Pedro Chávez - Academia.edu (original) (raw)

Papers by Pedro Chávez

Research paper thumbnail of Evaluation of the Response to Pharmacological Stress in Chronic Aortic Regurgitation

Journal of Echocardiography, 2001

We evaluated the hemodynamic response of patients with chronic aortic regurgitation and decreased... more We evaluated the hemodynamic response of patients with chronic aortic regurgitation and decreased ejection fraction (EF), mean value +/- SD (37 +/- 9), to dobutamine stress echocardiography (DSE). Eleven patients were studied with DSE. Nine patients were in New York Heart Association (NYHA) Class II and two in NYHA Class III. Ten patients received medical treatment in the only other periodic evaluation. With DSE in nine patients, a significant decrease in left ventricular end-diastolic and end-systolic diameters (LVEDD and LVESD) as well as LV end-diastolic and end-systolic volumes (LVEDV and LVESV) was documented in comparison to resting values. EF and fractional shortening (FS) improved significantly with DSE. Systolic wall stress (SWS) and pulmonary arterial systolic pressure (PASP) did not change. Average follow-up was 6.7 months. Three patients underwent valve replacement with mechanical prostheses. Two of them are in NYHA Class I and the other died of LV failure 3 days after surgery. One patient deteriorated beyond surgical treatment and was in NYHA Class II. The other seven patients remain in NYHA Class II and await valve replacement. In patients with chronic aortic regurgitation and depressed EF, the variables relevant to myocardial reserve appear to be EF, FS, LVEDD, LVESD, LVEDV, and LVESV.

Research paper thumbnail of The Effect of Kidney Transplant on Cardiac Function: An Echocardiographic Perspective

Journal of Echocardiography, 2001

Kidney transplant (KT) resolves many of the cardiac abnormalities associated with chronic kidney ... more Kidney transplant (KT) resolves many of the cardiac abnormalities associated with chronic kidney failure (CKF). This study analyzed cardiac alterations of kidney failure and their modification with transplant. Thirteen patients in CKF underwent conventional echocardiograms, dobutamine stress echocardiograms, and injection of contrast to examine perfusion before KT and 3 months after transplant. Nine patients had evidence of left ventricular hypertrophy and six had evidence of diastolic dysfunction. Wall thickness, left ventricular mass, and mass index diminished after KT; only two patients continued to manifest hypertrophy. Left ventricular systolic diameters and volumes diminished at 3 months, and diastolic diameters after 4 months. Left ventricular fractional shortening and ejection fraction increased 3 months after transplant. At the end of the study, only two patients continued to show diastolic dysfunction. Dobutamine echocardiograms showed no segmental wall-movement abnormalities. Myocardial perfusion was normal before and after transplant. The results suggest that KT diminishes hypertrophy and improves left ventricular systolic and diastolic function. Echocardiography provides valuable information for detection and follow-up of cardiac abnormalities in patients with kidney disease. Evaluation of segmental wall movement and myocardial perfusion aid in demonstrating that our studied patients with CKF had no indirect signs of coronary artery disease.

Research paper thumbnail of Evaluation of the Response to Pharmacological Stress in Chronic Aortic Regurgitation

Echocardiography, 2001

We evaluated the hemodynamic response of patients with chronic aortic regurgitation and decreased... more We evaluated the hemodynamic response of patients with chronic aortic regurgitation and decreased ejection fraction (EF), mean value +/- SD (37 +/- 9), to dobutamine stress echocardiography (DSE). Eleven patients were studied with DSE. Nine patients were in New York Heart Association (NYHA) Class II and two in NYHA Class III. Ten patients received medical treatment in the only other periodic evaluation. With DSE in nine patients, a significant decrease in left ventricular end-diastolic and end-systolic diameters (LVEDD and LVESD) as well as LV end-diastolic and end-systolic volumes (LVEDV and LVESV) was documented in comparison to resting values. EF and fractional shortening (FS) improved significantly with DSE. Systolic wall stress (SWS) and pulmonary arterial systolic pressure (PASP) did not change. Average follow-up was 6.7 months. Three patients underwent valve replacement with mechanical prostheses. Two of them are in NYHA Class I and the other died of LV failure 3 days after surgery. One patient deteriorated beyond surgical treatment and was in NYHA Class II. The other seven patients remain in NYHA Class II and await valve replacement. In patients with chronic aortic regurgitation and depressed EF, the variables relevant to myocardial reserve appear to be EF, FS, LVEDD, LVESD, LVEDV, and LVESV.

