Seizure and cognitive outcomes in children and adolescents with epilepsy treated with topiramate.

This 12-week open label study explored cognitive and seizure outcomes of 53 children treated with topiramate (TPM). The digit symbol test and verbal learning memory test were administered at baseline and study endpoint. Topiramate was started either in monotherapy or add-on therapy. Overall, 57% of children experienced a ≥50% seizure reduction, 36% became seizure free and cognitive testing revealed no significant changes during TPM therapy. Due to the heterogeneity of the study population, post hoc analyses were added to compare patients in initial or conversion to TPM monotherapy as well as patients who continued add-on therapy. Verbal learning memory test parameters showed neither significant differences within any subgroup comparing baseline with endpoint nor significant differences between described subgroups except for one finding. The digit symbol test revealed no differences between each subgroup between baseline and endpoint. Comparing pre-post differences, TPM monotherapy was associated with better cognitive outcomes than treatment in add-on therapy. These results have to be interpreted with caution given the short study duration and the heterogeneity of the study population. Despite these limitations, our overall results suggest that treatment with topiramate is associated with improved seizure control without significant changes in cognitive functions at the low doses tested.

Aicardi syndrome in a male patient.

Aicardi syndrome ( OMIM 304050) is defined by the clinical triad of early-onset infantile spasms, agenesis of the corpus callosum and chorioretinal lacunae. Almost all patients are females showing severe cognitive and physical disabilities, and early onset seizures. Astrocytic inclusions containing filamin have been found, but the molecular defect in Aicardi syndrome is not yet known. We report a male patient with Aicardi syndrome characterised by agenesis of the corpus callosum, infantile spasms, chorioretinal lacunae, severe psychomotor retardation, periventricular heterotopias, and patent ductus arteriosus. As the latter two symptoms are suggestive of a mutation in the FLNA gene encoding filamin A, this gene was sequenced, but the sequence did not reveal a disease-causing mutation.

Transgenic animals in experimental xenotransplantation models: orthotopic heart transplantation in the pig-to-baboon model.

Pig organs are at risk for hyperacute and acute vascular rejection mediated by anti-pig antibodies, mainly binding to the Galalpha(1,3)Gal epitope. Acute cellular rejection is characterized by progressive infiltration of mononuclear cells. There is an ongoing search for immunosuppressive regimens that provide adequate protection against all patterns of xenograft rejection, but have no severe impact on the condition of xenograft recipients. Herein orthotopic heart transplantations were performed from hDAF or hCD46 piglets to nonsplenectomized baboons. Basic immunosuppression consisted of tacrolimus, sirolimus, GAS914, steroids, and ATG. Group 1 received basic immunosuppression. Group 2 was additionally treated with rituximab and group 3 with half-dose cyclophosphamide. Group 4 received cyclophosphamide and an anti-HLA-DR antibody. Three baboons received GAS914 and TPC. Monitoring included the regular assessment of anti-porcine antibodies, blood counts, therapeutic drug monitoring, and graft histology. Two grafts failed due to technical mistakes. In group 1, baboons died after 1 and 9 days. In group 2, maximum survival was 30 hours. In group 3, baboons lived 20 hours, 25 days, and 14 days. Group 4 survival times were 9.5 hours, 5.5 hours, 4 days, 34 hours, and 3 days. An increase of non-Galalpha(1,3)Gal antibodies was observed. Depositions of immunoglobulins and complement revealed a humoral rejection process. No cellular infiltration could be observed. In conclusion, suppressing cellular rejection with half-dose cyclophosphamide together with tacrolimus and sirolimus produced longer graft survival with a good general condition. Prevention of acute xenograft rejection further needs inhibition of non-Galalpha(1,3)Gal cytotoxicity by sufficient depression of B-cell activation.

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.

Mean xenograft survival of 14.6 days in a small group of hDAF-transgenic pig hearts transplanted orthotopically into baboons.

