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1.
Chemistry ; 29(72): e202303299, 2023 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-37851861

RESUMEN

The development of higher-order cycloadditions has mainly been restricted by the requisite usage of highly conjugated and reactive π-systems. Recent years have witnessed organocatalysis as a potent mediator for several of the challenges associated herein, rendering higher-order cycloadditions a legitimate option for achieving the selective construction of specific molecular scaffolds. These developments reinvigorate the efforts to try to understand the underlying principles for cycloadditions involving a higher number of π-electrons than the "classical" cycloadditions; how do we properly address the impact which the addition of further π-electrons have on the reactivity of a system? Herein, computational investigations of two model higher-order cycloaddition systems have been performed to try to provide insights on changes in energetic barriers induced by the presence of benzofusions in a position which is unobstructive to the reactivity. With experimental substantiation as support, these studies might open up for a discussion on whether the π-electrons of benzofused systems simply act as spectator electrons, or play a tangible role on the observed reactivity to an extent where a distinct nomenclature is meritable.

2.
J Am Chem Soc ; 144(2): 1056-1065, 2022 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-34990550

RESUMEN

Nonbiaryl atropisomers are molecules defined by a stereogenic axis featuring at least one nonarene moiety. Among these, scaffolds bearing a conformationally stable C(sp2)-C(sp3) stereogenic axis have been observed in natural compounds; however, their enantioselective synthesis remains almost completely unexplored. Herein we disclose a new class of chiral C(sp2)-C(sp3) atropisomers obtained with high levels of stereoselectivity (up to 99% ee) by means of an organocatalytic asymmetric methodology. Multiple molecular motifs could be embedded in this class of C(sp2)-C(sp3) atropisomers, showing a broad and general protocol. Experimental data provide strong evidence of the conformational stability of the C(sp2)-C(sp3) stereogenic axis (up to t1/225 °C >1000 y) in the obtained compounds and show kinetic control over this rare stereogenic element. This, coupled with density functional theory calculations, suggests that the observed stereoselectivity arises from a Curtin-Hammett scenario establishing an equilibrium of intermediates. Furthermore, the experimental investigation led to evidence of the operating principle of central-to-axial chirality conversions.

3.
J Am Chem Soc ; 143(21): 8208-8220, 2021 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-34028261

RESUMEN

Isobenzopyrylium ions are unique, highly reactive, aromatic intermediates which are largely unexplored in asymmetric catalysis despite their high potential synthetic utility. In this study, an organocatalytic asymmetric multicomponent cascade via dienamine catalysis, involving a cycloaddition, a nucleophilic addition, and a ring-opening reaction, is disclosed. The reaction furnishes chiral tetrahydronaphthols containing four contiguous stereocenters in good to high yield, high diastereoselectivity (up to >20:1), and excellent enantioselectivity (93-98% ee). The obtained products are important synthetic intermediates, and it is demonstrated that they can be used for the generation of frameworks such as octahydrobenzo[h]isoquinoline and [2.2.2]octane scaffolds. Furthermore, mechanistic experiments involving oxygen-18-labeling studies and density functional theory calculations provide a vivid picture of the reaction mechanism. Finally, the bioactivity of 16 representative tetrahydronaphthol compounds has been evaluated in U-2OS cancer cells with some compounds showing a unique profile and a clear morphological change.

4.
Chemistry ; 27(44): 11352-11366, 2021 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-33963788

RESUMEN

Chiral phase-transfer catalysis provides high level of enantiocontrol, however no experimental data showed the interaction of catalysts and substrates. 1 H NMR titration was carried out on Cinchona and Maruoka ammonium bromides vs. nitro, carbonyl, heterocycles, and N-F containing compounds. It was found that neutral organic species and quaternary ammonium salts interacted via an ensemble of catalyst + N-C-H and (sp2 )C-H, specific for each substrate studied. The correspondent BArF salts interacted with carbonyls via a diverse set of + N-C-H and (sp2 )C-H compared to bromides. This data suggests that BArF ammonium salts may display a different enantioselectivity profile. Although not providing quantitative data for the affinity constants, the data reported proofs that chiral ammonium salts coordinate with substrates, prior to transition state, through specific C-H positions in their structures, providing a new rational to rationalize the origin of enantioselectivity in their catalyses.


