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Biomedical subjects

F Follath

Publications and source records attributed to F Follath.

At least 73 records · Page 4Linked to original sources
PubMed1998

Relative frequency of functional sympathetic and parasympathetic reinnervation after heart transplantation.

Although there is evidence of partial sympathetic reinnervation late after transplantation, little is known about the relative frequency of sympathetic and, in particular, parasympathetic reinnervation. We examined the heart rate response to various maneuvers (standing up, handgrip exercise, phase 2 of Valsalva maneuver for sympathetic function, carotid sinus massage, phase 4 of Valsalva maneuver, and atropine for parasympathetic function) in 65 patients 3 to 110 months after transplantation and in 16 healthy volunteers and defined reinnervation as either one normal (>50% of control group) and at least one partial (>33% of control group) heart rate response or partial responses in all three tests of the respective part of the autonomic nervous system. Thirty-five (54%) patients had sympathetic reinnervation, but only 16 (25%) had parasympathetic reinnervation (p < 0.001); earliest reinnervation was found 11 months after transplantation, and all but one patient with parasympathetic reinnervation also had sympathetic reinnervation. Signs of sympathetic but not parasympathetic reinnervation were common late (>5 years) after transplantation (74% vs 30%).

Heart↗
PubMed1998

[Regression of left ventricular hypertrophy with antihypertensive therapy].

The case report describes a 50-years-old patient with left ventricular hypertrophy, severe heart failure and ischemic chest pain due to untreated arterial hypertension. Coronary arteriography showed normal vessels. Under a combined drug treatment with an ACE-inhibitor, betablocker and diuretic the cardiac symptoms and the signs of heart failure disappeared within a few months. After 10 months the electrocardiographic signs of LV hypertrophy also disappeared. The therapeutic efficacy of the different antihypertensive drugs is discussed.

Antihypertensive Agents↗
PubMed1998

Do diuretics differ in terms of clinical outcome in congestive heart failure?

Diuretics are required in the majority of patients with symptomatic congestive heart failure (CHF). The reduction of pulmonary venous congestion results in rapid improvement of dyspnoea and increased exercise tolerance. In contrast to arterial hypertension, there are only a few studies comparing diuretics with other drugs in CHF. In particular, no reliable data exist on the effect of diuretics on mortality and major cardiac events in CHF. Diuretic agents differ in their mode of action, pharmacodynamics and pharmacokinetic properties. Loop diuretics are used in acute CHF and in severe chronic CHF, while thiazides, having a longer duration of action, are suitable for long-term therapy of mild CHF in ambulatory patients. Potassium-sparing diuretics are usually prescribed in combination with other preparations to prevent electrolyte disturbances. No randomized prospective large-scale trials have been carried out to compare the efficacy and tolerability of the various types of diuretics. With adequately chosen dosage, the effects of the different loop diuretics appear to be similar in CHF. However, observational data in ambulatory patient populations indicate that loop diuretics with high bioavailability and longer half-life may offer advantages in terms of clinical stability and resource utilization for cardiac decompensation. In patients with severe pulmonary congestion and oedema, combined use of loop diuretics and thiazides may improve the therapeutic response. Spironolactone can also be prescribed to increase diuresis in patients who are resistant to a combination of loop diuretics and ACE inhibitors.

Diuretics↗
PubMed1997

Determination of saquinavir in human plasma by high-performance liquid chromatography.

We developed and characterized a high-performance liquid chromatography (HPLC) assay for the determination of saquinavir, an HIV protease inhibitor, in human plasma samples. Extraction of plasma samples with diethyl ether resulted in quantitative recovery of both saquinavir and its stereoisomer Ro 31-8533 which was used as an internal standard. The assay was performed isocratically using 5 mM H2SO4 (pH 3.5) and acetonitrile (75.5:24.5, v/v) containing 10 mM tetrabutylammonium hydrogen sulfate (TBA) as a mobile phase, a Nucleosil 3C8 column kept at 45 degrees C and UV detection at 240 nm. Using this method, saquinavir and Ro 31-8533 can be separated from endogenous substances, and in the concentration range of 5-110 ng/ml the relative standard deviations for the determination of saquinavir were below 5%. The detection limit of saquinavir in human plasma was 1 ng/ml. The usefulness of the method was demonstrated by quantification of saquinavir in plasma of human subjects treated with 600 mg of saquinavir per os or 12 mg intravenously.

