[Diagnosis management of Warthin tumour: clinical presentation, fine needle cytology and MRI]

OBJECTIVES

Warthin tumour is the second most frequent benign tumour of the parotid gland after pleomorphic adenoma. The aim of this retrospective study was to define clinical, cytological and MRI characteristics in order to work out a therapeutic strategy.

MATERIAL AND METHOD

During the period May 1991-January 2003, 53 patients with Warthin tumors were treated in our institution. Clinical data were reported from medical records reviewing. Histological diagnoses were compared with FNAB and MRI results.

RESULTS

Warthin tumours represented 13% of all parotid lesions of our series. Mean age of patients was 58 year-old. Sex ratio was 3.8 men and 1 woman. Sensitivity of FNAB for Warthin tumour diagnosis was 75% while positive predictive value was 71%. Six cases of false positive patients were reported: 2 acinic cells carcinomas, 2 pleomorphic adenomas, 1 dermoid cyst, 1 branchial cyst.

CONCLUSIONS

Surgical management is based on partial parotidectomy that may be adapted to the tumour location. Because of elderly patients, benign nature and low risk of malignant transformation of Warthin tumours, one might prompt to adopt a conservative strategy, avoiding surgery in some cases. Despite diagnosis of Whartin tumour on FNAB and MRI, one must be cautious in recommending conservative treatment in order to avoid ignoring a surgical tumour.

An overview of nomegestrol acetate selective receptor binding and lack of estrogenic action on hormone-dependent cancer cells

The specific pharmacological profile of the 19-norprogestin nomegestrol acetate (NOMAC) is, at least in part, defined by its pattern of binding affinities to the different steroid hormone receptors. In the present study, its affinity to the progesterone receptor (PgR), the androgen receptor (AR) and the estrogen receptor (ER) was re-evaluated and compared to those obtained for progesterone (P) and several progestins. The characteristics of binding to the PgR in rat uterus were determined and Ki were found to be roughly similar with 22.8 and 34.3 nM for NOMAC and P, respectively. The binding characteristics of 3H-NOMAC were also determined and compared to that of 3H-ORG2058 with Kd of 5 and 0.6 nM, respectively for rat uterus and 4 and 3 nM, respectively for human T47-D cells. Structure-affinity and -activity relationships were studied on a variety of compounds related to NOMAC in order to assess its specificity as a progestin. The effects of NOMAC on the binding of androgen to the AR were investigated, using rat ventral prostate as target model. Contrary to what was observed for MPA, the RBA of NOMAC was found to decline with time, showing anti-androgenic rather than androgenic potential, a result that was confirmed in vivo. Regarding the ER, since none of the progestins were able to compete with estrogen for binding in rat uterus as well as in Ishikawa cells, the induction of alkaline phosphatase activity (APase) was used as an estrogen-specific response. It confirmed the intrinsic estrogenicity of progestins derived from 19-nor-testosterone (19NT), norethisterone acetate (NETA), levonorgestrel (LNG) or norgestimate (NGM) and others. In contrast, all P and 19-norP derivatives remained inactive. Finally, to complete this overview of NOMAC at the sex steroid receptor levels, the lack of estrogenic or estrogenic-like activity was checked out in different in vitro models. Data from this study have demonstrated that NOMAC is a progestin that has greater steroid receptor selectivity compared to MPA or some other synthetic progestins. It may provide a better pharmacological profile than those progestins currently in use in HRT and OC.

Transconjunctival approach in lower eyelid blepharoplasty

AIM

To specify interest and indications of the transconjunctival approach in lower-eyelid plastic surgery.

MATERIALS AND METHODS

Twenty-three cases of inferior blepharoplasty performed through a transconjunctival approach are reported. The authors describe the surgical technique, its indications and results.

RESULTS

The transconjunctival approach provides excellent access to the inferior fatty chambers and is cutaneous scar free. It has a lower complication rate than the classic transcutaneous approach, and no case of cyclid retraction has been reported.