INTRODUCTION: In a discordant orthotopic xenotransplantation model (pig-to-baboon) donor pigs expressing human decay accelerating factor (hDAF) as a regulator of complement activity were used to prevent hyperacute xenograft rejection (HXR). We investigated a modified immunosuppressive therapy consisting of ERL080 (Novartis Pharma AG, Base, Switzerland), cyclosporin A (Neoral), steroids, and a cyclophosphamide (CyP) induction protocol with several reduced doses to prevent acute vascular rejection (AVR). METHODS: Donor hearts were harvested from hDAF-transgenic pigs (18.8 +/- 2.6 kg, Imutran Ltd., a Novartis Pharma AG Company). Four adult baboons (25.6 +/- 2.7 kg) with high titers of xenoreactive antibodies (XAb) served as recipients. Serological and hemodynamic parameters were measured. Finally, myocardial tissue was sampled for histological and immunohistochemical examinations. RESULTS: In the first baboon, an acute graft failure occurred after 1 hour due to preservation injury. The second succumbed after 11.1 day due to an acute renal failure. The third died after 13.1 days of an ileus. The fourth baboon had continuously excellent cardiac function (mean echocardiographic ejection fraction, 69.2%), but succumbed on day 20 due to anemia. Corrected mean xenograft survival (excluding the first baboon because of a technical failure) was 14.6 +/- 2.6 days. XAb decreased after day 3 to constantly low levels (<1:64 titer) after CyP induction. White blood cell count decreased from 10.3 +/- 0.8 to 0.9 +/- 0.3 G/L after day 3. Macroscopically and histologically no typical signs of HXR or severe AVR could be detected. CONCLUSIONS: These results confirm that hDAF transgen blocks HXR in this life-supporting model. AVR was prevented by using a modified quadruple immunosuppressive drug combination (Neoral, ERL080, steroids, and several small single doses of CyP). An optimum "fine-tuning" of immunosuppression is required to achieve the best risk-benefit ratio.

Combination of hDAF-transgenic pig hearts and immunoadsorption in heterotopic xenotransplantation of immunosuppressed baboons.

INTRODUCTION: Hyperacute xenograft rejection (HXR) and acute vascular rejection (AVR) after xenotransplantation are triggered by xenoreactive antibodies (XAb) and an activated complement cascade. In a heterotopic (abdominal) xenotransplantation model we combined immunoadsorption (IA, Ig-Therasorb column) and a quadruple immunosuppressive drug therapy in recipient baboons with donor pig hearts transgenic for human decay accelerating factor (hDAF). METHODS: According to XAb titers between 6 and 14 cycles of IA were performed preoperatively in 4 recipient baboons (18.6 +/- 2.5 kg). Hearts of hDAF-transgenic donor pigs (6.1 +/- 1.1 kg, Imutran Ltd., a Novartis Pharma AG Company, Basel, Switzerland) were heterotopically transplanted using the abdominal technique in baboons. Immunosuppression consisted of cyclophosphamide (CyP) induction therapy, ERL080 (Novartis Pharma AG), cyclosporin A (CyA, Neoral), and steroids. Blood levels of mycophenolate, CyA, immunoglobulins (Ig), anti-pig-antibodies, complement factors, and cardiac enzymes were determined. Abdominal electrocardiography (ECG), echocardiography, and palpation were used for monitoring of the pig hearts. Myocardial tissue specimens were examined using immunohistochemistry, light microscope (LM), and electron microscope (EM). RESULTS: Ten cycles of IA alone removed 78% of XAb and accordingly IgM, IgG, IgA, complement C3, and C4. None of the xenografts was hyperacutely rejected, but xenograft failure occurred after 5.0 +/- 1.3 days (range, 2.4-8.0 days) because of an AVR associated with a rapid XAb increase within 24 hours. White blood cell count (10.3 +/- 2.2 G/L) showed a maximum of 13.1 +/- 2.1 (day 1) and constant levels (1.4 +/- 0.3-2.1 +/- 1.3 G/L) between day 3 and 6. Histology (LM/EM) showed massive hemorrhage, necrosis, and vascular thrombi as signs of AVR. CONCLUSION: Although HXR was prevented by using IA and hDAF-transgenic donor hearts, AVR was not avoided due to insufficient immunosuppressive regimen used and a missed postoperative IA treatment as a result of an inefficient control of XAb production.

Combining the hDAF transgene with the GP IIb/IIIa inhibitor tirofiban improves heart performance and reduces myocardial damage following hyperacute rejection in an ex vivo perfusion model.