Administration, Oral↗
PubMed1997

Atrioventricular block after administration of atropine in patients following cardiac transplantation.

BACKGROUND: Atropine is widely used as a parasympatholytic agent during diagnostic and therapeutic procedures. We observed an unexpected paradoxical response to atropine after cardiac transplantation. METHODS: In a study investigating the occurrence of autonomic reinnervation after cardiac transplantation, atropine, at 0.015 mg/kg body weight, was given intravenously to 23 patients (mean age, 56+/-8 years) 98 days to 6.4 years after transplantation. RESULTS: Two patients experienced a witnessed syncope 40 and 150 min after administration of atropine. Second-degree atrioventricular (AV) block was documented in the first patient immediately afterward, and third-degree AV block was seen on 24-hr electrocardiogram monitoring in the second patient. A third patient developed documented AV block 15 min after atropine but experienced no sequelae because of a previously implanted pacemaker. CONCLUSIONS: Although the underlying mechanism is not clear, these findings suggest that atropine may paradoxically cause high-degree AV block in patients after transplantation. Accordingly, it should be used with caution and appropriate monitoring in these patients.

Adult↗
PubMed1997

[Aortic valve insufficiency in Crohn disease].

We report on a 39-year-old man with Crohn's disease who was admitted with cardiogenic shock after a short history of progressive dyspnea. Echocardiographic examination (transthoracic echocardiography) showed severe aortic regurgitation, mild mitral regurgitation, and enlargement of the sinus of Valsalva and of the ascending aorta at the level of the right pulmonary artery. The left ventricular ejection fraction was 30%. After aortic valve replacement, histologic examination of the ascending aorta showed chronic aortitis resembling syphilitic aortitis (serology for syphilis was negative) and HLA B27 related aortitis. The aortic valve showed deformation and thickening of the cusps by fibrous tissue without evidence of endocarditis. The patient remained well after surgery and echocardiographic examination 6 months later showed normal function of the aortic valve prosthesis. The diameter of the sinus of Valsalva and of the ascending aorta was slightly bigger, possibly indicating ongoing destruction. The left ventricular ejection fraction nearly normalized. It seems possible that this type of aortitis, characterized by its proximity to the valve ring, is another extraintestinal cardiac manifestation of Crohn's disease. The possibility of ongoing destruction of the sinus of Valsalva and of the ascending aorta after valve replacement makes regular echocardiographic control necessary.

Adult↗
PubMed1997

Randomised study of effect of ibopamine on survival in patients with advanced severe heart failure. Second Prospective Randomised Study of Ibopamine on Mortality and Efficacy (PRIME II) Investigators.

BACKGROUND: Drugs that improve symptoms in patients with heart failure must also be assessed for their effects on survival. Ibopamine stimulates DA-1 and DA-2 receptors and causes peripheral and renal vasodilatation; the drug improves symptoms of heart failure. We assessed the effect of ibopamine on survival in patients with advanced heart failure in a multicentre, randomised placebo-controlled study. METHODS: Patients with advanced severe heart failure (New York Heart Association classes III and IV) and evidence of severe left-ventricular disease, who were already receiving optimum treatment for heart failure, were randomly allocated oral ibopamine 100 mg three times daily or placebo. The primary endpoint was all-cause mortality. The study was designed to recruit 2200 patients, and the minimum duration of treatment would be 6 months. We did intention-to-treat and on-treatment analyses; a post-hoc subgroup analysis was also done. FINDINGS: After we had recruited 1906 patients the trial was stopped early, because of an excess of deaths among patients in the ibopamine group. 232 (25%) of 953 patients in the ibopamine group died, compared with 193 (20%) of 953 patients in the placebo group (relative risk 1.26 [95% CI 1.04-1.53], p = 0.017). The average length of follow-up was 347 days in the ibopamine group and 363 days in the placebo group. In multivariate analysis, only the use of antiarrhythmic drugs at baseline was a significant independent predictor of increased fatality in ibopamine-treated patients. INTERPRETATION: Ibopamine seems to increase the risk of death among patients with advanced heart failure who are already receiving optimum therapy, but the reasons for this increase are not clear. Our finding that antiarrhythmic treatment was a significant predictor of increased mortality in ibopamine-treated patients may be important, but exploratory analyses must be interpreted with caution.

