Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The toxicity of Cu, Ni and Fe individually, as well as in combination (Cu + Ni, Cu + Fe, Ni + Fe), on growth-rate depression, uptake of NO3- and NH4+, photosynthesis, nitrate reductase and urease activity of Chlorella vulgaris has been studied. All the test metals when used individually showed pronounced toxicity on all the parameters studied. However, their interactive effect was mostly antagonistic except for Cu + Ni (synergism). Pre-addition of Fe offered more protection to the cells against copper and nickel toxicity. The data of statistical analysis reconfirmed that 14CO2 uptake is the most sensitive parameter (significant at P less than 0.005, both for time and treatment) than others in metal toxicity assessment. However, these results suggest further that exposure time and sequence of metal addition are very important in biomonitoring of heavy metal toxicity.
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PMID:Impact of bimetallic combinations of Cu, Ni and Fe on growth rate, uptake of nitrate and ammonium, 14CO2 fixation, nitrate reductase and urease activity of Chlorella vulgaris. 216 14

A 64-year-old woman with a history of hypertension for ten years and of syncope 18 month previously visited our Division of Cardiology on 12 June, 1989. The S4 and mitral regurgitation were audible at the apex, and her electrocardiogram showed ST-depression in leads II, aVF, V5-6 and prominent U-wave (PU) in V1-3 when first seen. Then, she was thought to have a posterior myocardial ischemia. PU in V1-3 diminished whereas T-wave increased after nitrate and Ca++ blocker. Ergometer exercise ECG showed ST-depression in II, III, aVF, V4-6 and PU with decreased T-wave in V2-3 with no apparent symptoms. Simultaneously, Tl-201 myocardial imaging demonstrated a transient posterior defect. A silent posterior myocardial ischemia was, therefore, confirmed. Coronary arteriograms demonstrated subtotal obstruction of the proximal left circumflex artery, and the peripheral site was filled by collaterals from the right coronary artery. Angina-induced PU in the right precordial leads proved to be useful in detection of posterior myocardial ischemia, and this marker may also improve the possibility of detection of silent posterior ischemia.
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PMID:[A case of silent posterior myocardial ischemia/left circumflex artery obstruction detected by prominent U-wave in right precordial leads]. 228 23

Forty clinically normal lactating Holstein cattle from a herd involved in a natural outbreak of chronic nitrate toxicosis were divided into 2 equal groups according to production, stage of lactation, age, and apparent pregnancy state (pregnant or nonpregnant). One group was fed a low-nitrate ration (average of 356 ppm on dry matter basis in concentrate; less than 400 ppm in free-choice hay for 1st 5 wks of study). The 2nd group was fed a high-nitrate (HN) ration (average of 1,600 ppm in protein concentrate-amemded corn silage; 4,000 ppm in free-choice hay for the 8-week study). At the end of the study, the 2 groups were classified according to their starting reproductive status: nonpregnant (open); early pregnant (less than 60 da); midpregnant (average of 105 da). Milk production, milk fat, and milk nitrate concentrations were similar for cows fed both rations. Serum progesterone concentration (SPC) was depressed (P less than 0.05) in cows fed the HN ration. This effect was prominent in open, luteal phase cows, less prominent but still apparent in early pregnant cows, and absent in midpregnant cows. The early reproductive problems of chronic nitrate toxicosis may be due to depression of SPC. A possible mechanism of inhibition of luteal progesterone synthesis by inhibition of cytochrome P-450 is presented.
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PMID:Serum progesterone and milk production and composition in dairy cows fed two concentrations of nitrate. 230 Nov 46

Previous studies by our laboratory have shown that lead nitrate when injected intravenously as a single dose to rats, induces a hyperplastic response in the liver. Liver hyperplasia was accompanied by an increase in cholesterol synthesis, an accumulation of cholesterol esters and by a stimulation of hexose-monophosphate (HMP) shunt enzyme activities. In the present report, hepatic DNA, mitotic index, cholesterol metabolism, as well as glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) activities, were investigated during liver hyperplasia induced by lead in fasted rats. Fasting was chosen as an experimental model characterized by a very strong depression of those metabolic pathways (cholesterol synthesis and HMP shunt) that we have found related to liver hyperplasia. The mitogenic response, even if at minor extent, also occurs in liver of fasted rats. A stimulation of cholesterol synthesis and HMP shunt enzyme activities, was also observed in lead-treated fasted rats, adding further support to the fact that an endogenous source of newly synthesized cholesterol together with a suitable increase of HMP shunt enzyme activities is needed during hepatic cell proliferation.
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PMID:Modifying influence of fasting on liver hyperplasia induced by lead nitrate. 234

