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1.
Clinical Oral Investigations - The aim of this study was the analysis of WNT10A variants in seven families of probands with various forms of tooth agenesis and self-reported family history of...  相似文献   
2.
Cancer Chemotherapy and Pharmacology - The present study evaluates the safety and efficacy of double-plasma filtration (PF) to remove the exceeding pegylated liposomal doxorubicin (PLD) in...  相似文献   
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Circular stereotactic callosotomy: A preliminary report   总被引:1,自引:0,他引:1  
Summary The authors propose a new method for performing Stereotactic callosotomy, which they have named circular callosotomy. The operating device is the original Riechert-Mundinger's string electrode, which can be protruded through a side window and by rotating the probe it is possible to cut the commisural pathways to the extent required. The anatomical results of the operation can be checked using MRI scanning.  相似文献   
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The reinnervation pattern of crural pacinian corpuscles was examined by light and electron microscopy in eight adult cats of both sexes 3–18 months after sciatic nerve crush. Normal pacinian corpuscles are each supplied with a single myelinated axon and a single cylindrical axon terminal which may branch in the distal part of the inner core. Reinnervation of these vibroreceptors was very satisfactory after sciatic nerve crush: in a sample of 68 corpuscles examined 3–18 months after the operation, 92.6% were found reinnervated, while only 7.4% remained denervated. At the nerve entry, 84.2% of the reinnervated corpuscles were supplied with a single myelinated axon, while 15.8% received two myelinated axons; some of the axons branched before or after entering the inner core. Near the mid-level of the inner core, 60.3% of 63 reinnervated corpuscles were innervated with a single axon terminal, 22.2% were biterminal, while 17.5% had three or more terminals. Regenerated axon terminals induced the formation of thin lamellar layers in the axial region of the original core and, exceptionally, also at the outer aspect of the original core. In monoterminal corpuscles, the shape and ultrastructure of regenerated endings resembled those of normal controls, whereas in multiterminal corpuscles their shape and profiles were variable. In contrast to previous reports, reinnervated corpuscles did not ultimately become monoterminal. On the contrary, the mean number of 1.3 terminals found in reinnervated crural corpuscles at 3–5 months increased to 1.9 terminals per corpuscle 6–18 months after axotomy. Received: 1 July 1996 / Revised, accepted: 30 September 1996  相似文献   
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We present a case of Merkel cell carcinoma of the thigh diagnosed by conventional histology, immunohistochemistry, electron microscopy and cytogenetics. A unique chromosome 6 trisomy characterized this primary neoplasm, as confirmed by FISH study. The role of chromosome analysis and interphase cytogenetics is emphasized as an adjunct in the subtyping of tumours and their prognostic evaluation.  相似文献   
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Summary The 275 Purkyn cells identified by the criteria of the previous paper have been investigated with respect to their role as units integrating the input to the anterior lobe from various limb nerves. The discharges from single Purkyn cells have been studied in lightly anesthetized (pentothal) or in decerebrate unanesthetized cats, there being averaging usually of 128 responses in the form of post-stimulus time histograms and cumulative frequency distributions.Single Purkyn cells exhibited a wide variation in their responses to the diverse inputs from the various afferent nerves. Attention was focussed on excitatory and inhibitory responses evoked by mossy fibers with a short latency, usually 10–15 msec for hindlimb afferents. With most Purkyn cells these responses were predominantly evoked from cutaneous nerves, low threshold fibers being particularly effective. A few Purkyn cells were preponderantly excited by afferent volleys from muscle nerves, but there was a large group with a mixed input from cutaneous and muscle nerves. Graded strengths of stimulation of muscle nerves showed that sometimes group I volleys were prepotent, but other Purkyn cells were selectively excited by group II volleys. Though sometimes the afferent volleys from antagonistic muscles had a reciprocal action on a Purkyn cell, as on a motoneurone, it was more common to find similar actions. Also convergence of inputs from forelimb and hindlirnb nerves, both cutaneous and muscular, was not uncommon, particularly in marginal areas between hindlimb and forelimb zones. A special design feature is the convergence onto a Purkyn cell of mossy fiber and climbing fiber inputs evoked by the same afferent volley. This convergence was of particular interest along the parasagittal strip of hindlimb climbing fiber distribution in lobule V.It was not possible to translate the observations into some map of the cerebellar cortex on which are marked the territorial distributions from the various limb afferent nerves. Rather, there was an ill-defined patchy character, closely adjacent Purkyn cells often receiving very different subsets of the total input from the various limb nerves. The unitary integrations accomplished by the individual Purkyn cells are further integrated when their axons converge onto and inhibit the neurones of the cerebellar nuclei, and this integration by convergence would occur in each successive relay on the output pathways from the cerebellum.It is pointed out that the experimental findings on the integrative action of the individual Purkyn cells provide basic information for attempts to construct models simulating cerebellar performance and control.Post-Doctoral Fellow NINDS (1F2NB40, 545101 NSRB).Post-Doctoral Fellow UHF Grant No. FTF-3-UB-70.  相似文献   
9.
