On the temperature sensitivity of multiple sclerosis patients (author's transl)]

Aggravation of neurological symptoms in MS patients in heating is well known. This phenomenon is explained by the change of conduction in demyelinated nerve fibers. In raised temperature conduction block occurs. The threshold of conduction block dependent on temperature, is probably proportional to the degree of demyelination. It is possible to inhibit this effect by tyrosin. This model may present a view to a part of neurophysiological mechanisms of MS, on which we possibly can take therapeutical influence. By way of a questionnaire 125 MS patients were asked about changes of their symptoms in heating or cooling. 93% had marked sensitivity to heating. In 90% worsening of neurological symptoms or of general feeling occured in a hot bath. On the other hand about half the patients reported improvement in a cold bath. Therefore we suggest, that a noticeable part of neurological deficit is reversible, if we were able to raise the threshold of conduction block, which depends on temperature, ph, electrolytes and neurotransmitters.     

Combination of betulinic acid with cisplatin--different cytotoxic effects in two head and neck cancer cell lines

Betulinic acid (BetA), a new experimental cytotoxic compound that is active against human melanoma cells and neuroectodermal tumor cells, has recently been shown to be also effective against head and neck squamous carcinoma cells (HNSCC). In this study we investigated BetA in combination with cisplatin in squamous cell carcinoma cell lines of the tongue. SCC25 and SCC9 were treated with BetA and/or cisplatin. Cells were counted with an automated analyzing system. Caspase activation was determined using the M30 Cyto-Death ELISA, expression of the anti-apoptotic protein Mcl-1 by Western blot analysis. Visualization of apoptotic cells was achieved by immunohistochemistry. Synergistic cytotoxic effect and the induction of apoptosis under combined treatment was observed in SCC25 cells only after 24 or 48 h, whereas treatment of SCC25 cells for 72 h with BetA and cisplatin showed antagonism or subadditive effects. In SCC9 cells, antagonism occurred over an increase of dose and time during treatment. Furthermore, we could not demonstrate a significant alteration in the expression of the anti-apoptotic protein, Mcl-1. Our in vitro data demonstrate that BetA seems to be an unlikely candidate for combination with cisplatin in the treatment of head and neck cancer.     

Tarsal navicular stress fractures: radiographic evaluation

Tarsal navicular stress fractures are a potential source of disabling foot pain in physically active individuals. The diagnosis of tarsal navicular stress fracture requires a high index of clinical and radiographic suspicion because the fracture is only rarely evident on routine radiographs or standard tomograms. The radiographic diagnosis of a tarsal navicular stress fracture may require anatomic anteroposterior tomograms or a radionuclide bone scan with plantar views. Radiographic examinations of 23 fractures in 21 patients are evaluated.     

Magnetization transfer micro-MR imaging of live excised lamprey spinal cord: characterization and immunohistochemical correlation

BACKGROUND AND PURPOSE: Membrane constituents may play a key role in the magnetization transfer (MT) effect. In lamprey spinal cord, axonal diameters range from <1 microm in the dorsal region to 20-40 microm in the ventral region. There is a corresponding range of axonal, and hence cell membrane, density. These characteristics permit determination of the effect of cell membrane density on MT. The purpose of this study was to characterize regional MT effects in lamprey spinal cord. METHODS: Excised spinal cords from eight sea lampreys were measured with a 9.4-T MR imaging system. MT saturation was applied for spin-echo sequences. The MT ratio (MTR) was calculated in each location (dorsal, lateral, and ventral columns). Spinal cords from five other lampreys were prepared with an antibody to lamprey glial keratin (LCM 29). The percentage of area staining with LCM29 was calculated for each location. RESULTS: Mean MTR (+/- SD) for the dorsal, lateral, and ventral columns were 62.4 +/- 4.2, 59.2 +/- 2.7, and 56.9 +/- 3.0, respectively; all differences were significant (P < .05). Mean LCM29-positive areas for the dorsal, lateral, and ventral columns were 85.1%, 69.7%, and 50.9%, respectively. MTR and percentage LCM29-positive area were significantly correlated (r(2) = 0.98). CONCLUSION: Regional differences in MT effect exist in the lamprey spinal cord. MTR is well correlated with percentage LCM29-positive area. These results support the hypothesis that membrane constituents are at least partly responsible for regional variations in MT effect.