Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “FASCIA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 451 records · Page 25Linked to original sources
PubMed2005

Pubovaginal bone anchor fixation with polyethylene versus fascia lata slings in the treatment of female stress incontinence: sling material and processing are predominant factors in success.

OBJECTIVE: The opponents of the In-Taca bone anchor system note the risk of a high rate of wound infection and osteitis pubis. We evaluated whether there is a difference in the outcome of the use of two different sling materials--polyethylene and fascia lata--with regard to wound infection, and analyzed the incidence of osteitis pubis further in a larger series. MATERIAL AND METHODS: A total of 61 women (mean age = 65.4 years) were treated for stress urinary incontinence (SUI) type II and III using the In-Taca bone anchor system. In 15 of 61 patients, we used a synthetic sling of polyethylene, and in 46, a fascia lata sling. The subjective success rate was determined with validated questionnaires (Urinary Distress Inventory-6, Symptom Severity Index and Symptom Impact Index). The objective assessment included a pad test according to the ICS- standard and a urogynecologic evaluation. Mean follow-up was 10.2 months. RESULTS: Wound inflammation of only very mild degree occurred in 15% in the fascia lata group, whereas 33% in the polyethylene group developed serious sling infection; in three patients explantation of the sling was necessary. Accordingly, satisfaction with the procedure was low in the polyethylene group. In both groups, there were no hints of osteitis pubis. The sling material used did not affect continence rate. CONCLUSION: Using the bone anchor system, the infection rate depends primarily on the sling material used and its processing: polyethylene is well tolerated in other reconstructive procedures (such as TVT, where a netlike mesh is used), so the processing of synthetic sling material plays an extremely important role in infection rate: platelike, dense synthetic material tends to cause wound infection.

Adult↗
PubMed2005

The use of tensor fascia lata pedicled flap in reconstructing full thickness abdominal wall defects and groin defects following tumor ablation.

BACKGROUND: The tensor fascia lata is a versatile flap with many uses in reconstructive plastic surgery. As a pedicled flap its reach to the lower abdomen and groin made it an attractive option for reconstructing soft tissue defects after tumor ablation. However, debate exists on the safe dimension of the flap, as distal tip necrosis is common. Also, the adequacy of the fascia lata as a sole substitute for abdominal wall muscles has been disputable. The aim of the current study is to report our experience and clinical observations with this flap in reconstructing those challenging defects and to discuss the possible options to minimize the latter disputable issues. PATIENTS AND METHODS: From April 2001 to April 2004, 12 pedicled TFL flaps were used to reconstruct 5 central abdominal wall full thickness defects and 6 groin soft tissue defects following tumor resection. In one case, bilateral flaps were used to reconstruct a large central abdominal wall defect. There were 4 males and 7 females. Their age ranged from 19 to 60. From the abdominal wall defects group, all repairs were enforced primarily with a prolene mesh except for one patient who was the first in this study. Patients presenting with groin defects required coverage of exposed vessels following tumor resection. All patients in the current study underwent immediate reconstruction. RESULTS: The resulting soft tissue defects in this study were due to resection of 4 abdominal wall desmoid tumors, a colonic carcinoma infiltrating the abdominal wall, 4 primary groin soft tissue sarcomas, a metastatic SCC of the leg to groin nodes, and a primary SCC of the groin. The size of the flaps used ranged from 20 x 10 cm to 31 x 18 cm. All flaps survived. However, distal flap necrosis occurred in 4 cases. Three of those cases developed in flaps reconstructing abdominal wall defects, and one case developed in a flap used to cover a groin defect. In the former 3 cases, the flap was simply transposed without complete islanding of the flap. In the latter case, a very large flap was harvested beyond the safe limits with its distal edge just above the knee. In addition, wound dehiscence of the flap occurred in 2 other cases from the groin 132 group. Nevertheless, all the wounds healed spontaneously with repeated dressings. Out of the 5 cases that underwent abdominal wall reconstruction, one case developed ventral hernia, in which bilateral TFL flaps were used without mesh enforcement. There was minimal donor site morbidity in the form of partial skin graft loss in 2 cases. The average follow up period in this study ranged from 6 months to 2 years. Only one patient died of distant metastasis of a SCC of the groin skin, 8 months postoperatively and another 2 patients with abdominal desmoid tumors developed local recurrence. CONCLUSION: The tensor fascia lata flap is a reliable and a versatile flap, with minimal donor site morbidity. Problems with the flap's vascularity of its distal part should not be encountered, if the flap is harvested within the safe limits and properly designed and the edges comfortably insetted to the defect. A pedicled flap would be appropriate for lower abdominal wall defects, and is better islanded to achieve extra mobilization and allow a tension free closure, while for groin defects, simple flap transposition should be enough. Nevertheless, reconstruction for full thickness abdominal wall defects by this flap is a static reconstruction. We therefore strongly recommend enforcing the repair with a synthetic mesh primarily to minimize the incidence of ventral hernia. However, further studies with larger number of cases are needed to confirm this observation.

