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Biomedical subjects

A Hartmann

Publications and source records attributed to A Hartmann.

At least 397 records · Page 22Linked to original sources
PubMed1991

Correlation of regional cerebral blood flow and blood flow velocity in normal volunteers and patients with cerebro-vascular disease.

Transcranial Doppler sonography and measurement of regional cerebral blood flow using the Xenon133-inhalation technique have been used simultaneously in 10 normal volunteers and 13 patients with acute-onset cerebrovascular disorders during normocapnia and during hyperventilatory hypocapnia. Hypocapnia led to a reduction of both blood flow and blood velocity in the territory of the middle cerebral artery. However, correlation was poor in most cases with respect: 1) to hemispheric blood flow and flow velocity over the middle cerebral artery (BFV), 2) cerebral blood flow (CBF) over the middle cerebral artery (MCA) and BFV and 3) percentage changes of CBF over the MCA and BFV during hypocapnia. In normals correlation usually was better than in patients with cerebrovascular disorders. It was concluded that measurement of BFV over the MCA using transcranial Doppler sonography does not reflect either cerebral tissue perfusion or changes of tissue perfusion induced by alteration of CO2-content in the arterial blood.

Adult↗
PubMed1991

Effects of isradipine on renal function in cyclosporin-treated renal transplanted patients.

The renal effects of the calcium-channel antagonist isradipine were evaluated in cyclosporin A (CsA)-treated renal allografted patients more than 5 months after transplantation. Twelve patients with stable renal function were given placebo for 2 weeks and then isradipine 1.25 mg x 2 for 1 week and 2.5 mg x 2 for the next 3 weeks in an open trial. The CsA dose was unchanged during the study. Isradipine did not interfere with the pharmacokinetics of CsA as both whole blood trough and peak levels were unchanged. Isradipine reduced mean arterial blood pressure (MAP) from 117.0 +/- 1.8 to 106.3 +/- 1.9 mmHg (P less than 0.01). The renal effects were studied during water diuresis 1-3 h after drug intake. Para-aminohippurate clearance (CPAH) increased from 256.4 +/- 21.5 to 291.5 +/- 26.3 ml/min (P less than 0.05), renal vascular resistance was reduced by 21.5% (P less than 0.01) and inulin clearance (CIn) was unchanged. Fractional proximal reabsorption, calculated from lithium clearance (CLi), was reduced by 11.9% (P less than 0.01) by isradipine. Isradipine also reduced proximal reabsorption of sodium (APRNa) and increased distal sodium delivery (DDNa). Distal sodium reabsorption (ADRNa) and free-water clearance (CH2O) were significantly increased. Urinary excretion of enzymes and proteins was unchanged by isradipine.

Adult↗
PubMed1991

Contrasting effects of lisinopril and nifedipine on albuminuria and tubular transport functions in insulin dependent diabetics with nephropathy.

An open, randomized, cross-over study was undertaken to assess the effects of lisinopril and nifedipine on albumin excretion, renal haemodynamics and segmental tubular reabsorption in overt diabetic nephropathy. The study consisted of a 4-week run-in period, a 3-week active treatment period, a 4-week wash-out period and a second 3-week active treatment period. Twelve patients with type 1 diabetes with albuminuria, mild to moderate hypertension and a serum creatinine level of less than 200 mumol l-1 were included. Lisinopril reduced albumin excretion from 1343 +/- 337 micrograms min-1 to 879 +/- 299 micrograms min-1 (P less than 0.01), whereas nifedipine was without effect, 1436 +/- 336 micrograms min-1 vs. 1319 +/- 342 micrograms min-1. Glomerular filtration rate (GFR) was unchanged by either drug. Both drugs increased effective renal plasma flow (ERPF) by about 20%. No differences between the drugs were observed with regard to their effect on renal haemodynamic parameters. By contrast, nifedipine exerted an inhibitory effect on several proximal tubular transport markers, whereas lisinopril was without effect. The different actions on tubular transport mechanisms exerted by lisinopril and nifedipine may contribute to the observed effect on albumin excretion.

Adult↗
PubMed1991

Recanalization of chronic coronary occlusions by low speed rotational angioplasty (ROTACS).