CONCLUSION

In our 'cosmetic society', the inferior blepharoplasty through a transconjunctival approach has taken a significant place in the armamentarium of the esthetic surgeon. Juvenile palpebral lipoptosis without skin excess constitutes the best indication for this technique. It is also indicated in secondary blepharoplasty and in patients presenting with a cicatricial risk or with orbital septum distention.

Effects of a progestogen on normal human breast epithelial cell apoptosis in vitro and in vivo

Many investigators have reported cyclic proliferation of normal human breast epithelial cells. A delicate balance between proliferation and apoptosis (programmed cell death) ensures breast homeostasis. Both the follicular and luteal phases of the menstrual cycle are characterized by proliferation, whereas apoptosis occurs only at the end of the latter phase. In this study, we observed that the withdrawal of a synthetic progestin (nomegestrol acetate or NOMAC), but not continuous treatment with it, induced apoptosis of normal human breast epithelial cells in vitro and in women who applied NOMAC gel to their breasts. Furthermore, this apoptotic response was specific to normal breast cells, since withdrawal of NOMAC did not induce apoptosis of tumoral T47D cells in vitro or of fibroadenoma cells in women. These observations open up new perspectives in the prevention of hyperplasia and breast cancer.

[Choanal atresia: therapeutic management and results]

OBJECTIVES

To assess and compare long term results after surgical correction (transnasal or transplatine approaches) of unilateral or bilateral choanal atresia, in children with or without associated anomalies.

PATIENTS

During a 13-year period, 58 children were included in this retrospective study. Seventy-five choanas were operated on (41 unilateral and 17 bilateral). The transpalatine approach was performed in 41 children (56 choanas) while the transnasal approach was performed in 17 patients (19 choanas). Associated anomalies were reported in 28 children and corresponded to CHARGE association in 13 cases.

RESULTS

With a mean follow-up of 7 years, perfect choanal permeability was reported in 90% of children operated on through a transpalatine approach and in 76% of children with a transnasal approach. A complementary therapeutic procedure was required in 54% of transpalatine approaches and 46% of transnasal approaches to yield these results. Postoperative choanal permeability was obtained in 93% of children without an associated anomaly and in 77% of those with associated anomalies, such as in 88% of unilateral atresias and 80% of bilateral ones.

CONCLUSION

Initial success rate after surgery is similar for all surgical procedure insofar as nearly half choanas required a complementary therapeutic procedure. The endonasal procedure using the microdebrider appears hopeful and the KTP laser is interesting in fibrous residual stenosis. Associated anomalies are factors which lower general prognosis while inducing a higher surgical failure rate.

[Multifactorial analysis of preoperative functional symptoms in nasal polyposis (report of 403 patients)]

PURPOSE

Nasal polyposis is an invading disease whose evolution is dominated by functional symptoms. The aim of this study was to evaluate in cortico-resistant patients with nasal polyps the pre-operative functional symptoms in order to define factors that might increase them.

METHODS

403 patients were included in this study. All of them met the inclusion criteria of follow-up and initial examination. Anosmia, pain, nasal obstruction, rhinorrhea and sneezing were evaluated by patients themselves. Radiological data, respiratory function test results and histological data were matched.

RESULTS

In our series, functional symptoms were dominated by anosmia, nasal obstruction and rhinorrhea. Pain and sneezing appeared to be less frequent. Analysis of co-variables allowed us to define factors which increased pre-operative functional symptoms. Some of them are well known (such as Fernand-Widal triad or stage 3 nasal polyposis), while others appear new or surprising. The same is true for frontal sinus involvement on CT-scan and glandular hyperplasia on histological study.

CONCLUSION

Analysis of the complete clinical, radiological and histological picture has allowed us to emphasise the importance of certain factors on the functional symptoms of 403 patients with polyps of the nose and sinuses, resistant to steroid treatment. The same is true for Widal's disease, for a higher endoscopic grading, for frontal sinus involvement, and for histological evidence of glandular hyperplasia.