Abdominal Neoplasms↗
PubMed2006

[Autologous transplantation of fascia into the vocal fold for sulcus vocalis].

OBJECTIVE: To evaluate the effects of vocal fold autologous fascia transplantation for treating sulcus vocalis. METHODS: Sulcus vocalis among 23 cases were dissected and vocal fold autologous fascia transplantation performed. For type III sulcus associated with thyroarytenoid muscle atrophy, autologous fat injection was carried out also. The voice acoustic quality and video laryngostroboscopic data were evaluated before and after surgery. RESULTS: Among 23 patients, 4 were excluded from the analysis because of failure of surgery or lost to follow-up, leaving a total of 19 patients who were included in the analysis. Until 6-8 weeks after surgery, patients could start to phonate. Vocal quality became better 3 months postoperatively. Vocal quality became steady 6 months after the surgery. Vocal improvement was obtained in 89. 5% (17/19) of the patients. The shapes, glottal closures and mucosal waves of vocal folds were improved. There was a significant decrease (improvement) in scales of grading, roughness, breathiness, and asthenic after surgery (P < 0.05). For the grade parameter, it improved 2 scales in 2 patients (10.5%) and 1 scale in 15 patients (79.0%). Acoustic analysis and maximum phonation time (MPT) were significantly improved after surgery (P < 0.01). Acoustic parameters of 42.0% (8/19) patients returned to normal range. MPT of 17 patients (89.5%) was in normal scopes. With 6 to 24 months follow-up, vocal function was steadily. There was no apparent reabsorption. CONCLUSIONS: Autologous transplantation of fascia into the vocal fold was a useful and safe procedure for pathological sulcus vocalis.

Adult↗
PubMed2006

Changes in collagen and elastic fiber contents of the skin, rectus sheath, transversalis fascia and peritoneum in primary inguinal hernia patients.

BACKGROUND: It has been claimed that inguinal hernia is not a local disease; it is a local manifestation of a systemic disorder of collagen metabolism. Previous studies have shown that patients with inguinal hernia have some anomalies in collagen metabolism and changed ratio of collagen types. AIM: To search the changes in collagen and elastic fiber contents of the skin, rectus sheath, transversalis fascia and peritoneum in primary inguinal hernia patients. METHODS AND MATERIALS: Twenty patients operated on for inguinal hernia (HR) included in the study (11 direct and 9 indirect). Nine patients underwent open cholecystectomy served as the control group (CC). A 0.5 x 1 cm. tissue was sampled from skin, rectus sheath, transversalis fascia and peritoneum in HR group. Skin, rectus sheath and peritoneum samples were taken from the patients in CC group. The sections of those samples were submitted to two different staining methods: "Masson's trichrome" for collagen and "van Gieson" for elastin fibers and graded with light microscopy. RESULTS: The rectus sheath samples of CC had higher staining scores for both collagen and elastin fibers in comparison with HR (p = 0.032 and p = 0.026, respectively). CC had a significantly higher score for collagen in peritoneum samples (p = 0.019). There were no statistically significant differences between the patients with direct and indirect inguinal hernias for collagen or elastin fibers scores in skin, rectus sheath, transversalis fascia and peritoneum samples. CONCLUSIONS: These findings, which concur with most of the previous studies, support the theory that inguinal hernia may not be merely a local disease and can be more generalized, at least a regional connective tissue disorder. Regarding the difference between direct and indirect hernias, it could not be possible to report a certain answer, and this issue should be considered together with previous quantitative researches and more sophisticated studies may take place in the future (Tab. 2, Fig. 2, Ref. 23).