The effect of a controlled-release formulation of isosorbide-5-mononitrate (IS-5-MN) was studied in patients with coronary heart disease (CHD), with the aim of comparing the acute effect with that after chronic administration on parameters of ischemia. To determine whether any tolerance developed, several aspects of ischemia were observed: ECG signs, clinical parameters, and left ventricular function. Fifteen patients with angiographically proven CHD were examined with 12-lead exercise ECG before, 2 h and 4 h after the first dose and after 10 days of therapy with 60 mg IS-5-MN (Coleb-Duriles) once daily. After 7 days, three radionuclide ventriculographies were performed: control, 2 h after nitrate and 2 h after 75 mg gallopamil. Plasma concentrations of IS-5-MN were measured before every exercise test. The results showed a reduction of total ST-segment depression from 0.59 mV to 0.29 mV after 2 h (NS) and 4 h (P less than 0.05) on the 1st day and from 0.48 mV to 0.32 mV (P less than 0.05) and 0.31 mV (NS) after 10 days. The severity of angina pectoris was diminished by about 50%. The effect on exercise duration and time to ST-segment depression by more than 0.1 mV remained unchanged after 10 days, whereas the effect on blood pressure, heart rate and time to onset of angina was attenuated. The mean decrease in ejection fraction (EF) from rest to exercise was reduced from--5.9% to -1.9% (P less than 0.05) after nitrate, while an increase of +1.4% was seen after gallopamil (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Lack of tolerance after chronic administration of controlled-release isosorbide-5-mononitrate. Interaction of nitrate and gallopamil. 235 12

Electrical stimulation of a lateral region of the cerebellar nodulus-uvula transition zone in anesthetized albino rabbits decreases mean arterial blood pressure in direct proportion to stimulus intensity. The hypotension has an abrupt onset and is phasic; heart rate is unaffected. Neural pathways that might mediate the depressor response were studied using autonomic-blocking agents. Pretreatment with 2 mg/kg iv of either propranolol HCl or atropine methyl nitrate did not alter the onset or duration of the hypotensive response. However, pretreatment with 2 mg/kg iv phentolamine HCl abolished the depressor response, and 7 mg.kg-1.min-1 iv tetraethylammonium infusion decreased the response by more than 50%. Ipsilateral injections of 200 ng bicuculline methiodide into an area immediately dorsal to the superior cerebellar peduncle or the dorsal aspect of the superior vestibular nucleus reversibly attenuated the nodulus-uvula evoked depression. Anterograde horseradish peroxidase-wheat germ agglutinin (HRP-WGA) transport experiments revealed that both these regions receive direct inputs from the nodulus-uvula. These data suggest that hypotensive events elicited by lateral nodulus-uvula stimuli represent a central, alpha-aminobutyric acid-mediated, phasic inhibition of vasomotor drive mediated through autonomic ganglia to alpha-adrenoreceptors in the vasculature.
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PMID:Nodulus-uvula depressor response: central GABA-mediated inhibition of alpha-adrenergic outflow. 247 76

Twenty-four patients with severe stable angina pectoris were included in a randomized, double-blind, placebo-controlled, cross-over study to assess the efficacy of a controlled-release preparation of isosorbide-5-mononitrate (ISMN-CR) 60 mg once daily or twice daily as adjunctive treatment to a beta blocker. In bicycle ergometer exercise tests performed 4 h after study drug intake, total exercise time and time until 1-mm ST-depression increased significantly during both regimens as compared with placebo (p less than 0.05). However, only the 60-mg once-daily regimen was significantly better than placebo with regard to time until angina pectoris. The results indicate that ISMN-CR 60 mg once daily is effective as adjunctive to beta-blocker treatment, and nitrate tolerance appeared to develop during the twice-daily regimen. In 10 of the patients, the effect of additional sublingual nitroglycerin (NTG) was studied. Exercise time after NTG remained remarkably constant throughout all study periods. Exercise time was significantly prolonged after additional NTG and independent of the dose level of ISMN-CR. This indicates that cross-tolerance to NTG was not induced during sustained treatment with ISMN-CR.
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PMID:Efficacy of controlled-release isosorbide-5-mononitrate as adjunctive treatment to beta-blocking agents in patients with stable angina pectoris. 247 13

