The denitrifying bacterium Thauera sp. MZ1T, a common member of microbial communities in wastewater treatment facilities, can produce different compounds from a range of carbon (C) and nitrogen (N) sources under aerobic and anaerobic conditions. In these different conditions, Thauera modifies its metabolism to produce different compounds that influence the microbial community.
View Article and Find Full Text PDFThe purple non-sulfur bacterium Rhodopseudomonas palustris is recognized as a critical microorganism in the nitrogen and carbon cycle and one of the most common members in wastewater treatment communities. This bacterium is metabolically extremely versatile. It is capable of heterotrophic growth under aerobic and anaerobic conditions, but also able to grow photoautotrophically as well as mixotrophically.
View Article and Find Full Text PDFThe reaction between the bis(ethylene) complex [TpRh(C2 H4 )2 ], 1, (Tp=hydrotris(pyrazolyl)borate), and dimethyl acetylenedicarboxylate (DMAD) has been studied under different experimental conditions. A mixture of products was formed, in which TpRh(I) species were prevalent, whereas the presence of trapping agents, like water or acetonitrile, allowed for the stabilization and isolation of octahedral TpRh(III) compounds. An excess of DMAD gave rise to a small amount of the [2+2+2] cyclotrimerization product hexamethyl mellitate (6).
View Article and Find Full Text PDFThe bis(ethylene) Ir(I) complex [Tp(Me(2))Ir(C(2)H(4))(2)] (1; Tp(Me(2))=hydrotris(3,5-dimethylpyrazolyl)borate) reacts with two equivalents of aromatic or aliphatic aldehydes in the presence of one equivalent of dimethyl acetylenedicarboxylate (DMAD) with ultimate formation of hydride iridafurans of the formula [Tp(Me(2))Ir(H){C(R(1))=C(R(2))C(R(3))O}] (R(1)=R(2)=CO(2) Me; R(3)=alkyl, aryl; 3). Several intermediates have been observed in the course of the reaction. It is proposed that the key step of metallacycle formation is a C-C coupling process in the undetected Ir(I) species [Tp(Me(2))Ir{η(1)-O-R(3)C(=O)H}(DMAD)] (A) to give the trigonal-bipyramidal 16e(-) Ir(III) intermediates [Tp(Me(2))Ir{C(CO(2)Me)=C(CO(2)Me)C(R(3))(H)O}] (C), which have been trapped by NCMe to afford the adducts 11 (R(3)=Ar).
View Article and Find Full Text PDFThe reaction of the bis(ethylene) complex [Tp(Me(2) )Ir(C(2)H(4))(2)] (1) (Tp(Me(2) ): hydrotris(3,5-dimethylpyrazolyl)borate) with two equivalents of dimethyl acetylenedicarboxylate (DMAD) in CH(2)Cl(2) at 25 degrees C gives the hydride-alkenyl species [Tp(Me(2) )IrH{C(R)=C(R)C(R)=C(R)CH=CH(2)}] (2, R: CO(2)Me) in high yield. A careful study of this system has established the active role of a number of intermediates en route to producing 2. The first of these is the iridium(I) complex [Tp(Me(2) )Ir(C(2)H(4))(DMAD)] (4) formed by substitution of one of the ethylene ligands in 1 by a molecule of DMAD.
View Article and Find Full Text PDFA new route to irida-aromatic derivatives which consists of the oxidation of bicyclic compounds has been disclosed. The iridanaphthalene 3 experiences hydrolytic cleavage of the Ir-carboxylate moiety regenerating the bicyclic structure 5, whereas treatment of 5 with ClC(O)CO2Me yields back the metalla-aromatic 3.
View Article and Find Full Text PDFThe reaction of different Tp(Me2)Ir derivatives and dimethylacetylene dicarboxylate (DMAD) allows the preparation of three different metallacycloheptatriene complexes and an unusual allyl-terminated metallacycle. The C atoms of distant C=C bonds in the metallacycles, including aromatic ones, can be converted selectively to the corresponding keto functionality under mild conditions.
View Article and Find Full Text PDFApolipoprotein a, is a high molecular weight glycoproteic component of Lp(a), a molecule associated with coronary arterial disease. Apo(a) exhibits considerable size heterogeneity due to variable repetitions of the carbohydrate-containing structural unit, termed kringle. There are five different kringle forms and 10 different kringle 4 types.
View Article and Find Full Text PDFTo evaluate the effect of various antihypertensive drugs on fasting and postprandial lipids and lipoproteins, we studied 39 normolipidemic hypertensive patients, 28 men and 11 women aged 52.3 +/- 9.0 and 58.
View Article and Find Full Text PDFA one-point cross-sectional study of 20 sedentary individuals, 20 low-aerobic athletes (body-builders), and 20 high-aerobic athletes (long distance, endurance runners) was conducted in Mexico City, Mexico to determine the influence of these diverse life-styles on the plasma levels of Lp(a). Only non-obese male subjects, aged 23-33, who were nonsmokers, non-alcoholics, and had never used anabolic steroids were included in this study. Blood samples were drawn 24 h following the last period of physical activity, and after a 12-14-h fast-period and a 15-min sitting-rest.
View Article and Find Full Text PDFA 17-year-old male was admitted with an acute myocardial infarction. A coronarography showed 90% occlusion in of the descendent anterior artery. A coronary angioplasty was done with excellent response.
View Article and Find Full Text PDFTo evaluate the effects of aerobic physical conditioning on plasma lipoproteins, we studied 26 previously untrained, apparently healthy, non obese volunteers. All participants underwent a treadmill test performed according to the protocol of Bruce with the direct measurement of maximal oxygen consumption (VO2max). A program of aerobic exercise was prescribed for each volunteer at 70% of their corresponding VO2max.