Collagen↗
PubMed2006

[Comparison between tympanoplasties with cartilage-perichondrium composite graft and temporal fascia graft in terms of hearing levels and healing].

OBJECTIVES: We compared the extent of healing and hearing improvement following tympanoplasties performed with the use of cartilage-perichondrium composite grafts and temporalis muscle fascia grafts. PATIENTS AND METHODS: Fifty consecutive patients (22 males, 28 females; mean age 30+/-14 years; range 11 to 63 years) with chronic otitis media were divided into two groups to receive cartilage-perichondrium composite grafts or temporal muscle fascial grafts. All the patients were evaluated by pure-tone audiometry and otomicroscopic examination in the 1st, 3rd, 6th, and 12th months. RESULTS: At the end of the first year, graft survival was 92% in the cartilage group, and 85% in the fascia group. Hearing levels improved at the end of the first year; however, the two groups did not differ significantly in terms of hearing improvement and graft survival. Hearing gains were greater in central and subtotal perforations. In comparison with a steady increase in the cartilage group, hearing levels remained unchanged after the sixth month in the fascia group. CONCLUSION: Cartilage-perichondrium composite grafts may be easily and safely used in type I tympanoplasties, with successful results including hearing improvement.

Adolescent↗
PubMed1991

Congenital ptosis. Long-term results of treatment using lyophilized fascia lata for frontalis suspensions.

This report extends a prospective collaborative study published in 1982 of congenital ptosis repair using lyophilized human fascia lata to investigate the permanency of banked human fascia lata. Fifty-six patients are described with a mean postoperative follow-up of 7.2 years and a median follow-up of 8.3 years. Significant recurrence of ptosis was documented in 24 of 56 (43%) patients. New failures continue to be recognized even in the eighth postoperative year. Life table and survival analysis predicts a success rate from frontalis suspension surgery using lyophilized human fascia lata of 90% at 2 to 3 years, 70% at 5 to 6 years, and 50% at 8 to 9 years.

Blepharoptosis↗
PubMedDate not supplied

Histochemical demonstration of adrenergic fibers in the fascia periosteum and retinaculum.

Adrenergic nerve fibers were demonstrated in the fascia, periosteum and retinaculum using the formaldehyde method of Falck--Hillarp and the recently developed glyoxylic acid method. A typical adrenergic plexus was seen around the vessels. The arteries and arterioles received a dense adrenergic nerve supply. The veins had a sparse adrenergic innervation and the venules and capillaries were apparently without adrenergic innervation. These distribution patterns of adrenergic fibers were fundamentally similar to those seen in various organs. A difference in the pattern of innervation was seen, however, in the arterioles betweeen the fascia, and periosteum and retinaculum. Furthermore, chemical sympathectomy induced by injection of 6-hydroxydopamine resulted in the disappearance of noradrenaline fluorescence and marked vasodilation in the fascial vascular bed, and a moderate vasodilation in the periosteum and retinaculum. These findings suggest that the role of adrenergic fiber is vasoconstrictor and these fibers regulate the circulation in the fascia, periosteum and retinaculum.