Xenograft rejection is associated with vascular injury resulting at least in part from platelet activation, and rejected xenografts invariably demonstrate intravascular thrombosis. Assuming that complement activation is a major determinant of humoral immune reactions bringing about platelet-endothelial cell interactions, we tested the effects of the specific platelet glycoprotein IIb/IIIa inhibitor tirofiban in combination with the human decay accelerating factor (hDAF) transgene on hyperacute rejection of pig hearts. Four groups were studied in a working heart-perfusion model. Pig hearts transgenic for hDAF and nontransgenic pig hearts were perfused with human blood containing tirofiban or with unmodified human blood. Cardiac output, stroke work index, and creatine phosphokinases were measured for the evaluation of the extent of myocardial damage. Consumption of complement components was determined. Endothelial deposition of fibrin and intravascular thrombosis were evaluated. Tirofiban improved cardiac output and stroke work index of nontransgenic pig hearts and was able to further increase hemodynamic function of hDAF transgenic pig hearts. Low levels of creatine phosphokinases also revealed a cardioprotective effect of tirofiban. However, a further extension of the survival of hDAF transgenic pig hearts could not be achieved, although tirofiban prolonged beating time of nontransgenic pig hearts. Tirofiban was able to reduce the consumption of complement components independently of hDAF. Intravascular evidence of fibrin and thrombosis tended to be particularly reduced by the combination of tirofiban and hDAF. Thus, the application of tirofiban together with hDAF improves the performance of pig hearts by reducing myocardial damage and intravascular thrombosis.

Noninvasive methods of rejection diagnosis after heart transplantation.

For clinical follow-up and prognosis in heart transplant patients, it is important to understand accurately the presence and extent of cardiac allograft rejection. Since the introduction of endomyocardial biopsy, almost 40 different noninvasive diagnostic procedures for the recognition of myocardial rejection have been proposed. However, endomyocardial biopsy is invasive and not suitable for frequent monitoring. If the pattern of rejection shows a focal distribution, false-negative results can be expected. Discrepancies between biopsy findings and allograft function are obviously possible. State-of-the-art information will be given on the most reliable noninvasive methods for rejection diagnosis, which can be differentiated from electrophysiology (fast-Fourier-transformed electrocardiography and intramyocardial electrocardiography), echocardiography, immunologic methods (cytoimmunologic monitoring, transferrin receptors, and interleukin-2 receptors), various biochemical markers (neopterines, prolactin, urinary polyamines, and beta 2-microglobulins), radioisotopic techniques (antimyosin-monoclonal antibodies, thallium, technetium, and gallium scintigraphy and indium-labeled cells), as well as magnetic resonance imaging. Thus modified and patient-adapted antirejection therapy can be provided if the decision for or against antirejection therapy is not based on biopsy findings alone but rather is confirmed along with histologic, electrophysiologic, biochemical, immunologic, and functional parameters.

Bridging to transplant: allogeneic heart transplantation after xenografting.

Xenografting seems to be a solution to use to bridge time intervals when desperately needed allograft cannot be obtained. A following allograft was never ventured. Nine dogs (weight, 20 to 25 kg; age, 2 years) underwent right cervical heart transplantation. Donors were silver foxes (3 to 4 kg). The animals were treated by triple-drug therapy consisting of cyclosporine, methylprednisolone, and azathioprine in clinical dosages. For control, six recipients received only allogeneic hearts and the identical immunosuppression. After rejection of the xenograft, a second allogeneic heart was anastomosed subsequently to the same right cervical vessels. Routine histologic and immunohistologic examinations were performed. Thromboxane B2 and 6-keto-prostaglandin F1 alpha were determined daily in peripheral blood. After final rejection the sensitization of the recipient was controlled by hemagglutination test. Survival time of the xenografts was 9.6 +/- 1.2 days; the subsequent allogeneic 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 F1 alpha showed no significant differences between longtime survivors and hyperacute rejecting hearts. After xenogeneic transplantation, all recipients showed hemagglutinating titers between 1:4 and 1:16. Allogeneic grafts have a different kinetics of rejection after xenogeneic heart transplantation compared with control hearts. Thromboxane B2 seems to be an important mediator in hyperacute rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Kinetics and dynamics of acute rejection after heterotopic heart transplantation.

