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Biomedical subjects

U Brandl

Publications and source records attributed to U Brandl.

At least 19 recordsLinked to original sources
PubMed2006

Fluorescent microspheres reveal different regional blood flow in hyperacutely rejected nontransgenic and hDAF pig hearts.

Classic features of hyperacute rejection show differential severity in the inner compared to the outer myocardium. In the present study, regional blood flow (RBF) measured by fluorescent microspheres served as a marker of the extent of hyperacute rejection. Using a working heart model, hearts of nontransgenic and hDAF transgenic pigs were perfused with human blood. Additionally, hDAF transgenic pig hearts were perfused with human blood containing GAS914 or the GPIIb/IIIa inhibitor tirofiban. Injections of fluorescent microspheres into the donor heart were performed in situ and during perfusion. Reference arterial blood samples were collected from the inferior aorta and the afterload line. Perfusion was terminated before hyperacutely rejected hearts failed to pump against the afterload column. RBF was determined in tissue samples of standardized areas of the left atrium and ventricle. Each specimen was divided into subepicardial and subendocardial tissue samples. Fluorescence intensity was measured using an automated luminescence spectrometer. At the end of perfusion with human blood, hyperacutely rejected nontransgenic pig hearts showed a higher RBF in the subendocardium. In hDAF-transgenic pig hearts perfused with unmodified human blood the subendocardial/subepicardial blood flow ratio changed in favor of the subepicardium. This ratio was not further improved by GAS914. In contrast, tirofiban was able to assimilate subepicardial and subendocardial blood flow. In conclusion, RBF of hyperacutely rejected pig hearts was inhomogeneous. Inhibition of complement activation improved the reduced subepicardial RBF, but depletion of antibodies had no positive effect. The ability of tirofiban to further increase subepicardial RBF affirms thrombosis of subepicardial veins as the defining characteristic of hyperacute rejection.

Acute Disease↗
PubMed1999

Late neurological sequelae of non-hemolytic hyperbilirubinemia of healthy term neonates.

Records of the only children's hospital equipped to perform exchange transfusions in West Berlin were used to identify all 29 non-hemolytic healthy term newborns with total serum bilirubin between 20 and 30 mg/dL, 16 of whom were available for follow-up neurological examination according to Touwen. Compared to 18 case controls with bilirubin <12 mg/dL, jaundiced children scored significantly worse only on the choreiform dyskinesia scale.

Anemia, Hemolytic↗
PubMed1998

Comparison of EEG, MRI and PET in reading epilepsy: a case report.

The pathophysiological and neuroanatomical bases of reading epilepsy (RE) are unclear. We performed video-EEG, high quality MRI and [11C]diprenorphine PET in a patient with RE to detect structural and functional abnormalities. EEG showed multifocal seizure onset bilaterally in temporal and fronto-central regions. MRI was normal, whereas [11C]diprenorphine PET revealed peri-ictal opioid binding decreases in both temporal lobes and the left frontal lobe. These findings confirm that RE is due to abnormal activity in the network subserving reading.

Adult↗
PubMed1998

Long-term follow-up study of vigabatrin in pretreated children with West syndrome.