Research paper thumbnail of Paging Materials to Maintain Quality Library Service During a Two-Year Renovation

Public Services Quarterly, 2006

an 11 million dollar renovation. During three phases of the renovation, parts of the collection w... more an 11 million dollar renovation. During three phases of the renovation, parts of the collection were inaccessible to patrons. In order to continue to make the library's collection available, library staff created a paging system. Patrons submitted requests for needed library materials using paper and electronic forms and library staff retrieved the requested items. The paging service was modified three times based on prior experi-Melanie J. Norton

Research paper thumbnail of A solar photobioreactor for the production of biohydrogen from microalgae

The green microalga Chlamydomonas reinhardtii is proposed to produce hydrogen in a low-cost syste... more The green microalga Chlamydomonas reinhardtii is proposed to produce hydrogen in a low-cost system using the solar radiation in Yucatan, Mexico. A two-step process is necessary with a closed photobioreactor, in which the algae are firstly growth and then induced for hydrogen generation. Preliminary results are presented in this work with some planning for the future. Different culture broths, temperatures and light intensities were tested for biomass and hydrogen production in laboratory conditions. The first experiments in external conditions with solar radiation and without temperature control have been performed, showing the potential of this technique at larger scales. However, some additional work must be done in order to optimize the culture maintenance, particularly in relation with the temperature control, the light radiation and the carbon dioxide supply, with the idea of keeping an economic production.

Research paper thumbnail of In Vitro Antibacterial Activity of Herbal Products Used in a Mexican-American Community

Journal of the Arizona-Nevada Academy of Science, 2007

... Hoang Huynh, Andrew Bohn, Daniel Cook, Bradlee Johnson, Lori Zuptich, Pedro Chavez, and Willi... more ... Hoang Huynh, Andrew Bohn, Daniel Cook, Bradlee Johnson, Lori Zuptich, Pedro Chavez, and William P. Baker. ... Pilot study data with herbal products from Phoenix resulted in 4 plants being active against Staphylococcus aureus and 1 active against Pseudomonas aeruginosa of ...

Research paper thumbnail of Antimicrobial Activity of Natural Plant Extracts Against Five Bacterial Species

Journal of the Arizona-Nevada Academy of Science, 2008

... The objective of the present study was to evaluate commercial products from one herbal store ... more ... The objective of the present study was to evaluate commercial products from one herbal store in south Phoenix frequented primarily by Latinos. Results indicate approximately 7% of these products were active against a selected group of bacteria. ... (Huynh et al. 2007). ...

Research paper thumbnail of <title>A solar photobioreactor for the production of biohydrogen from microalgae</title>

Solar Hydrogen and Nanotechnology II, 2007

The green microalga Chlamydomonas reinhardtii is proposed to produce hydrogen in a low-cost syste... more The green microalga Chlamydomonas reinhardtii is proposed to produce hydrogen in a low-cost system using the solar radiation in Yucatan, Mexico. A two-step process is necessary with a closed photobioreactor, in which the algae are firstly growth and then induced for hydrogen generation. Preliminary results are presented in this work with some planning for the future. Different culture broths, temperatures and light intensities were tested for biomass and hydrogen production in laboratory conditions. The first experiments in external conditions with solar radiation and without temperature control have been performed, showing the potential of this technique at larger scales. However, some additional work must be done in order to optimize the culture maintenance, particularly in relation with the temperature control, the light radiation and the carbon dioxide supply, with the idea of keeping an economic production.

Research paper thumbnail of A Qualitative and Quantitative Comparison of the Quinolizidine Alkaloids of the Fasciated and Normal Stems of Sophora secundiflora

Journal of Natural Products, 1984

Compound Area under the curve relative to Decrease (%E) Normal stem Fasciated stem ... N-methylcy... more Compound Area under the curve relative to Decrease (%E) Normal stem Fasciated stem ... N-methylcytisine . . Rhombifoline . . . . A5,6-dehydrolupanine N-formylcytisine . . Lupanine . . . . . . N-acetylcytisine . . . Epi-lupinine ... 100.00 102.79 28.50 7.91 5.36 3.61 2.42 1.67 ...

