiol Scand 1997; 41:1267-72. [PMID: 9422291 DOI: 10.1111/j.1399-6576.1997.tb04643.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Disease-induced modifications in the level of serum proteins may change the degree of binding of drugs highly bound to serum proteins. METHODS The serum protein binding of propofol, an intravenous anaesthetic agent was studied in vitro in samples of serum from healthy volunteers (n=28) and from critically ill patients (n=17). The free fraction was obtained by the ultrafiltration technique and was measured by high-performance liquid chromatography. Concentrations of serum albumin, alpha1-acid-glycoprotein and free fatty acids were also measured in all samples. RESULTS The percentage of free propofol was significantly increased (P<0.001) in critically ill patients (1.31 (1.06-2.25)%) vs control subjects (1.07 (0.49-1.47)%). Albumin levels were significantly decreased (P<0.001) in patients (16.3 (8.8-24.6) g x l(-1) vs 45.8 (31.4-55.5) g x l[-1]), while levels of alpha1-acid-glycoprotein were increased (P<0.001) (1.9 (0.9-2.8) g x l(-1) vs 0.9 (0.5-1.4) g x l[-1]), as were levels of free fatty acids (0.68 (0.50-1.14) mmol x l(-1) vs 0.37 (0.11-1.05) mmol x l(-1); P<0.05 ). No correlation was found between levels of alpha1-acid-glycoprotein or free fatty acids and the bound/free ratio of propofol. However, a linear relationship was found between levels of albumin and the bound/free ratio (r2=0.25; P<0.001). CONCLUSION In conclusion, in these critically ill patients, an increase in the percentage of free propofol occurs. The significance of this observation remains uncertain, but may be validated in future studies. However, the observation supports the common idea that potent drugs should be given with great care in critically ill patients.
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Trocóniz IF, Garrido MJ, García E, Suárez E, Calvo R. Pharmacokinetic-pharmacodynamic modeling of mivacurium in rats. J Pharm Sci 1997; 86:252-6. [PMID: 9040105 DOI: 10.1021/js960153d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of the neuromuscular blocking agent mivacurium were evaluated separately in two groups of rats receiving 0.6 mg kg-1 of mivacurium in a 2.5-min intravenous continuous (iv) infusion. The PK parameters for mivacurium were determined in the first group. A two-compartment model describes the kinetics of mivacurium in plasma. The estimates of the apparent volume of distribution at steady-state and plasma clearance [mean(SE)] were 650 (123) mL kg-1 and 9.9 (0.75) mL min-1 kg-1, respectively. In the second group, the evoked tibialis anterior muscle tension was monitored. The PK parameters derived from the first group were used to compute mivacurium plasma concentrations (C) at the times the PD measurements were recorded in the second group. The concentration-neuromuscular effect [% depression of initial twitch tension (E)] relationship was analyzed by two approaches. (1) The relationship of estimated effect site concentrations versus E; a sigmoidal Emax model described the effect compartment concentrations versus E relationship. The estimate [mean(SE)] of Cess50 (steady-state plasma concentration eliciting half of maximum E) was 0.65 (0.01) microgram mL-1. The value [mean-(SE)] of Keo (rate constant of equilibration between plasma and effect site) was estimated at 0.32 (0.03) min-1. (2) The relationship of descending limb C versus E; a sigmoidal Emax model described such relationship. The estimate [mean(SE)] of C50 (post-infusion C eliciting half of maximum E) was 0.57(0.03) microgram mL-1. The PD properties of mivacurium were also evaluated in another two groups of animals receiving either 5- or 10-min continuous iv infusion; PK and PD parameters obtained from the 2.5-min infusion experiments were used to predict the time course of E in the groups receiving 0.6 mg kg-1 of mivacurium in 5- and 10-min infusions; simulations using the estimated parameters adequately describe the time course of E in those groups. The effect of mivacurium on the mean arterial blood pressure (MAP) was also investigated; a 10% nonsignificant decrease (p > 0.05) in MAP was found in all groups.
