Generalized chronic itch induced by small-fibre neuropathy: clinical profile and proposed diagnostic criteria.

BACKGROUND: Small-fibre neuropathy (SFN) is a known cause for pain, however, it may be also associated with chronic itch. The clinical profile of chronic itch due to SFN is poorly defined and accordingly under-diagnosed in clinical care. OBJECTIVES: To establish the clinical profile of patients with SFN and to propose diagnostic criteria for this patient population. METHODS: Clinical data from patients diagnosed with SFN [chronic generalized itch and reduced intraepidermal nerve fibre density (IENFD)] were analysed retrospectively. RESULTS: A total of 142 patients (60 females, median age: 62.5 years) were included. Patients reported daily, moderate to severe itch intensity scores occurring mostly in attacks (62.5%). Only 11 patients experienced exclusively itch, while the remaining patients (92%) reported pruralgia (itch along with painful sensations). Burning (50%), a sensation like needle pricks (46%) and tingling (45%) were the sensory symptoms reported by most patients. Cold or ice application led to an alleviation of the symptoms. The IENFD did not correlate with itch intensity; however, patients with a severely reduced IENFD (<30% of the normative cut-off value) reported more frequently sharp, spiky and drilling sensations compared to the remaining patients. The quality of life was moderately impaired and correlated with itch intensity, whereas anxiety and depression scores were low. CONCLUSIONS: Onset of pruralgia on normal appearing skin, occurrence in attacks and symptomatic alleviation with cold/ice application should alert physicians for a possible neuropathic SFN-related origin of itch. A reduced IENFD can confirm the diagnosis of SFN.

[Teriflunomide for treatment of multiple sclerosis]. / Teriflunomid zur Behandlung der Multiplen Sklerose.

Interferon beta and glatiramer acetate are still considered to be the first-line therapeutics for treatment of relapsing forms of multiple sclerosis (MS). The use of new compounds, such as natalizumab or fingolimod, is restricted to severe forms of relapsing MS or cases refractory to first-line treatment owing to substance-specific risk-benefit considerations. Teriflunomide is a new compound which has recently been approved as a first-line treatment of relapsing forms of MS in the USA and Australia. It is characterized by a once daily oral administration and a comparably well-established long-term safety profile. The main therapeutic effect is considered to be mediated via the inhibition of the de novo synthesis of pyrimidine in proliferating immune cells. The pro-drug of teriflunomide, leflunomide, has a label for treating rheumatoid arthritis (RA) for many years. Two recently published phase III clinical trials (TEMSO, TOWER) tested teriflunomide in patients with relapsing forms of MS and efficacy was demonstrated, with positive effects on relapse rates and disease progression using 14 mg/day. Overall, the safety profile in these studies was favorable as expected from experiences with leflunomide in RA. In patients treated with teriflunomide regular monitoring of blood cell counts and liver enzymes is required. Teriflunomide must not be used during pregnancy. In this article the recent phase II and phase III clinical trial data are reviewed and the potential of teriflunomide for the treatment of relapsing forms of MS is discussed.

Central nervous system involvement in patients with monoclonal gammopathy and polyneuropathy.

BACKGROUND AND PURPOSE: To evaluate clinical presentation of patients with the clinical triad of monoclonal gammopathy, polyneuropathy and signs of CNS involvement. METHODS: Nineteen patients with monoclonal protein (M-protein, 9 IgM, 10 IgG) were studied. Clinical examination, MRI, cerebrospinal fluid analysis and immune reactivity against myelin-associated glycoprotein and gangliosides in serum were obtained. By immunohistochemistry, different binding patterns of M-proteins to human CNS tissue were investigated. RESULTS: Nine out of 19 patients (four IgM, five IgG) showed one or more clinical signs of CNS involvement. Clinical features associated with signs of CNS pathology were disease duration and greater concentration of IgM paraprotein. The IgM M-protein of two patients strongly stained the cortex/cerebellar neurons in human brain sections. CONCLUSION: Our results complement previous reports that some patients with monoclonal gammopathy and polyneuropathy can develop solitary or disseminated signs of CNS involvement. It indicates that pathological effects of M-proteins are not necessarily restricted to the peripheral nervous system. The specificity and affinity of circulating M-protein to antigens in the CNS might be critical for the development of different clinical phenotypes.

Micromanipulation by laser microbeam and optical tweezers: from plant cells to single molecules.

Complete manipulation by laser light allows precise and gentle treatment of plant cells, subcellular structures, and even individual DNA molecules. Recently, affordable lasers have become available for the construction of microbeams as well as for optical tweezers. This may generate new interest in these tools for plant biologists. Early experiments, reviewed in this journal, showed that laser supported microinjection of material into plant cells or tissues circumvents mechanical problems encountered in microinjection by fragile glass capillaries. Plant protoplasts could be fused with each other when under microscopical observation, and it was no major problem to generate a triple or quadruple fusion product. In the present paper we review experiments where membrane material was prepared from root hair tips and microgravity was simulated in algae. As many plant cells are transparent, it is possible to work inside living, intact cells. New experiments show that it is possible to release by optical micromanipulation, with high spatial resolutions, intracellular calcium from caged compounds and to study calcium oscillations. An example for avian cardiac tissue is given, but the technique is also suitable for plant cell research. As a more technical tool, optical tweezers can be used to spatially fix subcellular structures otherwise moving inside a cell and thus make them available for investigation with a confocal microscope even when the time for image formation is extended (for example at low fluorescence emission). A molecular biological example is the handling of chromosomes and isolated individual DNA molecules by laser microtools. For example, chromosomes can be cut along complex trajectories, not only perpendicular to their long axis. Single DNA molecules are cut by the laser microbeam and, after coupling such a molecule to a polystrene microbead, are handled in complex geometries. Here, the individual DNA molecules are made visible with a conventional fluorescence microscope by fluorescent dyes such as SYBRGreen. The cutting of a single DNA molecule by molecules of the restriction endonuclease EcoRI can be observed directly, i.e. a type of single molecule restriction analysis is possible. Finally, mechanical properties of individual DNA molecules can be observed directly.