Research paper thumbnail of Purification of Entamoeba histolytica DNA Containing Organelles (EkhOs): A Further Characterization

The Journal of Eukaryotic Microbiology, 2003

Research paper thumbnail of Partial inhibition of fatty acid oxidation increases regional contractile power & efficiency during demand-induced ischemia

Journal of Molecular and Cellular Cardiology, 2002

Clinical trials in patients with stable angina show that drugs that partially inhibit myocardial ... more Clinical trials in patients with stable angina show that drugs that partially inhibit myocardial fatty acid oxidation reduce the symptoms of demand-induced ischemia, presumably by reducing lactate production and improving regional systolic function. We tested the hypothesis that partial inhibition of fatty acid oxidation with oxfenicine (a carnitine palmitoyl transferase-I inhibitor) reduces lactate production and increases regional myocardial power during demand-induced ischemia. Methods: Demand-induced ischemia was produced in anesthetized open-chest swine by reducing flow by 20% in the left anterior descending coronary artery and increasing heart 21 21 rate and contractility with dobutamine (15 mg kg min i.v.) for 20 min. Glucose and fatty acid oxidation were measured with an 14 3 21

Research paper thumbnail of DURING A WEIGHT LOSS DIET THE USE OF MAP IN CONTRAST TO DIETARY PROTEINS OR MEAL SUBSTITUTES ALLOWS THE ACHIEVEMENT OF BODY'S NITROGEN BALANCE EQUILIBRIUM WITH ESSENTIALLY NO CALORIES

Confirming previous findings, the results of this study, performed on 500 overweight subjects hav... more Confirming previous findings, the results of this study, performed on 500 overweight subjects have showed a significant mean weight loss of 2.5 kg (5,5 Lb) per week. The results have showed that by providing MAP, a patented dietary supplement, in a dose of 400 mg/kg/day to each subject, in conjunction with the INRC's OMP diet, the subjects body overweight has been significantly reduced, both by reducing excessive fat tissue and by eliminating excessive water retention from the interstitial compartment. Providing, at the same time, the nitrogen balance equilibrium necessary: a. to preserve body's structural and functional proteins; b. to avoid or eliminate excessive water retention from the interstitial compartment; and c. to avoid the quick regain of the weigh lost, also known as the yo-yo effect.

Research paper thumbnail of In Vitro Antibacterial Activity of Herbal Products Used in a Mexican-American Community

Journal of The Arizona-nevada Academy of Science, 2007

... Hoang Huynh, Andrew Bohn, Daniel Cook, Bradlee Johnson, Lori Zuptich, Pedro Chavez, and Willi... more ... Hoang Huynh, Andrew Bohn, Daniel Cook, Bradlee Johnson, Lori Zuptich, Pedro Chavez, and William P. Baker. ... Pilot study data with herbal products from Phoenix resulted in 4 plants being active against Staphylococcus aureus and 1 active against Pseudomonas aeruginosa of ...

Research paper thumbnail of Experimental Hybridization of Xanthium strumarium (Compositae) from Asia and America. II. Sesquiterpene Lactones of F 1 Hybrids

American Journal of Botany, 1976

... CALVIN MCMILLAN, TOM J. MABRY, AND PEDRO I. CHAVEZ The Department of Botany and The Cell Rese... more ... CALVIN MCMILLAN, TOM J. MABRY, AND PEDRO I. CHAVEZ The Department of Botany and The Cell Research Institute, The ... at least eight major sesquiterpene lactones and has received various taxonomic treat-ments (Millspaugh and Sherff, 1919; Wilder, 1923; Love and ...

Research paper thumbnail of Purification of Entamoeba histolytica DNA Containing Organelles (EkhOs): A Further Characterization

Journal of Eukaryotic Microbiology, 2003

Research paper thumbnail of Novel 29- nor-3,4- seco-cycloartane triterpene methyl esters from the aerial parts of Antirhea acutata

Tetrahedron, 2001

Four novel 29-nor-3,4-seco-cycloartanes, (6S)-hydroxy-25-methoxy-29-nor-3,4-seco-cycloart-4(30),2... more Four novel 29-nor-3,4-seco-cycloartanes, (6S)-hydroxy-25-methoxy-29-nor-3,4-seco-cycloart-4(30),23-dien-3-oic acid methyl ester (1), (6S,25)-dihydroxy-29-nor-3,4-seco-cycloart-4(30),23-dien-3-oic acid methyl ester (2), (6S)-hydroxy-24-oxo-29-nor-3,4-seco-cycloart-4(30),25-dien-3-oic acid methyl ester (3), and (6S)-hydroxy-(24ξ)-hydroperoxy-29-nor-3,4-seco-cycloart-4(30),25-dien-3-oic acid methyl ester (4), along with a semi-synthetic acetylated derivative, (6S,24ξ)-diacetyloxy-29-nor-3,4-seco-cycloart-4(30),25-dien-3-oic acid methyl ester (5), were isolated and characterized from the aerial parts of Antirhea acutata (DC.) Urb. (Rubiaceae). Their structures and absolute stereochemistry were elucidated by spectroscopic and chemical methods. Compounds 1–5 are based on the unprecedented 29-nor-3,4-seco-cycloartane skeleton. Compound 4 showed moderate inhibitory activities in cyclooxygenase-1 and -2 assays (IC50 45.7 and 18.4 μM, respectively), while the other four isolates were inactive.Graphic