Asunto(s)
Ésteres , Cetonas , Amidas , Catálisis , Compuestos de Amonio Cuaternario , Sales (Química) , Estereoisomerismo
5.
Am J Emerg Med ; 40: 181-183, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33243536

RESUMEN

BACKGROUND: Several previous studies have investigated the clinical utility of age-adjusted D-dimer cutoffs for diagnosing pulmonary embolism (PE). OBJECTIVES: We performed a pre/post implementation study, using data from a mid-Atlantic healthcare system comprising 6 hospitals and 400,000 ED visits to determine whether implementing age adjusted D-dimer cutoffs reduced the number of imaging tests performed. METHODS: Retrospective study of all patients who had a D-dimer performed during ED visits between September 2015 to September 2018. On March 21, 2017, the D-dimer upper limit of normal system-wide was increased for patients over 50 to: Age (years) x 0.01µg/mL. D-dimer results were displayed as normal or high based on automated age adjustment. EHR Chart review was performed 1.5 years prior to implementation of age-adjusted D-dimer cutoffs, as well as 1.5 years after to evaluate mortality and test accuracy characteristics such as false negative rates. Comparisons were made using chi-square testing. RESULTS: 22,302 D-dimers were performed pre-implementation of which 10,837 (48.6%) were positive resulting in 7218 (32.3%) imaging studies. After implementation of age-adjusted d-dimer, 25,082 were performed of which 10,851 (43.2%) were positive resulting in 7017 (28.0%) imaging studies. (pre: 48.6%, post: 43.2%; p < 0.01). A significantly lower proportion of patients had a positive d-dimer (pre: 48.6%, post: 43.2%; p < 0.01) and underwent imaging post-implementation (pre: 32.3%, post: 28.0%; p < 0.05) a relative risk reduction of 13.3. This absolute risk reduction of 4.4% is associated with 1104 less scans in the post-implementation group while still increasing test accuracy from 53.7% to 59.2% (p < 0.05). CONCLUSION: Implementation of an automated age-adjusted D-dimer positive reference value reduced CT and V/Q imaging in this population by 4.4% while increasing test accuracy in a regional, heterogeneous six-hospital system.


Asunto(s)
Productos de Degradación de Fibrina-Fibrinógeno/análisis , Embolia Pulmonar/sangre , Embolia Pulmonar/diagnóstico por imagen , Factores de Edad , Anciano , Registros Electrónicos de Salud , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valores de Referencia , Estudios Retrospectivos , Procedimientos Innecesarios
6.
Circulation ; 139(18): 2098-2109, 2019 04 30.
Artículo en Inglés | MEDLINE | ID: mdl-30786754

RESUMEN

BACKGROUND: Empagliflozin, a sodium-glucose cotransporter 2 inhibitor indicated for type 2 diabetes mellitus (T2DM), can lower blood pressure (BP) and reduce cardiovascular mortality in patients with T2DM and preexisting cardiovascular disease. Its effects in blacks have been understudied. METHODS: In this 24-week study, 150 blacks with T2DM and hypertension had glycohemoglobin (primary end point), office and 24-hour ambulatory BP, body weight, and safety assessments. After a 2-week, open-label, placebo run-in, patients were randomly assigned to once daily empagliflozin (10 mg for the first 4 weeks, then force-titrated to 25 mg until week 24) or placebo. A mixed-effects model for repeated measures was performed on the primary and 2 key secondary end points, and an analysis of covariance for nonrepeated measures with last observation carried forward was performed for 2 other key secondary end points. Hierarchical testing was applied for these end points. RESULTS: Overall, 52.7% of participants were men, mean (SD) age, 56.8 (9.3) years; mean duration of T2DM, 9.3 (7.1) years. The baseline values of key parameters (mean [SD]) were as follows: glycohemoglobin, 8.59 (1.02)%; ambulatory systolic BP, 146.3 (11.0) mm Hg; and ambulatory diastolic BP, 89.4 (8.1) mm Hg. By week 24, the mean (standard error) change in glycohemoglobin in the empagliflozin group was -0.77 (0.15%) in comparison with an increase of 0.07 (0.16%) in the placebo group; placebo-corrected difference, -0.78% (95% CI, -1.18 to -0.38; P=0.0002). Reductions in body weight by week 24 were -2.38 (0.38) empagliflozin and -0.80 (0.47) placebo; the placebo-corrected difference was -1.23 kg (95% CI, -2.39 to -0.07; P=0.0382). Empagliflozin significantly reduced 24-hour ambulatory systolic BP versus placebo by weeks 12 and 24 (placebo-corrected difference, -5.21 mm Hg [95% CI, -9.24 to -1.18; P=0.0117] and -8.39 mm Hg [95% CI, -13.74 to -3.04; P=0.0025], respectively). Diastolic BP was also reduced. CONCLUSIONS: In blacks with T2DM, empagliflozin reduced glycohemoglobin, body weight, and BP. The effect of empagliflozin on BP increased from 12 to 24 weeks, suggesting a full antihypertensive effect takes ≥6 months to be fully realized. At week 24, the placebo-subtracted BP effect was similar to standard antihypertensive monotherapies, suggesting that empagliflozin may be beneficial for this high-risk population. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02182830.


