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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 68 (1997), S. 3405-3411 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: This article describes a power supply and data logger for a Langmuir probe interfaced to a personal computer. The system provides a voltage sweep range from −125 to +100 V in 100 steps in a time ∼0.15 s. Restricted sweep ranges and single point operation are also possible. Probe current measurements are in the range from −1.0 to +100 mA with a precision of 5 μA on the most sensitive range, while the voltage may be set with a precision of 56 mV. Novel features of the system include: the use of integrate-and-dump techniques to implement the process of analog-to-digital conversion and to provide effective noise suppression; a solution to the problem of floating the power supply on top of the potential developed across the grounded current sensing resistor based on the power supply rejection ratio characteristics of a high voltage operational amplifier; and the development of an interface and control board employing the GPIB protocol to communicate with a host computer. Successful operation of the system has been demonstrated in the electrically noisy environment of a helicon plasma source. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 40 (1983), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: Anterograde axonal transport was examined in sensory nerves of rats intoxicated with a low dose (group I) or a high dose (group II) of acrylamide. After injection of either [35S]methionine and [3H]fucose or [3H]proline into the dorsal root ganglia of the 5th lumbar roots, distribution of protein label was measured in 3-mm segments of the sciatic nerve at intervals of 2 h, 4 h, 10 days, and 26 days. No difference in ganglion incorporation was present at 4 h, and the fast transport velocity of methionine label also remained normal [14.7 ± 1.3 mm/h (mean ± SD) in controls versus 14.6 ± 0.3 mm/h and 15.4 ± 1.2 mm/h in acrylamide group I and II, respectively]. Neither was there any decrease in transport velocity of proline label of slow component b (4.18 ± 0.29 mm/day in controls versus 4.29 ± 0.17 mm/d and 4.22 ± 0.29 mm/day in acrylamide group I and II, respectively). In slow component a, however, a significant reduction in the fractional amount of proline label was found (20.8 ± 4.0% in controls versus 17.6 ± 14.9% and 9.7 ± 5.9% in acrylamide group I and II, respectively). Again no decrease in transport velocity was observed (1.03 ± 0.02 mm/day in controls versus 1.06 ± 0.08 mm/day and 1.07 ± 0.03 mm/day in acrylamide group I and II, respectively), and closer inspection of the activity along the nerve did not reveal any alteration in skewness or ‘peakedness’ of the distribution curve. The reduction in amount of protein carried in the slow axonal transport component in rats with severe acrylamide neuropathy (group II) could be associated with fibre breakdown at a late stage of the neuropathic process. The most important consequence of the study is, however, that in contrast to previous suggestions, during acrylamide intoxication no changes are present in protein incorporation or in anterograde axonal transport which can explain the initial pathological or functional abnormalities of the distal axons.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 40 (1983), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: The effect on retrograde axonal transport of doses of acrylamide ranging from 50 to 500 mg/kg was studied in sensory nerve of rats. Accumulation of trichloroacetic acid-phosphotungstic acid-insoluble label was measured in a collection segment distal to a double ligature placed on the sciatic nerve at intervals 9–15 h and 9–24 h following injection into the dorsal root ganglion of the fifth lumbar root of [35S]methionine and [3H]fucose. After a dose of 100 mg/kg of acrylamide no neurological signs of neuropathy had yet appeared, but retrograde buildup of protein label was significantly reduced for the long interval (2.20 ± 0.49 arbitrary units (AU) (mean ± SD) versus 2.81 ± 0.57 AU in controls, 2p = 0.034). No abnormality of the short interval appeared before a dose of 500 mg/kg was reached. The retrograde transport abnormality was dose-related (r =−0.85, n = 28 and 2p = 1.2 × 10-8), as was the degree of neuropathy evaluated by “blind” neurological scoring (r = 0.88, n = 14 and 2p = 2.8 × 10-5). After a dose of 500 mg/kg, when the rats were severely disabled with almost total incoordination of the hindlegs, the retrograde accumulation of the long interval was profoundly depressed (1.08 ± 0.28 AU versus 2.81 ± 0.57 AU in controls, 2p = 1.2 × 10-7). Similar changes were seen in accumulation of glycopro-tein label. After the rats had recovered for 4–10 weeks neurological signs of neuropathy had disappeared and the transport abnormality had improved. To test the specificity of acrylamide on the retrograde transport defect N-hydroxymethylacrylamide and methylene-bisacrylamide, which do not induce neuropathy, were studied. None of these related compounds influenced the transport. These observations imply that in acrylamide intoxication a defect in the amount of material carried by retrograde axonal transport rather than in “turnaround” time or in transport velocity is present, that the transport abnormality precedes the development of neuropathy and that it is related to the degree of the neurological disability. We suggest that the retention of protein in the distal axons is the functional counterpart of the well-known accumulation of vesicular organelles in the pre-terminals.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 33 (1979), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract— Anterograde and retrograde flux of axonal transported glycoproteins were examined in streptozotocin diabetic rats with 4 weeks’duration of the metabolic derangement.[3H]Fucose and [14C]NeuNAc were injected into the fifth lumbar root ganglion and the accumulation of TCA-PTA insoluble activity proximal and distal to a sciatic nerve ligature was measured.Accumulation of glycoproteins during 2 h collection periods was decreased distal to a ligature in diabetic animals whereas no abnormality of proximal accumulation was observed. These findings demonstrate an abnormality of the retrograde transport of glycoproteins in early experimental diabetes.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Radiation Measurements 23 (1994), S. 529-532 
