Distal muscle weakness and optic atrophy without central nervous system involvement in a patient with a homozygous missense mutation in the C19ORF12-gene.

Variants of the C19ORF12-gene have been described in patients with spastic paraplegia type 43 and in patients with mitochondrial membrane protein-associated neurodegeneration (MPAN), a subtype of neurodegeneration associated with brain iron accumulation (NBIA). In both subtypes optic atrophy and neuropathy have been frequently described. This case report describes a patient with bilateral optic atrophy and severe distal muscle weakness based on motor neuropathy without involvement of the central nervous system. Exome sequencing revealed a homozygous pathogenic missense variant (c.187G>C;p.Ala63Pro) of the C19ORF12-gene while iron deposits were absent on repeat MR-imaging of the brain, thus showing that peripheral neuropathy and optic neuropathy can be the sole manifestations of the C19ORF12-related disease spectrum whereby iron accumulation in the brain may be absent.

Long-term anti-ischemic effects of angiotensin-converting enzyme inhibition in patients after myocardial infarction. The Captopril and Thrombolysis Study (CATS) Investigators.

OBJECTIVES: This study was conducted to test the hypothesis that angiotensin-converting enzyme (ACE) inhibition reduces myocardial ischemia and related events after myocardial infarction (MI). BACKGROUND: The oxygen demand/supply ratio of the myocardium is influenced by angiotensin II as a result of its arterial vasoconstrictive and inotropic effects and through its interaction with the sympathetic nervous system. METHODS: We studied 244 patients who had been included in a double-blind, randomized, placebo-controlled, post-MI, ACE inhibition intervention study (Captopril and Thrombolysis Study [CATS]). All patients underwent exercise testing before and 3 and 12 months after hospital discharge. After 1-year double-blind treatment, all patients continued receiving single-blind placebo for 1 month. RESULTS: Total exercise time increased in both groups after 3 months (placebo: +86 +/- 13 s; captopril: +69 +/- 12 s, p = 0.8 between groups) and increased further after 1 year (placebo: +13 +/- 11 s; captopril: +33 +/- 13 s, p = 0.7 between groups). There were also no differences in mean ST segment depression. During the 12 months, significantly fewer ischemia-related events occurred in the captopril group (82 vs. 52, p = 0.015). This difference was found between 3 and 12 months but not during the first 3 months. After withdrawal from double-blind medication, nine ischemic events were reported in teh captopril group compared with one in the placebo group (p = 0.006 between groups). CONCLUSIONS: The present data show that captopril may reduce the incidence of ischemia-related events after MI, which becomes apparent after 3 months. However, no anti-ischemic effect was observed during exercise testing. After withdrawal from ACE inhibition, a high incidence of clinical events occurred, suggesting a rebound phenomenon.

Application of a DNA double labelling method for the flow cytometric analysis of recruitment of non-cycling cells in a mixed population of P and Q cells.

In this paper we describe the application of a non-radioactive DNA double labelling and staining method to an analysis of cell proliferation kinetics by flow cytometry, aimed at the direct measurement of recruitment rates in cell cultures. The method is based on the application of two halogenated deoxyuridines: iododeoxyuridine (IdUrd) and chlorodeoxyuridine (CldUrd) which are incorporated into DNA synthesizing cells. By applying two commercially available monoclonal antibodies both deoxyuridines can be detected separately. To measure recruitment all proliferating cells in a plateau phase culture were labelled first with IdUrd applied during a time interval approximately equal to the cell cycle time. Subsequently, recruitment induced by a medium change was analysed by flow cytometric assessment of incorporation of CldUrd in cells which had not taken up IdUrd. Experiments designed to determine the toxicity of continuous labelling with IdUrd in different concentrations and of pulse labelling with CldUrd showed that there was no effect on the progression of cells through the cell cycle. The aim of this study is to test the sensitivity of the procedure to detect changes in proliferation kinetics, in particular the entrance of resting cells into the S phase. Although the cell culture model used is very simple, the results demonstrate clearly that a low rate of recruitment can be detected. It is suggested that the procedure described here is specific and sensitive enough to quantify changes in cell proliferation in tumours induced by various treatments and has advantages over other methods, which measure recruitment indirectly, or directly by using two radioactive thymidines.

Comparison of effects on peak oxygen consumption, quality of life, and neurohormones of felodipine and enalapril in patients with congestive heart failure.