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Mayor Becerra AM, Suárez E, Morales Bedoya A. Pneumocystis carinii pneumonia versus wasting syndrome among AIDS cases in Puerto Rico: a survival analysis. PUERTO RICO HEALTH SCIENCES JOURNAL 1996; 15:257-60. [PMID: 9097342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To compare mortality of wasting syndrome (WS) versus Pneumocystis carinii pneumonia (PCP) in AIDS patients reported in Puerto Rico after controlling for gender, age, and CD4 levels. METHODS AIDS patients for which a diagnosis of WS (n = 1,180) or PCP (n = 765), who were reported to the AIDS Surveillance System of Puerto Rico between 1989 and 1992, were used to analyze the mortality risk among these diagnoses using a Cox's proportional hazard regression model. RESULTS Cox model showed that WS patients had a 14% to 33% reduction in mortality risk compared with PCP patients after adjusting for gender and age (95% confidence level). Mortality risks for males were 18% (95% CI: 1%, 39%) higher than females risk after adjusting for AIDS defining condition and age. It was shown that a decrease in 100 CD4 cells increased the mortality by 37% (95% CI: 16%, 62%) after adjusting for AIDS defining conditions, gender, and age.
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Costela JL, Jiménez R, Calvo R, Suárez E, Carlos R. Serum protein binding of propofol in patients with renal failure or hepatic cirrhosis. Acta Anaesthesiol Scand 1996; 40:741-5. [PMID: 8836272 DOI: 10.1111/j.1399-6576.1996.tb04521.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Serum protein binding is a limiting factor in the access of drugs to the central nervous system. Disease-induced modifications of the degree of binding may influence the effect of anesthetic drugs. METHODS The protein binding of propofol, an intravenous anaesthetic agent which is highly bound to serum albumin, has been investigated in serum samples from healthy volunteers, from patients with chronic renal failure not undergoing hemodialysis, from patients with chronic renal failure included in a regular hemodialysis program, and from patients with hepatic cirrhosis. Protein binding was determined by the ultrafiltration technique using an Amicon Micropartition System, MPS-1. RESULTS The percentage of unbound propofol (mean(SD)) in healthy volunteers (n = 16) was 0.98 (0.48) % showing a high interindividual variability. Chronic renal failure did not significantly modify serum protein binding of propofol. In the chronic renal failure group not undergoing regular hemodialysis (n = 9), unbound propofol was 0.92 (0.34) %. In addition, patients in periodic dialysis did not show changes in propofol binding either compared before (1.11 (0.33) %; n = 13) or after hemodialysis (0.87 (0.38) %; n = 12). A slight decrease in albumin concentration was found in all renal patients (P < 0.05) in comparison to healthy volunteers. Creatinine and urea concentrations were higher in these patients (P < 0.01) but in the postdialysis group, the differences in urea levels were not significant when compared with those of volunteers. No changes in the degree of propofol binding were observed in patients with hepatic cirrhosis (0.97 (0.30) %; n = 14) when compared with the group of healthy volunteers. Significant differences were observed in albumin (P < 0.01) and bilirubin (P < 0.05) concentrations. Considering all subjects, the degree of binding did not correlate with biomedical data. CONCLUSION Due to the absence of significant changes in the protein binding it is unlikely that there will be an exaggerated pharmacological response in patients with renal and hepatic disease following the administration of a standard propofol dose, although due to interpatient variability careful titration can be recommended.
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García E, Calvo R, Rodríguez-Sasiaín JM, Jiménez R, Trocóniz IF, Suárez E. Resistance to atracurium in rats with experimental inflammation: role of protein binding. Acta Anaesthesiol Scand 1995; 39:1019-23. [PMID: 8607301 DOI: 10.1111/j.1399-6576.1995.tb04221.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The influence of altered protein binding on the neuromuscular effect of atracurium has been studied in rats with experimental inflammation induced by subcutaneous injection of turpentine oil. Doses of atracurium ranging from 0.45 to 1.5 mg.kg-1 were administered to control (n = 30) and to experimental inflammation induced rats (n = 30). Neuromuscular transmission was monitored by recording the twitch tension of the tibialis-anterior muscle elicited by stimulation of the sciatic nerve. Three effect parameters were recorded: (i) intensity of the effect, measured as percentage depression of baseline twitch tension, (ii) duration of drug action (min) and (iii) recovery time (min). The dose-intensity of the effect relationship was modelled using a sigmoid Emax model. The ED50 (effective dose eliciting 50% of the maximum effect) was significantly increased (P < 0.01) in the inflammation group as compared to the control group (0.94 vs. 0.68 mg.kg-1). This change was reflected in a shift of the dose-response curve to the right in the pretreated rats. For equipotent doses ED95 (defined as the effective dose eliciting 95% of maximum effect), no differences were found in recovery time and duration of action between the two groups of rats. Mucoproteins levels (index of alpha 1-acid glycoprotein (AAG) and protein binding were significantly increased in rats with experimental inflammation as compared to control rats. Based on these results, altered serum protein binding of atracurium appears to be responsible, at least in part, for the resistance to atracurium.