A multicentre, long-term, open-label, add-on study of vigabatrin was undertaken in 23 pretreated children with infantile spasms. After 3 months of vigabatrin therapy 11 of the 23 patients had become seizure-free. At this time two-thirds of these 11 children still received other antiepileptic drugs (AEDs) in addition to vigabatrin (mostly valproic acid and/or dexamethasone). After a mean follow-up time of 5 1/4 years (range: 4 1/4-6 1/2) 72% of 18 evaluable patients (two children died, three were lost to follow-up) revealed seizure freedom for at least 1 year. The mean duration of vigabatrin therapy had been 2 1/2 years (range: 2 weeks to 4 3/4 years). Two-thirds of the 18 children continued to take AEDs, three of them undergoing vigabatrin monotherapy. Relapses of infantile spasms had occurred in 14% of the children. The rate of vigabatrin side effects (10%) was low. At follow-up, the EEG of 13 and the 18 patients demonstrated focal or multifocal epileptic discharges. Fifty-five percent had developed another epilepsy (focal epilepsy, secondary generalized epilepsy or myoclonic-astatic epilepsy). With respect to mental functions, three children were normal or slightly retarded, four showed moderate retardation and 11 revealed severe or very severe retardation. This long-term result is comparable to that in ACTH studies with unselected patients. The conclusions are: (1) vigabatrin is an effective drug for the short-term and long-term treatment of refractory infantile spasms; (2) the relapse rate is low; (3) vigabatrin is well tolerated; (4) with respect to secondary epilepsies and mental functions the long-term outcome in these pretreated children is similar to that in earlier studies with ACTH or corticosteroids.

Adrenocorticotropic Hormone↗
PubMed1998

Language dysfunction in children with Rolandic epilepsy.

Rolandic epilepsy is regarded as the classic example of benign focal epilepsy. However, neuropsychological deficits have been noted in affected children. As Rolandic discharges are mainly distributed over the centrotemporal region, specific interference with language function might be suspected. Therefore, we conducted a standardized neuropsychological assessment in children with Rolandic epilepsy which covered all important aspects of language processing. We measured intelligence Quotient, verbal memory, auditory discrimination, vocabulary, grammar and literacy in 20 children with an active Rolandic focus. Information about performance at school was obtained from teachers by means of a questionnaire. Patients with Rolandic epilepsy failed five of the twelve standardized language tests significantly more often than the normative population and consequently showed impairment of the following functions: reading, spelling, auditory verbal learning, auditory discrimination with background noise and expressive grammar. Thirteen of the 20 children showed language dysfunction with difficulties in two or more of the twelve standardized language tests. In eight of these 13 children the Full Scale Intelligence Quotient was within average range, indicating a specific language deficit. Language dysfunction was closely associated with learning difficulties at school. This study documents a consistent pattern of language dysfunction in children with Rolandic epilepsy which suggests interictal dysfunction of perisylvian language areas.

Adolescent↗
PubMed1997

Aggressive lowering of fibrinogen and cholesterol in the prevention of graft vessel disease after heart transplantation.

BACKGROUND: A combined treatment of statins and extracorporeal H.E.L.P.-apheresis (Heparin-mediated Extracorporeal LDL/fibrinogen Precipitation) has already been shown to be beneficial for coronary artery disease (CAD). Presumably high levels of LDL cholesterol, Lp(a), and fibrinogen also increase the risk for graft vessel disease (GVD). Therefore, we studied whether this concept can be applied in GVD, based on the hypothesis that GVD is an accelerated form of CAD. METHODS AND RESULTS: For comparison of statin treatment alone with the combined treatment, two matched groups of 10 cardiac transplant recipients were studied during a mean period of 3.6+/-1.0 years. Both groups were comparable in clinical characteristics, immunosuppressive medication, baseline plasma Lp(a), and high fibrinogen levels. Group I had normal LDL-C levels (3.36+/-0.60 mmol/L). Simvastatin alone was administered in this group to counteract the LDL-increasing effect of the immunosuppressive medication. Group II had marked hypercholesterolemia (LDL-C, 6.07+/-1.89 mmol/L), which was treated, in addition to simvastatin, with H.E.L.P.-apheresis weekly. GVD was assessed by coronary angiography. Simvastatin alone kept LDL-C levels within baseline limits but could not prevent GVD in 7 of 10 patients. In contrast, the combined treatment prevented GVD in 9 of 10 patients (P=.006) by simultaneous and drastic reduction of 48% LDL-C (P=.006), 35% fibrinogen (P=.002), and 47% Lp(a) (P=.006) below baseline. Both treatments were well tolerated and did not affect prevention of graft rejection and infections. CONCLUSIONS: A strategy of early, drastic lowering of fibrinogen, LDL-C, and Lp(a) helps to prevent GVD.

