26
|
Haider N, Expósito MT, Muñoz-Escalona A, Ramos J, Vega JF, Méndez L, Martínez-Salazar J. Synthesis and properties of ethylene/styrene copolymers produced by metallocene catalysts. J Appl Polym Sci 2006. [DOI: 10.1002/app.24147] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
27
|
Mata E, Méndez L, Delpiccolo C. Efficient Solid-Phase Synthesis of 1,3,4-Trisubstituted β-Thiolactams. Synlett 2005. [DOI: 10.1055/s-2005-869855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
28
|
Delpiccolo CML, Méndez L, Fraga MA, Mata EG. Exploring the Solid-Phase Synthesis of 3,4-Disubstituted β-Lactams: Scope and Limitations. ACTA ACUST UNITED AC 2005; 7:331-44. [PMID: 15762764 DOI: 10.1021/cc049825l] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This work describes a comprehensive study on the solid-phase synthesis of 3,4-disubstituted beta-lactams. In situ generated ketenes react with immobilized aldimines under mild conditions to generate libraries of beta-lactams in good to very good overall isolated yields. Different commercially available solid supports were studied, with the cost-effective Wang resin proving to be the most effective. The utility of the protocol was also demonstrated by the highly efficient asymmetric versions when homochiral ketenes or homochiral aldimines were used. A practical technique for the preparation of manual solid-phase parallel libraries of biologically interesting beta-lactam compounds, using Mukaiyama's salt as dehydrating agent, is also presented. Reactions were easily monitored by FT-IR and gel-phase 13C NMR using conventional equipment.
Collapse
|
29
|
Errea LF, Fernández L, Macías A, Méndez L, Rabadán I, Riera A. Sign-consistent dynamical couplings betweenab initiothree-center wave functions. J Chem Phys 2004; 121:1663-9. [PMID: 15260716 DOI: 10.1063/1.1766010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a method to ensure the sign consistency of dynamical couplings between ab initio three-center wave functions. The method also allows to systematically "diabatize" avoided crossings between two potential energy surfaces, including conical intersections. Illustrations are presented for H(3)(+), LiH(2)(+), and NH(2)(5+) quasimolecules.
Collapse
|
30
|
Méndez L, Acosta B, Arreola-Lizarraga A, Padilla G. Anomalous levels of heavy metals in sediments from Guaymas Bay, Mexico. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2004; 72:1101-1106. [PMID: 15362436 DOI: 10.1007/s00128-004-0357-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
|
31
|
Errea LF, Macı́as A, Méndez L, Pons B, Riera A. Quantum chemistry calculation of excited three center systems: Theoretical study of He2++H2 collisions. J Chem Phys 2003. [DOI: 10.1063/1.1571821] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
32
|
Campins Martí M, Méndez L, Ramos F, Moreno N, Altet N, Vaqué J. Sobredosis accidental de vacuna BCG. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1576-9887(03)70325-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
33
|
Méndez L, Alvarez-Castañeda ST, Acosta B, Sierra-Beltrán AP. Trace metals in tissues of gray whale (Eschrichtius robustus) carcasses from the Northern Pacific Mexican Coast. MARINE POLLUTION BULLETIN 2002; 44:217-221. [PMID: 11954738 DOI: 10.1016/s0025-326x(01)00235-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Samples of liver, lung, heart, muscle, and blubber tissue from the carcasses of juvenile gray whales (Eschrichtius robustus) found stranded on the coast off the Sea of Cortez, México were analyzed for a range of trace metals (Cu, Fe, Zn, Mn, Ni, Pb, and Cd). The highest concentrations of copper, iron, zinc, and manganese were found in liver; nickel and lead in heart, and cadmium in kidney. In all tissues analyzed, iron, zinc and copper were present in the highest concentrations; however, some whales also showed high levels of cadmium in the kidney which could be related to their diet. Elevated concentrations of copper were found only in the liver of one whale. In general, where low levels of iron were found in the liver, they were associated with poor nutrition. Lead, nickel, manganese and zinc levels in liver were within the normal range, indicating that these whales had not been exposed to high levels of these metals.