Research paper thumbnail of LA ACCION PAULIANA EN NUESTRA CORTE SUPREMA DE JUSTICIA

Research paper thumbnail of Sesquiterpenoids from Tithonia diversifolia with Potential Cancer Chemopreventive Activity

Journal of Natural Products, 2002

Activity-guided fractionation of an ethyl acetate extract of the aerial parts of Tithonia diversi... more Activity-guided fractionation of an ethyl acetate extract of the aerial parts of Tithonia diversifolia, using an antiproliferation bioassay performed with human colon cancer (Col2) cells, led to the isolation of three new sesquiterpenoids, 2alpha-hydroxytirotundin (1), tithofolinolide (2), and 3alpha-acetoxydiversifolol (3), along with eight known sesquiterpene lactones, 3beta-acetoxy-8beta-isobutyryloxyreynosin (4), tagitinin C (5), 1beta,2alpha-epoxytagitinin C (6), 4alpha,10alpha-dihydroxy-3-oxo-8beta-isobutyryloxyguaia-11(13)-en-12,6alpha-olide (7), 3alpha-acetoxy-4alpha-hydroxy-11(13)-eudesmen-12-oic acid methyl ester, 17,20-dihydroxygeranylnerol, tagitinin A, and tirotundin. These isolates were evaluated for their potential as cancer chemopreventive agents, by measuring antiproliferative activity in Col2 cells and induction of cellular differentiation in human promyelocytic leukemia (HL-60) cells. Selected compounds were then investigated for their ability to inhibit 7,12-dimethylbenz[a]anthracene-induced preneoplastic lesions in a mouse mammary organ culture assay. Among these isolates, 5 and 6 showed significant antiproliferative activity, 2, 4, and 7 induced HL-60 cellular differentiation, and 4 significantly inhibited (63.0% at 10 microg/mL) lesion formation in the mouse mammary organ culture assay. The chemical structures of 1-3 were elucidated by spectroscopic analysis. The absolute configurations of 1 and 2 were determined by Mosher ester methodology.

Research paper thumbnail of Evidence-based drug–herbal interactions

Life Sciences, 2006

Due to the growing use of herbals and other dietary supplements healthcare providers and consumer... more Due to the growing use of herbals and other dietary supplements healthcare providers and consumers need to know whether problems might arise from using these preparations in combination with conventional drugs. However, the evidence of interactions between natural products and drugs is based on known or suspected pharmacologic activity, data derived from in vitro or animal studies, or isolated case reports that frequently lack pertinent information. The usefulness of such information is questionable. More recently an increasing number of documented case reports, in vivo studies, and clinical trials have evaluated herbal–drug interactions. Results have sometimes been contradictory and more research is needed. Since there is a lack of rigorous studies that can establish the clinical significance of herb–drug interactions, an evidence-based evaluation of the current literature concerning commonly used herbal–drug interactions, as well as other dietary supplements, was conducted.

Research paper thumbnail of Cyclooxygenase-inhibitory and antioxidant constituents of the aerial parts of Antirhea acutata

Bioorganic & Medicinal Chemistry Letters, 2001

Two new compounds, (6S)-hydroxy-29-nor-3,4-seco-cycloart-4(30),24-dien-3-oic acid (1) and 8-[1-(3... more Two new compounds, (6S)-hydroxy-29-nor-3,4-seco-cycloart-4(30),24-dien-3-oic acid (1) and 8-[1-(3,4-dihydroxyphenyl)-3-methoxy-3-oxopropyl]epicatechin (3), were isolated by bioassay-guided fractionation from the aerial parts of Antirhea acutata (DC.) Urb. (Rubiaceae). Compound 1 showed moderate inhibitory activities in cyclooxygenase-1 and -2 assays (IC(50) 43.7 and 4.7 microM, respectively), while compound 3 was active in 1,1-diphenyl-2-picrylhydrazyl free-radical and cytochrome c reduction antioxidant assays (IC(50) 29.1 and 16.3 microM, respectively). Additionally, one further new compound was isolated, (3S,24S)-25-trihydroxy-9,19-cycloartane-29-oic acid (2), but this was inactive in the bioassay systems used. Compound 1 is based on the unprecedented 29-nor-3,4-seco-cycloartane skeleton.