Asunto(s)
Compuestos de Bencidrilo/administración & dosificación , Presión Sanguínea/efectos de los fármacos , Complicaciones de la Diabetes/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Glucósidos/administración & dosificación , Hipertensión/tratamiento farmacológico , Anciano , Complicaciones de la Diabetes/sangre , Complicaciones de la Diabetes/fisiopatología , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/fisiopatología , Femenino , Humanos , Hipertensión/sangre , Hipertensión/fisiopatología , Masculino , Persona de Mediana Edad
7.
Chemistry ; 26(67): 15727-15732, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-33006398

RESUMEN

The use of pseudo enantiomers is a well-known method of achieving products of complementary stereochemistry. Only rarely can different enantiomers of a product be accessed without modulation of the catalyst. Recently, a system was reported wherein two different enantiomers of spirocycles were obtained by a cascade reaction of unsaturated pyrrolin-4-ones with mercaptoacetaldehyde catalyzed by a single optimized cinchona alkaloid squaramide-derived organocatalyst. It was originally proposed that the E/Z geometry of the unsaturated pyrrolin-4-one dictated the stereochemistry of the spirocycle product, but this was not investigated further. In the present work, we have investigated the nature of a pseudo-enantiomeric organocatalyst conformation applying density functional theory calculations for investigating the transition states for the reaction. Furthermore, the influence of the double-bond geometry of the pyrrolin-4-one has been studied beyond what is possible to test experimentally. The results provide a greater understanding for this class of reactions that may be applicable in future methodology development.

8.
Org Biomol Chem ; 17(16): 3934-3939, 2019 04 17.
Artículo en Inglés | MEDLINE | ID: mdl-30942247

RESUMEN

The mechanism of the enantioselective Michael addition of diethyl malonate to trans-ß-nitrostyrene catalyzed by a tertiary amine thiourea organocatalyst is explored using experimental 13C kinetic isotope effects and density functional theory calculations. Large primary 13C KIEs on the bond-forming carbon atoms of both reactants suggest that carbon-carbon bond formation is the rate-determining step in the catalytic cycle. This work resolves conflicting mechanistic pictures that have emerged from prior experimental and computational studies.


Asunto(s)
Tiourea/química , Catálisis , Teoría Funcional de la Densidad , Malonatos/química , Estructura Molecular , Estereoisomerismo , Estirenos/síntesis química , Estirenos/química
9.
JAMA ; 322(11): 1077-1084, 2019 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-31475296

RESUMEN

IMPORTANCE: Compared with enalapril, sacubitril-valsartan reduces cardiovascular mortality and heart failure hospitalization in patients with heart failure and reduced ejection fraction (HFrEF). These benefits may be related to effects on hemodynamics and cardiac remodeling. OBJECTIVE: To determine whether treatment of HFrEF with sacubitril-valsartan improves central aortic stiffness and cardiac remodeling compared with enalapril. DESIGN, SETTING, AND PARTICIPANTS: Randomized, double-blind clinical trial of 464 participants with heart failure and ejection fraction of 40% or less enrolled across 85 US sites between August 17, 2016, and June 28, 2018. Follow-up was completed on January 26, 2019. INTERVENTIONS: Randomization (1:1) to sacubitril-valsartan (n = 231; target dosage, 97/103 mg twice daily) vs enalapril (n = 233; target dosage, 10 mg twice daily) for 12 weeks. MAIN OUTCOMES AND MEASURES: The primary outcome was change from baseline to week 12 in aortic characteristic impedance (Zc), a measure of central aortic stiffness. Prespecified secondary outcomes included change from baseline to week 12 in N-terminal pro-B-type natriuretic peptide, ejection fraction, global longitudinal strain, mitral annular relaxation velocity, mitral E/e' ratio, left ventricular end-systolic and end-diastolic volume indexes (LVESVI and LVEDVI), left atrial volume index, and ventricular-vascular coupling ratio. RESULTS: Of 464 validly randomized participants (mean age, 67.3 [SD, 9.1] years; 23.5% women), 427 completed the study. At 12 weeks, Zc decreased from 223.8 to 218.9 dyne × s/cm5 in the sacubitril-valsartan group and increased from 213.2 to 214.4 dyne × s/cm5 in the enalapril group (treatment difference, -2.2 [95% CI, -17.6 to 13.2] dyne × s/cm5; P = .78). Of 9 prespecified secondary end points, no significant between-group difference in change from baseline was seen in 4, including left ventricular ejection fraction (34%-36% with sacubitril-valsartan vs 33 to 35% with enalapril; treatment difference, 0.6% [95% CI, -0.4% to 1.7%]; P = .24). However, greater reductions from baseline were seen with sacubitril-valsartan than with enalapril in all others, including left atrial volume (from 30.4 mL/m2 to 28.2 mL/m2 vs from 29.8 mL/m2 to 30.5 mL/m2; treatment difference, -2.8 mL/m2 [95% CI, -4.0 to -1.6 mL/m2]; P < .001), LVEDVI (from 75.1 mL/m2 to 70.3 mL/m2 vs from 79.1 mL/m2 to 75.6 mL/m2; treatment difference, -2.0 mL/m2 [95% CI, -3.7 to 0.3 mL/m2]; P = .02), LVESVI (from 50.8 mL/m2 to 46.3 mL/m2 vs from 54.1 to 50.6 mL/m2; treatment difference, -1.6 mL/m2 [95% CI, -3.1 to -0.03 mL/m2]; P = .045), and mitral E/e' ratio (from 13.8 to 12.3 vs from 13.4 to 13.8; treatment difference, -1.8 [95% CI, -2.8 to -0.8]; P = .001). Rates of adverse events including hypotension (1.7% vs 3.9%) were similar in both groups. CONCLUSIONS AND RELEVANCE: Treatment of HFrEF with sacubitril-valsartan, compared with enalapril, did not significantly reduce central aortic stiffness. The study findings may provide insight into mechanisms underlying the effects of sacubitril-valsartan in HFrEF. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02874794.