[Recurrences of pleomorphic adenomas of the parotid: changing attitudes]

OBJECTIVE

The real issue of parotid surgery for pleomorphic adenoma is its risk of recurrence. The aim of this study was to compare the changing attitudes towards the pathology and surgical treatment in order to better define prevention and management of pleomorphic adenoma recurrences.

MATERIAL AND METHOD

Histological study was performed after reviewing of slides originating from 100 patients with pleomorphic adenomas of the parotid gland, treated in our institution during the period May 1992 - November 2002. Study of the diagnostic value of fine needle cytology aspiration and MRI for pleomorphic adenoma diagnosis was performed for 181 patients operated on for parotid tumors.

RESULTS

Hypocellular pleomorphic adenomas often have a thin capsule and constitute the most frequently encountered subtypes of recurrence. Pseudopodia are considered as an additional risk of recurrence. In our series, cytological study gave excellent diagnostic value with a sensitivity of 92% and a PPV of 96%. MRI study had a sensitivity of 83% and a PPV of 89%.

CONCLUSIONS

According to these findings, enucleation surgery on a pleomorphic adenoma should not be performed any more. Parotidectomy techniques (total or superficial) constitute the surgical treatment of choice. The management of recurrences is based on surgery, with total parotidectomy and facial nerve preservation. The rôle of radiotherapy is still indeterminate.

[Choanal atresia: therapeutic management and results in a series of 58 children]

INTRODUCTION

An error of table being slipped during the publication of this article in number 1 (2003), the Review republishes it in entirety for a better comprehension. The preceding reference must be replaced by this one: Rev Laryngol Otol Rhinol 2003;124,3:139-143.

OBJECTIVES

To assess and compare long term results after surgical correction (transnasal or transpalatine approaches) of unilateral or bilateral choanal atresia, in children with or without associated anomalies.

PATIENTS

During a 13-year period, 58 children were included in this retrospective study. Seventy-five choanas were operated on (41 unilateral and 17 bilateral). The transpalatine approach was performed in 41 children (56 choanas) while the transnasal approach was performed in 17 patients (19 choanas). Associated anomalies were reported in 28 children and corresponded to CHARGE association in 13 cases.

RESULTS

With a mean follow-up of 7 years, perfect choanal permeability was reported in 90% of children operated on through a transpalatine approach and in 76% of children with a transnasal approach. A complementary therapeutic procedure was required in 54% of transpalatine approaches and 46% of transnasal approaches to yield these results. Postoperative choanal permeability was obtained in 93% of children without an associated anomaly and in 77% of those with associated anomalies, such as in 88% of unilateral atresias and 80% of bilateral ones.

CONCLUSION

Initial success rate after surgery is similar for all surgical procedure insofar as nearly half choanas required a complementary therapeutic procedure. The endonasal procedure using the microdebrider appears hopeful and the KTP laser is interesting in fibrous residual stenosis. Associated anomalies are factors which lower general prognosis while inducing a higher surgical failure rate.

Carbazolequinone induction of caspase-dependent cell death in Src-overexpressing cells

We previously reported that RSV-transformed quail neuroretina cells (QNR-ts68) were highly resistant to apoptosis provoked by serum withdrawal, and that this property was due to v-Src kinase activity. The present study investigates the cytotoxic effect and the functional mechanism of carbazolequinone-mediated cell death in this system. QNR-ts68 cells were subjected to carbazolequinone treatment and both growth inhibition and cell death induction were examined using formazan assays. Cell death mechanism (both apoptosis and necrosis) was confirmed through phosphatidyl serine exposure and propidium iodide incorporation. Furthermore, the effect of active carbazolequinone was inhibited by a pan caspase inhibitor. Cytofluorimetric and immunofluorescence data demonstrated the activation of caspase-3 and the involvement of mitochondria. Therefore, this study clearly indicates that carbazolequinones could induce cell death in transformed cells displaying high levels of antiapoptotic tyrosine kinase activity. Further investigations would be necessary to elucidate the mechanisms by which these carbazolequinones act as antitumor agents.

