Control of meiotic crossover interference by a proteolytic chaperone network

Meiosis is a specialized eukaryotic division that produces genetically diverse gametes for sexual reproduction. During meiosis, homologous chromosomes pair and undergo reciprocal exchanges, called crossovers, which recombine genetic variation. Meiotic crossovers are stringently controlled with at least one obligate exchange forming per chromosome pair, while closely spaced crossovers are inhibited by interference. In Arabidopsis, crossover positions can be explained by a diffusion-mediated coarsening model, in which large, approximately evenly spaced foci of the pro-crossover E3 ligase HEI10 grow at the expense of smaller, closely spaced clusters. However, the mechanisms that control HEI10 dynamics during meiosis remain unclear. Here, through a forward genetic screen in Arabidopsis, we identified high crossover rate3 (hcr3), a dominant-negative mutant that reduces crossover interference and increases crossovers genome-wide. HCR3 encodes J3, a co-chaperone related to HSP40, which acts to target protein aggregates and biomolecular condensates to the disassembly chaperone HSP70, thereby promoting proteasomal degradation. Consistently, we show that a network of HCR3 and HSP70 chaperones facilitates proteolysis of HEI10, thereby regulating interference and the recombination landscape. These results reveal a new role for the HSP40/J3-HSP70 chaperones in regulating chromosome-wide dynamics of recombination via control of HEI10 proteolysis.

SCEP1 and SCEP2 are two new components of the synaptonemal complex central element

The synaptonemal complex (SC) is a proteinaceous structure that forms between homologous chromosomes during meiosis prophase. The SC is widely conserved across species, but its structure and roles during meiotic recombination are still debated. While the SC central region is made up of transverse filaments and central element proteins in mammals and fungi, few central element proteins have been identified in other species. Here we report the identification of two coiled-coil proteins, SCEP1 and SCEP2, that form a complex and localize at the centre of the Arabidopsis thaliana SC. In scep1 and scep2 mutants, chromosomes are aligned but not synapsed (the ZYP1 transverse filament protein is not loaded), crossovers are increased compared with the wild type, interference is lost and heterochiasmy is strongly reduced. We thus report the identification of two plant SC central elements, and homologues of these are found in all major angiosperm clades.

Combining immunotherapy with an epidrug in squamous cell carcinomas of different locations: rationale and design of the PEVO basket trial

Squamous cell carcinomas (SCCs) are among the most frequent solid tumors in humans. SCCs, related or not to the human papillomavirus, share common molecular features. Immunotherapies, and specifically immune checkpoint inhibitors, have been shown to improve overall survival in multiple cancer types, including SCCs. However, only a minority of patients experience a durable response with immunotherapy. Epigenetic modulation plays a major role in escaping tumor immunosurveillance and confers resistance to immune checkpoint inhibitors. Preclinical evidence suggests that modulating the epigenome might improve the efficacy of immunotherapy. We herein review the preclinical and the clinical rationale for combining immunotherapy with an epidrug, and detail the design of PEVOsq, a basket clinical trial combining pembrolizumab with vorinostat, a histone deacetylase inhibitor, in patients with SCCs of different locations. Sequential blood and tumor sampling will be collected in order to identify predictive and pharmacodynamics biomarkers of efficacy of the combination. We also present how clinical and biological data will be managed with the aim to enable the development of a prospective integrative platform to allow secure and controlled access to the project data as well as further exploitations.

Photochromic–fluorescent–plasmonic nanomaterials: towards integrated three-component photoactive hybrid nanosystems

Silica-coated gold nanorods functionalized with grafted fluorescent and photochromic derivatives were synthesized and cross-coupled interactions between plasmonic, photochromic, and fluorescence properties have been demonstrated.