10.
J Am Chem Soc ; 140(27): 8396-8400, 2018 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-29940119

RESUMEN

A novel mechanism for the epoxidation of enals with hydrogen peroxide catalyzed by diarylprolinol silyl ether supported by experimental 13C kinetic isotope effects (KIEs) and density functional theory calculations is presented. Normal 13C KIEs, measured on both the carbonyl- and ß-carbon atoms of the enal, suggest participation of both carbon atoms in the rate-determining step. Calculations show that the widely accepted iminium-ion mechanism does not account for this experimental observation. A syn-SN2' substitution mechanism, which avoids formation of a discrete iminium-ion intermediate, emerges as the most likely mechanism based on agreement between experimental and predicted KIEs.


Asunto(s)
Compuestos Epoxi/química , Peróxido de Hidrógeno/química , Iminas/química , Pirrolidinas/química , Catálisis , Éteres/química , Isótopos , Cinética , Modelos Moleculares
11.
Am J Emerg Med ; 36(11): 2061-2063, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30209006

RESUMEN

OBJECTIVES: Emergency Department crowding is an increasing problem, leading to treatment delays and higher risk of mortality. Our institution recently implemented a telemedicine physician intake ("tele-intake") process as a mitigating front-end strategy. Previous studies have focused on ED throughput metrics such as door to disposition; our work aimed to specifically assess the tele-intake model for clinical accuracy. METHODS: We retrospectively reviewed ED visits at a high acuity, tertiary care academic hospital before and after tele-intake implementation. We defined the primary outcome as the degree of additional laboratory, imaging, and medication orders placed by the subsequent ED provider. Our secondary outcomes were the cancellation rate of intake orders and the percentage of encounters where no additional second provider orders were necessary. RESULTS: For in-person and tele-intake physician encounters between September 2015 and February 2017, most labs and diagnostic radiology studies, and approximately half of CT, ultrasound, and pharmacy orders were initiated by the intake physician. We found no significant difference for our primary outcome (p = 0.2449). For both tele-intake and in-person encounters, <1% of orders were cancelled by the second provider. Additionally, 30.8% of in-person and 31.5% of telemedicine patient encounters required no additional orders to make a disposition decision. DISCUSSION: This novel analysis of an innovative patient care model suggests that the benefits of tele-intake as a replacement for in-person physician directed intake are not at the cost of over or under utilization of diagnostic testing or interventions.


Asunto(s)
Atención a la Salud/métodos , Servicio de Urgencia en Hospital/estadística & datos numéricos , Telemedicina/estadística & datos numéricos , Triaje/estadística & datos numéricos , Técnicas de Laboratorio Clínico/estadística & datos numéricos , Atención a la Salud/estadística & datos numéricos , Diagnóstico por Imagen/estadística & datos numéricos , Quimioterapia/estadística & datos numéricos , Servicio de Urgencia en Hospital/organización & administración , Femenino , Hospitales de Enseñanza , Humanos , Masculino , Estudios Retrospectivos , Telemedicina/normas , Centros de Atención Terciaria , Triaje/organización & administración
12.
J Am Chem Soc ; 139(30): 10267-10285, 2017 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-28657739

RESUMEN

VANOL and VAPOL ligands are known to react with three equivalents of B(OPh)3 to form a catalytic species that contains a boroxinate core with three boron atoms, and these have proven to be effective catalysts for a number of reactions. However, it was not known whether the closely related BINOL ligand will likewise form a boroxinate species. It had simply been observed that mixtures of BINOL and B(OPh)3 were very poor catalysts compared to the same mixtures with VANOL or VAPOL. Borate esters of BINOL have been investigated as chiral catalysts, and these include meso-borates, spiro-borates, and diborabicyclo-borate esters. Borate esters are often in equilibrium, and their structures can be determined by stoichiometry and/or thermodynamics, especially in the presence of a base. The present study examines the structures of borate esters of BINOL that are produced with different stoichiometric combinations of BINOL with B(OPh)3 in the presence and absence of a base. Depending on conditions, pyro-borates, spiro-borates, and boroxinate species can be generated and their effectiveness in a catalytic asymmetric aziridination was evaluated. The finding is that BINOL borate species are not necessarily inferior catalysts to those of VANOL and VAPOL but that, under the conditions, BINOL forms two different catalytic species (a boroxinate and a spiro-borate) that give opposite asymmetric inductions. However, many BINOL derivatives with substitutents in the 3- and 3'-positions gave only the boroxinate species and the 3,3'-Ph2BINOL ligand gave a boroxinate catalyst that gives excellent inductions in the aziridination reaction. BINOL derivatives with larger groups in the 3,3'-position will not form either spiro-borates or boroxinate species and thus are not effective catalysts at all.