From 1988 to 1990 chronic coronary occlusions were treated with a newly developed slowly rotating angioplasty system (ROTACS), which is designed for atraumatic passage of arterial obstructions. In all 152 patients (mean age 55 years, ranging from 29 to 78 years) attempts to recanalize the coronary occlusion with conventional guidewire systems had failed. In 74/152 patients the age of the occlusion could be estimated because of a previous angiogram or clinical event. It ranged from 1-192 months (median 6 months, mean value 14 months; in 20% of patients it was 1-3, in 37% 4-6, in 28% 7-12, and in 15% greater than 12 months). The occlusion was localized in the right coronary artery (RCA) in 86 cases, in the left anterior descending coronary artery (LAD) in 37 cases, and in the circumflex branch of the left coronary artery in 17 cases. Eleven bypass occlusions were treated. One patient had a LAD and RCA occlusion. Out of 152 patients 84 could be recanalized. The success rate rose with experience from 30% to 60%. It was 55% in the LAD, 52% in the RCA, 70% in the circumflex branch, and 63% in bypass grafts. The success rate in relation to the age of the occlusion was 93% in occlusions of 1-3 month duration, 74% in occlusions of 4-6 months duration, 52% in occlusions of 6-12 months duration, and 8% in occlusions older than 12 months. Seventy-six of the successfully treated patients underwent follow-up angiography after 4 months. In 56/76 (74%) the vessel remained open. Twenty-two patients (29%) had restenosis that was successfully dilated in 21 patients. Twenty patients (26%) had reocclusion. Thus, the angiographically determined long-term success rate was 72%. Emergency operation was necessary in two patients in whom reopening of the LAD was attempted although the occlusion was located directly at the take-off of the LAD from the left main. Since this type of occlusion was consequently considered a contraindication, no further serious complications occurred. There was one myocardial infarction, no death, no vessel wall perforation or other complications in the 152 patients. It is concluded that low speed ROTACS is a safe technique that can be applied in chronic coronary occlusions even if the duration of occlusion exceeds 6 months.

Adult↗
PubMed1991

Nitrate therapy in heart failure.

Nitrates are drugs of first choice in patients with acute heart failure. Acute pulmonary edema can be successfully treated with single or repeated doses of sublingual nitroglycerin. In cases of prolonged acute heart failure, e.g. in the setting of acute myocardial infarction, nitroglycerin or isosorbide dinitrate can be given by the intravenous route for up to 24 h. Patients with acute myocardial infarction usually benefit from nitrate therapy if filling pressures are high and/or left ventricular function is compromised. Nitrate therapy can be considered safe if arterial blood pressure is maintained above 95 mm Hg. With these precautions nitrates can reduce infarct size and the incidence of complications as well as improve long-term prognosis. In the chronic treatment concern has risen with regard to possible nitrate tolerance. Thus, therapy schedules allowing for nitrate-poor phases are generally recommended. Therapy schedules with constant-rate delivery of drugs achieved with patches or intravenous administration of nitrates should be used with caution.

Administration, Cutaneous↗
PubMed1991

Prognostic factors in outpatient psychotherapy of bulimia.

Little is known about prognostic factors in the treatment of bulimic patients. In the context of an ongoing study we looked at 1-year symptomatic outcome of 37 outpatients fulfilling DSM-III-R criteria for bulimia nervosa in relation to a variety of measures at first assessment. These included multiple measures of depression, measures of borderline personality disorder, a personality inventory, a symptom checklist and information about the history and the severity of the illness. Results add evidence to the importance of personality variables in predicting outcome: patients with high scores on the Borderline Syndrome Index indicating a severe disturbance tend to have poorer symptomatic outcome, especially when they also experience themselves as dominant (Giessen-Test). Other factors, including abuse of alcohol and history of anorexia did not allow prediction of outcome.

Adolescent↗
PubMed1991

Effect of stable xenon on regional cerebral blood flow and the electroencephalogram in normal volunteers.

We evaluated the effects of breathing 35% stable xenon in 65% oxygen on regional cerebral blood flow and the electroencephalogram in 20 normal volunteers. We measured blood flow in 32 brain regions over both hemispheres with the xenon-133 intravenous injection technique in two protocols. In the first protocol (n = 10), a baseline study was followed by a second study during 5 minutes of breathing stable xenon; in the other protocol (n = 8), the baseline study was followed by a second study after 5 minutes of breathing stable xenon. Two volunteers were excluded due to excessive movements during the inhalation of stable xenon. Some of the remaining 18 volunteers had varying alterations of consciousness accompanied by electroencephalogram changes. After stable xenon inhalation the electroencephalogram returned to normal within 2-3 minutes. During stable xenon inhalation mean +/- SD PECO2 dropped significantly from 39.4 +/- 4.4 to 33.3 +/- 5.4 mm Hg in the first protocol and from 39.4 +/- 2.6 to 34.8 +/- 4.1 mm Hg in the second protocol due to hyperventilation in 13 volunteers. Mean regional cerebral blood flow increased significantly by 13.5-25.4% without correction for PECO2. In the first protocol regional cerebral blood flow increased by greater than 12% in 11-14 (depending on the flow parameter) of the 20 hemispheres. In the second protocol regional cerebral blood flow increased by greater than 12% in 9-13 of the 16 hemispheres. We conclude that cautious interpretation is necessary in the assessment of regional cerebral blood flow with 35% xenon-enhanced computed tomography.