Collapse
|
34
|
Méndez L, Salas-Flores LM, Arreola-Lizarraga A, Alvarez-Castañeda ST, Acosta B. Heavy metals in clams from Guaymas Bay, Mexico. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2002; 68:217-223. [PMID: 11815791 DOI: 10.1007/s001280241] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2001] [Accepted: 09/28/2001] [Indexed: 05/23/2023]
|
35
|
Torres A, Méndez L, Olivares JM, Vaamonde A. [Cognitive deficit and schizophrenia]. ACTAS ESPANOLAS DE PSIQUIATRIA 2001; 29:1-9. [PMID: 11333512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
INTRODUCTION In the present paper, the results of a number of different studies that have tried to establish the characteristics of the cognitive deficit in schizophrenia are discussed. The principal objective of this study was to ascertain whether exist statistically significative differences in such deficit in schizophrenic patients in relation with their preponderant symptomathology (positive symptoms, negative symptoms, and disorganization) or their degree of defectual symptoms. METHODOLOGY Sixty three schizophrenic patients under treatment in a Day Hospital were divided in groups using the dimensions of Liddie and the Scale for assessing the Deficit Syndrome in Schizophrenia. Cognitive deficit was assessed by the Wisconsin Card Sorting Test (WCST). RESULTS Our results show that education and gender has no relation with the cognitive deficit exhibited, whereas there is a direct relation with age and years suffering the illness. Patients who exhibited preponderant disorganization symptoms and those describes as defectual syndrome schizophrenics showed more cognitive deficit in the WCST. The number of preservations in the WCST seems to be the main deficit. CONCLUSIONS The concept of planning in suggested as a schizophrenic marker in the frame of theories that claim there is a failure in the neurodevelopment of these patients.
Collapse
|
36
|
Méndez L, Alvarez-Castañeda ST. Comparative analysis of heavy metals in two species of ichthyophagous bats Myotis vivesi and Noctilio leporinus. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2000; 65:51-54. [PMID: 10874079 DOI: 10.1007/s0012800093] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
37
|
García-García JC, Montero C, Redondo M, Vargas M, Canales M, Boue O, Rodríguez M, Joglar M, Machado H, González IL, Valdés M, Méndez L, de la Fuente J. Control of ticks resistant to immunization with Bm86 in cattle vaccinated with the recombinant antigen Bm95 isolated from the cattle tick, Boophilus microplus. Vaccine 2000; 18:2275-87. [PMID: 10717348 DOI: 10.1016/s0264-410x(99)00548-4] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The recombinant Bm86-containing vaccine Gavac(TM) against the cattle tick Boophilus microplus has proved its efficacy in a number of experiments, especially when combined with acaricides in an integrated manner. However, tick isolates such as the Argentinean strain A, show low susceptibility to this vaccine. In this paper we report on the isolation of the Bm95 gene from the B. microplus strain A, which was cloned and expressed in the yeast Pichia pastoris producing a glycosylated and particulated recombinant protein. This new antigen was effective against different tick strains in a pen trial, including the B. microplus strain A, resistant to vaccination with Bm86. A Bm95-based vaccine was used to protect cattle against tick infestations under production conditions, lowering the number of ticks on vaccinated animals and, therefore, reducing the frequency of acaricide treatments. The Bm95 antigen from strain A was able to protect against infestations with Bm86-sensitive and Bm86-resistant tick strains, thus suggesting that Bm95 could be a more universal antigen to protect cattle against infestations by B. microplus strains from different geographical areas.
Collapse
|
38
|
García-García JC, Gonzalez IL, González DM, Valdés M, Méndez L, Lamberti J, D'Agostino B, Citroni D, Fragoso H, Ortiz M, Rodríguez M, de la Fuente J. Sequence variations in the Boophilus microplus Bm86 locus and implications for immunoprotection in cattle vaccinated with this antigen. EXPERIMENTAL & APPLIED ACAROLOGY 1999; 23:883-895. [PMID: 10668863 DOI: 10.1023/a:1006270615158] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Cattle tick infestations constitute a major problem for the cattle industry in tropical and subtropical regions of the world. Traditional control methods have been only partially successful, hampered by the selection of chemical-resistant tick populations. The Boophilus microplus Bm86 protein was isolated from tick gut epithelial cells and shown to induce a protective response against tick infestations in vaccinated cattle. Vaccine preparations including the recombinant Bm86 are used to control cattle tick infestations in the field as an alternative measure to reduce the losses produced by this ectoparasite. The principle for the immunological control of tick infestations relies on a polyclonal antibody response against the target antigen and, therefore, should be difficult to select for tick-resistant populations. However, sequence variations in the Bm86 locus, among other factors, could affect the effectiveness of Bm86-containing vaccines. In the present study we have addressed this issue, employing data obtained with B. microplus strains from Australia, Mexico, Cuba, Argentina and Venezuela. The results showed a tendency in the inverse correlation between the efficacy of the vaccination with Bm86 and the sequence variations in the Bm86 locus (R2 = 0.7). The mutation fixation index in the Bm86 locus was calculated and shown to be between 0.02 and 0.1 amino acids per year. Possible implications of these findings for the immunoprotection of cattle against tick infestations employing the Bm86 antigen are discussed.