Adult↗
PubMed1997

[Drug treatment of cardiac insufficiency with systolic dysfunction].

Improvement of symptoms, increase in exercise capacity and prevention of disease progression are the aims of drug therapy in patients with congestive heart failure. At present only the ACE inhibitors are able to achieve all therapeutic targets and should therefore be regarded as drugs of first choice in systolic dysfunction. Diuretics are also necessary in most patients since they rapidly reduce pulmonary congestion and peripheral oedema, but have no documented beneficial long term effects on the course of CHF. Digoxin remains a useful drug to treat symptomatic patients who do not respond adequately to the combination of ACE inhibitors and diuretics, as well as in patients with atrial fibrillation. However, a reduction of mortality by digitalis glycosides cannot be expected. A new trend in the treatment of CHF is the utilisation of beta blockers. These drugs showed positive effects in chronic CHF in several studies, particularly in patients with dilated cardiomyopathy. Newer drugs such as carvedilol, seem to improve the symptoms and reduce complications even in CHF due to coronary artery disease. The role of beta blockers in the routine management of patients with heart failure requires further evaluation.

Adrenergic beta-Antagonists↗
PubMed1997

Langerhans'-cell histiocytosis in adults.

Guided by a long-term retrospective observation, the clinical course and treatment of Langerhans'-cell histiocytosis (LCH) in adult patients are represented. The series included 19 patients meeting the histopathologic criteria of presumptive LCH who were followed for 1.5-20 years (average 7.7 years). Most frequently, skeletal lesions (16 patients), diffuse interstitial lung infiltrates (seven patients), and pituitary gland involvement with diabetes insipidus (four patients) were present. Bone lesions of the skull and axial skeleton were associated with an infiltration of adjacent soft tissues in 10 of 16 patients. Liver, lymph node, and bone marrow involvement appeared sporadically. LCH was divided into localized or multifocal form. Localized disease took a benign course with remission of bone (n = 4) or lymph node lesions (n = 2). Also, in isolated pulmonary LCH (n = 2), spontaneous transition to inactive disease occurred. With the exception of isolated bone lesions (n = 27), which remained asymptomatic or showed a remission to treatment, multifocal LCH had a more aggressive course. Osseous lesions with adjacent soft tissue infiltration (n = 20) showed a relapse rate in excess of 80% independent of the treatment applied. Pulmonary involvement led to a more marked functional impairment compared to the isolated form, and systemic treatment yielded no convincing effect. In three patients with liver or bone marrow involvement, LCH showed a persistent, serious disease activity. One patient died of transition into acute monomyelocytic leukemia 18 months after diagnosis without preceding chemotherapy. In adults, LCH seems to be limited to a few organ systems. Multifocal LCH represents the more aggressive form with unfavorable prognosis in patients with bone lesions spreading into the adjacent soft tissue and liver or bone marrow involvement.

Adult↗
PubMed1996

Natural course of moderate cardiac allograft rejection (International Society for Heart Transplantation grade 2) early and late after transplantation.