A newly developed glyceryl trinitrate (GTN) patch with biphasic release (7.5 mg GTN (24h)-1) was compared with placebo in 40 patients with stable angina pectoris, in a double-blind randomized crossover study. Exercise tests employing a bicycle ergometer were carried out 2 and 10h after application of the patch on the first day and after 7 days of continuous therapy and 2h after patch reapplication at the end of a 3-month period of once daily therapy. In comparison with placebo, 2h after acute dosing, ST-segment depression was decreased from 0.15 mV to 0.07 mV (P less than 0.001), the time to 0.1 mV ST-segment depression was increased from 3.6 to 5.0 min (P less than 0.001) and work capacity was increased from 280 W min-1 to 446 W min-1 (P less than 0.001). After 1 week of daily GTN therapy the effects at 2h were somewhat greater than in the acute test. Compared with the values 2h after GTN patch application, the effects after 10h, both on the first day and 7th day, were substantially lower. During long-term therapy, the effects observed after 1 week of GTN therapy were maintained. The decrease in effects between 2 and 10h probably represent partial nitrate tolerance but the similar effects on the first and 7th day indicate no change during sustained therapy.
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PMID:Antiischaemic effects of phasic release nitroglycerin system during acute and sustained therapy. 250 Oct 93

In 24 patients (pts) with proven coronary artery disease, stable angina pectoris (AP) and elevated pulmonary artery pressure (PAP) during bicycle exercise, the acute and chronic (4 and 8 months) effects of several long-acting nitrates in different dosages: 50-300 mg pentaerythrityltetranitrate (PETN) or 40-120 mg isosorbide dinitrate (ISDN) were evaluated in comparison to sublingual nitroglycerin. Nitroglycerin was about 30%-40% more effective than PETN and ISDN with regard to pulmonary artery pressure at exercise. Beneficial effects of both long-acting nitrates were shown with regard to the number of anginal attacks, nitroglycerin consumption, and ST-segment depression both during short- and long-term treatment. Both nitrates decreased exercise pulmonary artery pressure by 15%-20%, at acute testing and during chronic therapy. There was no difference with respect to the long-term effects of both long-acting nitrates. However, more side-effects were observed during ISDN treatment. There were no signs of nitrate tolerance development with the therapy schedules under investigation.
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PMID:[Long-term effect of various nitrates in ischemic heart disease and latent heart failure]. 251 96

ISDN (standard release formulation) 40 mg administered 6 times daily (= 240 mg) remained effective during a 4-week treatment of patients with stable angina in terms of decreasing anginal attacks and reducing ischemic ST segment depression at stress testing in the upright position (step climbing test). The sustained antianginal activity is explained by fluctuating plasma levels, provided by rapid drug release from the standard formulation, short administration intervals and an 7-hour-night pause. When comparing acute and chronic antianginal activity of ISDN (40 mg) administered 4 times daily with regard to the type of stress testing it became evident that a marked attenuation of antiischemic activity (-35%; p less than 0.01) occurred in the supine (bicycle ergometry) but not in the upright (step climbing test) position. The most probable explanation for the significant attenuation of efficacy in the supine position is marked blood redistribution into central compartments with increase of cardiac filling pressures during chronic therapy. Rapid development of tolerance both to the hemodynamic and antiischemic effects of glycerol trinitrate within 24 hours could be shown during intravenous administration (3 mg/h) in patients with stable angina. It is concluded that the antiischemic effects of oral ISDN (standard release formulation) administered 4-6 times daily is preserved during long-term therapy due to fluctuating plasma levels. Nitrate therapy providing constant doses over time (e.g. I.V. nitroglycerin) leads to a rapid attenuation of efficacy most probably due to counter regulatory mechanisms.
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PMID:[Long-term effect of organic nitrates in angina pectoris: dependence on the form of administration and mode of stress]. 253 10


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