Asunto(s)
Compuestos de Boro/química , Naftoles/química , Compuestos de Espiro/química , Ligandos , Estructura Molecular
13.
J Cardiovasc Pharmacol ; 69(6): 374-381, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28338503

RESUMEN

We compared the systolic blood pressure (SBP)-lowering efficacy and safety of crystalline valsartan/sacubitril (LCZ696, an angiotensin receptor blocker-neprilysin inhibitor) 400 mg daily against valsartan (320 mg once daily) alone or coadministered with placebo or increasing doses of free sacubitril (50, 100, 200, or 400 mg once daily) to identify the optimal antihypertensive combination dose. This multicenter, double-blinded, 7-arm parallel-group study recruited patients with mild-to-moderate systolic hypertension (office SBP 150-179 mm Hg). Primary-dependent variable was change in office SBP from baseline to week 8. At entry (n = 907), mean age was 61.5 years, sitting office BP 160/90.2 mm Hg, and mean 24-hour ambulatory BP 142/82.1 mm Hg; 852 participants completed the study. At week 8, there were greater reductions in sitting office SBP and 24-hour ambulatory SBP with LCZ696 400 mg than with valsartan 320 mg (-5.7 and -3.4 mm Hg, respectively, P < 0.05 each). The SBP reduction with LCZ696 400 daily was similar to coadministered free valsartan 320 mg and sacubitril 200 mg. Effects were similar in those older and younger than 65 years, and active therapies had adverse event rates similar to placebo. We conclude that crystalline valsartan/sacubitril 400 mg daily (1) is superior to valsartan 320 mg daily for lowering SBP, (2) has similar efficacy to the combination of free valsartan 320 mg plus free sacubitril 200 mg, (3) represents the optimal dosage for systolic hypertension in patients of any age, and (4) is safe and well tolerated.


Asunto(s)
Aminobutiratos/administración & dosificación , Bloqueadores del Receptor Tipo 1 de Angiotensina II/administración & dosificación , Antihipertensivos/administración & dosificación , Presión Sanguínea/efectos de los fármacos , Hipertensión/tratamiento farmacológico , Inhibidores de Proteasas/administración & dosificación , Tetrazoles/administración & dosificación , Valsartán/administración & dosificación , Anciano , Aminobutiratos/efectos adversos , Bloqueadores del Receptor Tipo 1 de Angiotensina II/efectos adversos , Antihipertensivos/efectos adversos , Argentina , Compuestos de Bifenilo , Método Doble Ciego , Combinación de Medicamentos , Europa (Continente) , Femenino , Humanos , Hipertensión/diagnóstico , Hipertensión/fisiopatología , India , Masculino , Persona de Mediana Edad , Neprilisina/antagonistas & inhibidores , Neprilisina/metabolismo , América del Norte , Inhibidores de Proteasas/efectos adversos , República de Corea , Sístole , Tetrazoles/efectos adversos , Factores de Tiempo , Resultado del Tratamiento , Valsartán/efectos adversos
14.
J Am Chem Soc ; 138(6): 1756-9, 2016 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-26772311

RESUMEN

The mechanism of l-proline-catalyzed α-amination of 3-phenylpropionaldehyde was studied using a combination of experimental kinetic isotope effects (KIEs) and theoretical calculations. Observation of a significant carbonyl (13)C KIE and a large primary α-deuterium KIE support rate-determining enamine formation. Theoretical predictions of KIEs exclude the widely accepted mechanism of enamine formation via intramolecular deprotonation of an iminium carboxylate intermediate. An E2 elimination mechanism catalyzed by a bifunctional base that directly forms an N-protonated enamine species from an oxazolidinone intermediate accounts for the experimental KIEs. These findings provide the first experimental picture of the transition-state geometry of enamine formation and clarify the role of oxazolidinones as nonparasitic intermediates in proline catalysis.

15.
Chemistry ; 22(48): 17339-17344, 2016 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-27763714

RESUMEN

Chiral bifunctional urea-containing ammonium salts were found to be very efficient catalysts for asymmetric α-hydroxylation reactions of ß-ketoesters with oxaziridines under base-free conditions. The reaction is accompanied by a simultaneous kinetic resolution of the oxaziridine and a plausible and so far unprecedented bifunctional transition-state model has been obtained by means of DFT calculations.

