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W Zenker

Publications and source records attributed to W Zenker.

At least 19 recordsLinked to original sources
PubMed1992

5'-nucleotidase in spinal meningeal compartments in the rat. An immuno and enzyme histochemical study.

The distribution of 5'-nucleotidase (5'-Nu) is reported in spinal meninges of the rat on the basis of an immunohistochemical and enzyme histochemical investigation. Strong immunoreactivity was found in the arachnoid membrane and in the sheaths of the spinal roots as well as in septa subdividing the roots. Also the superficial layer of the ligamentum denticulatum showed enzyme staining. No immunoreactivity could be detected in the pia mater or along the spinal nerve roots outside the subarachnoid space. Within the arachnoid mater the immunoreactivity was concentrated in the basal zone of the arachnoid membrane, thus appearing as a narrow fluorescent band near the border of the dura. An accentuation of immunoreactivity could be observed in areas where small dural blood vessels approach the subarachnoid space. It is well known that adenine nucleotides released from neural and glial cells of the central nervous system finally reach the cerebrospinal fluid. We presume that 5'-Nu in the arachnoid membrane and spinal root sheaths is responsible for the conversion of adenine nucleotides into adenosine and that this conversion is associated with the reabsorption process of cerebrospinal fluid which most probably also takes place in spinal meninges. Adenosine, the product of 5'-nucleotidase, could play a role in the reabsorption process by its vasodilatatory effect on dural and epidural vessels.

5'-Nucleotidase↗
PubMed1992

[Patterns of injuries: a guideline for evaluation of multiple injuries?].

By means of 468 patients with polytrauma the pattern of injuries were analysed. Separated into body regions the combinations of injuries to skeleton/thorax and skeleton/thorax/abdomen were found most often. A high lethality was evaluated for the combination of skeletal and abdominal injuries. 362 patients of the examined collective survived, 106 patients died. Among the deceased patients with head-injuries intracranial bleeding could be seen much more than in the group of survivors. Patients who died had also more ruptures of liver and other gastrointestinal injuries. Concerning the skeletal patterns of injuries they surprisingly had more fractures of shoulder, forearm and lower leg than the survivor-group. The statistic demonstrates clearly that in pattern of head or abdominal injuries the single diagnosis determines the rate of lethality. This correlation could not be seen in skeletal injuries. The pattern of injuries cannot be used as a guideline for the assessment of therapy of the severe trauma patient.

Abdominal Injuries↗
PubMed1992

[Stabilizing the pelvic ring with the external fixator. Biomechanical studies and clinical experiences].

Experimental studies were performed on anatomic pelvis specimens. In different series of experiments the positioning of the screws and the assembly of the external fixator were changed. We tried fixing the external fixator to the screws at varying distances from the body surface. For stabilisation of the fractured pelvic girdle a self-constructed "bow fixator", fixed to supra-acetabular screws with proximal compression and distal traction showed the best results. Homogeneous distribution of the pressure could be achieved on the unstable dorsal pelvic ring structures. In clinical routine we used the triangular external fixator, which in the experimental situation yielded results close to those of the bow fixator. External fixation of the pelvic girdle has been performed 128 times since 1977, in January 1991 a prospective study was started. For Tile type B injuries the external fixator itself represents an effective, minimally invasive system, but type C fractures often require an additional internal fixation of the dorsal lesion.

Acetabulum↗
PubMed1991

Conduction velocities of pyramidal tract fibres and lumbar motor nerve roots: normal values.

Measurements of spinal cord and individual lumbar nerve root lengths were performed in 20 dissected cadavers. These data were correlated with the pyramidal tract and motor root conduction times obtained in 53 healthy subjects using motor evoked potentials. The distance between motor cortex and the level of the anterior horn cells ranged from 50.2 +/- 3.0 cm (mean +/- standard deviation) for the L1 segment to 54.4 +/- 3.6 cm for the L5 segment. The length of the motor roots from their exit from the myelon to their exit from the intervertebral foramen ranged from 10.3 +/- 1.7 cm in the L1 root to 17.5 +/- 1.9 cm in the L5 root. The central motor conduction velocity calculated for the distance motor cortex - anterior horn cells of the L5 segment was 50.1 +/- 4.5 m/s. The proximal peripheral conduction velocity of the motor nerve root between its exit from the spinal cord and its exit from the intervertebral foramen was 75.9 +/- 29.0 m/s. The overall conduction velocities between motor cortex and exit of the nerve roots from the intervertebral foramen were 57.4 +/- 6.3 m/s for the L4 fibers to the quadriceps femoris and 57.3 +/- 6.1 m/s for the L5 fibers to the anterior tibial muscle.