[Pleomorphic adenoma of the nasal cavity: a case arising from the wall of the maxillary sinus]

INTRODUCTION

Pleomorphic adenoma is a common and benign tumour, originating from sero-mucous glands. Location in the nasal cavity and particularly on the medial wall of the maxillary sinus is very rare.

PATIENTS AND METHODS

One patient with a pleomorphic adenoma of the nasal cavity and a review of literature are reported in order to describe the diagnostic and therapeutic management of this tumour.

RESULTS

A 63-year-old woman was referred to our institution for evaluation of an unilateral nasal tumour. Clinical and radiological studies revealed an intra-nasal tumour, slightly lytic in nature, arising from the mucosa of the medial wall of the maxillary sinus. More than 2 years after complete excision of the tumour using an endoscopic procedure, the nasal cavity was free of tumour.

DISCUSSION

Pleomorphic adenoma of the nasal cavity is a rare and benign tumour, usually presenting as a unilateral nasal tumour. Prognosis of this tumour is mainly linked to recurrences in cases of incomplete resection and to possible metastasis, such as an eventual malignant evolution. The gold standard treatment is complete surgical resection. After a complete imaging study for patient selection (CT scan and MRI), endonasal endoscopic surgery seems to be a reliable therapeutic treatment.

CONCLUSION

Intra-nasal pleomorphic adenoma originates from nasal seromucous glands. Radiological study reveals a slightly lytic tumour developed from the septum of the medial wall of the maxillary sinus. Resecton can be performed with endoscopic endonasal surgery as long as the orbital bony framework and the ethmoidal roof are free of tumour. Whatever technique is employed, long term follow-up has to be used to detect any recurrence.

Cross-tolerance to otherwise lethal N-methyl-D-aspartate and oxygen-glucose deprivation in preconditioned cortical cultures

In vitro ischemic preconditioning induced by subjecting rat cortical cultures to nonlethal oxygen-glucose deprivation protects against a subsequent exposure to otherwise lethal oxygen-glucose deprivation. We provide evidence that attenuation of the postsynaptic N-methyl-D-aspartate (NMDA) receptor- and Ca(2+)-dependent neurotoxicity underlies oxygen-glucose deprivation tolerance. It is demonstrated that extended tolerance to otherwise lethal NMDA or oxygen-glucose deprivation can be induced by either of their sublethal forms of preconditioning. These four pathways are linked, since NMDA receptor blockade during preconditioning by oxygen-glucose deprivation eliminates tolerance. These results suggest that NMDA tolerance, induced by nonlethal activation of these receptors during oxygen-glucose deprivation preconditioning, underlies oxygen-glucose deprivation tolerance. Several neurotoxic downstream Ca(2+)-dependent signaling events specifically linked to NMDA receptor activation are attenuated during otherwise lethal oxygen-glucose deprivation in preconditioned cultures. Specifically, calpain activation, as well as degradation of microtubule-associated protein-2 and postsynaptic density-95, are attenuated 2 h following otherwise lethal NMDA treatment alone or oxygen-glucose deprivation in preconditioned cultures. Formation of microtubule-associated protein-2-labeled dendritic varicosities is also attenuated in preconditioned cultures within 1 h of lethal oxygen-glucose deprivation or NMDA application. Intracellular Ca(2+) levels, measured using the high- or low-affinity dyes Fluo-4 (K(d) approximately equal 345 nM) or Fluo-4FF (K(d) approximately equal 9.7 microM) respectively, are markedly attenuated during lethal oxygen-glucose deprivation in preconditioned cultures.Collectively, the results suggest the attenuation of the postsynaptic NMDA-mediated component of otherwise lethal oxygen-glucose deprivation through the suppression of Ca(2+)-dependent neurotoxic signaling, a mechanism that is initially induced by transient nonlethal activation of this receptor during ischemic preconditioning.