Research paper thumbnail of Evaluation of the Response to Pharmacological Stress in Chronic Aortic Regurgitation

Journal of Echocardiography, 2001

We evaluated the hemodynamic response of patients with chronic aortic regurgitation and decreased... more We evaluated the hemodynamic response of patients with chronic aortic regurgitation and decreased ejection fraction (EF), mean value +/- SD (37 +/- 9), to dobutamine stress echocardiography (DSE). Eleven patients were studied with DSE. Nine patients were in New York Heart Association (NYHA) Class II and two in NYHA Class III. Ten patients received medical treatment in the only other periodic evaluation. With DSE in nine patients, a significant decrease in left ventricular end-diastolic and end-systolic diameters (LVEDD and LVESD) as well as LV end-diastolic and end-systolic volumes (LVEDV and LVESV) was documented in comparison to resting values. EF and fractional shortening (FS) improved significantly with DSE. Systolic wall stress (SWS) and pulmonary arterial systolic pressure (PASP) did not change. Average follow-up was 6.7 months. Three patients underwent valve replacement with mechanical prostheses. Two of them are in NYHA Class I and the other died of LV failure 3 days after surgery. One patient deteriorated beyond surgical treatment and was in NYHA Class II. The other seven patients remain in NYHA Class II and await valve replacement. In patients with chronic aortic regurgitation and depressed EF, the variables relevant to myocardial reserve appear to be EF, FS, LVEDD, LVESD, LVEDV, and LVESV.

Research paper thumbnail of The Effect of Kidney Transplant on Cardiac Function: An Echocardiographic Perspective

Journal of Echocardiography, 2001

Kidney transplant (KT) resolves many of the cardiac abnormalities associated with chronic kidney ... more Kidney transplant (KT) resolves many of the cardiac abnormalities associated with chronic kidney failure (CKF). This study analyzed cardiac alterations of kidney failure and their modification with transplant. Thirteen patients in CKF underwent conventional echocardiograms, dobutamine stress echocardiograms, and injection of contrast to examine perfusion before KT and 3 months after transplant. Nine patients had evidence of left ventricular hypertrophy and six had evidence of diastolic dysfunction. Wall thickness, left ventricular mass, and mass index diminished after KT; only two patients continued to manifest hypertrophy. Left ventricular systolic diameters and volumes diminished at 3 months, and diastolic diameters after 4 months. Left ventricular fractional shortening and ejection fraction increased 3 months after transplant. At the end of the study, only two patients continued to show diastolic dysfunction. Dobutamine echocardiograms showed no segmental wall-movement abnormalities. Myocardial perfusion was normal before and after transplant. The results suggest that KT diminishes hypertrophy and improves left ventricular systolic and diastolic function. Echocardiography provides valuable information for detection and follow-up of cardiac abnormalities in patients with kidney disease. Evaluation of segmental wall movement and myocardial perfusion aid in demonstrating that our studied patients with CKF had no indirect signs of coronary artery disease.

Research paper thumbnail of Evaluation of the Response to Pharmacological Stress in Chronic Aortic Regurgitation

Echocardiography, 2001

We evaluated the hemodynamic response of patients with chronic aortic regurgitation and decreased... more We evaluated the hemodynamic response of patients with chronic aortic regurgitation and decreased ejection fraction (EF), mean value +/- SD (37 +/- 9), to dobutamine stress echocardiography (DSE). Eleven patients were studied with DSE. Nine patients were in New York Heart Association (NYHA) Class II and two in NYHA Class III. Ten patients received medical treatment in the only other periodic evaluation. With DSE in nine patients, a significant decrease in left ventricular end-diastolic and end-systolic diameters (LVEDD and LVESD) as well as LV end-diastolic and end-systolic volumes (LVEDV and LVESV) was documented in comparison to resting values. EF and fractional shortening (FS) improved significantly with DSE. Systolic wall stress (SWS) and pulmonary arterial systolic pressure (PASP) did not change. Average follow-up was 6.7 months. Three patients underwent valve replacement with mechanical prostheses. Two of them are in NYHA Class I and the other died of LV failure 3 days after surgery. One patient deteriorated beyond surgical treatment and was in NYHA Class II. The other seven patients remain in NYHA Class II and await valve replacement. In patients with chronic aortic regurgitation and depressed EF, the variables relevant to myocardial reserve appear to be EF, FS, LVEDD, LVESD, LVEDV, and LVESV.