Collapse
|
39
|
de la Fuente J, Rodríguez M, Montero C, Redondo M, García-García JC, Méndez L, Serrano E, Valdés M, Enríquez A, Canales M, Ramos E, Boué O, Machado H, Lleonart R. Vaccination against ticks (Boophilus spp.): the experience with the Bm86-based vaccine Gavac. GENETIC ANALYSIS : BIOMOLECULAR ENGINEERING 1999; 15:143-8. [PMID: 10596754 DOI: 10.1016/s1050-3862(99)00018-2] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The control of tick infestations and the transmission of tick-borne diseases remain a challenge for the cattle industry in tropical and subtropical areas of the world. Traditional control methods have been only partially successful and the parasites continue to result in significant losses for the cattle industry. Recently, vaccines containing the recombinant B. microplus gut antigen Bm86 have been developed. Our vaccine formulation (Gavac, Heber Biotec S.A., Havana, Cuba) has been registered and is commercially available in Cuba, Colombia, Dominican Republic, Brazil and Mexico. In controlled pen trials, Gavac has been effective for the control of artificial infestations of B. annulatus, B. decoloratus and chemical-sensitive and resistant B. microplus strains from Australia, Africa, America and Iran. In controlled field trials in Cuba, Brazil, Argentina and Mexico, Gavac has shown a 55-100% efficacy in the control of B. microplus infestations in grazing cattle 12-36 weeks after the first vaccination. Field trials under production conditions have been conducted in Cuba, Colombia, Brazil and Mexico in pure and cross-bred cattle herds. The application of Gavac has increased the time between acaricide treatments by an average of 32 /-21 days (P = 0.0005) resulting in important savings for the cattle industry. In Cuba, a cost-effectiveness analysis was conducted in more than 260000 animals. The cost-effectiveness analysis showed a 60% reduction in the number of acaricide treatments, together with the control of tick infestations and transmission of babesiosis, which resulted in savings of 23.4 dollars animal(-1) year (-1). These results clearly demonstrate the advantage of vaccination and support the application of Gavac for the control of Boophilus spp. infestations.
Collapse
|
40
|
Méndez L, Acosta B, Alvarez-Castañeda ST, Lechuga-Devéze CH. Trace metal distribution along the southern coast of Bahia de La Paz (Gulf of California), México. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 1998; 61:616-622. [PMID: 9841721 DOI: 10.1007/s001289900805] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
|
41
|
García-García JC, Montero C, Rodríguez M, Soto A, Redondo M, Valdés M, Méndez L, de la Fuente J. Effect of particulation on the immunogenic and protective properties of the recombinant Bm86 antigen expressed in Pichia pastoris. Vaccine 1998; 16:374-80. [PMID: 9607058 DOI: 10.1016/s0264-410x(97)80915-2] [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: 02/07/2023]
Abstract
The recombinant Bm86 tick antigen expressed in Pichia pastoris is obtained in a highly particulated form, as a distinguish feature of this expression system. This particulated protein, the active principle of the recombinant vaccine Gavac against the cattle tick, have shown high immunogenic and protective properties, probably associated with its own characteristics. To evaluate the effects of particulation on the properties of Bm86, three groups of calves were immunized with particulated or non-particulated recombinant Bm86 and the anti-Bm86 antibody response determined. Animals were challenged with a controlled tick infestation and the protective capacities of both proteins assessed. Humoral immune response and protection in cattle vaccinated with the particulated antigen were higher. These experiments suggested that particulation of the Bm86 expressed in P. pastoris is an important feature for the protective properties of the antigen in vaccine preparations.
Collapse
|
42
|
de la Fuente J, Rodríguez M, Redondo M, Montero C, García-García JC, Méndez L, Serrano E, Valdés M, Enriquez A, Canales M, Ramos E, Boué O, Machado H, Lleonart R, de Armas CA, Rey S, Rodríguez JL, Artiles M, García L. Field studies and cost-effectiveness analysis of vaccination with Gavac against the cattle tick Boophilus microplus. Vaccine 1998; 16:366-73. [PMID: 9607057 DOI: 10.1016/s0264-410x(97)00208-9] [Citation(s) in RCA: 160] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The control of tick infestations and the transmission of tick-borne diseases remains a challenge for the cattle industry in tropical and subtropical areas of the world. Traditional control methods have been only partially successful and the parasites continue to result in significant losses for the cattle industry. Recently, vaccines containing the recombinant Boophilus microplus gut antigen Bm86 have been developed. These vaccines have been shown to control tick infestations in the field. However, extensive field studies investigating the efficacy and cost-effectiveness of vaccination have not been reported and are needed to appraise the effect of this new approach for tick control. Here is reported the results of the application of Gavac in a field trial including more than 260,000 animals in Cuba. In this study the correlation between the antibody response to vaccination and the effect on ticks fertility is determined. Physiological status of the animals was found to affect the primary response to vaccination but not the antibody titers after revaccination. A cost-effectiveness analysis showed a 60% reduction in the number acaricide treatments, together with the control of tick infestations and transmission of babesiosis, which resulted in savings of $23.4 animal-1 year-1. These results clearly demonstrate the advantage of vaccination and support the application of Gavac for tick control.