    ISSN: 1350-4487
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 84 (1984), S. 544-548 
    ISSN: 1432-2072
    Keywords: Antidepressant drugs (side effects) ; Anticholinergic effects ; Heart rate variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The aim of the present study was to investigate whether heart rate variation as obtained simply from an electrocardiographic registration is influenced in subjects given antidepressive medication. The mean difference between consecutive R-R intervals (MCD) was reduced in patients (n=23) treated with various doses of tri- or tetracyclic antidepressants [7.7 (1.8–32.3) ms in patients versus 24.8 (7.0–87.7) ms in controls]. Among those receiving 1.67 mg tricyclic antidepressant or more per kilogram body wt (n=12) MCD was further reduced [5.0 (2.1–12.0) ms] with no overlapping of values as compared to controls (n=9). In a subgroup of patients treated with clomipramine the MCD was related inversely to the dosage (R=0.78, P〈0.02). In an additional group of seven patients, MCD was reduced following a few days of treatment with antidepressants as compared to pretreatment values (P〈0.02), indicating that the reduction is a result of therapy and not a concomitant of the affective state. We suggest that measurements of heart rate variation could be a useful tool to measure anticholinergic effects of antidepressants.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 56 (1982), S. 157-160 
    ISSN: 1432-0533
    Keywords: Diabetic neuropathy ; Streptozotocin diabetes ; Mast cells ; Peripheral nerves ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Mast cell proliferation has been reported in peripheral nerves of streptozotocin diabetic rats. We examined the question by light microscopy using morphometric techniques including estimation of shape and size. After 4 weeks of diabetes the mast cell area in transverse sections was 32.7±7.0 μm2 vs. 22.5±5.4 μm2 in controls (P〈102). Mast cell profiles approximated to ellipses in longitudinal sections, the long diameter being 11.4±1.2 μm vs. 14.0±1.0 μm in controls (P〈104). Correspondingly, the profile number was increased (30 ±6%) in longitudinal sections and decreased in transverse sections (11±16%). The present study does not provide evidence for mast cell proliferation in peripheral nerves in experimental diabetes, and, furthermore, underlines the need of evaluation of dimensions in studies of particle numbers.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Diabetologia 19 (1980), S. 222-228 
    ISSN: 1432-0428
    Keywords: Diabetic neuropathy ; axonal transport ; Streptozotocin diabetes ; nerve crush ; nerve regeneration ; insulin treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The axonal transport of proteins in crushed nerves of streptozotocin (40 mg/kg) diabetic rats was investigated 4 weeks after induction of diabetes. 35S-methionine was used as a marker for protein and 3H-fucose as a marker for glycoprotein. The precursors were injected into the fifth lumbar spinal ganglion and the accumulation of TCA-insoluble activity proximal and distal to a sciatic nerve ligature was measured at different time intervals after application of a crush. The start of accumulation distal to the ligature was delayed by 1 hour for proteins as well as for glycoproteins. Furthermore, the total amount of accumulated protein after 19 h was decreased by 18% while the decrease was 21% for glycoprotein. By insulin treatment the differences could both be prevented and reversed after 3 days of normoglycaemia. These findings demonstrate an impaired response to a nerve crush and might be the explanation for the regenerative abnormalities of peripheral nerves in diabetes.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Diabetologia 38 (1995), S. 1191-1196 
    ISSN: 1432-0428
    Keywords: Magnetic stimulation ; diabetic neuropathy ; motor pathway ; paired magnetic stimulation ; diabetic encephalopathy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Central motor pathways were studied in 17 normoalbuminuric insulin-dependent diabetic (IDDM) patients who had been diabetic for more than 20 years, and compared with findings in 17 age-, sex-, and height-matched control subjects. The central motor conduction time was calculated from recordings of the compound muscle action potentials of the abductor pollicis brevis muscle after single transcranial and spinal root magnetic stimulation. The central motor conduction time from motor cortex to cervical spinal roots was 9.8±1.65 ms in diabetic patients and 10.1±1.48 ms in control subjects. In diabetic patients with neuropathy the central motor conduction time was 9.5±1.76 ms vs 10.1±1.56 ms in patients without neuropathy. The excitability of the motor pathways was studied by paired transcranial magnetic stimulation at interstimulation intervals of 30–1000 ms. In normal control subjects, an early facilitation of the amplitude of the compound muscle action potential at an interstimulation interval of 30 ms was found, while no facilitation was present in diabetic patients. In addition the compound muscle action potential latencies were prolonged at interstimulation intervals of 30–50 ms in diabetic patients. The changes of excitability did not correlate with the presence of peripheral neuropathy, metabolic control or diabetes duration. It is concluded that long-term normoalbuminuric IDDM patients have impaired excitability but normal central conduction time of the motor pathways.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Diabetologia 12 (1976), S. 547-553 
    ISSN: 1432-0428
    Keywords: Streptozotocin diabetes ; myelinated nerve fibres ; nerve degeneration ; diabetic neuropathy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a morphometric study of isolated fibres of the common peroneal nerve in short-term diabetic rats reduced fibre calibre was observed. No segmental demyelination or remyelination was found, but the nodes of Ranvier were slightly widened and paranodal bulbi were swollen relative to fibre calibre. It is suggested that axonal dwindling is the primary event in experimental diabetes. The reduction of the myelin sheath may be a consequence of the abnormal nerve cell offshoot. The results obtained suggest that streptozotocin diabetes in the rat is a useful model for the elucidation of diabetic neuropathy.
    Type of Medium: Electronic Resource
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