Research paper thumbnail of Paging Materials to Maintain Quality Library Service During a Two-Year Renovation

Public Services Quarterly, 2006

an 11 million dollar renovation. During three phases of the renovation, parts of the collection w... more an 11 million dollar renovation. During three phases of the renovation, parts of the collection were inaccessible to patrons. In order to continue to make the library's collection available, library staff created a paging system. Patrons submitted requests for needed library materials using paper and electronic forms and library staff retrieved the requested items. The paging service was modified three times based on prior experi-Melanie J. Norton

Research paper thumbnail of A solar photobioreactor for the production of biohydrogen from microalgae

The green microalga Chlamydomonas reinhardtii is proposed to produce hydrogen in a low-cost syste... more The green microalga Chlamydomonas reinhardtii is proposed to produce hydrogen in a low-cost system using the solar radiation in Yucatan, Mexico. A two-step process is necessary with a closed photobioreactor, in which the algae are firstly growth and then induced for hydrogen generation. Preliminary results are presented in this work with some planning for the future. Different culture broths, temperatures and light intensities were tested for biomass and hydrogen production in laboratory conditions. The first experiments in external conditions with solar radiation and without temperature control have been performed, showing the potential of this technique at larger scales. However, some additional work must be done in order to optimize the culture maintenance, particularly in relation with the temperature control, the light radiation and the carbon dioxide supply, with the idea of keeping an economic production.

Research paper thumbnail of In Vitro Antibacterial Activity of Herbal Products Used in a Mexican-American Community

Journal of the Arizona-Nevada Academy of Science, 2007

... Hoang Huynh, Andrew Bohn, Daniel Cook, Bradlee Johnson, Lori Zuptich, Pedro Chavez, and Willi... more ... Hoang Huynh, Andrew Bohn, Daniel Cook, Bradlee Johnson, Lori Zuptich, Pedro Chavez, and William P. Baker. ... Pilot study data with herbal products from Phoenix resulted in 4 plants being active against Staphylococcus aureus and 1 active against Pseudomonas aeruginosa of ...

Research paper thumbnail of Antimicrobial Activity of Natural Plant Extracts Against Five Bacterial Species

Journal of the Arizona-Nevada Academy of Science, 2008

... The objective of the present study was to evaluate commercial products from one herbal store ... more ... The objective of the present study was to evaluate commercial products from one herbal store in south Phoenix frequented primarily by Latinos. Results indicate approximately 7% of these products were active against a selected group of bacteria. ... (Huynh et al. 2007). ...

Research paper thumbnail of <title>A solar photobioreactor for the production of biohydrogen from microalgae</title>

Solar Hydrogen and Nanotechnology II, 2007

The green microalga Chlamydomonas reinhardtii is proposed to produce hydrogen in a low-cost syste... more The green microalga Chlamydomonas reinhardtii is proposed to produce hydrogen in a low-cost system using the solar radiation in Yucatan, Mexico. A two-step process is necessary with a closed photobioreactor, in which the algae are firstly growth and then induced for hydrogen generation. Preliminary results are presented in this work with some planning for the future. Different culture broths, temperatures and light intensities were tested for biomass and hydrogen production in laboratory conditions. The first experiments in external conditions with solar radiation and without temperature control have been performed, showing the potential of this technique at larger scales. However, some additional work must be done in order to optimize the culture maintenance, particularly in relation with the temperature control, the light radiation and the carbon dioxide supply, with the idea of keeping an economic production.

Research paper thumbnail of A Qualitative and Quantitative Comparison of the Quinolizidine Alkaloids of the Fasciated and Normal Stems of Sophora secundiflora

Journal of Natural Products, 1984

Compound Area under the curve relative to Decrease (%E) Normal stem Fasciated stem ... N-methylcy... more Compound Area under the curve relative to Decrease (%E) Normal stem Fasciated stem ... N-methylcytisine . . Rhombifoline . . . . A5,6-dehydrolupanine N-formylcytisine . . Lupanine . . . . . . N-acetylcytisine . . . Epi-lupinine ... 100.00 102.79 28.50 7.91 5.36 3.61 2.42 1.67 ...