16.
N Engl J Med ; 364(10): 907-17, 2011 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-21388309

RESUMEN

BACKGROUND: Microalbuminuria is an early predictor of diabetic nephropathy and premature cardiovascular disease. We investigated whether treatment with an angiotensin-receptor blocker (ARB) would delay or prevent the occurrence of microalbuminuria in patients with type 2 diabetes and normoalbuminuria. METHODS: In a randomized, double-blind, multicenter, controlled trial, we assigned 4447 patients with type 2 diabetes to receive olmesartan (at a dose of 40 mg once daily) or placebo for a median of 3.2 years. Additional antihypertensive drugs (except angiotensin-converting-enzyme inhibitors or ARBs) were used as needed to lower blood pressure to less than 130/80 mm Hg. The primary outcome was the time to the first onset of microalbuminuria. The times to the onset of renal and cardiovascular events were analyzed as secondary end points. RESULTS: The target blood pressure (<130/80 mm Hg) was achieved in nearly 80% of the patients taking olmesartan and 71% taking placebo; blood pressure measured in the clinic was lower by 3.1/1.9 mm Hg in the olmesartan group than in the placebo group. Microalbuminuria developed in 8.2% of the patients in the olmesartan group (178 of 2160 patients who could be evaluated) and 9.8% in the placebo group (210 of 2139); the time to the onset of microalbuminuria was increased by 23% with olmesartan (hazard ratio for onset of microalbuminuria, 0.77; 95% confidence interval, 0.63 to 0.94; P=0.01). The serum creatinine level doubled in 1% of the patients in each group. Slightly fewer patients in the olmesartan group than in the placebo group had nonfatal cardiovascular events--81 of 2232 patients (3.6%) as compared with 91 of 2215 patients (4.1%) (P=0.37)--but a greater number had fatal cardiovascular events--15 patients (0.7%) as compared with 3 patients (0.1%) (P=0.01), a difference that was attributable in part to a higher rate of death from cardiovascular causes in the olmesartan group than in the placebo group among patients with preexisting coronary heart disease (11 of 564 patients [2.0%] vs. 1 of 540 [0.2%], P=0.02). CONCLUSIONS: Olmesartan was associated with a delayed onset of microalbuminuria, even though blood-pressure control in both groups was excellent according to current standards. The higher rate of fatal cardiovascular events with olmesartan among patients with preexisting coronary heart disease is of concern. (Funded by Daiichi Sankyo; ClinicalTrials.gov number, NCT00185159.).


Asunto(s)
Albuminuria/prevención & control , Bloqueadores del Receptor Tipo 1 de Angiotensina II/uso terapéutico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Imidazoles/uso terapéutico , Tetrazoles/uso terapéutico , Adolescente , Adulto , Anciano , Albuminuria/epidemiología , Bloqueadores del Receptor Tipo 1 de Angiotensina II/efectos adversos , Presión Sanguínea/efectos de los fármacos , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/etiología , Enfermedades Cardiovasculares/mortalidad , Enfermedad Coronaria/complicaciones , Diabetes Mellitus Tipo 2/complicaciones , Método Doble Ciego , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular/efectos de los fármacos , Humanos , Imidazoles/efectos adversos , Masculino , Persona de Mediana Edad , Tetrazoles/efectos adversos , Adulto Joven
17.
Ethn Dis ; 24(1): 41-7, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24620447

RESUMEN

OBJECTIVE(S): Evaluate efficacy/safety of olmesartan medoxomil (OM)/amlodipine (AML)/ hydrochlorothiazide (HCTZ) in Hispanic/Latino adults with hypertension. DESIGN: Randomized, double-blind, 12-week, parallel-group study followed by a 40-week open-label extension phase. SETTING: Clinical sites (317) in the United States and Puerto Rico. PATIENTS OR PARTICIPANTS: Individuals > or =18 years of age with mean seated blood pressure (BP) > or =140/100 or > or =160/90 mm Hg divided into Hispanic/Latino (369) and non-Hispanic/Latino (2122) subgroups. INTERVENTIONS: Participants were randomized to OM 40/AML 10 mg, OM 40/HCTZ 25 mg, AML 10/HCTZ 25 mg, or OM 40/AML 10/HCTZ 25 mg during the double-blind phase. During the open-label extension, all participants received OM 40/AML 5/HCTZ 12.5 mg; participants not reaching BP goal within 2 weeks were randomly titrated to OM 40/AML 10/HCTZ 12.5 mg or OM 40/AML 5/HCTZ 25 mg, then to OM 40/AML 10/ HCTZ 25 mg after another 2 weeks. MAIN OUTCOME MEASURE: Change in mean seated diastolic BP (SeDBP) from baseline (double-blind phase). RESULTS: Triple-drug therapy vs the dual therapies resulted in greater mean reduction in SeBP (Hispanic/Latino: 35.0/20.9 mm Hg vs 27.8-30.9/15.3-17.7 mm Hg; non-Hispanic/Latino: 39.0/21.7 mm Hg vs 28.9-31.5/14.6-17.8 mm Hg) and enabled more participants to reach BP goal (Hispanic/Latino: 56.8% vs 40.6%-51.2%; non-Hispanic/Latino: 65.7% vs 33.8%-46.6%) irrespective of ethnicity. The efficacy of triple-drug therapy in achieving BP goal was sustained long-term (40-week open-label extension period) in Hispanic/Latino (63.3%) and non-Hispanic/ Latino (64.2%) participants. Triple-drug therapy was well tolerated in Hispanic/Latino and non-Hispanic/Latino participants. CONCLUSIONS: In this study, OM/AML/HCTZ was an effective treatment option in Hispanic/ Latino patients with hypertension.