Adult↗
PubMed1990

Multifocal innervation and muscle length. A morphological study on the role of myo-myonal junctions, fiber branching and multiple innervation in muscles of different size and shape.

The dependence of the inner organisation and innervation of a skeletal muscle on its size was studied at the level of single muscle fiber architecture and motor endplate topography in muscles of different size, all of them lacking a tendinous scaffolding. The muscles evaluated in this study were: Mm. sternomastoideus, gracilis and latissimus dorsi of the rat and the M. sternocephalicus of the horse. In these muscles a subdivision into two or more 'innervation-compartments' becomes obvious in fascicles reaching a certain length. This provides the possibility of an almost synchronous activation of the entire muscle by its nerve. At the level of single muscle fiber elements, large numbers of myo-myonal junctions were discernible in many sites. However, unequivocal multiple innervation was found, with several end-plates per single muscle fiber, without the interposition of any junctional structure. Myo-myonal junctions, combined with a characteristic branching pattern of many muscle fibers, and scattered innervation sites, obviously play an important role in the architecture of fan-like muscles lacking a tendinous scaffolding.

Animals↗
PubMed1989

Central distribution of cervical primary afferents in the rat, with emphasis on proprioceptive projections to vestibular, perihypoglossal, and upper thoracic spinal nuclei.

The projections of primary afferents from rostral cervical segments to the brainstem and the spinal cord of the rat were investigated by using anterograde and transganglionic transport techniques. Projections from whole spinal ganglia were compared with those from single nerves carrying only exteroceptive or proprioceptive fibers. Injections of horseradish peroxidase (HRP) or wheat germ agglutinin-horseradish peroxidase conjugate (WGA-HRP) were performed into dorsal root ganglia C2, C3, and C4. Free HRP was applied to the cut dorsal rami C2 and C3, greater occipital nerve, sternomastoid nerve, and to the C1/2 anastomosis, which contains afferents from suboccipital muscles and the atlanto-occipital joint. WGA-HRP injections into ganglia C7 and L5 were performed for comparative purposes. Injections of WGA-HRP or free HRP into rostral cervical dorsal root ganglia and HRP application to C2 and C3 dorsal rami produced labeling in dorsal and ventral horns at the level of entrance, the central cervical nucleus, and in external and main cuneate nuclei. From axons ascending to pontine and descending to upper thoracic spinal levels, medial collaterals were distributed to medial and descending vestibular, perihypoglossal and solitary nuclei, and the intermediate zone and Clarke's nucleus dorsalis in the spinal cord. Lateral collaterals projected mainly to the trigeminal subnucleus interpolaris and to lateral spinal laminae IV and V. Results from HRP application to single peripheral nerves indicated that medial collaterals were almost exclusively proprioceptive, whereas lateral collaterals were largely exteroceptive with a contribution from suboccipital proprioceptive fibers. WGA-HRP injections into dorsal root ganglia C7 and L5 failed to produce significant labeling within vestibular and periphypoglossal nuclei, although they demonstrated classical projection sites within the brainstem and spinal cord. The consistent collateralisation pattern of rostral cervical afferents along their whole rostrocaudal course enables them to contact a variety of precerebellar, vestibulospinal, and preoculomotor neurons. These connections reflect the well-known significance of proprioceptive neck afferents for the control of posture, head position, and eye movements.

Afferent Pathways↗
PubMed1988

The distribution of anterogradely labeled I--IV primary afferents in histochemically defined compartments of the rat's sternomastoid muscle.

The sternomastoid muscle of the rat is divided into a white (dominated by fast-glycolytic twitch fibers) and a red (dominated by fast oxidative-glycolytic twitch fibers, but also containing slow-oxidative twitch fibers) compartment. Previous reports on exclusive location of muscle spindles in the red portion were confirmed. On the basis of anterograde labeling with horseradish peroxidase-wheat germ agglutinine conjugate (WGA-HRP) it was shown in this study that, in addition to muscle spindle compartmentalisation, there was also an exclusive occurrence of tendon organs in the red part of the muscle; moreover, fine afferents (III- and IV-afferents) were mainly distributed to this portion as well. Radioimmunassay studies revealed that this part of the muscle contained twice as much substance P as the white part. It could be shown by acetylcholinesterase (AChE) histochemistry that the myelinated fibers of the white branch to the muscle exclusively displayed high enzyme activity which is characteristic for motor fibers; on the other hand, in the branch to the red portion two classes of AChE-positive fibers were found: a large one with a peak in the alpha-range, and a small one with a peak in the gamma-range. In addition, there was also a group of enzyme-negative (sensory) fibers. These results also indicate the red portion of the sternomastoid muscle to be its "sensory compartment".