Angiotensin-converting enzyme (ACE) inhibition is currently the cornerstone of congestive heart failure (CHF) therapy, but these drugs are not tolerated in up to 20% of patients. For these patients, therapeutic alternatives with comparable efficacy are needed. Felodipine, a vasoselective dihydropyridine calcium antagonist with a slow onset of action and a long plasma half-life, may be such an agent. Therefore, the efficacy and safety of felodipine were examined and compared with enalapril using a double-blind design. We studied 46 patients with a left ventricular ejection fraction < 0.40, peak oxygen consumption < 20 ml.min-1.kg-1, and symptoms of CHF despite therapy with diuretics and digoxin. After 16 weeks of therapy, there were no statistically significant differences in peak oxygen consumption (felodipine +1.6, enalapril +2.5 ml.min-1.kg-1) and exercise tolerance (felodipine +61 seconds, enalapril +64 seconds). Quality-of-life parameters were affected slightly better by felodipine than by enalapril. Plasma norepinephrine decreased by 143 pg.ml-1 with enalapril and by 12 pg.ml-1 with felodipine (p < 0.20 between groups). Both drugs were generally well tolerated. These data suggest that felodipine and enalapril have comparable effects on exercise parameters in patients with CHF. Neurohumoral activation was not observed with either drug.

Comparison between felodipine and isosorbide mononitrate as adjunct to beta blockade in patients > 65 years of age with angina pectoris.

Coronary artery disease is an increasingly common medical problem in the elderly, and relatively few studies investigating drug therapy focus on this population. To assess the efficacy and safety of the calcium channel blocker, felodipine, and isosorbide mononitrate (ISMN), as adjunct to optimal beta-blocker therapy in elderly patients, a placebo-controlled, double-blind study was conducted in 46 patients, aged between 65 and 80 years, with documented stress-induced angina pectoris and myocardial ischemia. With use of a latin-square design, with 3 periods of 4 weeks each, exercise testing was performed after each period. Felodipine, 5 mg once daily, significantly improved both time to ischemic threshold and pain threshold (p = 0.02 and p = 0.003, respectively, vs placebo), and tended to increase total exercise time (p = 0.06 vs placebo). In contrast, ISMN, 20 mg twice daily, did not significantly affect these parameters. Comparison of the 2 active treatment arms showed that, overall, felodipine was more effective than ISMN, with a statistically significant difference for time to ischemic threshold (p = 0.02). With regard to safety, felodipine was also better tolerated than ISMN, which led to more patients discontinuing study medication with ISMN (p < 0.05 between ISMN and felodipine). It is concluded that in elderly patients who are treated with optimal beta blockade, felodipine, but not ISMN, leads to an additional significant reduction in ischemic parameters during exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of lacidipine on peak oxygen consumption, neurohormones and invasive haemodynamics in patients with mild to moderate chronic heart failure.

OBJECTIVE: To evaluate the efficacy and safety of the second generation dihydropyridine calcium channel blocker lacidipine in patients with heart failure. DESIGN: Placebo controlled, parallel group, double blind study over 8 weeks. SETTING: General community hospital in Breda, The Netherlands. PATIENTS: A random sample was studied of 25 outpatients with symptoms of mild to moderate heart failure, despite treatment with diuretics, digoxin, and angiotensin converting enzyme inhibitors. Their mean age was 65 years, with mean left ventricular ejection fraction of 0.24 and a peak oxygen consumption of 14.4 ml/min/kg. Two patients dropped out on lacidipine, one patient on placebo. INTERVENTION: Treatment with lacidipine 4 mg once daily or placebo for eight weeks. MAIN OUTCOME MEASURE: Cardiopulmonary exercise testing, invasive haemodynamics, and plasma neurohormones. RESULTS: Treatment with lacidipine 4 mg once daily, as compared to placebo treatment, significantly improved peak oxygen consumption (P < 0.02), cardiac index (P < 0.01), and stroke volume (P < 0.03) paralleled by a decrease in systemic vascular resistance (P < 0.03) and arteriovenous oxygen content difference (P < 0.01). Plasma noradrenaline, plasma renin activity, and aldosterone values did not differ between lacidipine and placebo. CONCLUSIONS: This second generation dihydropyridine may be of value as an adjunct to standard treatment in congestive heart failure patients.

Nifedipine gastrointestinal therapeutic system versus atenolol in stable angina pectoris. The Netherlands Working Group on Cardiovascular Research (WCN).