Agri-environmental thresholds using Mehlich III soil phosphorus saturation index for vegetables in histosols

The P concentration in Norton Creek which drains cultivated Histosols in Quebec showed median concentration exceeding up to 14 times the environmental guideline of 0.03 mg total P L(-1). The aim of this study was to develop environmental and agronomic thresholds using soil tests to provide a tool for P management in Histosols. Soil samples were collected from Histosols across Quebec (82) and in fertilizer trials (66) to calibrate soil test methods against the degree of P saturation (DPS(OX)) using the acid-oxalate method and setting alpha(m) = 0.4, and the water-extractable P (P(W)) (Sissingh, 1971). The field trials on crop response to added P were conducted with carrots (8), potatoes (11), onions (10), Chinese cabbage (7), celery (10), and lettuce (20). Relative yields were computed as yield in control without P divided by highest yield with added P. The Mehlich III (M-III) P extraction was more closely related (r(2) = 0.73) to DPS(OX) than the Bray 1 method (r(2) = 0.62) and the Florida extraction method (r(2) = 0.53). The [P/(Al+gammaFe)](M-III) ratio as index of P saturation (IPS(M-III)) was the most closely related to DPS(OX) (r(2) = 0.88) setting gamma = 5. The critical [P/(Al+5Fe)](M-III) ratio of 0.05 at DPS(OX) = 0.25 and P(W) = 9.7 mg P L(-1) was validated by an independent study from North Carolina. The soil group (low- vs. high-IPS(M-III) soils) significantly influenced crop response to added P. Critical agronomic IPS(M-III) values were found between 0.10 and 0.15. Those environmental and agronomic benchmarks are instrumental for managing the P in vegetable-grown Histosols.

Sacral neuromodulation in lower urinary tract dysfunction

Vesico-urethral dysfunction is a major problem in daily medical practice due to its psychological disturbances, its social costs and its high impact on quality of life. Recently, sacral neuromodulation, namely the electrical stimulation of the sacral nerves, appears to have become an alternative for radical bladder surgery particularly in cases of idiopathic bladder overactivity. The mechanism of action is only partially understood but it seems to involve a modulation in the spinal cord due to stimulation of inhibitory interneurons. Temporary sacral nerve stimulation is the first step. It comprises the temporary application of neuromodulation as a diagnostic test to determine the best location for the implant and to control the integrity of the sacral root. If test stimulation is successful, a permanent device is implanted. This procedure is safe in experienced hands. So-called idiopathic bladder overactivity still the major indication for this technique. Patients not likely to benefit from the procedure were those with complete or almost complete spinal lesions, but incomplete spinal lesions seemed to be a potential indication. This technique is now also indicated in the case of idiopathic chronic retention and chronic pelvic pain syndrome. When selection is performed, more than three-quarters of the patients showed a clinically significant response with 50% or more reduction in the frequency of incontinent episodes, but the results vary according to the author's mode of evaluation. From the economic point of view, the initial investment in the device is amortized in the mid-term by savings related to lower urinary tract dysfunction. Finally, this technique requires an attentive follow-up and adjustments to the electric parameters so as to optimize the equilibrium between the neurological systems.

Interferometric Coupling of the Keck Telescopes with Single-Mode Fibers

Here we report successful interferometric coupling of two large telescopes with single-mode fibers. Interference fringes were obtained in the 2- to 2.3-micrometer wavelength range on the star 107 Herculis by using the two Keck 10-meter telescopes, each feeding their common interferometric focus with 300 meters of single-mode fibers. This experiment demonstrates the potential of fibers for future kilometric arrays of telescopes and is the first step toward the 'OHANA (Optical Hawaiian Array for Nanoradian Astronomy) interferometer at the Mauna Kea observatory in Hawaii. It opens the way to sensitive optical imagers with resolutions below 1 milli-arc second. Our experimental setup can be directly extended to large telescopes separated by many hundreds of meters.

[Delayed facial palsy after vestibular schwannoma resection: the role of viral reactivation. Our experience in 8 cases]

OBJECTIVE

To study the role of herpes virus reactivation in the onset of more than three days-delayed facial paralysis (FP) following vestibular schwannoma (VS) surgery and advocate a specific medical management.

MATERIAL AND METHODS

Retrospective study on 8 cases from a series of 348 patients operated on of a VS between 1996 and 2002. Seven of the eight patients were given intravenously acyclovir (30 mg x kg(-1) x d(-1) for 5 days) and methyl-prednisolone (2 mg x kg(-1) x d(-1) for 7 days). A serologic testing looking for specific anti-herpes simplex viruses type 1 and 2 (HSV-2) and varicella-zoster virus (VZV) antibodies at the onset of the FP and 2 weeks later could be done in only 3 cases.