TheS. pombeaurora-related kinase Ark1 associates with mitotic structures in a stage dependent manner and is required for chromosome segregation

Metazoans contain three aurora-related kinases. Aurora A is required for spindle formation while aurora B is required for chromosome condensation and cytokinesis. Less is known about the function of aurora C. S. pombe contains a single aurora-related kinase, Ark1. Although Ark1 protein levels remained constant as cells progressed through the mitotic cell cycle, its distribution altered during mitosis and meiosis. Throughout G2 Ark1 was concentrated in one to three nuclear foci that were not associated with the spindle pole body/centromere complex. Following commitment to mitosis Ark1 associated with chromatin and was particularly concentrated at several sites including kinetochores/centromeres. Kinetochore/centromere association diminished during anaphase A, after which it was distributed along the spindle. The protein became restricted to a small central zone that transiently enlarged as the spindle extended. As in many other systems mitotic fission yeast cells exhibit a much greater degree of phosphorylation of serine 10 of histone H3 than interphase cells. A number of studies have linked this modification with chromosome condensation. Ark1 immuno-precipitates phosphorylated serine 10 of histone H3 in vitro. This activity was highest in mitotic extracts. The absence of the histone H3 phospho-serine 10 epitope from mitotic cells in which the ark1+ gene had been deleted (ark1.Δ1); the inability of these cells to resolve their chromosomes during anaphase and the co-localisation of this phospho-epitope with Ark1 early in mitosis, all suggest that Ark1 phosphorylates serine 10 of histone H3 in vivo. ark1.Δ1 cells also exhibited a reduction in kinetochore activity and a minor defect in spindle formation. Thus the enzyme activity, localisation and phenotype arising from our manipulations of this single fission yeast aurora kinase family member suggest that this single kinase is executing functions that are separately implemented by distinct aurora A and aurora B kinases in higher systems.

A 27-year follow-up of patients with borderline personality disorder

Sixty-four patients with borderline personality disorder (BPD) were followed up for a mean of 27 years. Outcome was assessed using the Diagnostic Interview for Borderlines, Revised (DIB-R); the Schedule for DSM-III-R Diagnosis (SCID); Global Assessment of Functioning (GAF); the Symptom Check List-90 (SCL-90); and the Social Adjustment Scale (SAS-SR). Most patients showed significant improvement as compared to a previous 15-year follow-up, with only five currently meeting criteria for BPD. Mean GAF score was 63.3, mean SCL-90 raw score was 0.7, and mean SAS-SR score was 2.0. Fourteen subjects met SCID criteria for dysthymia, and this subgroup had a significantly poorer outcome on all measures. The total percentage of suicides from the original cohort has reached 10.3%, with 18.2% of all patients now deceased.

[Should the lingual nerve be protected during germectomy? A prospective study apropos of 300 procedures]

PURPOSE

Lingual nerve damage is one of the main complications of mandibular third molar removal. In literature, the series published are heterogeneous so we have decided to study the importance of the lingual protection only during germectomies (wisdom teeth without root formation).

METHODS

We conducted a randomized prospective study in 300 germectomies, operated by the same skilled surgeon. These 300 third molar removals have been divided in two groups, one with lingual nerve protection and one without.

RESULTS

Lingual nerve injuries following germectomies, with or without lingual protection was 0%.

CONCLUSION

In germectomies, one can avoid lingual protection.

Hemangioma of the facial nerve

To discuss the interest of the etiologic diagnosis of a facial palsy.

STUDY DESIGN AND PATIENTS

Two cases of geniculate ganglion hemangioma with progressive facial palsy are reported.