Research paper thumbnail of Purification of Entamoeba histolytica DNA Containing Organelles (EkhOs): A Further Characterization

The Journal of Eukaryotic Microbiology, 2003

Research paper thumbnail of Partial inhibition of fatty acid oxidation increases regional contractile power & efficiency during demand-induced ischemia

Journal of Molecular and Cellular Cardiology, 2002

Clinical trials in patients with stable angina show that drugs that partially inhibit myocardial ... more Clinical trials in patients with stable angina show that drugs that partially inhibit myocardial fatty acid oxidation reduce the symptoms of demand-induced ischemia, presumably by reducing lactate production and improving regional systolic function. We tested the hypothesis that partial inhibition of fatty acid oxidation with oxfenicine (a carnitine palmitoyl transferase-I inhibitor) reduces lactate production and increases regional myocardial power during demand-induced ischemia. Methods: Demand-induced ischemia was produced in anesthetized open-chest swine by reducing flow by 20% in the left anterior descending coronary artery and increasing heart 21 21 rate and contractility with dobutamine (15 mg kg min i.v.) for 20 min. Glucose and fatty acid oxidation were measured with an 14 3 21

Research paper thumbnail of DURING A WEIGHT LOSS DIET THE USE OF MAP IN CONTRAST TO DIETARY PROTEINS OR MEAL SUBSTITUTES ALLOWS THE ACHIEVEMENT OF BODY'S NITROGEN BALANCE EQUILIBRIUM WITH ESSENTIALLY NO CALORIES

Confirming previous findings, the results of this study, performed on 500 overweight subjects hav... more Confirming previous findings, the results of this study, performed on 500 overweight subjects have showed a significant mean weight loss of 2.5 kg (5,5 Lb) per week. The results have showed that by providing MAP, a patented dietary supplement, in a dose of 400 mg/kg/day to each subject, in conjunction with the INRC's OMP diet, the subjects body overweight has been significantly reduced, both by reducing excessive fat tissue and by eliminating excessive water retention from the interstitial compartment. Providing, at the same time, the nitrogen balance equilibrium necessary: a. to preserve body's structural and functional proteins; b. to avoid or eliminate excessive water retention from the interstitial compartment; and c. to avoid the quick regain of the weigh lost, also known as the yo-yo effect.

Research paper thumbnail of In Vitro Antibacterial Activity of Herbal Products Used in a Mexican-American Community

Journal of The Arizona-nevada Academy of Science, 2007

... Hoang Huynh, Andrew Bohn, Daniel Cook, Bradlee Johnson, Lori Zuptich, Pedro Chavez, and Willi... more ... Hoang Huynh, Andrew Bohn, Daniel Cook, Bradlee Johnson, Lori Zuptich, Pedro Chavez, and William P. Baker. ... Pilot study data with herbal products from Phoenix resulted in 4 plants being active against Staphylococcus aureus and 1 active against Pseudomonas aeruginosa of ...

Research paper thumbnail of Experimental Hybridization of Xanthium strumarium (Compositae) from Asia and America. II. Sesquiterpene Lactones of F 1 Hybrids

American Journal of Botany, 1976

... CALVIN MCMILLAN, TOM J. MABRY, AND PEDRO I. CHAVEZ The Department of Botany and The Cell Rese... more ... CALVIN MCMILLAN, TOM J. MABRY, AND PEDRO I. CHAVEZ The Department of Botany and The Cell Research Institute, The ... at least eight major sesquiterpene lactones and has received various taxonomic treat-ments (Millspaugh and Sherff, 1919; Wilder, 1923; Love and ...

Research paper thumbnail of Purification of Entamoeba histolytica DNA Containing Organelles (EkhOs): A Further Characterization

Journal of Eukaryotic Microbiology, 2003

Research paper thumbnail of Novel 29- nor-3,4- seco-cycloartane triterpene methyl esters from the aerial parts of Antirhea acutata

Tetrahedron, 2001

Four novel 29-nor-3,4-seco-cycloartanes, (6S)-hydroxy-25-methoxy-29-nor-3,4-seco-cycloart-4(30),2... more Four novel 29-nor-3,4-seco-cycloartanes, (6S)-hydroxy-25-methoxy-29-nor-3,4-seco-cycloart-4(30),23-dien-3-oic acid methyl ester (1), (6S,25)-dihydroxy-29-nor-3,4-seco-cycloart-4(30),23-dien-3-oic acid methyl ester (2), (6S)-hydroxy-24-oxo-29-nor-3,4-seco-cycloart-4(30),25-dien-3-oic acid methyl ester (3), and (6S)-hydroxy-(24ξ)-hydroperoxy-29-nor-3,4-seco-cycloart-4(30),25-dien-3-oic acid methyl ester (4), along with a semi-synthetic acetylated derivative, (6S,24ξ)-diacetyloxy-29-nor-3,4-seco-cycloart-4(30),25-dien-3-oic acid methyl ester (5), were isolated and characterized from the aerial parts of Antirhea acutata (DC.) Urb. (Rubiaceae). Their structures and absolute stereochemistry were elucidated by spectroscopic and chemical methods. Compounds 1–5 are based on the unprecedented 29-nor-3,4-seco-cycloartane skeleton. Compound 4 showed moderate inhibitory activities in cyclooxygenase-1 and -2 assays (IC50 45.7 and 18.4 μM, respectively), while the other four isolates were inactive.Graphic

