Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The acute effects of an injection of contrast material (Renovist) on intraerythrocytic and extracellular pH was studied at cardiac catheterization in 72 patients with congenital heart disease. A decrease in mean extracellular (plasma) pH (7.444 plus or minus .006 to 7.419 plus or minus 0.009) and an increase in mean intraerythrocytic pH (7.204 plus or minus .005 to 7.232 plus or minus .006) were observed within minutes after injection (p smaller than .01). In 17/72 patients, simultaneous measurements of oxygen affinity for hemoglobin as characterized by P50 (oxygen tension at 50% O-2 saturation) corrected to in vivo arterial pH decreased from a mean of 26.4 to 25.2 mm Hg (p smaller than .01). It is postulated that the acute increase in intraerythrocyte pH and increased affinity of hemoglobin for oxygen are due to a decrease in intracellular hydrogen ion concentration induced by the increase in plasma osmolality with subsequent shift of hemoglobin oxygen equilibrium via the Bohr effect.
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PMID:The relationship between angiography, intraerythrocytic pH and hemoglobin oxygen equilibrium. 23 27

The study was performed on 612 routine cultures of material obtained from root canals of teeth at the time of filling (r-cultures) by students at the Department of Endodontics during a continuous period of one year. Twenty-nine isolates from 27 (29.3%) of the 92 positive cultures filled the criteria of enterococci (Sherman, 1937) and had demonstrable group D-antigen. With a set of tests these isolates were identified as follows: Strep. faecalis subsp. faecalis (10), Strep. faecalis subsp. zymogenes (3), Strep. faecalis subsp. liquefaciens (8), atypical variants of Strep. faecalis (6), Strep. faecium var. faecium (1) and Strep. faecium var. durans (1). Five tests in the present study clearly differentiated Strep. faecalis from Strep. faecium i.e. fermentation of sorbitol, glycerol (anaerobic) and melezitose, tolerance to potassium tellurite (0.1%) (positive for Strep. faecalis) and production of hydrogen peroxide (positive for Strep. faecium). In the inocula 10(3) or more colony forming units of enterococci were found more often of other identified microorganisms. This means that enterococci are of special interest in studies on the influence of infection at the time of filling of root canals on the prognosis of root canal therapy. The isolates were also tested for susceptibility to azidocillin, ampicillin, penicillin-G, penicillin-V and erythromycin with the paper disc method. All the isolates were susceptible to azidocillin and ampicillin (sensitivity group I), while the majority of the isolates showed a lower susceptibility to the other three antibiotics (sensitivity group II). The significance of these findings in the choice of prophylactic antibiotic to prevent bacterial endocarditis in patients with a history of rheumatic or congenital heart disease are discussed, when bacteremia from dental procedures may be expected.
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PMID:Streptococcus faecalis and Streptococcus faecium in infected dental root canals at filling and their susceptibility to azidocillin and some comparable antibiotics. 81 Jul 53

Atrial septal defects may have clinical consequences regardless of their size. We evaluated the incidence of clinically unsuspected atrial septal defects in 4,411 consecutive adult patients referred for cardiac catheterization by the previously validated method of inspired hydrogen appearance time. Oximetry was performed only when an abnormally short inspired hydrogen appearance time was measured. Seventy-five patients (1.7%) were discovered to have a left-to-right shunt by this method. The shunting was at the atrial level in 65 patients. Thirty-five of these patients (0.8% of all catheterizations) were not suspected of having any form of congenital heart disease by history, physical examination, chest X-ray, EKG, or echocardiogram. In 19 cases there was no significant oxygen step-up and the diagnosis would have been missed by oximetry. The atrial septum was explored during open heart surgery in 7 patients. Atrial septal defects were detected and closed in all. Four patients had the finding confirmed by echocardiography after the catheterization. Small atrial septal defects are frequently not detected by clinical evaluation, noninvasive testing, or oximetry and are easily detected by the rapid, safe, and accurate method of inspired hydrogen appearance time.
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PMID:Diagnosis of unexpected atrial septal defect by inspired hydrogen appearance time in adult patients referred for cardiac catheterization. 222 36