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Gómez E, Martínez-Jordá R, Suárez E, Garrido MJ, Calvo R. Altered methadone analgesia due to changes in plasma protein binding: role of the route of administration. GENERAL PHARMACOLOGY 1995; 26:1273-6. [PMID: 7590118 DOI: 10.1016/0306-3623(95)00022-s] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
1. The effect of experimental inflammation on methadone analgesia was evaluated in rats, by the tail-flick test, after single intravenous (0.35 mg/kg) and subcutaneous (3 mg/kg) doses. 2. After i.v. administration a significant decrease (P < 0.05) in the area under the methadone time-response curve was seen in rats with experimental inflammation, when compared with control. However, no differences in the analgesic response to methadone were detected between control rats and rats with inflammation when the drug was administered by s.c. injection. 3. Plasma mucoprotein levels were significantly increased (P < 0.001) and methadone free fraction was significantly decreased in rats with inflammation (P < 0.05). In addition, after i.v. methadone a decrease in brain uptake in rats with inflammation was detected. A significant correlation between brain uptake index and plasma free fraction was also observed. 4. These results suggest that a decreased immediate response to i.v. methadone may occur in circumstances in which there is an increase in alpha 1 acid glycoprotein, but that this is not likely to be observed when the absorption is not instantaneous.
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Torres I, Suárez E, Rodríguez-Sasiaín JM, Gomez E, Calvo R. Changes in the analgesic effects of mianserin associated with altered plasma protein binding in experimental cancer. RESEARCH COMMUNICATIONS IN MOLECULAR PATHOLOGY AND PHARMACOLOGY 1995; 89:341-50. [PMID: 8680802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In a group of mice bearing experimentally induced tumors, the protein binding of mianserin in vitro was measured and compared with a control group. The analgesic effect and the brain uptake of drug was also compared with a control group after an intraperitoneal dose of mianserin. The unbound percentage of mianserin in the plasma of mice with experimental cancer decreased with respect to control animals (5.20 +/- 0.12 vs 6.06 +/- 0.26; p<0.05) and alpha1-acid glycoprotein (AAG) levels, measured as plasma mucoprotein concentrations, were significantly increased (p<0.05). The brain/plasma drug concentration ratio of mianserin decreased in mice with experimental cancer when compared with control mice (1.11 +/- 0.03 vs 1.42 +/- 0.10; p<0.02). In both groups of mice, the mianserin analgesic effect was evaluated by the hot plate test after intraperitoneal drug administration. When the analgesia response-dose curve (0-60 mg/kg) was studied, a significant decrease in the response in mice with experimental cancer versus control mice was observed. These results suggest that resistance to the mianserin analgesic response may occur in animals with cancer disease. This resistance may be associated, in part, with an altered plasma protein binding, but other mechanisms could be involved.
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Torres I, Suárez E, Rodríguez-Sasiain JM, Aguirre C, Calvo R. Differential effect of cancer on the serum protein binding to mianserin and imipramine. Eur J Drug Metab Pharmacokinet 1995; 20:107-11. [PMID: 8582434 DOI: 10.1007/bf03226363] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Protein binding of mianserin and imipramine in vitro was determined in sera from 10 patients with cancer and from 28 drug-free normal subjects. alpha 1-acid glycoprotein (AAG) concentrations ranged from 0.91 +/- 0.04 g/l in control subjects to 2.17 +/- 0.18 g/l in cancer patients. Albumin concentrations ranged from 55.80 +/- 1.68 g/l in control subjects to 39.71 +/- 4.40 g/l, respectively. Serum samples containing concentrations of 100 ng/ml for mianserin and 500 ng/ml for imipramine were ultrafiltered and the free concentration were measured with scintillation spectrophotometer. The mean free percentage of mianserin was significantly less in patients with cancer (8.70 +/- 0.29% in patients vs 14.30 +/- 0.50% in control subjects P < 0.001). A multiple regression analysis revealed a significant contribution of plasma AAG (r2 = 0.56, P < 0.01), but not of albumin to the overall variability in mianserin binding. No correlation was observed between protein binding of imipramine and AAG concentrations in serum of cancer patients. No significant changes were observed for protein binding of imipramine in cancer patients as compared with control subjects. Our results suggest that for antidepressant (AD) drugs, of which the binding depends on AAG, variability in protein binding could be expected in cancer patients. Thus, in cancer therapy, changes in analgesic doses could be necessary with this kind of antidepressant drug.
