Topiramat in der Behandlung des Status epilepticus

In den neuen Leitlinien der Deutschen Gesellschaft für Neurologie wird als Medikament der weiteren Wahl zur Behandlung des fokalen konvulsiven und des non-konvulsiven Status epilepticus (SE) unter anderem auch Topiramat (TPM) vorgeschlagen. Ziel dieser Übersichtsarbeit ist es, die vorliegenden Daten zur Verwendung von TPM bei der Behandlung des SE zu sichten. Auf Einzelfallebene wurden 13 Behandlungsepisoden mit einer Erfolgsrate von 30,8% publiziert. In 12 Fallserien wurden zusammen 147 Behandlungsepisoden mit TPM beim SE beschrieben. TPM wurde in Dosen zwischen 50 mg und 1000 mg/Tag bereits zu Beginn der Behandlung angewandt. Dabei ergab sich auf der Basis der von den jeweiligen Autoren als sicheren Behandlungserfolg eingeschätzten Episoden ein Mittelwert der Erfolgsraten von 36,78%. Obwohl theoretisch gut begründet kann der Einsatz von Topiramat beim therapierefraktären Status epilepticus nur empfohlen werden, wenn etabliertere Substanzen entweder nicht zum Erfolg führten oder kontraindiziert sind.

Lymphatic vessels in pancreatic islets implanted under the renal capsule of rats

Transplantation of pancreatic islets necessitates an engraftment process, including revascularization of the graft. Studies of graft vasculature have demonstrated that islets become revascularized during the first post-transplant week through an angiogenic process. If this also involves lymphatic vessels is unknown. The aim of the present study was to functionally evaluate if lymphatic vessels, which are absent in endogenous islets, form after islet transplantation. To achieve this, inbred Wistar-Furth rats were transplanted with 250 syngeneic islets under the renal capsule. Intra-vital microscopy of the graft in combination with interstitial injection of Evans Blue was performed 1 week, 1 month or 9-12 months later. In all animals studied, there was drainage through intra-graft lymphatic capillaries emptying into larger lymphatic vessels associated with the renal capsule. The number was slightly lower 1 week post-transplantation. Most of the lymphatic capillaries were present in the graft stroma, rather than interspersed among the endocrine cells. In some animals, we were able to demonstrate dye in regional lymph nodes. We conclude that unlike endogenous islets, islet grafts develop a lymphatic drainage. Its functional importance and characteristics remain to be established. However, it can be speculated that immune reactions may be facilitated by the presence of lymphatic vessels.

Angiotensin II type 1 receptor inhibition markedly improves the blood perfusion, oxygen tension and first phase of glucose-stimulated insulin secretion in revascularised syngeneic mouse islet grafts

AIMS/HYPOTHESIS

We recently found evidence of an angiotensin-generating system in pancreatic islets. The present study investigated the effect of endogenously produced angiotensin II on microcirculation and function in transplanted islets.

MATERIALS AND METHODS

Losartan, an angiotensin II type 1 receptor inhibitor, was administered either acute intravenously to mice with 4-week-old islet renal subcapsular transplants, or added to the drinking water for the final 14 days or throughout the 4-week post-transplantation period. The graft-bearing kidney was, in some cases, dissected out and perfused in vitro to evaluate the effect of angiotensin II and losartan on glucose-stimulated insulin release from the grafts.

RESULTS

Losartan treatment throughout the 4-week post-transplantation period had negative effects on islet revascularisation as well as on islet graft insulin release. However, administration of losartan, either intravenously or orally, after the formation of a new vascular network, improved islet graft blood perfusion. PO2 in the islet transplants was also effectively improved by the losartan treatment. Graft perfusion experiments showed a markedly better first phase of glucose-stimulated insulin release in transplanted islets when exposed to losartan. In contrast, acute administration of angiotensin II decreased islet graft blood flow, PO2 and glucose-stimulated insulin release.

CONCLUSIONS/INTERPRETATION

This study shows that inhibition of the islet reninangiotensin system may be a feasible strategy to increase the blood perfusion, PO2 and function within islet grafts. Such treatment should not be initiated, however, before the islet vascular system has been formed.

Increased survivin transcript levels: an independent negative predictor of survival in soft tissue sarcoma patients

Survivin, a recently identified inhibitor of apoptosis protein (IAP), is expressed in diverse embryonic tissues and in various human cancers. We have investigated the quantitative expression of survivin mRNA by a sensitive TaqMan-based RT-PCR assay in tissue samples from 94 patients with soft tissue sarcomas (STS). Survivin transcript levels were measured and normalized to GAPDH transcripts. By using a multivariate Cox regression analysis, we found an inverse correlation between the level of survivin mRNA (ratio >2 zmol survivin/amol GAPDH) and the rate of overall survival (p = 0.009, RR = 2.7). Survivin transcript variants as detected by qualitative RT-PCR analysis were revealed in 36 of 56 STS patients (64%). Only survivin DeltaEx3 and/or full-length survivin variants but not survivin 2B were identified. Our results suggest that a higher level of survivin mRNA is an independent predictor of survival for STS patients.