Collapse
|
43
|
Errea LF, Gorfinkiel JD, Kryachko ES, Macı́as A, Méndez L, Riera A. Ab initiopotential energy surfaces and nonadiabatic couplings involved in Be4++H2electron rearrangement. J Chem Phys 1997. [DOI: 10.1063/1.473033] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
44
|
Errea LF, Harel C, Jimeno P, Jouin H, Méndez L, Riera A. Molecular treatment of electron detachment in H++H- collisions. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1996; 54:967-969. [PMID: 9913559 DOI: 10.1103/physreva.54.967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
|
45
|
Errea LF, Harel C, Jouin H, Méndez L, Pons B, Riera A. Molecular treatment of H++He+(1s) collisions including pseudostates. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1995; 52:R2505-R2507. [PMID: 9912635 DOI: 10.1103/physreva.52.r2505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
|
46
|
Castillo JF, Errea LF, Macías A, Méndez L, Riera A. Ab initio calculation of nonadiabatic couplings using MELD. J Chem Phys 1995. [DOI: 10.1063/1.469687] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
47
|
Elfant AB, Levine SM, Cencora B, Spiegel TA, Méndez L, Pello MJ, Alexander JB, Atabek U, Camishion RC, Peikin SR. Bioavailability of medication after laparoscopic cholecystectomy. JOURNAL OF LAPAROENDOSCOPIC SURGERY 1995; 5:237-40. [PMID: 7579676 DOI: 10.1089/lps.1995.5.237] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Bioavailability of medication after laparoscopic cholecystectomy has not been studied previously. There is concern about the ability of patients to tolerate oral medication postoperatively and the optimal timing of hospital discharge. In this study, each subject received 20 mg/kg acetaminophen (po) preoperatively, with a repeat dose at 6 (group 1), 12 (group 2), or 24 h (group 3) postoperatively. Serum levels were obtained 40 and 90 min after each ingestion. Bioavailability of medication was significantly decreased (p < 0.01) 6 h (group 1) and 12 h (group 2) postoperatively. Bioavailability returned to baseline by 24 h after laparoscopic cholecystectomy (group 3). This study indicates that oral medication should be used judiciously during the first 12 h after laparoscopic surgery.
Collapse
|
48
|
Elfant AB, Levine SM, Peikin SR, Cencora B, Méndez L, Pello MJ, Atabek UM, Alexander JB, Spence RK, Camishion RC. Bioavailability of medication delivered via nasogastric tube is decreased in the immediate postoperative period. Am J Surg 1995; 169:430-2. [PMID: 7694985 DOI: 10.1016/s0002-9610(99)80192-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND A study was performed to determine bioavailability of medication delivered via nasogastric tube in patients after abdominal surgery. METHODS Acetaminophen (20 mg/kg) was administered to each patient per os at least 48 hours prior to abdominal surgery and via nasogastric tube 3 hours postoperatively. The nasogastric tube was clamped for 30 minutes after drug administration, prior to resuming suction. Serum levels of acetaminophen were measured 0, 40, and 90 minutes after each dose. RESULTS Acetaminophen levels were significantly lower (P < 0.001) when the drug was administered via nasogastric tube postoperatively. CONCLUSIONS Decreased bioavailability of medications delivered via nasogastric tube may have important clinical implications and should be taken into consideration during the postoperative period.
Collapse
|
49
|
Elfant AB, Peikin SR, Alexander JB, Méndez L. Conservative management of endoscopic sclerotherapy-induced esophageal perforation. Am Surg 1994; 60:985-7. [PMID: 7992981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Esophageal perforation is a rare though potentially lethal complication of variceal sclerotherapy. Diagnosis is usually made after recognition of often subtle clinical symptoms. Surgical and nonsurgical modalities have been proposed, and nonoperative management can be successful even in patients thought to have absolute indications for surgery.
Collapse
|
50
|
Errea LF, Méndez L, Riera A, Harel C, Jouin H, Pons B. Common-translation-factor method with an atomic basis. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1994; 50:418-422. [PMID: 9910910 DOI: 10.1103/physreva.50.418] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
|