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Matthias Boentert

Publications and source records attributed to Matthias Boentert.

5 recordsLinked to original sources
PubMed2006

Treatment for obstructive sleep apnoea: effect on peripheral nerve function.

BACKGROUND AND OBJECTIVE: Obstructive sleep apnoea (OSA) is suggested to be associated with peripheral nerve damage. A case-control study was conducted to provide further support to this observation. In a longitudinal intervention study, it was examined whether treatment for OSA has a possible beneficial effect on peripheral nerve function. METHODS: Participants were 23 patients with OSA and 23 controls matched for age and body mass index (BMI), all without any known cause of peripheral nerve damage. The sensory nerve action potential (SNAP) amplitudes of both sural nerves were determined. After 6 months of treatment for OSA, treatment compliance was evaluated and nerve conduction studies were repeated. RESULTS: Patients with OSA had significantly lower mean (standard deviation) sural SNAP amplitudes than controls (6.3 (3.5) v 11.2 (5.0), p < 0.001). Multivariate regression analysis including the variables age, BMI and Apnoea-Hypopnea Index (AHI) showed that both age (p < 0.01) and AHI (p < 0.05) were inversely related to the SNAP amplitude. On follow-up, the sural SNAP showed an increase of 2.6 mV on average (p < 0.001). Multivariate regression analysis including the variables age, BMI, AHI, pretreatment SNAP and treatment compliance identified only treatment compliance as being significantly related to the SNAP increase (p < or = 0.005). CONCLUSION: OSA is an independent risk factor for axonal dysfunction of peripheral sensory nerves. Impaired neural function is at least partly reversible with treatment for sleep apnoea.

Action Potentials↗
PubMed2006

Cell cycle inhibitors p21 and p16 are required for the regulation of Schwann cell proliferation.

Regulated cell proliferation is a crucial prerequisite for Schwann cells to achieve myelination in development and regeneration. In the present study, we have investigated the function of the cell cycle inhibitors p21 and p16 as potential regulators of Schwann cell proliferation, using p21- or p16-deficient mice. We report that both inhibitors are required for proper withdrawal of Schwann cells from the cell cycle during development and following injury. Postnatal Schwann cells express p21 exclusively in the cytoplasm, first detectable at postnatal day 7. This cytoplasmic p21 expression is necessary for proper Schwann cell proliferation control in the late development of peripheral nerves. After axonal damage, p21 is found in Schwann cell nuclei during the initiation of the proliferation period. This stage is critically regulated by p21, since loss of p21 leads to a strong increase in Schwann cell proliferation. Unexpectedly, p21 levels are upregulated in this phase suggesting that the role of p21 may be more complex than purely inhibitory for the Schwann cell cycle. However, inhibition of Schwann cell proliferation is the overriding crucial function of p21 and p16 in peripheral nerves as revealed by the consequences of loss-of-function in development and after injury. Different mechanisms appear to underlie the inhibitory function, depending on whether p21 is cytoplasmic or nuclear.

Adenoviridae↗
PubMed2005

An animal model for Charcot-Marie-Tooth disease type 4B1.

Charcot-Marie-Tooth disease (CMT) comprises a family of clinically and genetically very heterogeneous hereditary peripheral neuropathies and is one of the most common inherited neurological disorders. We have generated a mouse model for CMT type 4B1 using embryonic stem cell technology. To this end, we introduced a stop codon into the Mtmr2 locus within exon 9, at the position encoding amino acid 276 of the MTMR2 protein (E276X). Concomitantly, we have deleted the chromosomal region immediately downstream of the stop codon up to within exon 13. The resulting allele closely mimics the mutation found in a Saudi Arabian CMT4B1 patient. Animals homozygous for the mutation showed various degrees of complex myelin infoldings and outfoldings exclusively in peripheral nerves, in agreement with CMT4B1 genetics and pathology. Mainly, paranodal regions of the myelin sheath were affected, with a high degree of quantitative and qualitative variability between individuals. This pathology was progressive with age, and axonal damage was occasionally observed. Distal nerve regions were more affected than proximal parts, in line with the distribution in CMT. However, we found no significant electrophysiological changes, even in aged (16-month-old) mice, suggesting that myelin infoldings and outfoldings per se are not invariably associated with detectable electrophysiological abnormalities. Our animal model provides a basis for future detailed molecular and cellular studies on the underlying disease mechanisms in CMT4B1. Such an analysis will reveal how the disease develops, in particular, the enigmatic myelin infoldings and outfoldings as well as axonal damage, and provide mechanistic insights that may aid in the development of potential therapeutic approaches.

Alleles↗