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A Tessler

Publications and source records attributed to A Tessler.

63 records · Page 4Linked to original sources
PubMed1985

Sciatic nerve transection produces death of dorsal root ganglion cells and reversible loss of substance P in spinal cord.

Sciatic nerve section has been shown to reduce substance P (SP) in the dorsal horn of the spinal cord, but the mechanism which underlies the reduction is not understood. Whether SP levels subsequently recover as they do after dorsal rhizotomy has also been unknown. To test the hypothesis that transganglionic degeneration of primary afferents contributes to the reduction of SP, we have studied the changes in SP which result from section of the cat sciatic nerve and determined the extent of dorsal root ganglion (DRG) cell death. Sciatic nerve section resulted in DRG cell death, but the amount was variable and not seen in all animals. Reduction in dorsal horn and DRG SP was seen in all animals, and in the spinal cord it was followed by recovery. These sequelae resemble the changes which follow dorsal rhizotomy. After sciatic nerve section, the reduction in dorsal horn SP is smaller than after rhizotomy, the recovery more complete, and both the reduction and the recovery proceed more slowly. Evidence is presented that similar mechanisms may contribute to depletion of intraspinal SP after sciatic nerve section and after dorsal rhizotomy. The mechanisms contributing to recovery of spinal cord SP after sciatic nerve section may resemble known mechanisms of recovery that occur when the lesion is central.

Animals↗
PubMed1984

Recovery of substance P but not somatostatin in the cat spinal cord after unilateral lumbosacral dorsal rhizotomy: a quantitative study.

The dorsal horn of the cat spinal cord contains substance P and somatostatin within nerve endings which arise from cells located in dorsal root ganglia and from cells within the neuraxis. Previous studies from this laboratory have demonstrated that dorsal rhizotomy depletes both peptides from the dorsal horn. However, the changes in the two peptides differ. Substance P is at first severely depleted by dorsal rhizotomy and then recovers in part, whereas somatostatin is diminished less but does not recover. In the present experiments the validity of these conclusions which were based on anatomical observations has been evaluated quantitatively with the use of radioimmunoassay. After a 74% reduction at 10-14 days postoperative, substance P immunoreactivity in the deafferented dorsal horn shows a small, statistically significant recovery by 30 days to 60% of normal values. In contrast, somatostatin is reduced by 46% at 10-14 days but does not return significantly. As previously suggested by immunocytochemistry, dorsal rhizotomy produces no significant decline of either peptide in the ventral horn. The differing response of the two peptides is consistent with the hypothesis that intrinsic spinal substance P-containing neurons increase their projections (or their production of substance P) in the deafferented dorsal horn, but that somatostatin-containing neurons do not. Because synaptic number returns to normal in at least the deafferented lamina II of the cat yet substance P recovers only partially, it is likely that axons which contain transmitters other than substance P or somatostatin also increase the numbers of their terminals in response to dorsal rhizotomy.

Animals↗
PubMed1981

Spinal neurons mediate return of substance P following deafferentation of cat spinal cord.

Deafferentation of the cat dorsal horn by complete unilateral lumbosacral dorsal rhizotomy produces a loss and subsequent partial recovery of substance P (SP) immunoreactivity as visualized by the peroxidase-antiperoxidase technique. The present experiments aimed to determine whether this return of SP represents a generalized response of all fiber systems afferent to the denervated segments or a more selective response of a specific spinal system. Although a contribution from other sources cannot be excluded by this qualitative immunocytochemical technique, several observations indicate that the return of SP staining depends on interneurons which contain SP immunoreactivity: (1) the amount of SP staining in the chronically deafferented dorsal horn deprived of extrinsic fiber systems is comparable to that seen after deafferentation alone; (2) SP-containing neurons are present within the lumbar segments; and (3) destruction of lumbar neurons by the intraspinal injection of kainic acid abolishes SP staining from the chronically deafferented dorsal horn. From these observations it would appear that the anatomical plasticity of SP-containing fibers in the deafferented dorsal horn is due to the response of a particular system rather than to a generalized response of all systems which terminate there.

Afferent Pathways↗
PubMed1980

Recovery of substance P in the cat spinal cord after unilateral lumbosacral deafferentation.

Changes in substance P in the cat spinal cord after deafferentation of the hindlimb were investigated using the peroxidase-antiperoxidase technique. Unilateral lumbosacral dorsal root section (L1-S3) is followed by a decrease in dorsal horn (laminae I, II and V) substance P reaction product which is most marked at 10-11 days. There is no observable change in the ventral horn. The 13 or 15 day survivors demonstrate an increase over that seen at 10-11 days, and still greater amounts appear in the dorsal horn of 1 month survivors. After 1 month there is little further observable increase. The location of the returned reaction product resembles that of normals, but differs in its staining characteristics. Substance P containing cell bodies are observed in normal animals and on intact and deafferented sides of experimentals, suggesting that interneurons and propriospinal fibers may be a source of the returning substance P reaction product. The decrease in dorsal horn substance P at short times after rhizotomy followed by an increase at longer times is consistent with axonal sprouting. If so, then the time course of sprouting parallels that of locomotor recovery and supports the hypothesis that the two phenomena are related.

Afferent Pathways↗
PubMed1980

Axonal growth during regeneration: a quantitative autoradiographic study.

The intraaxonal distribution of labeled glycoproteins in the regenerating hypoglossal nerve of the rabbit was studied by use of quantitative electron microscope autoradiography. 9 d after nerve crush, glycoproteins were labeled by the administration of [3H]fucose to the medulla. The distribution of transported 3H-labeled glycoproteins was determined 18 h later in segments of the regenerating nerve and in the contralateral, intact nerve. At the regenerating tip, the distribution was determined both in growth cones and in non-growth cone axons, 6 and 18 h after labeling. The distribution within the non-growth cone axons of the tips was quite different at 6 and 18 h. At 6 h, the axolemma region contained < 10% of the radioactivity; at 18 h, it contained virtually all the radioactivity. In contrast, the distribution within the growth cones was similar at both time intervals, with 30% of the radioactivity over the axolemmal region. Additional segments of the regenerating nerve also showed a preferential labeling of the axolemmal region. In the intact nerve, 3H-labeled glycoproteins were uniformly distributed. These results suggest that: (a) in this system the labeled glycoproteins reaching the tip of the regenerating axons are inserted into the axolemma between 6 and 18 h after leaving the neuronal perikaryon; (b) at the times studied, there is a fairly constant ratio between glycoproteins reaching the growth cone through axoplasmic transport and glycoproteins inserted into the growth cone axolemma; (c) the axolemma elongates by continuous insertion of membrane precursors at the growth cone; the growth cone then advances, leaving behind an immature axon with a newly formed axolemma; and (d) glycoproteins are preferentially inserted into the axolemma along the entire regenerating axon.

Animals↗
PubMed1978

Inverted papilloma of the bladder: a distinct urological lesion.

With the addition of six new cases, 104 cases of inverted papilloma of the bladder are reviewed. Pathological and epidemiological characteristics of this distinct bladder lesion are outlined, comparison with transitional cell papilloma is investigated, and recommended therapy and follow-up are offered.

Adult↗
PubMed1978

Retroperitoneal neurilemmoma.

The clinical and pathologic features of benign and malignant retroperitoneal neurilemmoma are reviewed, and the pertinence of this tumor to the urologist is stressed. Two additional case reports are added to the literature.

Female↗