Adult↗
PubMed1995

What is the role of lipid lowering therapy in heart-allograft failure?

Hypercholesterolemia is often the cause for the primary heart disease ultimately necessitating heart transplantation (HTx). After transplantation, persisting hypercholesterolemia results in an increased peroxidation of LDL retained by extracellular matrix of the intima. Oxidized LDL accumulates in monocyte derived macrophages, it leads to immobilization of tissue macrophages and provokes the expression of vascular adhesion molecules, growth factors and cytokines. In a prospective open controlled study, the impact of long-term cholesterol reduction by diet in combination with the HMG-CoA-reductase inhibitor Simvastatin on graft vessel disease (GVD) was evaluated. Patients of the control group received only a low fat diet. Simvastatin treatment decreased total and LDL-cholesterol significantly and was not associated with adverse effects. The one year angiographies revealed GVD in 24.1% of the control and 12.1% of the Simvastatin group (Study I). In high risk patients with LDL-cholesterol concentrations above 135 mg/dl, in spite of maximal Simvastatin treatment or plasma fibrinogen concentrations above 400 mg/dl, the heparin mediated extracorporeal low density lipoprotein precipitation (H.E.L.P.)-system was applied. H.E.L.P. was used either for prevention of GVD soon after HTx or for treatment of GVD after development of coronary lesions. Study II proved that the H.E.L.P.-system could significantly lower LDL-cholesterol, Lp(a) and fibrinogen in most high risk patients after HTx, resulting in successful prevention or even treatment of GVD.

Coronary Angiography↗
PubMed1994

Intragraft events after heart transplantation: an experimental study comparing cytology in coronary sinus blood, peripheral blood, and daily histology.

Acute rejection is a frequent consequence after heart transplantation. To expand our knowledge of the rejection process and to investigate some intragraft events during acute rejection, the following experimental transplantation model was designed. Right cervical heart transplantation was performed in 12 mongrel dogs. Two experimental groups of six animals each received different immunosuppressive regimens. All animals were treated with daily triple drug therapy. In contrast to group 1, the animals in group 2 received high-dose steroids during rejection. The condition of the hearts was examined by daily transmural biopsies, graded according to the Billingham classification. To detect and quantify alterations in the mononuclear cell subsets of the myocardial venous return, blood samples from the coronary sinus blood (CS) and from peripheral blood (PB) were taken simultaneously with the biopsy. The total number of lymphoblasts and activated lymphocytes was determined and an activation index (AI) was calculated. The data referred to was established from 337 transmural biopsies. The AI of PB (n = 287) correlated well with the different stages of acute rejection (grade B0: AI = 2.2 +/- 2.1; grade B1 + 2: AI = 6.3 +/- 1.7; grade B3: AI = 10.0 +/- 4.7; P < 0.001). The rejection kinetics of both groups, including the rejection-free interval following high-dose steroid administration in group 2, could be expressed accurately by the AI. The time course of the total number of lymphoblasts in CS versus PB demonstrated that the lymphoproliferative response started 4 days prior to the first intramyocardial signs of rejection (mean = 3.8 +/- 0.7; n = 12).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1993

Stimulus specificity of P300.

P300 recordings are valuable and noninvasive neurophysiological research tool to gain further insight into higher cerebral function. Due to methodological and technological restrictions the clinical applicability of these investigations for neuropediatric purposes was limited. To enhance the usefulness of this phenomenon for clinical practice in neuropediatrics a convenient, painless and short-lasting procedure was imperative. For this purpose we developed a visual priming technique to average P300 components in children. To estimate the sensitivity of this procedure two classes of modality-different stimuli were used to prime visual P300 recordings. Forty children were examined, while P300 averagings for target and related nontarget events were recorded during spatial and verbal stimulation. Topographical brain electrical activities of match/mismatch events were compared by complex statistical MANOVA methods for each period to compute modality-specific components within the surface recorded P300 waveforms. Latency statistics were correlated. Our data indicate significant differences between various topographical P300 distributions, showing a close relationship between the experimental priming period and the activity of distinct cortical regions involved in spatial-imagination and language-processing.