Adrenergic Fibers↗
PubMed1983

[The parotid fascia].

The parotid fascia is not the superficial layer of the investing layer of the cervical fascia. The dissection of 21 cadavers, the histological studies and the compared anatomy of 3 apes show that the parotid gland lies between the platysma muscle on the lateral side and the superficial layer of the cervical fascia on the medial side. The upper part of the platysma, large muscle in apes, has regressed as a fibrosis layer in man.

Adult↗
PubMed1994

Secondary reconstruction for unfavorable microtia results utilizing temporoparietal and innominate fascia flaps.

Unfavorable results in reconstruction of the auricle for microtia can be encountered from time to time, in which secondary reconstruction of the auricle is usually performed. One must note that secondary reconstruction is much more difficult than primary reconstruction for the following reasons: (1) all necrotic skin and scar tissue from the primary reconstruction must be removed, thus limiting the surface area of the skin for the secondary reconstruction; (2) the presence of scar tissue and loss of tensility in the subdermal layer makes it difficult to construct a subcutaneous pocket for grafting of the three-dimensional costal cartilage framework; and (3) in patients with full-thickness skin grafts in the conchal and postauricular regions, contraction of the grafted skin was noted. In order to resolve these problems, the temporoparietal fascia flap was used in the first-stage three-dimensional frame grafting operation, and the innominate fascia flap, obtained from the same site as the temporoparietal fascia in the first-stage operation, was used for the second-stage operation. The retroauricular full-thickness skin graft was utilized for color match on the anterior surface of the auricle where it is visible, and substitute skin from the groin was used to cover the donor site. The procedures and results for secondary reconstruction for unfavorable microtia are presented in this article.

Adolescent↗
PubMed1994

[Reconstruction of the medial collateral ligament of the knee in rats using a free autogeneic transplant of fascia lata, ligament or tendon].

After resecting the lateral collateral ligament of the knee in 56 male mature rats, the authors replaced it by an autogenous transplant of the same size, made of fascia lata, ligament or patellar tendon. The authors then studied this transplant after an evolution of 2 days to 5 1/2 months. This lapse of time can be divided into three stages: an initial stage (first week), marked by transplant necrosis and acute inflammation--an early stage (from the second to the fourth week), which shows the migration of the cells from the host to the transplant and the rebuilding of collagen fibers. Tissues with a loose, extensible, but weak texture, such as the fascia lata, are totally colonized by the fibroblasts. Tissues with a dense, strong, but less extensible texture, as the patellar tendon, are soon destroyed and recolonized at the periphery, whereas their center is destroyed and recolonized by fibroblasts later and more irregularly--a late phase of consolidation (from the second to the fifth month), which shows the rebuilding of a dense collagen network and its reorientation. In fascia lata transplants, this new collagen is homogeneous and is made of parallel bundles. In tendon transplants, the network is not homogeneous. It has a persistent nodular aspect at the periphery and well-oriented bundles, separated by calcified or granulomatous foci at the center. In the case of ligament transplants, the new collagen network shows an intermediate aspect between the two described above. The weakest regular connective tissues are the best for ligamentoplasties, and tendons are the worst.

Animals↗
PubMed1996

Applied anatomy of the cremasteric muscle and fascia.

PURPOSE: Although the cremasteric muscle is a prominent structure of the inguinal canal, specific details of its anatomy are seldom discussed in either anatomical or surgical texts. Therefore, a detailed description of the anatomy of the cremasteric muscle and fascia is provided, followed by descriptions of new applications of this knowledge for operations on the inguinal canal. MATERIALS AND METHODS: Observations are described based on more than 1,000 operations on the inguinal canal conducted during a 15-year period. Magnification of 3.5 x was used in all dissections. RESULTS: Careful dissections of the cremasteric muscle and fascia allowed for development of new approaches to enhance exposure of the inguinal canal and internal ring, and to mobilize the spermatic cord and testes. CONCLUSIONS: Knowledge of the anatomy of the cremasteric muscle and fascia, and techniques for dissection are adjuncts to surgery of the inguinal canal, including inguinal hernia repair and orchiopexy.