Acetylcholinesterase↗
PubMed1986

Fiber type and non-endplate acetylcholinesterase in normal and experimentally altered muscles.

The non-endplate (sarcoplasmic) acetylcholinesterase (AChE) was investigated in eight different muscles of the rat. Serial consecutive sections were stained for AChE, myofibrillar ATPase (after alkaline and acid preincubation), and cytochrome C-oxidase. The following general correlation could be established: within a given muscle the sarcoplasmic AChE was highest in type IIB fibers, lowest in type I and intermediate in type IIA. Additionally, the intensity of the reaction was directly proportional to the size of the type IIA fibers. The distribution of sarcoplasmic AChE was correlated to the ATPase fiber types but was complementary to the cytochrome C-oxidase staining pattern. In single fiber preparations, accumulation of AChE at the myotendinous junction was found to occur in "cap-like" form exclusively in fibers with very low or absent sarcoplasmic AChE. To study the role of innervation in the expression of the sarcoplasmic AChE, we cross-reinnervated the extensor digitorum longus (EDL) muscle with the soleus (SOL) nerve and vice versa (X-EDL, X-SOL). In the X-EDL the sarcoplasmic AChE was transformed to that of a normal SOL as were also the ATPase and the cytochrome oxidase. Surprisingly, in the X-SOL the high AChE activity typical for a normal EDL was present after 3 weeks but decreased steadily to very low levels lacking any correlation with ATPase and cytochrome oxidase. The results suggest that the cytoplasmic AChE of the SOL muscle depends more on the load-bearing function of the muscle than on the imposed impulse pattern. There is additional evidence for a retrograde effect of the X-SOL upon its motoneurons.

Acetylcholinesterase↗
PubMed1986

Unmyelinated axons in a muscle nerve. Electron microscopic morphometry of the sternomastoid nerve in normal and sympathectomized rats.

In continuation of earlier studies on the innervation of the sternomastoid muscle of the rat, a detailed morphometric analysis was performed on the unmyelinated axons of the nerve, in normal rats and after extensive cervical sympathectomy. In 4 normal rats an average of 314 myelinated and 319 unmyelinated axons were present. 42 days after surgery, the 3 animals showed Horner's syndrome and a highly significant 40% loss of unmyelinated axons. We therefore suggest that 40% of the C-fibers in this nerve are postganglionic sympathetic efferents and that the remaining 60% are type IV fibers, i.e., unmyelinated afferents. Our counts also indicate that part of the Remak bundles of the Schwann cells contain only sympathetic axons, whereas others contain mixed groups of sympathetic and afferent axons. Myelinated nerve fibers were not lost due to sympathectomy. Unexpectedly, the 3 animals analyzed 7-13 days after surgery showed Horner's syndrome but only a 16% loss of unmyelinated axons, which was not even statistically significant. Morphological signs of degeneration and sprouting did not provide any clue, but a possible explanation would be that a transitory sprouting of the remaining afferent C-fibers or Schwann cells occurred.

Animals↗
PubMed1986

[Effectiveness of tetrachlorodecaoxide (TCDO) in the treatment of complicated disorders of wound healing. A controlled study: TCDO versus PVP-iodine complex].

In a controlled study on the treatment of wound-healing impairments 29 patients underwent local treatment with TCDO (Oxoferin) while Beta-isodona was used in 31 cases. Regarding the criterion of reducing the wound area, i.e. epithelization, a highly significant superiority of Oxoferin could be demonstrated in the treatment of complicated wounds. The evaluation of the state of granulation, that was documented by a semiquantitative procedure, indicated that Oxoferin tends to be slightly superior. However, the following observations have to be emphasized: Oxoferin induces a development of granulation tissue on exposed tendons, bones, and fasciae and the granular tissue is of much better quality than after treatment with Betaisodona. Concerning its effect on the degree of contamination, Oxoferin proved to be at least as efficacious as the established and effective antiseptic Betaisodona. Both substances are tolerated well and the application is simple, they do not differ here.