BACKGROUND: The significance of International Society for Heart Transplantation (ISHT) grade 2 cardiac allograft rejection has been questioned, and the medical community is not in complete agreement as to its clinical management. We therefore retrospectively analyzed the follow-up of all available endomyocardial biopsy samples obtained from 161 transplant patients since introduction of the ISHT nomenclature at our institution. METHODS AND RESULTS: Of 2868 biopsies performed 3 days to 8.9 years after transplantation, 420 biopsies had no follow-up or were preceded by intensified immunosuppression and were excluded from analysis. Of the remaining 2448 biopsies, 374 (15.3%) were repeat biopsies performed 7 to 10 days after prior ISHT 2 rejection without change of treatment. Of these, 70 (18.7%) had progressed to > or = ISHT 3A, whereas 82 (21.9%) remained unchanged and 222 (59.4%) resolved. In contrast, follow-up of 2074 biopsies with lower-grade rejection showed graft rejection classified as > or = ISHT 3A in 153 (7.4%), ISHT 2 in 240 (11.6%), and < or = ISHT 1B in 1681 (81.1%) biopsy samples (P < .0001). In univariate analysis, the odds ratio (OR) of graft rejection > or = ISHT 3A after ISHT 2 rejection was 2.89. Other univariate predictors of rejection > or = ISHT 3A were time after transplantation (OR = 0.96 per month, P < .0001), blood group type B (OR = 1.62, P < .005), "Quilty" lesion on previous biopsy (OR = 1.70, P < .005), number of HLA mismatches (OR = 1.27 per mismatch, P < .005), female sex (OR = 1.55, P < .05), and serum creatinine level (OR = 0.93 per 10 mumol/L, P < .005). Young age of recipients was a risk factor during long-term (> or = 2 years) follow-up (P < .002), and lower cyclosporine level was a risk factor during the first month after transplantation (P < .01). In multivariate logistic regression analysis, ISHT 2 rejection on previous biopsy remained the strongest predictor of rejection > or = ISHT 3A (OR = 2.40, P < .0001). CONCLUSIONS: Several factors independently increase the risk of rejection classified as > or = ISHT 3A. The strongest predictor of a grade of > or = ISHT 3A was ISHT 2 rejection on the previous biopsy obtained 7 to 10 days earlier. Therefore, ISHT 2 graft rejection is of clinical significance, and short-term follow-up appears to be warranted even late after transplantation.

Adolescent↗
PubMed1996

Biotransformation of caffeine by cDNA-expressed human cytochromes P-450.

OBJECTIVES: The biotransformation of caffeine has been studied in vitro using human cytochrome P-450 isoenzymes (CYPs) expressed in human B-lymphoblastoid cell lines, namely CYP1A1, 1A2, 2A6, 2B6, 2D6-Val, 2E1 and 3A4, and microsomal epoxide hydroxylase (EH). In addition, CYP2D6-Met was also studied, in which a valine in the wild type (CYP2D6-Val) has been replaced by a methionine due to a G to A mutation in position 112. RESULTS: At caffeine 3 mmol center dot l-1, five CYPs (1A1, 1A2, 2D6-Met, 2E1 and 3A4) catalysed the biotransformation of caffeine. Among the enzymes studied, CYP1A2, which predominantly catalysed paraxanthine formation, had the highest intrinsic clearance (160 l center dot h-1 center dot mmol-1 CYP). Together with its high abundance in liver, it should be considered, therefore, to be the most important isoenzyme in caffeine metabolism. The affinity of caffeine for CYP1A1 was comparable to that of its homologue 1A2. CYP2D6-Met, which catalysed caffeine metabolism by demethylation and 8-hydroxylation, also had a relatively high intrinsic clearance (3.0 l center dot h-1 mmol-1 CYP), in particular for theophylline and paraxanthine formation, with kM values between 9-16 mmol center dot l-1. In contrast, the wild type, CYP2D6-Val, had no detectable activity. In comparison, CYP2E1 played a less important role in in vitro caffeine metabolism. CYP3A4 predominantly catalysed 8-hydroxylation with a kM value of 46 mmol center dot l-1 and an intrinsic clearance of 0.60 l center dot h-1 center dot mmol-1 CYP. Due to its high abundance in human liver, the latter CYP may contribute significantly to the in vivo formation of TMU. CONCLUSION: The findings of this study indicate that i) microsomes from transfected human B-lymphoblastoid cell lines give results close to those obtained with microsomes isolated from human liver, ii) at least four CYP isoforms are involved in caffeine metabolism, iii) at a substrate concentration <0.1 mmol center dot l-1, CYP1A2 and 1A1 are the most important isoenzymes, iv) at higher concentrations the participation of other isoenzymes, in particular CYP3A4, 2E1 and possibly also CYP2D6-Met, are important in caffeine metabolism, and v) the nucleotide composition at position 1120 of CYP2D6 determines the activity of this isoenzyme in caffeine metabolism.

Biotransformation↗
PubMed1996

Toxoplasmosis in heart transplant recipients.