RESULTS

Hemangioma of the facial nerve is a rare and benign vascular tumor that originates from the venous plexus surrounding the facial nerve. The most common locations are the internal auditory canal and the geniculate ganglion. Diagnosis of these small tumors is radiological with CT-scan and MRI studies. Surgical excision through a supra-petrosal approach is the gold standard treatment. Hemangiomas of the facial nerve and particularly those developed in the geniculate ganglion area constitute a rare but not inconsiderable facial palsy etiology. An acute diagnosis and an early excision are fundamental to preserve a satisfactory facial function.

Prognostic factors of sudden hearing loss in children

OBJECTIVE

Sudden hearing loss in children under 15 years old is rare and its pathophysiology remains unclear. The aim of this retrospective study was to define prognostic factors of sudden hearing loss in children under 15 years old.

METHODS

Among the patients referred to our institution during the period 1990-1999 for sudden hearing loss, 12 children were considered eligible for this study (mean age=9.5 years old). Patients were divided into three groups according to hearing recovery and seven putative prognostic factors were analyzed.

RESULTS

Total hearing recovery (group I: 90-100%) occurred in 28.5% of cases, partial hearing recovery (group II: 11-89%) occurred in 28.5% of cases and absence of recovery (group III: 0-10%) was reported in 43% of cases. Factors such as age, sex, and bilaterality of hearing loss were not correlated with hearing recovery.

CONCLUSIONS

Initial severe hearing loss, associated vertigo and 'downward' audiometric curve were three negative prognostic factors of hearing recovery. Tinnitus has only been reported in children with partial or total hearing recovery.

Diagnosis and treatment of juvenile nasopharyngeal angiofibroma

The aim of this retrospective study was to compare clinical and radiological findings and discuss optimal surgical approach in patients with juvenile nasopharyngeal angiofibroma (JNA). Forty-three cases of JNA were treated at our institution from 1975 to 1999. Thirty-three male patients aged between 8 and 25 years (mean 15.3) were included. Twenty-nine patients underwent primary surgical treatment at our institution and four were treated for recurrence following primary surgery elsewhere. Tumors were staged according to Fisch's staging. Preoperative embolization was performed in 22 cases. Surgical techniques consisted of the transantral approach, lateral rhinotomy approach, transmaxillary via midfacial degloving approach, and the subtemporal preauricular infratemporal fossa approach. Tumors were classified stage I in seven cases, stage II in 11, stage III in 13 and stage IV in two. The mean delay between the initial symptom and surgery was 14 months overall, 18 months for stage I, 14 for stage II, 13 for stage III and 12 for stage IV. The transantral approach was used in 11 patients, lateral rhinotomy approach in 11 cases, transmaxillary via midfacial degloving approach in three patients, and pre-auricular infra-temporal approach in eight patients. Mean follow-up after surgery was 56 months. Six patients had recurrent tumors. Surgery is the gold standard for treatment of JNA. Modern imaging techniques allow accurate diagnosis and staging of JNA. Our experience and a review of the literature shows that the surgical approach should be selected according to tumor stage.

Management and aesthetic results of support grafts in saddle nose surgery

To define the surgical management and long-term aesthetic results of patients undergoing rhinoplasty with support graft for saddle nose, 147 patients have been included in this retrospective study. One hundred forty-four autogenous grafts (bone or cartilage) and three processed irradiated bovine cartilage grafts have been used during the period 1980-1997. Two approaches have been employed: open rhinoplasty and endonasal approach. Most of cases have been treated with bony grafts (116 bone graft versus 26 cartilage grafts). Global follow-up after surgery for long-term aesthetic study was 8.5 years. Among the different autogenous that have been used in our series, the calvarial bone had the most interesting results in terms of resorption. In patients with important saddle nose deformity, we recommend calvarial bone as a material of choice for dorsonasal reconstruction. It provides excellent and natural long-term feel to the nasal complex.

