Lambert-Eaton myasthenic syndrome IgG depletes presynaptic membrane active zone particles by antigenic modulation

The Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disease that can be transmitted from human to mouse with immunoglobulin G (IgG). Electrophysiological studies indicate that LEMS IgG acts on presynaptic voltage-sensitive calcium channels, probably reducing their number, and freeze-fracture electron microscopy demonstrates that LEMS IgG has an effect on the presynaptic active zone particles, which represent putative voltage-sensitive calcium channels. The active zone particles, normally arranged in double parallel rows, move closer together, form clusters, and are reduced in number. The morphological data suggest modulation of the active zone particles crosslinked by LEMS IgG. If this were the case, then only divalent LEMS IgG and F(ab')2 should alter the deployment of active zone particles and monovalent Fab should be without effect. To test this hypothesis, mouse diaphragms were exposed to control and LEMS IgG and IgG fragments in organ culture for 24 hours and then studied by quantitative freeze-fracture electron microscopy. Divalent LEMS IgG and F(ab')2 aggregated and depleted the active zone particles, whereas monovalent Fab had no effect. The findings reconfirm that the active zone particles are targets of LEMS IgG and are direct evidence for modulation of the particles by LEMS IgG. The findings are in harmony with parallel electrophysiological studies of the effects of LEMS IgG fragments on transmitter release in the same diaphragm muscles (Lang et al, J Physiol 1987;390:173P).     

Zentrale Gallengangskarzinome

Surgical resection provides the only chance of cure for patients suffering from hilar cholangiocarcinoma. Due to the central anatomic localization within the liver hilum, established guidelines of oncologic surgery are difficult to apply. Resection of the hilar bifurcation alone or in combination with limited hepatic resection can be performed with low morbidity and low mortality but shows a high rate of local tumor recurrence. Usually, extended resection is required to achieve adequate safety margins. Right trisectionectomy complies best with the basic rules of oncologic surgery while allowing the maximum safety margin. The 5-year survival rates reported after right trisectionectomy range between 20% and 40% and reach 59% in selected patients. The increasing experience with living donor transplantation and recent advances in neoadjuvant tumor therapy may lead to renewed discussion of liver transplantation in hilar cholangiocarcinoma.     

A randomized clinical trial of ceftriaxone and teicoplanin versus ceftazidime and teicoplanin as antibiotic therapy in febrile neutropenic cancer patients and bone marrow transplant recipients

Summary A prospective, randomized clinical trial comparing combination therapy with ceftriaxone and teicoplanin versus ceftazidime and teicoplanin in the treatment of febrile episodes in neutropenic cancer patients and bone marrow transplant recipients was performed. One hundred and two patients were randomized, but two patients were considered unevaluable for efficacy, and three patients were withdrawn due to incorrect randomization. Of the remaining 97 patients, infection resolved without modification of therapy in 31/49 (63%) patients treated with ceftriaxone/teicoplanin versus 27/48 (56%) patients treated with ceftazidime/teicoplanin (P=0.48). Of all 97 patients treated therapy was modified in 18/49 (36%) with ceftriaxone/teicoplanin and 21/48 (43%) with ceftazidime/teicoplanin. Nineteen patients treated with ceftriaxone/teicoplanin received netilmicin and 21 patients treated with ceftazidime/teicoplanin also received netilmicin according to the study design (escalation therapy). When netilmicin was added infection resolved in 78% of patients treated with ceftriaxone/teicoplanin versus 84% of those treated with ceftazidime/teicoplanin. It was concluded that combination therapy with ceftriaxone/teicoplanin is an alternative to combination therapy with ceftazidime/teicoplanin, and has the advantage of once daily administration.

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Antibiotische Therapie der febrilen Neutropenie von Tumor- und Knochenmarktransplantationspatienten. Eine randomisierte Studie mit Ceftriaxon und Teicoplanin im Vergleich mit Ceftazidim und Teicoplanin

Zusammenfassung In einer prospektiven, randomisierten klinischen Studie wurde die Kombinationstherapie mit Ceftriaxon und Teicoplanin gegen die Kombinationspartner Ceftazidim und Teicoplanin bei neutropenischen Patienten oder Patienten nach Knochenmarktransplantation verglichen. Insgesamt wurden 101 Patienten in die Studie eingebracht, davon waren 97 Patienten auswertbar. In der Ceftriaxon/Teicoplanin-Gruppe waren 63% der Patienten geheilt, gegenüber 56% der Patienten in der Ceftazidim/Teicoplanin-Gruppe. Dieses Ergebnis war ohne Modifikation der Studien-Medikamente erreicht worden. Bei 18 von 49 Patienten in der Ceftriaxon/Teicoplanin-Gruppe und 21 von 48 Patienten in der Ceftazidim/Teicoplanin-Gruppe wurde von der Studienmedikation abgegangen und zusätzlich Netilmicin (Eskalationstherapie) gegeben. Durch die zusätzliche Gabe von Netilmicin waren 78% der Patienten in der Ceftriaxon/Teicoplanin-Gruppe und 84% in der Ceftazidim/Teicoplanin-Gruppe geheilt. Diese Daten deuten darauf hin, daß die Kombinationstherapie mit Ceftriaxon/Teicoplanin eine Alternative zur Kombinationstherapie mit Ceftazidim und Teicoplanin darstellt, zumal die Gabe von Ceftriaxon und Teicoplanin den Vorteil hat, daß diese Medikamente nur einmal pro Tag gegeben werden müssen.

     

Cranial dystonia, blepharospasm and hemifacial spasm: clinical features and treatment, including the use of botulinum toxin.

Blepharospasm, the most frequent feature of cranial dystonia, and hemifacial spasm are two involuntary movement disorders that affect facial muscles. The cause of blepharospasm and other forms of cranial dystonia is not known. Hemifacial spasm is usually due to compression of the seventh cranial nerve at its exit from the brain stem. Cranial dystonia may result in severe disability. Hemifacial spasm tends to be much less disabling but may cause considerable distress and embarrassment. Patients affected with these disorders are often mistakenly considered to have psychiatric problems. Although the two disorders are quite distinct pathophysiologically, therapy with botulinum toxin has proven very effective in both. We review the clinical features, proposed pathophysiologic features, differential diagnosis and treatment, including the use of botulinum toxin, of cranial dystonia and hemifacial spasm.     

Lipofibrom des Nervus medianus

The following article presents two new cases of a lipofibroma of the median nerve. This formation is a very rare benign tumor of peripheral nerve tissue. Up to now 30 cases have been reported in the literature and are reviewed in this article and are compared with the two cases reported. Besides the operative treatment, which made the neuropathological diagnosis possible, preoperative diagnosis has been extended by MNT-scans of the involved parts of the nerve. The noninfiltrating character of the tumor could be well recognized on these scans. The signal quality and the anatomical proximity to the median nerve made the diagnosis of a lipofibroma likely. By the postoperative histological reviews the diagnosis was confirmed in classic manner. The immunological marking of the S-100 protein showed a remarkable reduction of this protein in these peripheral nerve tumors. The two cases reported by us recapitulate the clinical history typically and describe symptoms and our treatment for the lipofibroma of the median nerve.