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Calvo R, Suárez E, Aguilera L, Rodríguez Sasiaín JM. Influence of halothane anaesthesia on protein binding of drugs. Eur J Clin Pharmacol 1994; 46:484. [PMID: 7957550 DOI: 10.1007/bf00191918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Casado L, Hevia C, Colunga D, Suárez E, Carton JA, Arribas JM. [Splenic abscess caused by Salmonella enteritidis. Successful percutaneous drainage in 2 patients]. Enferm Infecc Microbiol Clin 1994; 12:46-7. [PMID: 8155762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Aguirre G, Correa JJ, Camuñas JF, Suárez E, Rivera-Brown AM, Frontera WR. [Morbidity during the XVI Central American and Caribbean Games: Puerto Rican delegation, Mexico 1990]. PUERTO RICO HEALTH SCIENCES JOURNAL 1993; 12:163-7. [PMID: 8272481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The health services offered to the Puerto Rican Delegation during the XVI Central American and Caribbean Sports Games in México in 1990 included: medical, dental and psychological assistance, physical therapy and services on the playing field. From the consultation sheets completed during the Games we obtained information about the use of these services. The 336 members of the Puerto Rico Delegation in the village at México City had 1,838 encounters with the health team. Of these, 991 were medical consults, 55 group therapies, 466 physical therapy sessions and 326 encounters in the sports venues. Among the encounters for medical evaluation the most frequent problems were athletic injuries (318; 32.1%), respiratory problems (240; 24.2%), gastrointestinal conditions (126; 12.7%) and dental services (119; 12.0%). The most frequent athletic injuries were first degree strains (83; 26.1%), tendinitis (56; 17.6%), contusions (42; 13.2%), myositis (40; 12.6%) and first degree sprains (28; 8.8%). The health problems found were diversed and in the majority of cases mild in character, which can be attend by adequately trained on sports health primary health professionals.
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Rodríguez J, Ollero M, Suárez E, Pujol E. Empiema por fístula esofagopleural tras escleroterapia de varices. Arch Bronconeumol 1993. [DOI: 10.1016/s0300-2896(15)31236-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Calvo R, Suárez E, Rodríguez-Sasiain JM, Martínez I. The influence of renal failure on the kinetics of intravenous midazolam: an "in vitro" and "in vivo" study. RESEARCH COMMUNICATIONS IN CHEMICAL PATHOLOGY AND PHARMACOLOGY 1992; 78:311-20. [PMID: 1475530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effect of renal failure upon the "in vitro" binding of midazolam, a new water-soluble short-acting benzodiazepine, has been studied in man. An increase of its free fraction (ranging from 2.52 to 5.17%) in serum from uremic patients was observed. A similar situation was originated in rabbits by administering uranyl nitrate (2 mg/Kg i.v.) and posterior hypnosis with midazolam. Uremic rabbits showed a marked increase in the free concentration of midazolam in serum (ranging from 8.9 to 13.7 micrograms/ml) and in midazolam brain levels (156.2 micrograms/g in cortex vs 84.5 micrograms/g in control animals). A positive correlation between brain and serum free concentration of midazolam was also observed. It is concluded that in renal patients more unbound drug is available to produce central nervous system effects, and a decrease in intravenous dose of midazolam could be recommended in this clinical situation.