Increased survivin transcript levels: an independent negative predictor of survival in soft tissue sarcoma patients

Survivin, a recently identified inhibitor of apoptosis protein (IAP), is expressed in diverse embryonic tissues and in various human cancers. We have investigated the quantitative expression of survivin mRNA by a sensitive TaqMan-based RT-PCR assay in tissue samples from 94 patients with soft tissue sarcomas (STS). Survivin transcript levels were measured and normalized to GAPDH transcripts. By using a multivariate Cox regression analysis, we found an inverse correlation between the level of survivin mRNA (ratio >2 zmol survivin/amol GAPDH) and the rate of overall survival (p = 0.009, RR = 2.7). Survivin transcript variants as detected by qualitative RT-PCR analysis were revealed in 36 of 56 STS patients (64%). Only survivin DeltaEx3 and/or full-length survivin variants but not survivin 2B were identified. Our results suggest that a higher level of survivin mRNA is an independent predictor of survival for STS patients.

Effects of Th-2 type cytokines on human airway epithelial cells: interleukins-4, -5, and -13

Proliferation and death of airway epithelial cells may be of importance in the pathogenesis of asthma. T-helper (Th)-2 response interleukins (IL)-4, -5, and -13 have the ability to induce proliferation of airway epithelial cells.

Effects of hypochlorite on cultured respiratory epithelial cells

Neutrophils and eosinophils are involved in the pathogenesis of many respiratory diseases. The enzymes myeloperoxidase and eosinophil peroxidase catalyze the reaction of H2 O2 with Cl to produce the reactive oxygen species HOCl. Normal human bronchial epithelial (NHBE) cells were exposed to 0.18-0.90 mM HOCl for 48 h, and studied with immunohistochemical, metabolic and morphological studies. The ability of the cells to attach to each other and/or to the matrix was altered. Immunohistochemical studies showed a decreased amount of desmosomes and focal adhesion sites, although the morphology of the cells was not affected. The ability of the mitochondria to oxidize glucose was reduced. HOCl-exposed cells had an increased production of NO, probably by an increased activity of cNOS, due to increased intracellular Ca2+. The antioxidant N-acetylcysteine inhibited both the NO production and the effects of HOCl on glucose oxidation. The cNOS-inhibitor N-propyl-L-arginine inhibited HOCl-induced NO production. X-ray microanalysis showed an increase in the intracellular Na+ /K+ ratio, which indicates cell damage. In conclusion, exposure to HOCl results in cell detachment and metabolic alterations in normal human bronchial epithelial cells. Oxygen radicals could in part mediate the effects. Oxygen radicals could hence contribute to the observed epithelial damage in respiratory diseases.

Effects of TNF-alpha, IFN-gamma and IL-beta on normal human bronchial epithelial cells

Several diseases affecting the airways such as asthma are associated with both epithelial damage and increased levels of pro-inflammatory cytokines. To investigate the possible relation between cytokines and epithelial damage, the effects of tumour necrosis factor-alpha (TNF)-alpha, interferon gamma (IFN-gamma) and interleukin-1 beta (IL-1beta) on normal human bronchial epithelial cells in vitro were studied. The cells were exposed to these cytokines for 48 or 72 h, followed by morphological, immunohistochemical and metabolic studies. Transmission and scanning electron microscopical analyses demonstrated damage to the mitochondria and an increase in cell processes induced by the cytokines. The use of antibodies against desmosomal cytokeratin showed a decrease in desmosome formation in IFN-gamma-exposed cells. Decreased glucose oxidation rate and increased accumulation of nitric oxide were found in cytokine-exposed cells. Nomega-monomethyl-L-arginine (L-NMMA) reduced nitrite production. X-ray microanalysis showed an increase in the intracellular sodium/potassium ratio of the cells after exposure to cytokines, which is an indication of cell damage. The cytokines induced both necrosis and apoptosis to varying degrees. IFN-gamma and TNF-alpha generally potentiate each other's effects. In conclusion tumour necrosis factor-alpha and interferon gamma, and to a lesser extent interleukin-1beta, can cause damage to epithelial cells, which may be a factor involved in epithelial shedding in airway diseases.