Adolescent↗
PubMed1985

Ectopic parvalbumin-positive cells in the cerebellum of the adult mutant mouse 'nervous'.

The basket and stellate cells of the 'nervous' mouse cerebellum lose 50% of their presynaptic parallel fibres and more than 90% of Purkinje cells, their major postsynaptic targets, after postnatal day 23. To study the fate of these molecular layer cells we examined the cerebellum of the mutant mouse 'nervous' with antisera against the 'marker protein' parvalbumin, which exclusively tags Purkinje, basket, and stellate cells. Ten homozygous 'nervous' mice, 12-14 weeks old, and 30 control animals of several inbred strains were examined. The number of basket and stellate cells decreased in affected areas of the molecular layer. In addition, parvalbumin-positive cells were detected in the granular layer, in the white matter of the cerebellum and in the area of the cerebellar peduncles of all 'nervous' mice, but not in those of the control animals. These cells mainly occurred in areas which still displayed degenerating Purkinje cell axons. Ectopic parvalbumin-positive cells could either represent a class of interneurons, which have changed their antigenic properties, and therefore happen to stain with antisera against parvalbumin, or stratum moleculare cells which have failed to recognise their proper position during ontogenesis. Alternatively these cells could represent postdevelopmental basket cells, which have acquired the ability to migrate.

Animals↗
PubMed1984

The splenius capitis muscle of the rat, architecture and histochemistry, afferent and efferent innervation as compared with that of the quadriceps muscle.

The splenius muscle of the rat was investigated with regard to its structure and innervation. The latter was compared with that of the quadriceps muscle. The results can be summarized as follows: The splenius muscles of both sides form a bipennate muscle plate connecting the occipital bone with the spinous process of the second thoracic vertebra. The lateral parts of both muscles are attached directly to this prominent bony process, whereas the medial parts end in a median raphe which forms a tendinous cranial extension of the second thoracic vertebra. This tendinous extension, showing no connection to the cervical vertebrae, serves also for the attachment of acromio-trapezius muscle fibers. The lateral part of the splenius muscle is divided into two parts by a tendinous intersection. The splenius muscle consists mainly of fast twitch fibers: 55% were characterized as IIB and 40% as IIA fibers by histochemical demonstration of myosin ATPase-activity. A high content of muscle spindles--57 spindles per gram of muscle tissue--was found. Comparing several aspects of the innervation of the splenius to that of the quadriceps muscle, the following results could be obtained: The ratio of motor end plate size to muscle fiber volume is significantly higher in the splenius than in the quadriceps muscle. As demonstrated by transganglionary HRP-transport, the main part of labeled splenius afferents to the spinal cord terminates in the central cervical nucleus. Quadriceps afferents, entering the lower thoracic and upper lumbar segments, mainly end in the area of Clarke's column. Several labeled fibers descend to the sixth lumbar and first sacral segments, where they terminate in the area of Stilling's nucleus. A group of primary afferents from both muscles--most probably III- and IV-afferents--projects to the dorsal laminae of the dorsal horn; terminals from the splenius are accumulated in the lateral parts of these laminae, whereas those of the quadriceps are more concentrated in the medial areas. Within the brain stem, most afferents from the splenius terminate in the external cuneate nucleus. Most of the quadriceps afferents course to the gracile nucleus. Terminals from both muscle nerves were found in the area of the spinal vestibular nucleus. In conclusion, the most conspicuous results were: 1) Besides the segmental projection to the dorsal horn there is an almost exclusive projection of splenius primary afferents to relay nuclei to the cerebellum. 2) The relatively high ratio: end plate size/muscle fiber volume, which is characteristic of finely adjusting muscles.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

Afferent and efferent innervation of the rat esophagus. A tracing study with horseradish peroxidase and nuclear yellow.