RESULTS

Mean delay of FP onset was 8.75 days. Mean time for recovery with intravenous treatment was 90 days. All treated patients had a House and Brackmann grade 1 recovery. The last one had only a grade 3 after 400 days of evolution: he could not be treated because of postoperative transient psychiatric problems. Serologic testing revealed in those patients in whom it could be done either a high level of anti-HSV or -VZV antibodies at the time of onset or a dramatic increase in anti-HSV or anti-VZV antibodies between the two samples, strongly suggesting a HSV or VZV reactivation.

CONCLUSION

HSV or VZV reactivation can be evocated in most cases of delayed FPs arising in the postoperative course of VSs, suggesting usefulness of emergency-given steroid and acyclovir intravenous regimen to block virus replication and fight secondary oedema and inflammation causative of nerve lesions. Evoked reactivation mechanism is comparable to that already suspected in delayed FP arising with the same delay in middle ear surgical procedures.

[Acoustic neuroma surgery. Results and complications in 348 cases]

OBJECTIVES

The aim of this study was to evaluate post-operative complications after acoustic neuroma surgery.

METHODS

This was a retrospective study of 348 patients, who had acoustic neuroma surgery between 1984 and 1999. Symptoms, pre-operative evaluation, surgery and post-operative complications were analysed.

RESULTS

174 men and 174 women had an operation. Mean age was 51.8 years (11-78). 31 patients had a grade I tumour, 106 a grade II, 71 a grade III and 140 had a grade IV tumour. 195 patients have been operated through the translabyrinthine approach, 110 through the retrolabyrinthine approach, 42 through the sub-occipital approach, and one through the transcochlear approach. Mortality was 0.85%, 59.2% patients had a post-operative facial paralysis. Most of patients had post-operative dizziness, and 30% still had vestibular disturbances after one year. 9 patients (2.6%) had a cerebrospinal rhinorrhea and 24 patients had a cerebrospinal wound leak (6.9%). 22 patients had post-operative meningitis (6.3%). 2 patients had a cerebello pontine angle haemorrhage, and 3 patients had a brain stem infarct.

CONCLUSION

Transpetrous approaches are safe for acoustic neuroma removal and the post-operative complication rate is low. The retrolabyrinthine approach seems to be a good hearing preservative approach, regardless of tumour volume.

[Neurosurgical and endovascular treatment of intracranial aneurysms: a cost analysis of two different strategies at the University Hospital of Bordeaux (France)]

BACKGROUND

Rupture of intracranial aneurysms causes major mortality and morbidity. Moreover, treatment of this vascular malformation generates high medical costs. We compared the cost of two different strategies employed at the University of Bordeaux to prevent aneurysms from rebleeding: a classical neurosurgical technique consisting in clipping the neck of the aneurysm and a new less invasive neuroradiological technique based on embolization using platinum coils.

METHOD

A micro-cost study was carried out retrospectively from May 1998 to June 2000) comparing data from 44 patients admitted for ruptured intracranial aneurysm: 22 operated patients and 22 patients treated with an endovascular approach. Each operated patient was matched with an embolized patient for clinical status at admission (World Federation of Neurological Surgeons Scale) and complications resulting from cerebral hemorrhage (hydrocephalus, vasospasm, rebleeding).

RESULTS AND CONCLUSION

Our results showed the same cost for the same efficiency . Expenditures are however made differently. The endovascular technique allows a shorter hospital stay (8 days less), balancing the high cost of single use medical supplies (coils, microcatheters.). The endovascular technique has many advantages for the patients, but cannot be successful in all types of intracranial aneurysms. Both techniques remain indispensable.

In vitro study of the effect of titanium on porphyromonas gingivalis in the presence of metronidazole and spiramycin

Septic peri-implantitis is the main clinical complication encountered following the insertion of titanium implants. It may be resistant to conventional antibiotic treatments. Reports in the literature about antibiotic behavior in the presence of titanium remain controversial. They vary from a bacteriostat to a decreased effect of antibiotic. This study examined, in vitro, the viability of Porphyromonas gingivalis, frequently associated with periodontal diseases, in the presence of titanium and antibiotics (spiramycin and metronidazole alone or in combination). Viability of P. gingivalis was determined, versus a standard curve using the Live/dead Baclight Bacteria Viability Kit on 96 well microplates. The results of 48 experiments (60 measurements each) were compiled in a database and compared to each other using the chi2p < 0.05 test. When used alone, titanium enhanced bacterial growth as the nickel-chrome control. However, when titanium was used in the presence of antibiotics, antibiotics kept their own effects. Even more, titanium was shown to potentialize the effect of metronidazole. The strengthening of effectiveness of metronidazole by titanium may be due to the oxidation potential of the metal. This chemical property could explain the conflicting data reported in the literature.