In cardiac transplant recipients, infection with Toxoplasma gondii may be transmitted with the transplanted organ to immunosuppressed recipients or may be due to reactivation under immunosuppression in cases of pretransplant infection. In the present study the incidence of infection with Toxoplasma gondii and the clinical presentation of the infection in 121 consecutive heart transplant recipients were investigated. Data on IgG and IgM antibodies for Toxoplasma gondii measured by a semiquantitative microparticle immunoassay of donors and recipients were collected prospectively in 121 patients. Infection with Toxoplasma gondii was defined as IgM seroconversion with proven pre-transplant seronegativity (primary infection) or at least a fourfold increase of IgG antibodies (reactivation). Infection with Toxoplasma gondii occurred in 16 of 121 patients (13%) whereas overt clinical disease occurred in 5 of 121 patients (4%). Organ-transmitted infection was more frequent (11/18, 61%) and more often associated with acute disease than reactivation of latent infection (5/69 patients, 7%) (p < 0.01), although one case of Toxoplasma retinochoroiditis occurred in a patient with recrudescence of latent pretransplant infection. Treatment with pyrimethamine and sulfadiazine was efficient in all patients with acute disease and in controlling disease in patients with evidence of acute infection.

Animals↗
PubMed1996

Are there stereoselective electrophysiologic effects of intravenously administered (S)- or (R)-propafenone hydrochloride in patients with supraventricular tachycardia?

OBJECTIVE: The electrophysiological effects of intravenously administered pure (S)- and (R)-propafenone hydrochloride has been determined for the first time in humans-12 patients with supraventricular tachycardia. METHODS: Measurements were performed before and during drug therapy. RESULTS: (S)- and (R)-propafenone prolonged the AH interval from 82 to 107 ms and 75 to 84 ms, respectively, and significantly increased the V nodal Wenckebach cycle length by 58 ms and 37 ms, respectively. The AV nodal effective refractory period in both groups was increased significantly to the same extent (45 vs 42 ms). Sinus node recovery times were not significantly influenced by either enantiomers. Both (S)- and (R)-propafenone significantly prolonged the HV interval to the same extent (from 41 to 51 ms, and 42 to 53 ms). Changes in the electrophysiological characteristics of the myocardium were more pronounced in the atria than in the ventricles. Only (S)-propafenone significantly increased the atrial effective refractory period from 204 to 230 ms, and the ventricular effective refractory period from 225 to 241 ms compared to (R)-propafenone (from 221 to 239 ms, and from 219 to 222 ms, respectively). There was a more pronounced electrophysiological effect on AV nodal conduction of (S)- than (R)-propafenone, probably as a result of its beta-blocking activity. CONCLUSION: The electrophysiological effects of (S)-compared to (R)-propafenone were not very pronounced, so it still remains questionable whether one of the enantiomers might be clinically superior to the other, or to the racemic mixture.

Adult↗
PubMed1996

Pretransplant malignancy in candidates and posttransplant malignancy in recipients of cardiac transplantation.

BACKGROUND: Malignancy is generally considered a contraindication for cardiac transplantation, whereas secondary malignancy has been described under chronic immunosuppression. PATIENTS AND METHODS: We report here the frequency of malignancy encountered among the 495 patients evaluated at our cardiac transplant centre as well as the incidence and the course of post-transplant malignancy among 129 consecutive patients who underwent cardiac-transplantation, with a subsequent minimum follow-up of 6 months. RESULTS: A total of 10 out of 495 patients (2%) evaluated for heart transplantation presented with a history of previous malignancy: 3 of them underwent transplantation (2 survive, 1 died) whereas in the remaining 7 patients neoplasia was considered a contraindication for cardiac transplantation, and all 7 died (4 cardiac, 3 tumor-related deaths). Post-transplant malignancy was diagnosed in 10 of 129 patients (9%) 35 +/- 15 months after transplantation (6 skin cancers, 1 lymphoproliferative disease, 3 solid tumors). No significant association was found between post-transplant malignancy and primary prophylaxis with antithymocyte globulin (ATG) or murine antihuman T-cell monoclonal antibodies (OKT3). CONCLUSION: These results confirm that pre-transplant malignancy is not an absolute contraindication for cardiac transplantation and that post-transplant follow-up must include careful monitoring of post-transplant malignancy.

Adolescent↗
PubMed1996

Interaction between amiodarone and lidocaine.