The technique of retrograde labeling of nerve cells with HRP and nuclear yellow as well as transganglionic anterograde HRP-tracing of sensory projections into the CNS were used to establish the motor and sensory innervation pattern of two parts of the rat esophagus: the cervical and the abdominal segment. For comparison, also the innervation of the anterior wall of the stomach was studied. Application of HRP to the cervical part of the esophagus resulted in bilateral labeling of neurons in the nucleus ambiguus exclusively, while application of the tracer to the abdominal part was followed by labeling of cells in both the nucleus ambiguus and the dorsal motor nucleus of the vagus. Application of tracer to the wall of the stomach caused labeling of cells in the dorsal motor nucleus of the vagus exclusively. Labeling appeared always bilaterally. In all experiments there was a profuse labeling of primary afferent neurons with cell bodies in both nodose ganglia and endings in certain subnuclei of the solitary nucleus. Endings related to the cervical esophagus projected into the ventral subnuclei, projections from the abdominal esophagus were located in the ventral and medial subnuclei, those from the stomach in the medial subnucleus solely. The area postrema and the commissural nucleus received afferents from both organs, the esophagus and the stomach. Double labeling experiments with HRP and nuclear yellow provided no signs of overlap of sensory innervation areas of the sites investigated in this study. Within the wall of the esophagus no labeled intramural cells nor nerve fibers were found in sections beyond the injection sites.

Afferent Pathways↗
PubMed1983

Afferent projections from the rat longus capitis muscle studied by transganglionic transport of HRP.

Using the method of transganglionic transport of horseradish peroxidase (HRP) according to Mesulam (1978), the course and central terminations of the afferents from the longus capitis muscle were studied in the rat. Application of HRP to the cut muscle nerves was followed by heavy labeling of a considerable number of cell bodies of different sizes in the spinal ganglia C2 and C3. The labeled central processes follow two distinct main routes: one to the external cuneate nucleus, which is known to project ipsilaterally to the cerebellum, the other to the central cervical nucleus (CCN) of the spinal cord. The latter nucleus contains dense arborizations and terminals of muscle afferents in close relationship to medium sized cells which project contralaterally to the cerebellum. This could be shown in double labeling experiments with HRP as a tracer for primary afferents and Nuclear yellow for the cerebellar pathway. The labeled area of CCN extends from the fourth cervical segment up to the medulla oblongata where it lies laterally adjacent to the hypoglossal nucleus, though clearly separated from the latter. In the cervical part of CCN, dendrites of neck muscle motoneurons arborize within the area of afferent terminals. Besides the external cuneate and the central cervical nuclei, afferent projections were seen in lamina X, partly in close contact with the central canal, and in more lateral areas of lamina VII. In contrast to results from studies on other neck muscles, no reaction product was observed in dorsal horn laminae I-VI.

Afferent Pathways↗
PubMed1983

Substance P--positive structures in rat spinal cord--a longitudinal bundle ventral to the central canal.

Using the immunoperoxidase method, the distribution of substance P (SP)-positive structures was studied in different levels of the rat spinal cord. In general, the density of SP-positive sites proved to be higher in lumbar and sacral than in cervical and thoracic segments. In transverse sections, the density was highest in lamina I, and decreased in dorso-ventral direction. Following colchicine injection into the spinal cord, many SP-positive cell bodies could be visualized in the dorsal and lateral horn as well as in the lateral spinal nucleus. In front of the central canal, an SP-immunoreactive longitudinal bundle (FLCV) showing close relation to the ependyma, extends throughout the whole length of the spinal cord. This bundle, which also displays acetylcholinesterase activity, electronmicroscopically consists of thin myelinated and unmyelinated fibers, some of which containing numerous synaptic vesicles. SP-positive fibers penetrating between ependymal cells and abuting on the luminal surface of the central canal probably arise from the FLCV.

Acetylcholinesterase↗
PubMed1981

Enzyme-histochemistry of the juxtaoral organ in man ("organ of Chievitz").

The activities of several enzymes - hydrolases, oxidoreductases and carbonic anhydrase - were demonstrated histochemically in the epithelial parenchyma of the human juxtaoral organ. Two characteristics enzyme-activity-patterns provided morphological distinction between two different forms of the juxtaoral organ, independently of the sex or age of the patient. Provisionally we have called them type I and type II. Type I showed a strong activity of alkaline phosphatase and carbonic anhydrase and low activity of non-specific esterases, whereas type II showed just the contrary. The enzyme activities in the epithelial parenchyma displayed obvious similarities to those of the duct cells of salivary glands but they were different from those of the oral mucosa studied. Only alkaline phosphatase of the enzymes demonstrated, showed activity in the epithelia of the juxtaoral organ but none in the oral mucosa or salivary glands. On account of the multiple nerve endings present, a receptor function is presumed for these, whereas the function of the epithelial parenchyma is still unknown.

Adult↗