Adult↗
PubMed1991

Hemodilution in cerebral infarcts.

To evaluate the effect of hypervolemic hemodilution on cerebral blood flow (CBF) two protocols have been performed: A) Ten randomly selected baboons have been treated with either low molecular dextrane (10 ml/kg) or normal saline (10 ml/kg). Regional cerebral ischemia was produced in all baboons. CBF increased selectively in the ischemic territory but not in the normally perfused tissue. B) Forty patients with acute cerebral ischemia were treated on day onset of symptoms with either dextrose, low molecular weight dextrane, hydroxyethyl starch or pentoxifylline. After intravenous infusion of the substances CBF increased only in the groups treated with dextrane- or starch-solution. Ischemic tissue benefitted more from hypervolemic hemodilution than normally perfused tissue. It was concluded that hypervolemic hemodilution leads to increase of cerebral blood flow, more in ischemic than in normally perfused brain tissue.

Acute Disease↗
PubMed1991

Immunocytochemical localization of the storage protein phaseolin in the embryo-suspensor of Phaseolus coccineus.

Antibodies against the bean storage protein, phaseolin, were induced in rabbits. Sections of bean embryos of various age were incubated with the antibodies, and exposed to fluorescein isocyanate (FITC) conjugated goat anti-rabbit immunoglobulin. Distinct positive signals were found in vacuoles of the suspensor giant cells. Immunofluorescent staining of protein bodies in cotyledon cells, histochemical staining reactions of the sections, as well as gel electrophoretic analysis of the proteins, isoelectric focusing and Western blotting confirmed the specificity and reliability of the immunochemical staining of the suspensor cells. The results give evidence for synthesis of storage proteins in the embryo-suspensor and indicate a function so far not detected of this embryonal nutritive organ.

Blotting, Western↗
PubMed1991

Protein kinase C activation and protooncogene expression in differentiation/retrodifferentiation of human U-937 leukemia cells.

Human U-937 leukemia cells differentiate along the monocytic lineage following 3-day exposures to 12-O-tetradecanoylphorbol-13-acetate (TPA). This induction of differentiation is accompanied by adherence and loss of proliferation, as well as expression/repression of differentiation-associated genes. Long term culture of TPA-differentiated U-937 cells in the absence of phorbol ester for 32-36 days resulted in a process of retrodifferentiation. The retrodifferentiated cells detached from the substrate and reinitiated proliferation. Other cellular parameters, such as glycosidase activities, cytokine release, and filament expression, returned to levels similar to that observed in uninduced cells. Treatment of U-937 cells with TPA resulted in a rapid translocation of protein kinase C (PKC) from the cytosol to cell membrane fractions within 2-8 min. Increased levels of membrane-associated PKC activity persisted until 17-29 days. However, longer periods of incubation were associated with a return to the distribution of PKC in control cells. Activation of PKC has been implicated in the regulation of certain immediate early response genes, and in the present studies, TPA rapidly induced c-fos and c-jun gene expression. Levels of c-fos and c-jun transcripts remained elevated during periods of PKC activation and also returned to levels observed in control cells by 30-36 days, when the cells entered retrodifferentiation. Staurosporine, a nonspecific inhibitor of PKC, partially blocked TPA-induced adherence and growth inhibition and concomitantly prevented TPA-induced c-fos and c-jun gene expression.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaloids↗
PubMed1991

[Course of dilatative hypertrophic cardiomyopathy].

Five patients with hypertrophic cardiomyopathy developed left-ventricular dilatation and congestive heart failure during an observation period of 16-29 years. In one patient cardiac transplantation had to be performed. The initial predominant symptoms of outflow-tract obstruction and diastolic dysfunction developed into progressive left-ventricular systolic failure. The question of whether this is a well-defined subgroup of patients with hypertrophic cardiomyopathy, or whether hypertrophic cardiomyopathy turns into a phase of left-ventricular dilatation and failure after some years remains to be elucidated by long-term studies.

Adult↗
PubMed1991

[Experiences with the application of monoclonal Indium-111 antimyosin scintigraphy in the diagnosis of rejection episodes following orthotopic heart transplantation].