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72
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Suárez E, San Martín F, Alvarez R, Coca J. Reverse osmosis of whey. Determination of mass transfer coefficients. J Memb Sci 1992. [DOI: 10.1016/0376-7388(92)85031-d] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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73
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Suárez E, Aguilera L, Calvo R, Rodríguez-Sasiaín JM, Martínez-Jorda R. Effect of halothane anesthesia and trifluoroacetic acid on protein binding of benzodiazepines. METHODS AND FINDINGS IN EXPERIMENTAL AND CLINICAL PHARMACOLOGY 1991; 13:693-6. [PMID: 1770832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The in vitro effect of the halothane metabolite, trifluoroacetic acid, on the protein binding of three different benzodiazepines (diazepam, lorazepam and midazolam) has been investigated. Furthermore, protein binding of these drugs was studied in serum from patients under the effect of halothane anesthesia (1-2.5%; 2.5 h). Trifluoroacetic acid, 4 mmol/l, displaced diazepam and midazolam from serum and produced a marked increase in the free percentage, but did not influence lorazepam binding. Moreover, 48 h after the end of halothane anesthesia, there were changes in protein binding of diazepam (3.9 +/- 0.3% at 48 h vs. 3.3 +/- 0.3% before halothane anesthesia; p less than 0.05). It can be concluded that halothane anesthesia (1-2.5%; 2.5 h) may temporarily potentiate the pharmacological effect of diazepam in the postoperative period following anesthetic procedures.
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Suárez L, Santaella A, Mariño I, Toro M, Luiggi M, Muñoz Dones E, Suárez E, Figueroa I, López-Baez P. [Cervico-facial heterotopic brain tissue with a mandibular deformity]. BOLETIN DE LA ASOCIACION MEDICA DE PUERTO RICO 1991; 83:545-7. [PMID: 1811608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Case report of a premature baby girl who presented with a right cervico-facial mass which caused severe respiratory difficulty. The patient underwent subtotal resection of the mass whose pathologic specimen report revealed heterotopic cerebral tissue compatible with encephalocele. A head and neck CT Scan performed could not evidence a connection between the mass and the cranial cavity, reason for which the possibility of encephalocele was disregarded. After subtotal resection of the mass, the tumor began to grow from soft palate and the patient died from respiratory complications at four months of age. Autopsy reported heterotopic cerebral tissue from neck and soft palate; right lung pneumonia and infection by CMV. Although the heterotopic cerebral tissue was reported as benign, the clinical characterization of this mass is compatible with a malignant behavior due to the aggressiveness of its growth.
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75
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Rivera MA, Suárez E. The somatotype of Puerto Rican male athletes at the X Pan American Games: a brief descriptive report. PUERTO RICO HEALTH SCIENCES JOURNAL 1990; 9:207-13. [PMID: 2087548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The purpose of this study was to determine and describe the Health-Carter anthropometric somatotype and other selected anthropometric characteristics of top class Puerto Rican athletes. One hundred and forty seven (147) male athletes, members of the Puerto Rico Olympic Committee delegation to the X Pan American Games were evaluated. The sample represented 84% of the total number of male athletes. Nineteen different sports were represented. The results indicated that gymnasts (18.3 +/- 4.0 years), swimmers (18.5 +/- 2.9 years) and table tennists (19.3 +/- 3.5 years) were the group with the minimum age. The maximal age was demonstrated by shooters (40.2 +/- 7.8 years). The height range was 158.1 +/- 6.3 cm (judoists) to 193.8 +/- 15.2 cm (basketball players). The minimum weight was demonstrated by the group of gymnasts (57.8 +/- 10.3 kg) and the maximal by basketball players (94.2 +/- 18.6 kg). The endomorphy ratings for track and field-jumpers [TF JUMPS] (1.8 +/- 0.6), gymnasts (1.8 +/- 0.4) and rowers (1.9 +/- 0.5) were low. The group with the maximal endomorphy rating was the shooters (5.4 +/- 1.6). The minimum and maximal ratings for mesomorphy was 3.8 +/- 0.8 (TF JUMPS) and 8.9 +/- 1.9 (weight lifters), respectively. The range of the ectomorphy rating was 0.4 +/- 0.6 (weight lifters) to 3.8 +/- 0.9 (TF JUMPS). In conclusion, the results seem to indicate that the somatotypes of the Puerto Rican top class athletes are within the range demonstrated by international top class athletes.
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