[Fractionated radiation therapy long-term effectiveness in the treatment of cerebello-pontine angle schwannomas: 12 years of experience in 30 cases]

The purpose of this research was to evaluate long-term results of fractionated radiation therapy (RT) in the treatment of cerebello-pontine angle schwannomas.

METHODS

from January 1986 to October 1995, 29 patients with stage III and IV scwhannomas were treated with external fractionated RT. One patient was irradiated on both sides and indication for RT was as follows: a) poor general condition or old age contraindicating surgery, 16 cases; b) hearing preservation in bilateral tumors after contralateral tumor removal, 6 cases; c) partial resection or high risk of recurrence after subsequent surgery for relapse, 5 cases; d) non surgical relapse, 3 cases. Most patients were irradiated with 6 to 10 MV photons. A three- to four-field technique with coplanar static beams and conformal blocks was used. Doses were calculated on a 95 % isodose and were given 5 days a week for a mean total dose of 51 Gy (1.8 Gy/fraction).

RESULTS

Median follow-up from RT was 66 months (7 to 120); seven patients died, two with progressive disease, five from non tumoral cause. Two patients underwent total removal after RT (1 stable and 1 growing tumor). On the whole, tumor shrinkage was observed in 13 patients (43.3 %), stable disease in 14 (46.6 %), and tumor progression in three. Hearing was preserved in 4 out of 6 hearing patients (1 class A hearing, 2 class B and 1 class C). No patient experienced CN5 or CN7 neuropathy.

CONCLUSION

long-term efficacy or fractionated RT is well documented in this series. Acute and delayed tolerance was excellent. Hearing can be preserved for a long time.

Cognitive behavior therapy versus supportive therapy in social phobia: a randomized controlled trial

BACKGROUND

The efficacy of cognitive behaviour therapy (CBT) in social phobia has been demonstrated in several controlled trials and meta-analyses, but no comparison of CBT with supportive therapy (ST) can be found in the literature.

METHOD

The aim of the trial was to study the effectiveness of CBT versus ST carried out 'as usual'. Sixty-seven DSM-4 social phobic patients (89% generalized subtype, most with avoidant personality) were randomly allocated into two groups. Group 1 (CBT) received 8 1-hour sessions of individual cognitive therapy (CT) for 6 weeks, followed by 6 2-hour sessions of social skills training (SST) in group weekly. Group 2 received ST for 12 weeks (6 half-hour sessions), then the patients were switched to CBT. All patients agreed not to take any medication during the whole trial. In group 1, 29 patients reached week 6, 27 reached week 12, and 24 weeks 36 and 60 (endpoint). In group 2, 29 patients reached week 6, 28 reached weeks 12 and 18, 26 week 24, and 23 reached weeks 48 and 72 (endpoint).

RESULTS

At week 6, after CT, group 1 was better than group 2 on the main social phobia measure. At week 12, after SST, group 1 was better than group 2 on most of the measures and demonstrated a significantly higher rate of responders. This finding was replicated after switching group 2 to CBT. Sustained improvement was observed in both groups at follow-up. Compliance with abstinence from medication increased over time.

CONCLUSIONS

CBT was more effective than ST and demonstrated long-lasting effects. This may suggest that social phobia management requires more than a simple and inexpensive psychological intervention.

Psychometric appraisal of the Scale for Interpersonal Behavior (SIB) in France

The present study was carried out in France to evaluate the reliability and validity of the Scale for Interpersonal Behavior (SIB), a multidimensional measure of difficulty and distress in assertiveness that was originally developed in The Netherlands. This appraisal was conducted with a clinical sample (N = 166) and a general population sample (N = 150). The clinical series comprised 115 patients with social phobia and 51 patients with personality disorder, 28 of whom were of the avoidant type. Support was found for internal consistency and test-retest reliability of the French SIB. Compared to controls, both social phobics and patients with an avoidant personality disorder had significantly lower mean scores on all performance scales and significantly higher ones on all distress scales, with the social phobics occupying a position in between. Findings in relation to convergent and divergent validity were quite satisfactory. Sensitivity of the French SIB for detecting change was demonstrated in a subgroup of the clinical Ss who had undergone 15 sessions of cognitive-behavioral group therapy for underassertiveness.