Abdominal Muscles↗
PubMed1996

Fascia--defects and repair.

Endopelvic fascia contributes to the support of the uterus and vagina. There is increasing evidence that alteration in the fascial extracellular matrix may lead to weakening of the fascia and development of prolapse. Other workers have identified discrete defects in endopelvic fascia that can be rectified to cure prolapse. This paper reviews fascial defects and their repair.

Fascia↗
PubMed1997

Comparative cost analysis of collagen injection and fascia lata sling cystourethropexy for the treatment of type III incontinence in women [ssee comments].

PURPOSE: We examined the cost of 2 common forms of surgical treatment of genuine stress urinary incontinence due to intrinsic sphincter deficiency, that is sling cystourethropexy and periurethral collagen injection. MATERIALS AND METHODS: Between May 1994 and July 1995, 14 women with intrinsic sphincter deficiency underwent sling cystourethropexies. A total of 14 matched patients with intrinsic sphincter deficiency underwent endoscopic collagen injection during the same period. RESULTS: The total cost per treatment of fascia lata sling cystourethropexy ($10,382) was 2.1 times greater than that for collagen injection ($4,996, p < 0.001). At an average followup of 14.9 months for fascia lata cystourethropexy and 21.3 months for collagen injection, 71.4% of patients in the former and 26.7% in the latter groups were completely continent (p = 0.05). One or no pads were used daily by 85 and 40% of the patients, respectively. CONCLUSIONS: Fascia lata sling cystourethropexy may be a more cost-effective surgical treatment than periurethral endoscopic collagen injection for treating genuine stress urinary incontinence in women with intrinsic sphincter deficiency when the greater success rate of the former procedure is considered.

Collagen↗
PubMed1986

The cholinergic innervation of the rat fascia dentata: identification of target structures on granule cells by combining choline acetyltransferase immunocytochemistry and Golgi impregnation.

A monoclonal antibody against choline acetyltransferase (ChAT), the acetylcholine-synthesizing enzyme, was used to study cholinergic synapses on identified (Golgi stained) granule cells in the rat fascia dentata. Choline acetyltransferase immunocytochemistry was applied to 40-microns Vibratome sections cut perpendicular to the longitudinal axis of the hippocampus. Light microscopy revealed fine varicose ChAT-immunoreactive axons in all layers of the fascia dentata, i.e., in the stratum moleculare, the stratum granulosum, and the subgranular polymorph zone. Most fibers were observed in the vicinity of granule cell bodies where they ran mainly parallel to the granular layer. Next, the immunostained Vibratome sections were sandwiched between small pieces of Parafilm and piled to form a block that was covered with agar and Golgi stained. After that, the sections were separated by cutting away the agar and removing the Parafilm. Sections containing well-impregnated granule cells were gold-toned (Fairén et al., '77), embedded in Araldite, and subjected to ultrathin sectioning for electron microscopy. A total of 14 gold-toned granule cells were examined in the electron microscope for synaptic contacts with cholinergic afferents. Choline acetyltransferase-immunoreactive axon terminals were observed that established symmetric synaptic contacts with the cell bodies and dendritic shafts of the gold-toned identified granule cells. Two types of contact were observed on spines arising from gold-toned granule cell dendrites. Immunoreactive terminals established asymmetric synaptic contacts with the head of small spines and symmetric contacts with the stalk of large, complex spines. The boutons forming asymmetric synaptic contacts with the cup-shaped spine head of the complex spines were not found to be immunoreactive. Our results demonstrate that cholinergic fibers to the rat fascia dentata establish characteristic types of synaptic contact with different postsynaptic elements of granule cells, suggesting a complex function of this afferent system.