Adolescent↗
PubMed1992

Allogeneic heart transplantation following xenogeneic bridging.

Xenografting seems to be a solution to bridge the time intervals when an essential allograft cannot be obtained. A subsequent allograft was never tried. Eight dogs (20-24 kg) of 2 years of age underwent right cervical heart transplantation. Donors were silver foxes (3-4 kg). The animals were treated by triple drug therapy consisting of cyclosporin A, methylprednisolone and azathioprine in clinical dosages. For control, six recipients received allogeneic heart transplantation (AHTP) and the identical immunosuppression. After rejection of the xenograft, a second allogeneic heart was anastomosed to the same right cervical vessels. Routine histology and immunohistology were performed. Thromboxane B2 and 6-keto-prostaglandin Fla were determined daily in peripheral blood. After final rejection sensitization of the recipient was controlled by haemagglutination tests. Survival times of the xenografts were 9.6 +/- 1.2. The subsequent hearts under the same therapy beat for 4.5 +/- 5.0 days. The average survival time of control hearts was 18 +/- 1.9 days. The five hyperacute second allografts showed signs of humoral rejection by absence of inflammation. The release of thromboxane B2 was different in hyperacute, accelerated or cellular rejection. In contrast to the long-functioning grafts, thromboxane B2 persisted during hyperacute rejection at a high level. However 6-keto-prostaglandin Fla showed no significant differences between long-time survivors and hyperacute rejecting hearts. After xenogeneic transplantation all recipients showed haemagglutinating titres between 1:4 and 1:16. Allogeneic grafts have different kinetics of rejection following xenogeneic heart transplantation (XHTP) compared with control hearts. Thromboxane B2 seems to be an important mediator in hyperacute rejection. This type of rejection is not associated with a change in 6-keto-prostaglandin Fla levels. These results indicate, that xenogeneic bridging under a common immunosuppressive regimen could lead to accelerated rejection of the following allograft. Under this condition clinical bridging is not advisable.

6-Ketoprostaglandin F1 alpha↗
PubMed1991

Comparison of acute rejection in sensitized ("domino") and unsensitized donor hearts following heterotopic transplantation.

Right cervical heart transplantation was performed in 18 mongrel dogs. Three experimental groups (6 dogs in each) were set up. Group I and II dogs received unsensitized donor hearts, while Group III dogs received the potentially sensitized native hearts of Group I and II dogs, following final rejection episodes in those animals. We call the transplantation of a native heart out of a previous recipient "domino" transplantation. Immunosuppression consisted of standard triple-drug therapy in all dogs. Groups II and III received, additionally, high-dose steroids during acute rejection episodes. The donor hearts were assessed daily via transmural biventricular biopsy (graded according to Billingham's criteria), and these results were compared with results of daily cytoimmunologic monitoring (n=259 for activation-index), used as a noninvasive method. Supplementally, antimyosin scintigraphy (n=25, heart-to-lung ratio) was employed for rejection diagnosis. The rejection type was determined by calculating T-cell/B-cell ratios with the aid of fluorescein-conjugated monoclonal antibodies. The invasive data consisted of 587 transmyocardial biopsy results, which were used to establish the rejection kinetics. In the domino grafts of Group III, acute rejection had an earlier onset (an average of 3.2 days) and was permanent, despite repeated cortisonepulse therapy. In contrast, acute rejection followed a biphasic course in Group II (average rejection-free interval, 6.8 days) and was non-uniform in Group I (onset after an average of 5.7 days). Cytoimmunologic monitoring corresponded significantly (p < 0.001) with daily histologic findings in Groups I and II, but not with those in Group III (domino grafts). The T-cell/B-cell ratio increased in Groups I and II (to an average of 3.9), as would be expected during acute cellular rejection. In contrast, the T-cell/B-cell ratio decreased in Group III (to an average of 1.1). The heart-to-lung ratio, as determined by antimyosin scintigraphy, accurately revealed the various stages of acute rejection in all groups (p < 0.001). We conclude that the native heart appears to become sensitized during acute rejection episodes of a heterotopically transplanted heart. Cytoimmunologic monitoring and calculation of T-cell/B-cell ratios support this conclusion. In addition, we conclude that cyto-immunologic monitoring and antimyosin scintigraphy are highly specific and sensitive tools for diagnosis of cellular rejection.