To assess myocardial perfusion intraoperatively and to evaluate the adequacy of coronary bypass grafting, we measured regional myocardial blood flow by the electrolytic hydrogen clearance method in 49 patients. Group I comprised 10 patients with nonischemic heart disease and group II, 39 patients with ischemic heart disease undergoing coronary bypass grafting. Group II was subdivided according to the percent stenosis of the coronary arteries supplying the ventricular regions: group IIa, less than 75% stenosis; group IIb, greater than or equal to 75% stenosis. Mean myocardial blood flows were 154 +/- 7, 145 +/- 5, and 98 +/- 9 ml/min/100 gm in groups I, IIa, and IIb, respectively (p less than 0.01, group IIb versus groups I and IIa). Mean blood flows were 161 +/- 19, 159 +/- 12, 78 +/- 12, and 59 +/- 15 ml/min/100 gm in areas of the left anterior descending coronary artery with less than 50%, 75%, 90%, and 99% stenosis in group II. In areas with a totally occluded left anterior descending coronary artery with collaterals, mean flow was 90 +/- 15 ml/min/100 gm. The mean myocardial blood flows were 40 +/- 7 and 100 +/- 14 ml/min/100 gm in areas with anterior Q wave and non-Q wave infarction, respectively (p less than 0.01). After cardiopulmonary bypass, the mean flow increased from 99 +/- 11 to 150 +/- 7 ml/min/100 gm in the grafted areas in group IIb (p less than 0.01), but it did not change in group I or IIa. The electrolytic hydrogen clearance method provided quantitative evaluation of myocardial perfusion and recovery from hypoperfusion by coronary bypass grafting. This method was especially useful in patients undergoing mammary artery grafting.
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PMID:Measurement of regional myocardial blood flow. Application of the electrolytic hydrogen clearance method in man. 326 49

Ca influx in cultured neonatal myocardium can be augmented by metabolic inhibition or free radical exposure. This increase cannot be prevented by blockade of L-type Ca channels or inhibition of Na-Ca exchange. It is speculated that a specific Ca leak may be involved in this process. In the present study patch clamp techniques were used to examine this hypothesis. Currents were measured in a recording configuration of cell attached or excised inside-out membrane patches in adult rat ventricular myocytes as affected by metabolic inhibition or free radical exposure. The metabolic inhibition was achieved by use of 1 mM iodoacetic acid and 10 mM 2-deoxyglucose with omission of glucose in the perfusate. Free radicals were generated by application of 100 microM hydrogen peroxide in the perfusate. Specific Ca leak channels were identified. The channels were not significantly permeable to monovalent cations. The activity of these channels was increased markedly over a period of minutes by metabolic inhibition or free radical exposure. In the presence of 100 microM hydrogen peroxide the open probability (NPo) of the channels increased from 0.0083 +/- 0.003 (mean +/- S.D.) in control to 0.09 +/- 0.024 (P < 0.01). During metabolic inhibition it was augmented from 0.0075 +/- 0.0035 to 0.062 +/- 0.018 (P < 0.01). The increase of the Ca leak channel activity under both conditions could be completely blocked by addition of polycationic protamine to the patch pipette solution. The results support the hypothesis that Ca leak channels are involved in the Ca overload induced by metabolic inhibition or free radical exposure. The inhibitory effect of polycation may have important therapeutic implications for the treatment of ischemic cardiac heart disease.
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PMID:Increase in calcium leak channel activity by metabolic inhibition or hydrogen peroxide in rat ventricular myocytes and its inhibition by polycation. 776 Mar 45

We have evaluated the accuracy and reliability of the Paratrend 7 continuous blood-gas analyser in infants and small children under conditions of severe hypoxaemia admitted to the paediatric intensive care unit in the perioperative period with cyanotic congenital heart disease. PO2, PCO2 and pH (hydrogen ion concentration) were measured continuously via a femoral arterial sensor and compared with 100 simultaneous paired arterial blood-gas measurements. Data were analysed by Bland-Altman analysis for bias and precision. Sensors were placed in 10 children of median age 5.43 (range 0.03-45) months, median weight 3.74 (2.79-15.4) kg and remained in place for up to 27 h after operation. PO2 values were 2.5-8.2 kPa (median 5.3 kPa). Co-oximeter saturation ranged from 37.1% to 90.6% (median 75.8%). Bias and precision values were 0.04/0.87 kPa for PO2, -0.44/0.74 kPa for PCO2 and -2.61/6.98 nmol litre-1 for hydrogen ion concentration (i.e. 0.02/0.06 for pH). We conclude that perioperative continuous arterial gas monitoring is clinically accurate under conditions of severe hypoxaemia in small infants and children with cyanotic congenital heart disease.
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PMID:Continuous intra-arterial blood-gas monitoring in infants and children with cyanotic heart disease. 942 10

