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Biomedical subjects

L de Medinaceli

Publications and source records attributed to L de Medinaceli.

30 records · Page 2Linked to original sources
PubMed1985

Posttraumatic autoimmune reaction in peripheral nerve: effect of a single injury.

This study was conducted to show that local autoimmune reactions could be observed in rat sciatic nerve after a single injury. Furthermore, we attempted to correlate the intensity of the immunological reaction with the severity of nerve damage, with the type of surgical treatment and with the degree of functional recovery. Through the use of direct immunofluorescence techniques, we found that the severity of the initial damage was associated with the intensity of the local immunological response assessed 2.5 months after surgery. There was an association between type of surgical treatment and intensity of the autoimmune reaction. A correlation between autoimmune reaction and degree of long-term functional impairment was not immediately clear. The probable factors that underlie these results are discussed.

Animals↗
PubMed1985

Posttraumatic autoimmune reaction in peripheral nerve: effect of two successive injuries at the same site.

We studied local autoimmune reactions in rat sciatic nerve after two successive injuries at the same site. The behavioral consequences of these injuries were also examined. We found that repetitive injuries had a moderately adverse effect on function and were accompanied by local autoimmune reactions. A causal relation between the two phenomena was possible but not clearly established.

Animals↗
PubMed1985

Posttraumatic autoimmune reaction in peripheral nerve: effect of two successive injuries at different locations.

We studied the influence of previous nerve damage on the evolution of recovery that follows a second nerve injury. Recovery from nerve injury was assessed by analyzing rats' foot prints during a 74-day period. In addition, at the end of this period, the surgically treated sciatic nerves were immunohistochemically stained for the presence of immunoglobulins, an indicator of an autoimmune reaction. We found there was a moderately adverse effect of previous nerve damage on the sciatic functional recovery, a fact that suggests some systemic response to the distantly placed initial damage. Immunohistochemical staining showed various degrees of immunoglobulin deposition depending on the type of the two injuries. An interpretation of our results is proposed.

Animals↗
PubMed1984

Rat sciatic functional index data management system with digitized input.

Quantification of the functional condition of rat sciatic nerve is an important experimental procedure. In the present study, a system for management of the sciatic functional index ( SFI ) data is described. Results obtained with the Sciatic Index Management System (SIMS) were compared with results obtained with other measurement techniques. Validity and reliability of the SIMS were found to be excellent, and speed of data analysis was increased. It is concluded that the SIMS represents a significant advance in the quantification of nerve regeneration data.

Animals↗
PubMed1984

Peripheral nerve reconnection: inhibition of early degenerative processes through the use of a novel fluid medium.

Two pharmacologic manipulations were applied to injured nerves in the rat to minimize the secondary damage that accompanies peripheral nerve transection. It is known that calcium influx into the nerve is responsible for some of the processes that have been termed Wallerian degeneration. These disruptive effects of high intracellular calcium were retarded by chlorpromazine, a potent inhibitor of calmodulin. Our results suggested a new method for reducing posttraumatic neural disruption and supported our hypothesis regarding the involvement of calmodulin or some other Ca2+ binding protein in Wallerian degeneration. The second part of this report describes changes observed at the tips of a severed nerve and their prevention through the use of polyvinyl alcohol. Finally, we showed that neither substance produced functional deficits when injected directly into the sciatic nerve of rats and could thus be used in animal experimentation.

Animals↗
PubMed1983

Peripheral nerve reconnection: immediate histologic consequences of distributed mechanical support.

We tested the possibility of improving the quality of axonal repair after peripheral nerve transection by suppression of all mechanical stresses from the zone of repair. A method was developed involving mechanical support of the sciatic nerve from below in a grooved chamber with additional support provided by suturing the nerve to a rubber sleeve. Histological studies of silver-impregnated specimens from rabbit sciatic nerve using this technique revealed that the axons' tips were closely reconnected with minimal disruption in their direction or in the alignment of fibers and without extraneous material between the severed stumps. Comparison of these results with those of current microsurgical techniques showed the unequivocal superiority of this method in terms of immediate histologic aspects. The course of Wallerian degeneration was not modified.

Animals↗
PubMed1983

Peripheral nerve reconnection: mechanical, thermal, and ionic conditions that promote the return of function.

Current microsurgical techniques for repairing peripheral nerves do not take into account a number of factors that are of importance. A technique was developed that considered 17 factors, the major ones of which are proper alignment of the stumps, sharpness of cut, and prevention of physical and chemical damage. The clinical results after transection of rats' sciatic nerve were assessed in terms of functional recovery. When all 17 conditions were met, our technique was significantly superior to microsutures, suggesting the possible use of this method to improve the return of function after peripheral nerve injury.

Animals↗
PubMed1983

Peripheral nerve reconnection: improvement of long-term functional effects under simulated clinical conditions in the rat.

Despite increasing precision of the microsurgical management of peripheral nerve injuries, measured by eventual return of function, there has been no clear improvement in the outcome. By taking into consideration a number of chemical and physical factors that could influence the condition of injured nerves, we developed a reconnection technique and have applied that technique under conditions mimicking those of human nerve injury. Within 4 weeks, all rats treated by reconnection had substantial return of motor function as measured by gait. Seventy-four days after surgery, performance of the animals receiving this reconnection treatment was 66% better than that of the animals treated by conventional microsuturing.

Animals↗
PubMed1979

[180 cases of umbilical hernia repaired in a new way (author's transl)].

We describe a new method for the cutaneous repair of umbilical hernias. The cut of the skin makes two flaps suppressing the navel which is generally salient. After the aponevrotic repair which is made by vertical suture with slowly resorbable material, the repair of the two cutaneous flaps builds a new navel which aspect is very close to the natural one. This method has been used once with complete satisfaction, for the repair of an omphalocel.

Adolescent↗
PubMedDate not supplied

A method for shortening of the rat spine and its neurologic consequences.

Large laboratory animals are the usual choice for complex surgical procedures on the spine and spinal cord, such as shortening of the spine. It would, however, be advantageous to be able to use a small inexpensive mammal like the rat. We describe a procedure which allows thoracic spondylectomy (T8-T9) to be performed in the rat with a satisfactory survival rate (69%). Functional consequences of the procedure on animals with uninjured spinal cord were monitored over a period of six months, at which time histologic examination was performed. There was a good correlation between operative trauma, consisting of mechanical injury to the cord assessed from the surgical notes, and the duration of postoperative spinal shock. Animals for which the cord appeared laminated or deformed at the time of sacrifice tended to show incomplete functional recovery. Cord cavitation developed in most surviving animals (78%) but did not have a measurable adverse effect on functional outcome. In the present study, the cord was not intentionally injured; however, availability of this procedure may facilitate the future development of methods to implement recovery of function following spinal cord injury.

Animals↗
PubMedDate not supplied

Neurobehavioral evaluation of function following experimental nerve damage.

Accuracy of axonal regrowth is a major factor of recovery after a peripheral nerve lesion. In sciatic nerve studies, gait is a simple indicator of the precision of repair. It is possible to quantify nerve function through measurements made from rats' walking tracks. The rat sciatic nerve trunk was injured in several ways and the resulting changes in sciatic function were measured using tracks. The advantages and limits of the method are discussed.

Animals↗