The gastrointestinal therapeutic system formulation of nifedipine enables a once-daily dosing resulting in predictable, relatively constant plasma concentrations. To evaluate the efficacy and safety of this formulation and to compare this with the beta-blocker atenolol, we conducted a double-blind, randomised, multi-centre study in 129 male patients with documented exercise induced angina pectoris. After 4 weeks' treatment, nifedipine (60 mg), improved time to onset of 0.1 mV ST-segment depression from 536 s by 72 +/- 117s, time to onset of pain from 619 s by 56 +/- 120 s, and total exercise time from 685 s by 40 +/- 88 s. Atenolol 100 mg, had a comparable effect, time to onset of 0.1 mV ST-segment depression improved from 496 s by 53 +/- 129 s, time to onset of pain from 572 s by 57 +/- 118 s, and total exercise time from 653 s by 33 +/- 99 s. Between group analysis revealed no statistically significant differences for these exercise parameters. Atenolol, but not nifedipine, significantly reduced heart rate and systolic blood pressure at rest and during exercise (P < 0.001 between groups), indicating different modes of action of the drugs. With regard to safety, both drugs were generally well tolerated. There were significantly (P = 0.01) more vasodilation related side effects with nifedipine. These data demonstrate that gastrointestinal therapeutic system formulation of nifedipine and atenolol as once-daily monotherapy are equally effective and safe, but with different effects on exercise parameters.

Monotherapy with nifedipine GITS compared with atenolol in stable angina pectoris. The Working Group on Cardiovascular Research (WCN).

This double-blind, randomised multicentre study compares nifedipine gastrointestinal therapeutic system (GITS) with atenolol in 129 male patients, with exercise-induced angina pectoris. At 4 weeks, there was no significant difference between nifedipine GITS 60 mg o.d. and atenolol 100 mg o.d., in respect of improved time to onset of 0.1 mV ST-segment depression, time to onset of pain, and total exercise time. Atenolol, but not nifedipine, significantly reduced heart rate and systolic blood pressure at rest and during exercise. There were significantly more vasodilator-related side effects with nifedipine. Nifedipine GITS and atenolol as once-daily monotherapy are equally effective and safe, but have different effects on exercise parameters.

The potential role of calcium antagonists in the management of congestive heart failure: initial experience with lacidipine.

First-generation calcium antagonists have been used in patients with congestive heart failure with rather disappointing results. Therefore, second-generation dihydropyridine calcium-channel blockers, such as felodipine and lacidipine, have been developed that may be beneficial in congestive heart failure owing to their high vasoselectivity and more favorable neurohumoral modulation. The effects of lacidipine in patients with congestive heart failure, who remain symptomatic despite receiving long-term therapy with angiotensin-converting enzyme inhibitors, digoxin, and diuretics, were investigated during a prospective, double-blind, randomized, placebo-controlled, parallel-group study. Twenty-five patients were randomized to receive either lacidipine (4 mg once daily; 12 patients) or placebo (once daily; 13 patients). After 8 weeks of treatment patients receiving lacidipine showed a significantly higher increase in cardiac output (p < 0.01), and a significantly greater reduction in vascular resistance (p < 0.02) than those patients in the placebo group. No significant changes were observed in filling pressures and heart rate. The arteriovenous oxygen content difference was significantly reduced in the lacidipine group (p < 0.01) without significant changes in arterial oxygenation, suggesting an increase in flow that was not a result of pulmonary shunting. Further peak oxygen consumption during cardiopulmonary exercise testing increased significantly in the lacidipine patients (p < 0.02). These beneficial effects were achieved without significant changes in neurohumoral parameters. Analysis of right and left ventricular ejection fractions revealed no cardiodepressant effects. Lacidipine was well tolerated during the course of the study, and adverse reactions were minor. These data suggest that lacidipine has a promising profile for the treatment of congestive heart failure patients, and that further investigation with second-generation dihydropyridines in the field of congestive heart failure appears warranted.

Efficacy and safety of calcium channel blockers in heart failure: focus on recent trials with second-generation dihydropyridines.