Magnetic resonance imaging (MRI) is a diagnostic technique used clinically in cardiology over the last ten years. It offers great advantages over other methods as it is noninvasive, does not use radiation, is tomographic and multiplanar. MRI is a very flexible technique based on the interaction between atomic nuclei, usually hydrogen, and external magnetic fields. This leads to image formation and to other important functional diagnostic information. MRI has undergone great technical developments and has proven to be most useful in several areas: cardiovascular structure; global and regional cardiac function; cardiovascular flow; coronary anatomy; myocardial perfusion and metabolism. The initial clinical diagnostic goals of MRI were mainly the anatomic characterization of aortic pathology, congenital heart disease, pericardium diseases and cardiac masses. With the development of cine MRI and, more recently, with rapid imaging and flow evaluation techniques, it has been increasingly used in the functional assessment of cardiovascular diseases. The functional study of the above mentioned clinical pathologies is now possible and information can also be obtained in other important areas; cardiac volumes and function; cardiovascular shunts, valvular heart disease; ischemic heart disease (ischemia detection, infarction quantification, coronary anatomy and flow). It also has an important role in myocardial characterization and is promising for myocardial metabolism, evaluated by spectroscopy. The goal of this review is the presentation of the main MRI techniques and the present clinical applications of this imaging method in cardiovascular diagnosis.
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PMID:[Magnetic resonance in cardiology. The current clinical outlook]. 974 Dec 18

Diabetic patients have reduced antioxidant defenses and suffer from an increased risk of free radical-mediated diseases such as coronary heart disease. Epidemiological evidence has suggested that antioxidant dietary flavonoids may protect against heart disease, but a biological effect has yet to be demonstrated directly in humans. In this study, 10 stable type 2 diabetic patients were treated for 2 weeks on a low-flavonol diet and for 2 weeks on the same diet supplemented with 76-110 mg of flavonols (mostly quercetin) provided by 400 g of onions (and tomato sauce) and six cups of tea daily. Freshly collected lymphocytes were subjected to standard oxidative challenge with hydrogen peroxide, and DNA damage was measured by single-cell gel electrophoresis. Fasting plasma flavonol concentrations (measured by high-performance liquid chromatography) were 5.6 +/- 2.9 ng/ml on the low-flavonol diet and increased 12-fold to 72.1 +/- 15.8 ng/ml on the high-flavonol diet (P < 0.001). Oxidative damage to lymphocyte DNA was 220 +/- 12 on an arbitrary scale of 0-400 U on the low-flavonol diet and 192 +/- 14 on the high-flavonol diet (P = 0.037). This decrease was not accounted for by any change in the measurements of diabetic control (fasting plasma glucose or fructosamine) or by any change in the plasma levels of known antioxidants, including vitamin C, carotenoids, alpha-tocopherol, urate, albumin, and bilirubin. In conclusion, we have shown a biological effect of potential medical importance that appears to be associated with the absorption of dietary flavonols.
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PMID:Dietary flavonols protect diabetic human lymphocytes against oxidative damage to DNA. 989 40