Animals↗
PubMed1987

GABAergic nonpyramidal neurons in intracerebral transplants of the rat hippocampus and fascia dentata: a combined light and electron microscopic immunocytochemical study.

Glutamate decarboxylase (GAD) immunocytochemistry was used to study GABAergic neurons and synapses in intracerebral allografts of the rat hippocampus and fascia dentata. Tissue blocks of regio inferior of Ammon's horn (hippocampal field CA3) or of the fascia dentata were taken from newborn rats and transplanted to the hippocampal region of young adult rats. After 6 1/2 months' survival the recipient brains were fixed by perfusion and serially sectioned on a Vibratome. Sections containing the transplant and/or the host hippocampal region were immunostained for GAD and flat-embedded in Araldite for a correlated light and electron microscopic analysis. Immunostained neurons and terminals in the transplants were compared to immunoreactive elements in the hippocampus and fascia dentata of the hosts and other, normal rats. As in the hippocampal formation in situ, GAD-immunoreactive neurons and terminals in the transplants were observed in all layers. In dentate transplants a preponderance of immunostained cells was found just beneath the granule cell layer. In both hippocampal and dentate transplants, immunoreactive terminals were most abundant in the cell layers where they formed characteristic pericellular baskets around the pyramidal and granule cell bodies. In the electron microscope, the transplant GAD-immunoreactive neurons exhibited numerous cytoplasmic organelles, deeply infolded nuclei, and nuclear rods. Immunoreactive terminals formed symmetric synaptic contacts on the cell bodies, dendritic shafts, and spines of transplant pyramidal cells, granule cells, and hilar neurons. These are normal characteristics of GAD-immunoreactive neurons and terminals as also observed in the hippocampus of the host rats and the normal controls. Our results demonstrate that GABAergic neurons survive transplantation and develop a cell-specific morphology that includes the axonal projections.

Animals↗
PubMed1990

Afferent and efferent synaptic connections of somatostatin-immunoreactive neurons in the rat fascia dentata.

The aim of this study was to determine whether somatostatin (SS)-immunoreactive neurons of the rat fascia dentata are involved in specific excitatory circuitries that may result in their selective damage in models of epilepsy. Synaptic connections of SS-immunoreactive neurons were determined at the electron microscopic level by using normal and colchicine pretreated rats. Vibratome sections prepared from both fascia dentata of control animals and from rats that had received an ipsilateral lesion of the entorhinal cortex 30-36 hours before sacrifice were immunostained for SS by using a monoclonal antibody (SS8). Correlated light and electron microscopic analysis demonstrated that many SS-immunoreactive neurons in the hilus send dendritic processes into the outer molecular layer of the fascia dentata, and dendrites of the same neurons occupy broad areas in the dentate hilar area. The majority of SS-immunoreactive axon terminals form symmetric synapses with the granule cell dendrites in the outer molecular layer and also innervate deep hilar neurons. Via their dendrites in the outer molecular layer, the SS-immunoreactive neurons receive synaptic inputs from perforant pathway axons which were identified by their anterograde degeneration following entorhinal lesions. The axons from the entorhinal cortex are the first segment of the main hippocampal excitatory loop. The hilar dendrites of the same SS-immunoreactive cells establish synapses with the mossy axon collaterals which represent the second member in this excitatory neuronal chain. These observations suggest that SS-immunoreactive neurons in the dentate hilar area may be driven directly by their perforant path synapses and via the granule cells which are known to receive a dense innervation from the entorhinal cortex. These observations demonstrate that SS-immunoreactive neurons in the hilar region are integrated in the main excitatory impulse flow of the hippocampal formation.

Animals↗
PubMed1991

The mossy cells of the fascia dentata: a comparative study of their fine structure and synaptic connections in rodents and primates.