Journal Article↗
PubMed1988

Urinary factors of kidney stone formation in patients with Crohn's disease.

An increased frequency of kidney stone formation is reported in patients with inflammatory bowel disease. In order to investigate its pathogenesis, the concentrations of factors known to enhance calcium oxalate stone formation (oxalate, calcium, uric acid) as well as of inhibitory factors for nephrolithiasis (magnesium, citrate) were determined in the urine of 86 patients with Crohn's disease and compared with those of 53 metabolically healthy controls. Six patients with Crohn's disease already had experienced calcium oxalate nephrolithiasis. Patients with Crohn's disease had significantly higher urinary oxalate and lower magnesium and citrate concentrations. Among all patients magnesium and citrate were significantly lower in those with a positive history of kidney stones. Our results demonstrate that the increased propensity for renal stone formation in patients with Crohn's disease is a result not only of increased urinary oxalate, but also of decreased urinary magnesium and citrate concentrations.

Adult↗
PubMed1988

Visual evoked potentials in tumors from orbita to occipital lobe in childhood.

68 infants and children with proven tumours along the visual pathway visually evoked potentials with pattern reversal and flash were investigated. Subdivided in 5 locational groups (orbital, optic nerve, chiasmatic, retrochiasmatic and occipital lobe) best results were obtained by stimulation with pattern reversal using variable checksizes (91.2%) versus 61.8% by using flash evoked responses. Furthermore, using patterned stimuli not only latency shifts are best detected but also hints for visual function correlating to visual acuity could be given also in nonverbal or disabled children. For long term follow-up studies in known space-occupying lesions along the visual pathway, the use of pattern VEP is extraordinary because of its high sensitivity and complete harmlessness. Pattern VEP are even more sensitive than visual acuity testing in cooperative patients. The close interdisciplinary follow-up controls in these children between pediatric neurophysiologists and neurosurgeons are, therefore, strongly recommended.

Adolescent↗
PubMed1985

[Sonographic diagnosis of hypertrophic pyloric stenosis in childhood].

In most cases, diagnosis of hypertrophic pyloric stenosis is now based on real-time ultrasound examination. We employed the criteria stated in literature for sonographic diagnosis of hypertrophic pyloric stenosis, to evaluate our results. We studied 15 patients with symptoms of hypertrophic pyloric stenosis via real-time ultrasound, as well as 15 healthy infants. 10 patients were boys and 5 were girls, between 19 and 83 days of age (average age 45 days). 15 healthy infants of the same age were studied (average age 41 days) for comparison. In the healthy group, the average transverse pyloric diameter was 1.0 cm (0.6-1.5 cm); the mean wall thickness was 0.24 cm (0.2-0.3 cm) and mean pyloric length was 1.29 cm (1.0-1.6 cm). Analysis of the results in hypertrophic condition showed that the mean transverse pyloric diameter was 1.6 cm (1.2-1.9 cm). The wall thickness ranged from 0.4 to 0.8 cm with an average of 0.56 cm. The muscle length ranged from 1.7 to 2.5 cm with an average of 2.1 cm. On comparing the data of both groups we found significant differences in wall thickness and length. There was no false negative scan. Sonographic diagnosis was confirmed in all cases by surgical intervention. Our results agree with those obtained by other authors.

Female↗