Research paper thumbnail of LA ACCION PAULIANA EN NUESTRA CORTE SUPREMA DE JUSTICIA

Research paper thumbnail of Sesquiterpenoids from Tithonia diversifolia with Potential Cancer Chemopreventive Activity

Journal of Natural Products, 2002

Activity-guided fractionation of an ethyl acetate extract of the aerial parts of Tithonia diversi... more Activity-guided fractionation of an ethyl acetate extract of the aerial parts of Tithonia diversifolia, using an antiproliferation bioassay performed with human colon cancer (Col2) cells, led to the isolation of three new sesquiterpenoids, 2alpha-hydroxytirotundin (1), tithofolinolide (2), and 3alpha-acetoxydiversifolol (3), along with eight known sesquiterpene lactones, 3beta-acetoxy-8beta-isobutyryloxyreynosin (4), tagitinin C (5), 1beta,2alpha-epoxytagitinin C (6), 4alpha,10alpha-dihydroxy-3-oxo-8beta-isobutyryloxyguaia-11(13)-en-12,6alpha-olide (7), 3alpha-acetoxy-4alpha-hydroxy-11(13)-eudesmen-12-oic acid methyl ester, 17,20-dihydroxygeranylnerol, tagitinin A, and tirotundin. These isolates were evaluated for their potential as cancer chemopreventive agents, by measuring antiproliferative activity in Col2 cells and induction of cellular differentiation in human promyelocytic leukemia (HL-60) cells. Selected compounds were then investigated for their ability to inhibit 7,12-dimethylbenz[a]anthracene-induced preneoplastic lesions in a mouse mammary organ culture assay. Among these isolates, 5 and 6 showed significant antiproliferative activity, 2, 4, and 7 induced HL-60 cellular differentiation, and 4 significantly inhibited (63.0% at 10 microg/mL) lesion formation in the mouse mammary organ culture assay. The chemical structures of 1-3 were elucidated by spectroscopic analysis. The absolute configurations of 1 and 2 were determined by Mosher ester methodology.

Research paper thumbnail of Evidence-based drug–herbal interactions

Life Sciences, 2006

Due to the growing use of herbals and other dietary supplements healthcare providers and consumer... more Due to the growing use of herbals and other dietary supplements healthcare providers and consumers need to know whether problems might arise from using these preparations in combination with conventional drugs. However, the evidence of interactions between natural products and drugs is based on known or suspected pharmacologic activity, data derived from in vitro or animal studies, or isolated case reports that frequently lack pertinent information. The usefulness of such information is questionable. More recently an increasing number of documented case reports, in vivo studies, and clinical trials have evaluated herbal–drug interactions. Results have sometimes been contradictory and more research is needed. Since there is a lack of rigorous studies that can establish the clinical significance of herb–drug interactions, an evidence-based evaluation of the current literature concerning commonly used herbal–drug interactions, as well as other dietary supplements, was conducted.

Research paper thumbnail of Cyclooxygenase-inhibitory and antioxidant constituents of the aerial parts of Antirhea acutata

Bioorganic & Medicinal Chemistry Letters, 2001

Two new compounds, (6S)-hydroxy-29-nor-3,4-seco-cycloart-4(30),24-dien-3-oic acid (1) and 8-[1-(3... more Two new compounds, (6S)-hydroxy-29-nor-3,4-seco-cycloart-4(30),24-dien-3-oic acid (1) and 8-[1-(3,4-dihydroxyphenyl)-3-methoxy-3-oxopropyl]epicatechin (3), were isolated by bioassay-guided fractionation from the aerial parts of Antirhea acutata (DC.) Urb. (Rubiaceae). Compound 1 showed moderate inhibitory activities in cyclooxygenase-1 and -2 assays (IC(50) 43.7 and 4.7 microM, respectively), while compound 3 was active in 1,1-diphenyl-2-picrylhydrazyl free-radical and cytochrome c reduction antioxidant assays (IC(50) 29.1 and 16.3 microM, respectively). Additionally, one further new compound was isolated, (3S,24S)-25-trihydroxy-9,19-cycloartane-29-oic acid (2), but this was inactive in the bioassay systems used. Compound 1 is based on the unprecedented 29-nor-3,4-seco-cycloartane skeleton.