BACKGROUND: Chronic heart failure (CHF) has high morbidity and mortality rates despite treatment with angiotensin-converting enzyme inhibitors, diuretics, and digoxin. Adjunctive vasodilation through calcium channel blockade has been suggested as potentially useful. However, the first-generation calcium channel blockers, including the dihydropyridine nifedipine, showed disappointing results in CHF. The second-generation dihydropyridines were expected to be of more value, and of all the calcium channel blockers, these drugs were the ones most studied in patients with CHF. METHODS AND RESULTS: The Medline databank was used to search studies in human beings (published in 1990 or later) that used dihydropyridines in patients with CHF. The references of the studies found were subsequently checked for additional data. In 17 studies and more than 2000 patients with CHF, no consistent beneficial effect was observed with regard to exercise tolerance and functional capacity, whereas plasma neurohormones were not affected. On the other hand, in general, no worsening of CHF was seen with these second-generation dihydropyridines. Two larger studies (PRAISE and V-HeFT III) have given some estimates on the long-term effects of dihydropyridines, and no overall influence on mortality rate was found. Of note, subanalysis of the PRAISE study has suggested that in patients with a nonischemic cause of CHF, amlodipine might have a beneficial effect on survival. CONCLUSIONS: In this review we have focused on the efficacy and safety of dihydropyridines in patients with CHF, as reported in recent trials. The data do not support the use of dihydropyridines when primarily given as treatment for CHF. The results, however, suggest that these drugs can be safely given to patients with left ventricular dysfunction or CHF who need additional treatment for angina pectoris or hypertension.

Effects of amlodipine on endothelial function in rats with chronic heart failure after experimental myocardial infarction.

In chronic heart failure, the role of endothelial dysfunction is not yet well established. As calcium metabolism plays an important role in the endothelium, it might be suggested that calcium channel blockers influence endothelial function. Although calcium channel blockers are generally contraindicated in chronic heart failure, because they are believed to stimulate neurohumoral mechanisms and to exert negative inotropic effects, recently it has been suggested that amlodipine might have a favorable affect on mortality in patients with heart failure. The mechanism of amlodipine that contributes to this beneficial effect is not known. Therefore we investigated whether 10 weeks of amlodipine treatment could influence endothelial function in rats with congestive heart failure induced by myocardial infarction. The main finding of our study was that amlodipine, when administered for 10 weeks to rats after a myocardial infarction had been induced, had no significant effects on in vitro and in vivo hemodynamics or neurohormones. The effect of amlodipine on endothelium-intact, norepinephrine-precontracted aortic rings appears to differ from the placebo treatment with respect to the endothelium-dependent relaxation, whereas no differences are seen in endothelium-independent relaxation. We conclude that our data do not support a beneficial role of amlodipine on endothelial function in chronic heart failure.

Physiological parameters during the initial stages of cardiopulmonary exercise testing in patients with chronic heart failure. Their value in the assessment of clinical severity and prognosis.

AIMS: To analyse the relationship between initial exercise parameters and peak oxygen consumption and prognosis in 96 patients with congestive heart failure. METHODS AND RESULTS: Comparison of responses during the initial 6 min of cardiopulmonary exercise testing (Naughton modified protocol) in patients stratified to the Weber classification, and analysis of their predictive value with respect to peak oxygen uptake and prognosis. All patients had a left ventricular ejection fraction < 0.45 and a valid cardiopulmonary exercise test, during which they remained in sinus rhythm. Significant differences in several parameters were seen in the initial stages, including oxygen pulse (P < 0.04) and ventilation equivalent for oxygen (P < 0.004). These parameters remained as independent predictors of peak oxygen uptake in the algorithm derived from baseline and initial stage variables. In a multivariate Cox proportional hazards model, the predicted peak oxygen uptake (P < 0.003) was an independent predictor of mortality. CONCLUSION: In patients with congestive heart failure, the initial 6 min parameters of a cardiopulmonary exercise test have additional value in the assessment of clinical severity and prognosis. This may be of clinical relevance since a limited incremental exercise protocol may be more objective than more traditional 6 min walking tests and less demanding.

Effect of isradipine and nifedipine on diastolic function in patients with left ventricular dysfunction due to coronary artery disease: a randomized, double-blind, nuclear, stethoscope study.

To elucidate the effect of isradipine and nifedipine on left ventricular (LV) systolic and diastolic function, each drug was given intravenously (i.v.) in equihypotensive doses to 10 patients accepted for coronary arteriography for stable angina pectoris. All 20 patients had LV ejection fraction (LVEF) of < 40% owing to previous myocardial infarction (MI). Systolic and diastolic function was assessed by standard hemodynamic parameters and pressure-volume relations measured by nuclear stethoscope. All measurements were taken at rest and during ischemia caused by right atrial pacing. Both systolic and diastolic parameters improved equally with isradipine and nifedipine. LVEF and cardiac output (CO) increased owing to peripheral vasodilatation. A decrease in P/Vmax, indicating a negative inotropic effect, was noted in patients at rest with both medications, but not during pacing-induced ischemia. With either medication, the time constant of relaxation and the end-diastolic elasticity constant decreased during pacing, indicating improvement in diastolic function, probably owing to relief of myocardial ischemia.