[Fractionated radiotherapy of intracranial meningiomas: 15 years' experience at the Bordeaux University Hospital Center]

PURPOSE

To evaluate the long-term results of external fractionated radiation therapy (RT) in the treatment of intracranial meningiomas.

PATIENTS AND METHODS

From January 1981 to December 1996, 156 patients with intracranial meningiomas were treated with external fractionated RT. Median age was 57. Indications for radiation therapy were as follows: (1) completely excised histologically aggressive tumors (12 patients); (2) incomplete surgical resection (37 patients); (3) medically inoperable or basilar tumors where operation would involve considerable danger or permanent neurological damage (77 patients); and, (4) tumor recurrences (30 patients). Most patients were irradiated with 6 to 9 MV photon beams. A three to four-field technique with coned-down portals was used. Since 1993, 71 patients had a three dimensional dosimetry. Doses were calculated on the 95% or 98% isodoses, all fields were treated every day, five days a week, for a median total dose of 50 Gy (1.8 Gy/Fraction).

RESULTS

Median follow-up from radiation therapy was 40 months. Acute tolerance was excellent; an early clinical improvement during radiation therapy was noted in 19 patients (17.8%). Clinical improvement or stabilization was observed in 130 patients (83.4%). Radiologically, local control was obtained in 124 cases (79.4%) and tumor recurrences occurred in 21 cases (ten progressions in the treated volume, five borderline, six new locations). Overall and cause specific-survival rates were 75% and 89% at five years, and 45 and 76% at 10 years, respectively.

CONCLUSION

These results reassess the role of fractionated RT in the treatment of intracranial meningiomas. Long-term tolerance is excellent for a majority of patients. The study of recurrences confirms the importance of the definition of the target volume, and asks questions about total given doses.

[Central nervous system. Experience of the Bordeaux University Hospital Center and review of the literature]

PURPOSE

Retrospective analysis of 17 patients with intracranial germ cell tumors treated in a multidisciplinary consultation at the Bordeaux University Hospital a and literature review.

MATERIALS AND METHODS

Seventeen consecutive patients were treated from 1978 to 1995 for a primary intracranial germ cell tumor. Median age was 14 (range 3-29 years). There were two malignant teratoma, six proved germinoma and nine presumed germinoma (diagnostic based on biological, radiological and treatment criteria). All received radiotherapy from 30 to 60 Gy (median 40 Gy) in different volumes. Chemotherapy was administered in 15 cases, three after surgery and 12 after radiotherapy.

RESULTS

All tumours were in complete remission after initial treatment. The two malignant teratomas recurred in non-irradiated area after nine and 48 months, and the patients died. None of the germinoma recurred within a follow-up period of two to 17 years (median 65 months). Five and 10 year actuarial overall survival rates were the same: 84% for all histologies and 100% for germinomas. Only two patients developed school difficulties and six presented an hypopituitarism, of which one was consecutive to radiotherapy. Chemotherapy was well tolerated.

CONCLUSION

This retrospective study and literature analysis are in favor of limited dose and volume of radiation therapy associated with chemotherapy.

[Fractionated irradiation of cerebellopontine angle neurinoma: 12 years' experience of the Bordeaux University Hospital Center]

PURPOSE

To evaluate retrospectively the long-term results of fractionated radiation therapy (RT) in cerebello-pontine angle neurinomas (CPA).

METHODS AND MATERIAL

From January 1986 to October 1995, 29 patients with stage III and IV neurinomas were treated with external fractionated RT. One patient was irradiated on both sides and indications for RT were as follows: (1) general contraindications for surgery (16 patients); (2) hearing preservation in bilateral neurinomas after controlateral tumor exeresis (six patients); (3) partial tumor removal (five patients); and, (4) non-surgical recurrence (three patients). A three to four fields technique with coplanar static beams and conformal cerobend blocks was used; doses were calculated on a 95 to 98% isodoses and were given five days a week for a median total dose of 51 Gy (1.8 Gy/fraction). Most patients were irradiated with 6 to 10 MV photons).