Right cervical, heterotopic heart transplantation was performed in 18 mongrel dogs. Study design was based on three different groups (n = 3 x 6). Standard immunosuppression consisted of triple drug therapy in all dogs. Groups II and III received high dose steroids during acute rejection. In group III the native hearts of previous recipients (groups I and II) were used as donors for heterotopic transplantation ("domino" principle). The hearts were examined by daily transmural biventricular biopsies and graded according to Billingham classification. Cytoimmunologic monitoring (n = 345; activation index from peripheral and coronary sinus blood) and fast Fourier transformation ECG (n = 80; area under the curve; surface recordings) served as daily noninvasive methods. Optionally antimyosin scintigraphy (n = 25; single photon emission computed tomography; heart-to-lung ratio) was performed and immunohistologically confirmed by peroxidase staining of the antibody (n = 61). Kinetics of rejection was not uniform in group I (onset after 5.7 days) and biphasic in group II (clear rejection-free interval: 6.8 days). Group III developed a continuously persisting rejection, despite repeated high-dose steroids, with an early onset (3.2 days). The invasive data, consisting of 587 punch biopsies, showed no significant difference between right and left ventricular rejection. Clearly focal rejection appeared in 51.5% of the cases, with subendocardial involvement in 54%. Cytoimmunologic monitoring significantly (p less than 0.001) correlated with daily biopsies in groups I and II. The activation index from coronary sinus blood was two times higher than in peripheral blood. Fast Fourier transform ECG identified the onset of rejection with great accuracy (p less than 0.01). The heart-to-lung ratio of antimyosin scintigraphy corresponded exactly to the various stages of rejection (p less than 0.001). High-dose steroids led to a clear reduction of the ratio in 26% cases. Peroxidase staining showed typical locations of the antibody, depending on the grade of rejection (p less than 0.001). Considering the results of pathology in this transplantation model, relying on endomyocardial biopsy alone in a clinical setting may not seem advisable. Although the results of this study must be confirmed clinically, the simultaneous use of cytoimmunologic monitoring and fast Fourier transformation ECG may prove to be valuable to day-to-day monitoring for acute rejection in the early postoperative course. If both methods indicate the onset of an acute rejection, antimyosin scintigraphy and endomyocardial biopsy, respectively, should be performed to confirm and grade the suspected diagnosis.

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.

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.

Tissue carnitine concentrations after total parenteral nutrition with and without L-carnitine supplementation.

The concentrations (mumoles/g dry weight) of total carnitine (TC), free carnitine (FC) and acylcarnitine (AC) were determined in skeletal muscle, heart, liver, kidney and brain cortex of male mini pigs (4000-5000 g) after seven days of total parenteral nutrition (TPN) with amino acids 5% (3.0g/kg/d), glucose (25g/kg/d) and lipids 20% (4g/kg/d). This regime was administered with L-carnitine supplementation (1.5 mg/kg/d; n = 7) (group 1) and without it (n = 5) (group 2). Orally alimented animals (n = 5) served as controls (group 3). (Average carnitine intake: 3 mg/d) Carnitine free TPN affected only the concentrations in muscle. TC was markedly reduced (3.6 +/- 0.8) when compared with oral controls (5.8 +/- 0.7) (p<0.01). This decrease was exclusively due to AC, whereas FC concentrations remained almost unchanged. In group 1 the concentrations of TC in skeletal muscle, heart and brain cortex were higher than in both the other groups. The increase was mainly due to AC and FC remained unchanged in heart and brain. The concentrations in liver and kidney were not affected by either carnitine free or carnitine supplemented TPN. AC, determined as described, consists almost entirely of acid soluble acetyl-carnitine, the major product of fatty acid oxidation. Since the AC concentrations were almost exclusively altered by the two TPN-regimes we conclude that the observed changes reflect regulatory changes of fatty acid oxidation. Thus the decrease of muscle TC in group 2 is considered a consequence of an insulin induced down regulation (plasma insulin: mean 20 muU/ml; maximum: 60 muU/ml) of fatty acid oxidation in consequence of high glucose intake (25 g/kg/d). The increased TC concentrations after carnitine supplemented TPN are discussed to reflect an enhancement of oxidative degradation of fatty acids as a pharmacological effect of L-carnitine.

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.

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.