Summary This paper is the first of a series in which the processing of information in the cerebellum has been studied by investigating the effects that known inputs from limb nerves produce on the unitary spike potentials in the cerebellar cortex. These spikes have been recorded extracellularly at all depths along microelectrode tracks in the 5th, 4th and 3rd lobules of the anterior lobe in the lateral vermis or in the pars intermedia. These units have a background frequency of discharge, often very irregular, and computer averaging techniques have been employed in order to derive reliable information on the time course and intensity of the excitatory and/or inhibitory actions produced by the input against this background.Most of the spike responses recorded from the granular layer fall into two classes, one characteristic of impulses in mossy fibers, and the other of impulse discharges from granule cells. Both in the spontaneous background and in the response to afferent volleys in limb nerves the mossy fibers exhibit a performance in close accord with that described for the discharges up the spino-cerebellar tracts. The short latency of 6–9 msec for hindlimb stimuli and the high frequency burst response of 2–4 impulses are characteristic. The mossy fibers displayed a wide variety of responses to the wide range of testing inputs, there being various combinations of excitatory and inhibitory responses and also delayed excitatory actions, all of which must be assumed to be reflections of synaptic influences on the cells of origin of the mossy fibers in the spinal cord.Granule cells have a longer latency by several milliseconds, 9–20 msec for the hindlimb, and a slower frequency in their burst response which tended to be longer and more irregular. The small unitary spike potentials are more difficult to isolate. Also with repetitive stimulation granule cells are more readily depressed than are mossy fibers.Usually a granule cell exhibits a wider range of response to the various cutaneous and muscular afferents of a limb. Both mossy fibers and granule cells may display reciprocal responses to volleys from muscle nerves to antagonistic muscles. This attempt to define properties of the mossy fiber and granule cell spike potentials should help in their identification in future investigations.Post-Doctoral Fellow NINDS (1F2NB40,544101 NSRB).Post-Doctoral Fellow UHF Grant No. FTF-3-UB-70.  相似文献   
10.
1.  The relationship of the contractile response of cat papillary muscles and of the slow inward current, recorded under voltage clamp conditions (single sucrose gap), has been studied. The preparations were driven at a rate of 30 per min at 31° C. Both variables were recorded during a train of 7 identical clamp depolarizations (for 1 s from resting potential to –15 to +40 mV). The contractility increased severalfold and reached the steady state within 5–6 consecutive depolarizations.
2.  The voltage-dependence of slow inward current was confirmed: maximum was found at depolarizations near 0 mV. On repetition of clamp pulses the slow current gradually diminished in amplitude and was more slowly activated and inactivated. The shift of the current-voltage curve indicated a decrease of the reversal potential.
3.  Under non-steady state conditions the amplitude of the slow current was found to correlate closely with the magnitude of the contractile response at any given level of depolarization. The relation was linear with negative slope. The largest contractile response was not found at voltages which elicited maximum slow current.
4.  The progressive decrease of the slow current during repetition of voltage clamp depolarizations is not significantly affected by inadequate time for recovery of slowly changing conductances, since it occurs also at stimulation frequency 15 per min and the slow current remains virtually unaltered after 20 s period of quiescence.
5.  The course of total ionic current during phase 1 and 2 of action potential was reconstructed from a family of current curves obtained as a response to clamp depolarizations to various voltages, respecting the contractility-dependence of the current. The resulting course was correlated with the first derivative of action potential. A general conformity was ascertained.
6.  The correlation of slow inward current with action potential configuration indicates that the rate of its activation determines the depth of the notch separating spike and plateau, its magnitude determines the voltage of the plateau phase and its rate of inactivation affects repolarization.
7.  It is concluded that the described simultaneous changes of mechanical and electrical phenomena might be due to increased [Ca]i, which is responsible for more intense activation of the contractile proteins on the one hand, and decreased driving force of the slow inward current, carried by Ca ions, on the other.
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