RESULTS

Median follow-up was 66 months (seven to 120 months). Seven patients died, two with progressive disease, five from non-tumoral causes. Tumor shrinkage was observed in 13 patients (43.3%), stable disease in 14 (46.6%), and tumor progression in three. Two patients underwent total tumor removal after RT (one stable and one growing tumor). Hearing was preserved in four out of six patients. No patient experienced facial or trigeminal neuropathy.

CONCLUSION

Fractionated RT is a well tolerated and efficacious treatment of large non-surgical CPA neurinomas.

Prognostic factors in pediatric spinal cord astrocytoma

BACKGROUND

Factors that could optimize the management of pediatric spinal cord astrocytoma remain unclear and controversial.

METHODS

To determine the factors that influence the prognosis of pediatric patients with spinal cord astrocytomas, a series of 73 consecutive patients at 13 French treatment centers with histologically proven spinal cord astrocytomas was retrospectively reviewed. Hospital records, operative records, and results of radiologic investigations were available in all cases. Follow-up was achieved in 94% of cases.

RESULTS

Seventy percent of the patients had low grade (1 or 2) tumors. Total or subtotal surgical resection was achieved in 43%. Thirty-six patients were irradiated following surgery. Fifty-one patients were alive at a median follow-up of 54 months. Twenty-three patients relapsed. Univariate analysis showed that good outcome was correlated with male gender, age younger than 7 years, duration of presenting symptoms longer than 2 months, the presence of spinal deformities, and low grade histology, whereas sensory loss was associated with decreased survival. Multivariate analysis using the Cox proportional hazards model confirmed that histology (relative risk [RR] = 7.69) and the interval between first symptoms and diagnosis (RR = 4.93) were significant independent prognostic factors. The extent of surgery or radiotherapy had no clear influence on survival.

CONCLUSIONS

This review sheds light on the prognoses of pediatric patients with spinal cord astrocytomas and may help to determine therapeutic strategies based on patients' clinical, radiologic, and pathologic features.

[Oculomotor paralysis and head trauma]

Few studies have dealt with post-trauma ocular motor palsy. We analyzed 31 personal cases and reviewed the literature, focusing on pathogenesis. We emphasize the importance of a complete radiological examination including magnetic resonance imaging when the CT-scan does not provide a satisfactory correlation between anatomic findings and clinical presentation. Systematic detection, early management and regular follow-up is mandatory.

Oral complications during treatment of malignant diseases in childhood: effects of tooth brushing

During anticancer treatment, oral lesions considerably aggravate the child's clinical condition and increase the risk of infection. This prospective study evaluated the incidence, nature and chronology of oral complications arising during the first 6 weeks of chemotherapy. 131 children were included in this study, and their oral and dental health evaluated on enrolment. Each child was observed once a week, for 6 weeks. Fifty-two per cent (68/131) of the children presented with at least one oral lesion. Two oral healthcare regimens (with or without tooth brushing) were evaluated. Tooth brushing significantly reduced the number of children affected. Standardised multicentre studies should permit the definition of oral care regimens which would eliminate pain and reduce the risk of infection in children hospitalised for cancer.

Suppression of heparinization of central venous catheters between cycles of chemotherapy. Results of a phase I study

A phase I study to evaluate heparinization of tunnelled subclavian catheters (TSC) was conducted in 42 patients who each had a TSC for chemotherapy. They were enrolled in the study from August 1994 to December 1995. The inclusion criteria were: age 18-70, no general anticoagulant treatment, TSC used only for chemotherapy, informed consent. Heparinization was performed at the end of each cycle and then at increasing intervals: 11, 13, 15, 17, 19, and 21 days. A 21-day interval was intended to mimic the suppression of heparinization between cycles. Heparinization was performed with a 250 IU/ml heparin solution. Anti-Xa activity was studied before each heparinization. For each interval, at least 5 patients were followed up for two cycles. If no blockages were present progression to the next step was authorized. If one blockage was observed 5 additional patients were required to have their TSCs heparinized after the same interval. Two blockages (block) after the same interval meant that the previous interval was recorded as the longest tolerable. There were no blocks with the 11-day interval (6 patients), 1 block after 13 days (10 patients), 1 block after 15 days (10 patients), and no blocks after 17 days (5 patients), 19 days (6 patients), or 21 days (5 patients). The median anti-Xa activity (curative rate 0.2-0.6) was, respectively 11 days 6.74; 13 days 5.47; 15 days 4.71; 17 days 3.61; 19 days 3.67; 21 days 5.10 (NS). Heparinization between two cycles of chemotherapy is unnecessary. A high level of heparin activity persisted constantly inside the catheter lumen through the 3-week observation period.