Asunto(s)
Amlodipino/administración & dosificación , Antihipertensivos/administración & dosificación , Hispánicos o Latinos , Hidroclorotiazida/administración & dosificación , Hipertensión/tratamiento farmacológico , Hipertensión/etnología , Imidazoles/administración & dosificación , Tetrazoles/administración & dosificación , Anciano , Método Doble Ciego , Femenino , Humanos , Análisis de los Mínimos Cuadrados , Masculino , Persona de Mediana Edad , Olmesartán Medoxomilo
18.
Eur Heart J ; 34(9): 676-83, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22963833

RESUMEN

AIMS: To investigate the effect of antihypertensive therapy on ventricular-arterial mechanics, coupling, and efficiency in early-stage hypertension. METHODS AND RESULTS: We studied 527 participants from two clinical trials assessing the effect of blood pressure lowering on diastolic function. Participants were aged ≥45 years with early-stage hypertension, no heart failure, ejection fraction (EF) ≥50%, and diastolic dysfunction using Doppler echocardiography. Effective arterial afterload and its components were assessed along with measures of left ventricular (LV) structure and function prior to and after 24-38 weeks of antihypertensive therapy. Systolic blood pressure decreased from 154 ± 18 to 137 ± 15 mmHg at follow-up. Blood pressure reduction was associated with decreases in ventricular and arterial stiffness, improvements in systemic arterial compliance and resistance, enhanced LV ejection, and reduction in cardiac work (all P < 0.001). Changes in Ea/Ees ratio were inversely correlated with those in EF (r = -0.25; P < 0.001), stroke work index (r = -0.13; P = 0.007), and LV efficiency (r = -0.98; P < 0.001); and directly related to changes in mitral E/e' (r = 0.12; P = 0.01). Adjusting for age and blood pressure change, women and obese individuals had less enhancement in ventricular-arterial coupling and efficiency compared with men and non-obese individuals (P = 0.04 and 0.007, respectively). CONCLUSION: Antihypertensive therapy reduces arterial and ventricular stiffness, enhances ventricular-arterial coupling, reduces cardiac work, and improves LV efficiency, systolic, and diastolic function. Attenuated responses in women and among obese subjects suggest that structure-function changes may be less reversible in these groups, possibly explaining their greater susceptibility to ultimately develop heart failure.


Asunto(s)
Antihipertensivos/uso terapéutico , Hipertensión/tratamiento farmacológico , Factores de Edad , Anciano , Arterias/fisiología , Presión Sanguínea/efectos de los fármacos , Ensayos Clínicos como Asunto , Femenino , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/prevención & control , Humanos , Hipertensión/fisiopatología , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores Sexuales , Volumen Sistólico/efectos de los fármacos , Rigidez Vascular/efectos de los fármacos , Disfunción Ventricular Izquierda/fisiopatología , Función Ventricular Izquierda/efectos de los fármacos , Remodelación Ventricular/efectos de los fármacos
19.
J Hum Hypertens ; 37(10): 891-897, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-36494516

RESUMEN

Mean arterial pressure (MAP) is often estimated from cuff systolic (S) and diastolic (D) blood pressure (BP) using a fixed arterial form factor (FF, usually 0.33). If MAP is measured directly, a true FF can be calculated: FF = [MAP-DBP]/[SBP-DBP]. Because waveform shapes vary, true FF should also vary and MAP accuracy will be affected. We studied factors affecting FF using radial tonography (SphygmoCor, n = 376) or brachial oscillometry (Mobil-O-Graph, n = 157) and to compare devices, 101 pairs were matched precisely for SBP and DBP. SphygmoCor brachioradial FF correlated strongly with central FF (r2 = 0.75), central augmentation index (cAI, r2 = 0.39), and inversely with pulse pressure amplification (PPA) ratio (r2 = 0.44) [all p < 0.000]; brachioradial FF was lower than central (c) FF (0.34 vs. 0.44, 95% CI's [0.23,0.46] and [0.34,0.54], p < 0.000). On forward stepwise regression, brachioradial FF correlated with PPA ratio, age, heart rate, and cAI (multiple-r2 0.63, p < 0.000). With Mobil-O-Graph: brachial FF was fixed, lower than the corresponding cFF [mean(SD)] 0.46(0.00098) vs. 0.57(0.048), p < 0.000], and uncorrelated with clinical characteristics; MAP and cSBP were higher than SphygmoCor by 6.3 and 2.2 mmHg (p < 0.005) at the midpoint with systematic negative biases. We conclude that FF derived from radial tonometry (SphygmoCor) varies with pulse wave morphology within and between individuals and by measurement site, age, and heart rate. With oscillometry (Mobil-O-Graph), brachial FF was fixed and high and unrelated to other clinical variables; MAP and cSBP were higher than tonometry, with systematic negative biases.