Melatonin was found to be a potent free radical scavenger in 1993. Since then over 800 publications have directly or indirectly confirmed this observation. Melatonin scavenges a variety of reactive oxygen and nitrogen species including hydroxyl radical, hydrogen peroxide, singlet oxygen, nitric oxide and peroxynitrite anion. Based on the analyses of structure-activity relationships, the indole moiety of the melatonin molecule is the reactive center of interaction with oxidants due to its high resonance stability and very low activation energy barrier towards the free radical reactions. However, the methoxy and amide side chains also contribute significantly to melatonin's antioxidant capacity. The N-C=O structure in the C3 amide side chain is the functional group. The carbonyl group in the structure of N-C=O is key for melatonin to scavenge the second reactive species and the nitrogen in the N-C=O structure is necessary for melatonin to form the new five membered ring after melatonin's interaction with a reactive species. The methoxy group in C5 appears to keep melatonin from exhibiting prooxidative activity. If the methoxy group is replaced by a hydroxyl group, under some in vitro conditions, the antioxidant capacity of this molecule may be enhanced. However, the cost of this change are decreased lipophility and increased prooxidative potential. Therefore, in in vivo studies the antioxidant efficacy of melatonin appears to be superior to its hydroxylated counterpart. The mechanisms of melatonin's interaction with reactive species probably involves donation of an electron to form the melatoninyl cation radical or through an radical addition at the site C3. Other possibilities include hydrogen donation from the nitrogen atom or substitution at position C2, C4 and C7 and nitrosation. Melatonin also has the ability to repair damaged biomolecules as shown by the fact that it converts the guanosine radical to guanosine by electron transfer. Unlike the classical antioxidants, melatonin is devoid of prooxidative activity and all known intermediates generated by the interaction of melatonin with reactive species are also free radical scavengers. This phenomenon is defined as the free radical scavenging cascade reaction of the melatonin family. Due to this cascade, one melatonin molecule has the potential to scavenge up to 4 or more reactive species. This makes melatonin very effective as an antioxidant. Under in vivo conditions, melatonin is often several times more potent than vitamin C and E in protecting tissues from oxidative injury when compared at an equivalent dosage (micromol/kg). Future research in the field of melatonin as a free radical scavenger might be focused on: 1), signal transduction and antioxidant enzyme gene expression induced by melatonin and its metabolites, 2), melatonin levels in tissues and in cells, 3), melatonin structure modifications, 4), melatonin and its metabolites in plants and, 5), clinical trials using melatonin to treat free radical related diseases such as Alzheimer's, Parkinson's, stroke and heart disease.
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PMID:Chemical and physical properties and potential mechanisms: melatonin as a broad spectrum antioxidant and free radical scavenger. 1189

Flow-induced dilation (FID) is dependent largely on hyperpolarization of vascular smooth muscle cells (VSMCs) in human coronary arterioles (HCA) from patients with coronary disease. Animal studies show that shear stress induces endothelial generation of hydrogen peroxide (H2O2), which is proposed as an endothelium-derived hyperpolarizing factor (EDHF). We tested the hypothesis that H2O2 contributes to FID in HCA. Arterioles (135+/-7 micro m, n=71) were dissected from human right atrial appendages at the time of cardiac surgery and cannulated with glass micropipettes. Changes in internal diameter and membrane potential of VSMCs to shear stress, H2O2, or to papaverine were recorded with videomicroscopy. In some vessels, endothelial H2O2 generation to shear stress was monitored directly using confocal microscopy with 2',7'-dichlorofluorescin diacetate (DCFH) or using electron microscopy with cerium chloride. Catalase inhibited FID (%max dilation; 66+/-8 versus 25+/-7%; P<0.05, n=6), whereas dilation to papaverine was unchanged. Shear stress immediately increased DCFH fluorescence in the endothelial cell layer, whereas treatment with catalase abolished the increase in fluorescence. Electron microscopy with cerium chloride revealed shear stress-induced increase in cerium deposition in intimal area surrounding endothelial cells. Exogenous H2O2 dilated (%max dilation; 97+/-1%, ED50; 3.0+/-0.7x10(-5) mol/L) and hyperpolarized HCA. Dilation to H2O2 was reduced by catalase, 40 mmol/L KCl, or charybdotoxin plus apamin, whereas endothelial denudation, deferoxamine, 1H-(1,2,4)-oxadiazole-[4,3-a]quinoxalin-1-one, or glibenclamide had no effect. These data provide evidence that shear stress induces endothelial release of H2O2 and are consistent with the idea that H2O2 is an EDHF that contributes to FID in HCA from patients with heart disease. The full text of this article is available at http://www.circresaha.org.
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PMID:Role for hydrogen peroxide in flow-induced dilation of human coronary arterioles. 1257 54


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