In this study the fine structure and synaptic connections of mossy cells in the rat and monkey fascia dentata were analyzed. In order to study commissural connections of identified mossy cells in the rat, hilar neurons were retrogradely labeled by horseradish peroxidase (HRP) or Fast Blue (FB) injections into the contralateral hippocampus. Vibratome sections containing retrogradely HRP-labeled hilar neurons were Golgi-impregnated and gold-toned. Hilar commissural neurons identified by contralateral FB injection were intracellularly labeled with Lucifer Yellow (LY). Lucifer Yellow staining was made electron-dense by photoconversion thereby allowing for an electron microscopic analysis of the retrogradely labeled and intracellularly stained neurons. With these two different approaches, we succeeded in identifying rat mossy cells projecting to the contralateral hippocampus. Mossy cells in the fascia dentata of primates (Papio anubis, Macaca mulatta, Saimiri sciureus) were, like mossy cells of rats, either Golgi-impregnated and gold-toned or intracellularly injected with LY. No major differences were found between mossy cells of rats and monkeys. The mossy cell dendrites originated from the two sides of an ovoid cell body and were mainly oriented parallel to the granule cell layer. In contrast to the rat, dendrites of mossy cells in the primate did not respect the granule cell layer and penetrated frequently into the molecular layer. The occurrence of excrescences on proximal dendrites was a characteristic feature of all mossy cells. These large spines were more complex in the primate than in the rat. In both rats and primates they formed numerous asymmetric synapses with large boutons of mossy fibers. Peripheral dendrites were covered with small, simple spines. Interestingly, these peripheral dendrites lacking excrescences also established asymmetric synapses with mossy fiber boutons as well as asymmetric and symmetric contacts with smaller terminals of unknown origin. These findings indicate that in both rats and primates the thorny excrescences are not the only target of the mossy terminals. While the proximal portions of the mossy cell dendrites appear to be exclusively contacted by the granule cells, a larger number of neuron types may converge on the distal dendrites. The axons of mossy cells, in both rats and primates, although incompletely stained with the present methods, were seen to ramify in the hilar region. Our results demonstrate that, despite minor species differences, the mossy cells of the fascia dentata represent a cell type that is preserved in phylogenetically distant species.

Amidines↗
PubMed2006

Tumor necrosis factor and its p55 and p75 receptors are not required for axonal lesion-induced microgliosis in mouse fascia dentata.

Tumor necrosis factor (TNF) is a potent pro-inflammatory and neuromodulatory cytokine. In the CNS it is produced primarily by microglia and considered to regulate microglial activation. On the basis of previous observations of increased microglial TNF mRNA synthesis in areas of anterograde axonal and terminal degeneration in mice, we studied the effect of TNF and its p55 and p75 receptors on axonal lesion-induced microglial activation in fascia dentata following transection of the perforant path (PP) projection. Unexpectedly, cell counting showed that the axonal lesion-induced microglial response in TNF and TNF-p55p75 receptor knock out mice and C57BL/6 mice was similar 5 days after the lesion. In addition, the microglial expression of the lysosomal-associated antigen CD68, and the clearance of MBP(+) myelin debris appeared similar in TNF and TNF-p55p75 receptor knock out mice compared to C57BL/6 mice. Quantitative PCR and in situ hybridization showed the expression of TNF mRNA to be maximally upregulated 6 h after the lesion, and confirmed that TNF mRNA was still upregulated 5 days after lesion when microglial numbers, CD11b mRNA level, and cellular TNF-p55 and -p75 receptor mRNA level reached maximum. However, in spite of the induction of TNF mRNA, TNF protein level remained at base-line in fascia dentata using immunohistochemistry and ELISA. In conclusion, the results showed a lower than expected lesion-induced increase in TNF protein, and that neither TNF nor its receptors were required for the axonal lesion-induced microglial morphological transformation and proliferation or for the initial clearance of degenerated myelin in the PP-deafferented fascia dentata.

Animals↗