View Article and Find Full Text PDFArch Inst Cardiol Mex
February 1989
Spontaneous autoimmune thyroid disease (SATD) shows familial aggregation. Some patients receiving amiodarone treatment have been found to develop thyroid dysfunction. Previously, we reported genetic predisposition among this group of patients, now we inform a prospective study which includes the search for autoantibodies and family history to identify risk factors in amiodarone treated patients, 40 of them with amiodarone related thyroid disfunction, and 100 without it; for comparison, 30 patients with SATD and a control group of healthy subjects were also studied.
View Article and Find Full Text PDFAdministration of pertussis toxin to rats induced a significant increase in heart rate that was evident as soon as 24 hours after the administration of the toxin and that persisted for at least 15 days. Electrical stimulation of the vagus decreased dramatically the heart rate of control animals but was unable to do it so in rats treated with pertussis toxin. In cardiac membranes muscarinic agonists decreased adenylate cyclase activity (approximately equal to 20-25%); no effect was observed in membranes obtained from toxin-treated animals.
View Article and Find Full Text PDFThe effect of pertussis toxin on the affinity for agonists and antagonists of the heart muscarine acetylcholine receptor was studied using the radiolabeled antagonist [3H]quinuclidinyl benzylate ([3H]QNB). In cardiac membranes from control rats the displacement of [3H]QNB by carbachol was consistent with two classes of binding sites, kDH 25 +/- 10 nM and kDL 3,006 +/- 869 nM. The proportion of sites in the high and low affinity state for agonists was 55 and 45% respectively.
View Article and Find Full Text PDFArch Inst Cardiol Mex
October 1986
Recent evidences suggest that the sympathetic nervous system plays a major role in the pathogenesis and maintenance of several clinical forms of hypertensive disease. The clonidine suppression test allows us to uncover the subtle changes in neuronal noradrenaline release in essential hypertension. To prove this possibility, we selected 16 patients: 7 borderline hypertensives (BH) (4 males and 3 females), mean age: 24 years; and 9 established hypertensives (EH) (6 males and 3 females), mean age: 25 years.
View Article and Find Full Text PDFBiochem Biophys Res Commun
January 1986
The effect of guanine nucleotides on the binding of [3H] Quinuclidinyl benzilate to heart muscarinic receptors was studied. It was observed that GTP and Gpp (NH)p increased antagonist binding. Scatchard transformation of the data resulted in curvilinear plots (downward concavity) consistent with positive cooperativity.
View Article and Find Full Text PDFAmiodarone (2-n-butyl-3,4-diethylaminoethoxy-3',-diiodobenzoyl-benzofurone ) is a drug widely used for the treatment of cardiac arrhythmias. Due to its high iodine content and structural similarity to thyroxine it produces abnormalities in thyroid hormone metabolism and, in some cases, clinical thyroid dysfunction as well. We report 18 patients, 11 females and 7 males, whose thyroid disease developed during treatment with amiodarone (A).
View Article and Find Full Text PDFThe hyperglycemia usually observed in patients undergoing heart surgery with extracorporeal circulation (EC) represents a difficult therapeutic problem. We studied the effects of several regimens of insulin therapy on serum glucose (SG) in 24 noninsulin dependent diabetic patients (NIDDs). The patients were randomly divided in five groups; group A received on IV bolus of 10.
View Article and Find Full Text PDFThe effect of pertussis toxin treatment on the guanine nucleotide-induced modulation of the affinity of renal alpha 1- and alpha 2-adrenergic receptors was investigated. Pretreatment of rats with pertussis toxin did not induce any change in the number of or affinity for antagonists of alpha 1- or alpha 2-receptors studied using [3H]prazosin and [3H]yohimbine, respectively. Guanyl-5'-yl imidodiphosphate induced an "up-shift" in the number of alpha 2-adrenergic receptors; this up-shift was not observed for alpha 1-adrenergic receptors.
View Article and Find Full Text PDFAdministration of purified pertussis toxin to rats induced persistent tachycardia, (observed in conscious rats but not after pithing); as little as 0.05 microgram/100 g produced a significant effect. Pertussis toxin-treatment did not affected the pressor response produced in the pithed rats by the alpha 2-adrenergic agonist methoxamine but markedly diminished the pressor effect of the alpha 2-adrenergic agonists clonidine and azepexole.
View Article and Find Full Text PDFArch Inst Cardiol Mex
February 1984
The usefulness of fluorimetric techniques in the diagnosis of pheochromocytoma was investigated. In the 63 cases studied during 25 years by measuring simultaneously various aminergic parameters, including plasma catecholamines and urinary adrenaline (A), noradrenaline (N) and vanilmandelic acid (VMA), we were able to establish the diagnosis of pheochromocytoma in all cases. Adrenaline excretion was found to be higher in patients with tumors located on the adrenal region, whereas N excretion was predominantly increased in patients with extra-adrenal tumors.
View Article and Find Full Text PDFEur J Pharmacol
September 1982
Administration of pertussis vaccine to rats markedly diminished the sensitivity of their vascular alpha 2-adrenoceptors as evidenced by shifts to the right and decreased maximal pressor responses to clonidine and azepexole in pithed rats. No effect was observed on the sensitivity of alpha 1-adrenoceptors as evidenced by the dose-response curve to methoxamine. A slight persistent tachycardia was also produced by the vaccine.
View Article and Find Full Text PDFThe response of arterial blood pressure, plasma renin activity (PRA) and plasma (PA) or urinary aldosterone (UA) concentrations to the administration of captopril, was studied in patients with established essential hypertension. Captopril was effective in lowering significantly the blood pressure (189.4/111.
View Article and Find Full Text PDF