Aims/hypothesis Inappropriate insulin secretion and biosynthesis are hallmarks of beta cell dysfunction and contribute to the progression from a prediabetic state to overt diabetes mellitus. During the prediabetic state, beta cells are exposed to elevated levels of proinflammatory cytokines. In the present study the effect of these cytokines and mitogen-activated protein kinase kinase kinase 1 (MEKK1), which is known to be activated by these cytokines, on human insulin gene (INS) transcription was investigated. Methods Biochemical methods and reporter gene assays were used in a beta cell line and in primary pancreatic islets from transgenic mice. Results IL-1β and MEKK1 specifically inhibited basal and membrane depolarisation and cAMP-induced INS transcription in the beta cell line. Also, in primary islets of reporter gene mice, IL-1β reduced glucose-stimulated INS transcription. A 5′-and 3′-deletion and internal mutation analysis revealed the rat insulin promoter element 3b (RIPE3b) to be a decisive MEKK1-responsive element of the INS. RIPE3b conferred strong transcriptional activity to a heterologous promoter, and this activity was markedly inhibited by MEKK1 and IL-1β. RIPE3b is also known to recruit the transcription factor MafA. We found here that MafA transcription activity is markedly inhibited by MEKK1 and IL-1β. Conclusions/interpretation These data suggest that IL-1β through MEKK1 inhibits INS transcription and does so, at least in part, by decreasing MafA transcriptional activity at the RIPE3b control element. Since inappropriate insulin biosynthesis contributes to beta cell dysfunction, inhibition of MEKK1 might decelerate or prevent progression from a prediabetic state to diabetes mellitus.
The Polyneuropathy And Treatment with Hizentra (PATH) study required subjects with chronic inflammatory demyelinating polyneuropathy (CIDP) to show dependency on immunoglobulin G (IgG) and then be restabilized on IgG before being randomized to placebo or one of two doses of subcutaneous immunoglobulin (SCIG). Nineteen of the 51 subjects (37%) randomized to placebo did not relapse over the next 24 weeks. This article explores the reasons for this effect. A post‐hoc analysis of the PATH placebo group was undertaken. A literature search identified other placebo‐controlled CIDP trials for review and comparison. In PATH, subjects randomized to placebo who did not relapse were significantly older, had more severe disease, and took longer to deteriorate in the IgG dependency period compared with those who relapsed. Published trials in CIDP, whose primary endpoint was stability or deterioration, had a mean non‐deterioration (placebo effect) of 43%, while trials with a primary endpoint of improvement had a placebo response of only 11%. Placebo is an important variable in the design of CIDP trials. Trials designed to show clinical improvement will have a significantly lower effect of this phenomenon than those designed to show stability or deterioration.
Dystonia is a chronic movement disorder that is associated with a reduction in health-related quality of life (HR-QoL) and restriction of activities of daily living. Botulinum neurotoxin (BT) improves disease-specific HR-QoL by reducing abnormal movements, postures, and pain. We examined the burden of the corresponding primary caregiver as a potential important factor for disease management and HR-QoL of dystonia patients under treatment with BT. 114 patients with focal, segmental, or generalized dystonia were recruited, together with 93 corresponding caregivers, whose burden was investigated using the Caregiver Burden Inventory. In addition, all participants were assessed for cognitive impairment, depression, anxiety, alexithymia, and HR-QoL. Only a small proportion of caregivers suffered from caregiver burden. Despite BT therapy, patients' HR-QoL was decreased compared to the age-matched general German population. Psychological symptoms, notably anxiety, and depression correlated significantly with reduced HR-QoL. Our data imply that caregiver burden emerged to be an issue in subgroups of dystonia patients. Furthermore, HR-QoL of dystonia patients is reduced even under optimized BT treatment in a specialized center.
Study design Case series on four dogs. Objectives To determine the alleviation of motor symptoms in spinal cord injury (SCI) by tetanus neurotoxin (TeNT). Setting Different Berlin veterinary clinics, Germany. Methods We report on the effect of intramuscular injections of low-dose TeNT into paretic hind limb muscles 2-157 weeks after SCI due to lumbar disc herniation in a clinical case series on four dogs. All dogs underwent unsuccessful or incomplete surgical decompression prior to TeNT treatment. TeNT was injected on a compassionate basis. Stance, gait ability and the diameter of the rectus femoris muscle were assessed as parameters. Results All four dogs improved their stance and three of these dogs improved in gait at 4 and 6 weeks after TeNT injections without evidence of side effects or spreading of TeNT effects. At the same time, the size of the rectus femoris muscle diameter increased considerably as compared with baseline (baseline: 100%; 4 weeks: 148.7% ± 10.9%; 6 weeks: 137.1% ± 7.9%). Conclusions Facilitation of α-motor neurons by TeNT injections into paretic hind limb muscles of four dogs improved standing and/or gait abilities and partly reversed muscle atrophy after SCI. The absence of generalized or painful muscle spasms supports the safety of low-dose TeNT. Therefore, TeNT might evolve as a promising therapeutic option for muscle paresis of central origin, e.g. in individuals with SCI, stroke or multiple sclerosis.
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