Asunto(s)
Presión Arterial , Determinación de la Presión Sanguínea , Humanos , Presión Sanguínea/fisiología , Arteria Braquial/fisiología , Frecuencia Cardíaca
20.
Cardiovasc Diabetol ; 11: 134, 2012 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-23110471

RESUMEN

BACKGROUND: Patients with hypertension and cardiovascular disease (CVD), diabetes, or chronic kidney disease (CKD) usually require two or more antihypertensive agents to achieve blood pressure (BP) goals. METHODS: The efficacy/safety of olmesartan (OM) 40 mg, amlodipine besylate (AML) 10 mg, and hydrochlorothiazide (HCTZ) 25 mg versus the component dual-combinations (OM 40/AML 10 mg, OM 40/HCTZ 25 mg, and AML 10/HCTZ 25 mg) was evaluated in participants with diabetes, CKD, or chronic CVD in the Triple Therapy with Olmesartan Medoxomil, Amlodipine, and Hydrochlorothiazide in Hypertensive Patients Study (TRINITY). The primary efficacy end point was least squares (LS) mean reduction from baseline in seated diastolic BP (SeDBP) at week 12. Secondary end points included LS mean reduction in SeSBP and proportion of participants achieving BP goal (<130/80 mm Hg) at week 12 (double-blind randomized period), and LS mean reduction in SeBP and BP goal achievement at week 52/early termination (open-label period). RESULTS: At week 12, OM 40/AML 10/HCTZ 25 mg resulted in significantly greater SeBP reductions in participants with diabetes (-37.9/22.0 mm Hg vs -28.0/17.6 mm Hg for OM 40/AML 10 mg, -26.4/14.7 mm Hg for OM 40/HCTZ 25 mg, and -27.6/14.8 mm Hg for AML 10/HCTZ 25 mg), CKD (-44.3/25.5 mm Hg vs -39.5/23.8 mm Hg for OM 40/AML 10 mg, -25.3/17.0 mm Hg for OM 40/HCTZ 25 mg, and -33.4/20.6 mm Hg for AML 10/HCTZ 25 mg), and chronic CVD (-37.8/20.6 mm Hg vs -31.7/18.2 mm Hg for OM 40/AML 10 mg, -30.9/17.1 mm Hg for OM 40/HCTZ 25 mg, and -27.5/16.1 mm Hg for AML 10/HCTZ 25 mg) (P<0.05 for all subgroups vs dual-component treatments). BP goal achievement was greater for participants receiving triple-combination treatment compared with the dual-combination treatments, and was achieved in 41.1%, 55.0%, and 38.9% of participants with diabetes, CKD, and chronic CVD on OM 40/AML 10/HCTZ 25 mg, respectively. At week 52, there was sustained BP lowering with the OM/AML/HCTZ regimen. Overall, the triple combination was well tolerated. CONCLUSIONS: In patients with diabetes, CKD, or chronic CVD, short-term (12 weeks) and long-term treatment with OM 40/AML 10/HCTZ 25 mg was well tolerated, lowered BP more effectively, and enabled more participants to reach BP goal than the corresponding 2-component regimens. TRIAL IDENTIFICATION NUMBER: NCT00649389.


Asunto(s)
Amlodipino/administración & dosificación , Antihipertensivos/administración & dosificación , Enfermedades Cardiovasculares/tratamiento farmacológico , Complicaciones de la Diabetes/tratamiento farmacológico , Hidroclorotiazida/administración & dosificación , Hipertensión/tratamiento farmacológico , Imidazoles/administración & dosificación , Insuficiencia Renal Crónica/tratamiento farmacológico , Tetrazoles/administración & dosificación , Anciano , Enfermedades Cardiovasculares/complicaciones , Método Doble Ciego , Quimioterapia Combinada , Femenino , Humanos , Hipertensión/complicaciones , Hipertensión/fisiopatología , Masculino , Persona de Mediana Edad , Olmesartán Medoxomilo , Insuficiencia Renal Crónica/complicaciones
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