We investigated the in vitro and in vivo interaction between amiodarone and lidocaine. The interaction on a molecular level was first studied in microsomes from 11 human livers. Close correlations between amiodarone N-monodesethylase activities and (a) the amounts of cytochrome P-4503A4 (CYP3A4), and (b) the rates of lidocaine N-monodesethylation were observed. Lidocaine inhibited amiodarone N-monodesethylation (Ki = 120 microM) competitively; inversely, amiodarone suppressed lidocaine N-monodesethylase activity in the same manner (Ki = 47 microM). Moreover, the metabolite N-monodesethylamiodarone (DEA) was stable and inhibited lidocaine metabolism in a concentration-dependent manner. The in vivo interaction was investigated in 6 cardiac patients. Each of them received a dose of 1 mg/kg lidocaine hydrochloride intravenously (i.v.) on three different occasions: before amiodarone treatment (control), and after cumulative doses of 3 g (phase I) and 13 g (phase II), respectively, amiodarone hydrochloride. The analysis of lidocaine pharmacokinetics showed an increase in lidocaine area under the curve (AUC) when amiodarone was administered, whereas that of N-monodesethylated lidocaine decreased. Moreover, the systemic clearance of lidocaine decreased, while the elimination half-life (t1/2) and the distribution volume at steady state of lidocaine remained unchanged. The pharmacokinetic parameters during phase II were the same as those during phase 1, indicating that the interaction had already occurred early in the loading phase of amiodarone administration. The interaction between amiodarone and lidocaine may be explained by the inhibition of CYP3A4 by amiodarone and/or by its main metabolite DEA.

Adult↗
PubMed1996

Low-dose cyclosporine treatment fails to prevent coronary luminal narrowing after heart transplantation.

BACKGROUND: Cyclosporine has been reported to induce endothelial dysfunction, arterial vasculitis, and accelerated atherosclerosis in experimental models. The purpose of the present study was to evaluate whether low-dose cyclosporine treatment started 1 year after heart transplantation reduces graft coronary artery narrowing compared with conventional cyclosporine doses. METHODS: One year after heart transplantation, 30 patients were randomly assigned to receive low-dose cyclosporine A (whole-blood polyclonal cyclosporine target trough levels 200 to 400 micrograms/L; group A; n = 15) or usual cyclosporine dosage (target levels 400 to 600 micrograms/L; group B; n = 15). Proximal and distal diameters of the left anterior descending, circumflex, and right coronary arteries were measured by quantitative coronary angiography at baseline (1 year after transplantation) and at 2 and 3 years after transplantation. RESULTS: One major cardiac event occurred in group A (retransplantation) and two in group B (sudden deaths). Moderate to severe allograft rejection (International Society for Heart and Lung Transplantation score 3A or higher) occurred in seven patients in group A and five in group B during the study period. Mean biopsy sample rejection score during the same period was increased in group A compared with that in group B (1.44 +/- 0.63 versus 1.05 +/- 0.59; p < 0.05). New angiographic evidence of vascular disease was observed in four patients of group A and in one patient of group B. Proximal coronary artery diameter was slightly, although not significantly, reduced in both groups at follow-up angiography. Distal segments showed a significant diameter reduction, which was greater in group A than in group B (-9.7% +/- 1.1% and -5.2% +/- 1.3%, respectively; p < 0.05). CONCLUSIONS: Cyclosporine dose reduction started 1 year after heart transplantation is ineffective in reducing coronary luminal narrowing and may be associated with an increased prevalence of cardiac allograft vasculopathy, especially in the distal coronary tree. Low-dose cyclosporine treatment may slightly enhance the risk of allograft rejection. Further investigations are needed to evaluate the effects of cyclosporine dose reduction started at an earlier time after heart transplantation.

Adult↗
PubMed1995

[Drug therapy in angina pectoris].

The currently available antianginal drugs act by reduction of myocardial O2 requirement and/or by coronary vasodilatation. The choice between beta blockers, nitrates, calcium antagonists or their combination depends on the clinical presentation, coexisting disorders and specific factors in individual patients. In addition to symptomatic treatment, secondary prophylactic measures, such as aspirin and reduction of serum cholesterol, are also necessary to prevent progression of the underlying coronary artery disease. In this paper the comparative efficacy and the indications of the various types of antianginal drugs are discussed.

Angina Pectoris↗