Association of serotonin and cortisol indices with childhood abuse in bulimia nervosa

BACKGROUND

Bulimia nervosa (BN) is reported to co-occur with childhood abuse and alterations in central serotonin (5-hydroxytryptamine [5-HT]) and cortisol mechanisms. However, findings also link childhood abuse to anomalous 5-HT and cortisol function, and this motivated us to explore relationships between childhood abuse and neurobiological variations in BN.

METHODS

Thirty-five bulimic and 25 nonbulimic women were assessed for childhood physical and sexual abuse, eating symptoms, and comorbid psychopathological tendencies. These women provided blood samples for measurement of platelet hydrogen-3-paroxetine binding and serial prolactin and cortisol responses following oral administration of the partial 5-HT agonist meta-chlorophenylpiperazine (m-CPP).

RESULTS

Bulimic women showed markedly lower mean +/- SD density (B(max)) of paroxetine-binding sites (631.12 +/- 341.58) than did normal eaters (1213.00 +/- 628.74) (t(54) = -4.47; P =.001). Paroxetine binding did not vary with childhood abuse. In contrast, measures of peak change on prolactin levels after m-CPP administration (Delta-peak prolactin) indicated blunted response in abused bulimic women (7.26 +/- 7.06), nonabused bulimic women (5.62 +/- 3.95), and abused women who were normal eaters (5.73 +/- 5.19) compared with nonabused women who were normal eaters (13.57 +/- 9.94) (F(3,51) = 3.04, P =.04). Furthermore, individuals reporting childhood abuse showed decreased plasma cortisol levels relative to nonabused women who were normal eaters.

CONCLUSION

Findings imply that BN and childhood abuse are both generally associated with reduced 5-HT tone but that childhood abuse may be somewhat more specifically linked to reduced cortisol levels (ie, hypothalamic-pituitary-adrenal axis) activity.

Synthesis and antiproliferative activity of [2-(phthaloylamino)alkyl]triphenyl phosphonium derivatives against K562 cell line

Given the reported cytotoxicity of phthaloylaminoethyltriphenylphosphonium bromide 2a in the P-388 cell line, we have developed new [2-(phthaloylamino)alkyl]phosphonium derivatives 2b-e and evaluated their cytotoxic activity. These compounds have been synthetized from N,N-phthaloylaminoalcohols and triphenylphosphonium hydrobromide via a one-pot reaction. 2a was found inactive in the K562 cell line, but 2c-e exhibited a cytotoxic activity with IC50 values about 1 microM.

Attenuation of neurotoxicity in cortical cultures and hippocampal slices from E2F1 knockout mice

The E2F1 transcription factor modulates neuronal apoptosis induced by staurosporine, DNA damage and beta-amyloid. We demonstrate E2F1 involvement in neuronal death induced by the more physiological oxygen-glucose deprivation (OGD) in mouse cortical cultures and by anoxia in mouse hippocampal slices. E2F1(+/+) and (-/-) cultures were comparable, in that they contained similar neuronal densities, responded with similar increases in intracellular calcium concentration ([Ca(2+)]i) to glutamate receptor agonists, and showed similar NMDA receptor subunit mRNA expression levels for NR1, NR2A and NR2B. Despite these similarities, E2F1(-/-) cultures were significantly less susceptible to neuronal death than E2F1(+/+) cultures 24 and 48 h following 120-180 min of OGD. Furthermore, the absence of E2F1 significantly improved the ability of CA1 neurons in hippocampal slices to recover synaptic transmission following a transient anoxic insult in vitro. These results, along with our finding that E2F1 mRNA levels are significantly increased following OGD, support a role for E2F1 in the modulation of OGD- and anoxia-induced neuronal death. These findings are consistent with studies showing that overexpression of E2F1 in postmitotic neurons causes neuronal degeneration and the absence of E2F1 decreases infarct volume following cerebral ischemia.