Indium-111-labeled Fab fragment imaging using a murine antimyosin monoclonal antibody (Myoscint, Centocor, Leiden) was evaluated for efficacy in detecting cardiac allograft rejection. Diagnosis of rejection was made by endomyocardial biopsy with four to five samples taken for each procedure. Eighty-one studies were performed in 25 patients (21 men, four women, mean age 50 +/- 9 years) from 2 weeks to 45 months after cardiac transplantation. 0.5 mg of the monoclonal antibody labeled with 60 MBq Indium-111 (Antimyosin-Fab-DTPA) was administered i.v. Planar scintigraphic images were obtained in LAO 45 and anterior projections as well as "half-body-scintigrams" 48 h after injection. Using the regions-of-interest-(ROI)technique the relative uptake over the lung and the heart was determined and an index of In-111 uptake was calculated. A heart-to-lung ratio of 1.5 or higher was considered indicative for moderate to severe rejection. Specificity was 86% (nine false-positive In-111 studies in 68 negative biopsy studies), sensitivity was 85% (two false-negative In-111 studies in 13 pathological biopsy studies). It is concluded that the In-111 method has a high sensitivity and specificity in detecting heart transplant rejection and may be useful in the monitoring of patients in the chronic phase after heart transplantation. The 48-h delay in establishing the diagnosis limits the applicability in acute severe rejection.

Adult↗
PubMed1991

[Comparison of ischemic pain threshold and reactive hyperemia in autonomic diabetic neuropathy and silent myocardial ischemia].

31 patients with coronary artery disease (11 patients with diabetes mellitus and autonomic neuropathy. 10 patients with diabetes without neuropathy, and 10 patients with asymptomatic myocardial ischemia) participated in a study designed to investigate whether there is a difference in forearm skeletal muscle ischemia and pain threshold. The degree of ischemia was determined by plethysmographically measured reactive hyperemia. There was no difference in maximum reactive hyperemia after passive forearm ischemia of 5-min duration in the three groups. After symptom-limited ischemic work, there was significantly more reactive hyperemia in patients with silent myocardial ischemia as compared to diabetic patients. Exercise time was longer in patients with silent myocardial ischemia (153 +/- 51 s) than in patients with diabetic neuropathy (139 +/- 45 s) and diabetics without neuropathy (120 +/- 45 s). Pain as a cause of termination of symptom-limited ischemic forearm exercise occurred less frequently in patients with diabetic neuropathy (2/11) and patients with silent myocardial ischemia (3/10) as compared to patients with diabetes without neuropathy. Patients with silent myocardial ischemia had a higher ischemic tolerance in the ischemic working forearm than did diabetic patients with and without neuropathy. In patients with neuropathy, however, ischemic pain occurred less frequently at the same ischemic work level compared to diabetics without neuropathy. Therefore, diabetic neuropathy appears to facilitate the occurrence of silent myocardial ischemia. The data presented here suggest that there is a qualitative difference in ischemic tolerance between patients with silent myocardial ischemia and patients with diabetic neuropathy.

Angina Pectoris↗
PubMed1991

[Multiparametric analysis using radionuclide ventriculography in the assessment of left ventricular function following heart transplantation].

Left ventricular systolic and diastolic performance was evaluated by radionuclide angiography in 17 patients following cardiac transplantation and compared with normal persons. Both groups performed supine bicycle exercise during the investigation, the control group at 102 +/- 73 W and the transplanted patients at 61.2 +/- 15 W. The ejection fraction increased in the normal persons from 61 +/- 8 to 69 +/- 10% whereas in the transplanted patients it did not increase significantly. There were no relevant changes in systolic parameters during exercise in the transplant recipients. The changes in diastolic parameters were significantly smaller in transplant patients than in normals. After correction for heart rate-induced changes a significantly different time course of the systolic-diastolic sequence during the cardiac cycle became evident in the transplanted group at rest. During exercise the systolic-diastolic sequence during the cardiac cycle became similar in both groups. It is concluded that the reduced exercise capacity of patients in the late phase after cardiac transplantation is partially due to the absence of an EF increase and a limitation of diastolic reserve during exercise.

Adult↗
PubMed1990

[Regression of cerebral post-transplantation lymphoma under cyclosporin A reduction].

4.5 months after successful kidney transplantation a Non-Hodgkin-lymphoma with polymorph centroblastic appearance of the tonsillar gland developed in a 21 years old male patient during immunosuppressive therapy with cyclosporine A and prednisone parallel to infection with Epstein Barr virus. Focal epileptic seizures occurred and were due to cerebral posttransplantation lymphomas as proven by brain biopsy. Reduction of immunosuppressive therapy led to complete remission as shown by CCT and MRI.

Adult↗
PubMed1990

Gastrointestinal type 1 hypersensitivity to azathioprine.

We report the case of a 49-year-old patient with progressive sensomotor polyneuropathy who developed nausea, vomiting, and diarrhea after 2 1/2 months of azathioprine therapy. Administration of the drug was interrupted. These symptoms recurred immediately after rechallenge with azathioprine. A duodenal biopsy demonstrated a massive local eosinophilia without peripheral blood eosinophilia. Cutane testing with azathioprine showed a positive type 1 reaction. We diagnosed a hypersensitive reaction type 1 in the duodenal mucosa on the basis of the histological features, the history, and the cutane reaction.

Azathioprine↗