[Temporo-sphenoidal giant cell tumors, apropos of a case]

The authors report an extremely rare case: a bony giant cell tumour in the temporo-sphenoidal region presenting with hearing loss and vertigo. The main characteristics of these tumours are given, together with a literature review. This is the 5th published case of this tumour in the temporo-sphenoidal region. The treatment of these tumours is essentially surgical, and the authors emphasise the use of Sekhar's approach.

Psammomatous melanotic schwannoma of a spinal nerve root. Relationship with the Carney complex

A 36-year-old man had an oval, black, extradural tumor partly removed from the left C4 spinal root, with total removal 4 months later. In both specimens, most tumor cells were spindle-shaped. A few cells were large, epithelioid-like, with a prominent nucleolus. Mitoses were rarely seen. Many tumor cells contained coarse or fine granules of a brown pigment. Such cells were immunopositive for S-100 protein and HMB-45. Additionally, psammoma bodies were numerous in certain areas, indicating a diagnosis of psammomatous melanotic schwannoma (PMS). Periumbilical spotty pigmentation was found in the patient and in six of his siblings and their mother. The search for cardiac myxoma and endocrine overactivity was negative in the patient. Features of Carney's complex must be sought in a patient with PMS and in their primary relatives. So far, more than 150 patients and seven families with Carney's complex have been reported.

Use of a biodegradable elastin-fibrin material, Neuroplast, as a dural substitute

Since the new Neuroplast biomaterial is now commonly used in several domains of restorative and curative surgery, its preliminary evaluation as a dura mater substitute in the rabbit was performed and is described herein. Whereas the importance of prosthesis thickness was implicated and solved (0.2 rather than 1.0 mm), both macroscopic examination and histological studies revealed for the neotissue an effective patency, a good continuity and especially no or almost no adherence at all. As Neuroplast is now available for use everywhere in humans, this material is being developed in several fields of neurosurgery.

[Clinical presentation and prognosis of brain tumors]

The diagnosis of a cerebral tumor is received as dramatic by the patient or his family on account of the fonctional and symbolic idea of the brain and the perspectives of neurosurgical and psychological disabilities. Nowadays it is simplified because actual techniques of imagery are atraumatic and reliable. So the first signs are not to be undervaluated. Prognostic depends of identifiable factors. They lead the choice of therapy and help the medical doctor for the treatment follow-up and for answering to the patient's life questions.

Glial cell line-derived neurotrophic factor (GDNF) gene expression in the human brain: a post mortem in situ hybridization study with special reference to Parkinson's disease

Glial cell line-derived neurotrophic factor (GDNF) is a potent neurotrophic factor for dopaminergic neurons. Since dopaminergic neurons degenerate in Parkinson's disease, this factor is a potential therapeutical tool that may save dopaminergic neurons during the pathological process. Moreover, a reduced GDNF expression may be involved in the pathophysiology of the disease. In this study, we tested whether altered GDNF production may participate in the mechanism of cell death in this disease. GDNF gene expression was analyzed by in situ hybridization using riboprobes corresponding to a sequence of the exon 2 human GDNF gene. Experiments were performed on tissue sections of the mesencephalon and the striatum from 8 patients with Parkinson's disease and 6 control subjects matched for age at death and for post mortem delay. No labelling was observed in either group of patients. This absence of detectable expression could not be attributed to methodological problems as a positive staining was observed using the same probes for sections of astroglioma biopsies from human adults and for sections of a newborn infant brain obtained at post-mortem. These data suggest that GDNF is probably expressed at a very low level in the adult human brain and its involvement in the pathophysiology of Parkinson's disease remains to be demonstrated. GDNF may represent a powerful new therapeutic agent for Parkinson's disease, however.

Fractionated radiation therapy in the treatment of intracranial meningiomas: local control, functional efficacy, and tolerance in 91 patients

PURPOSE

To evaluate efficacy and tolerance of external fractionated radiation therapy (RT) in the treatment of intracranial meningiomas.

METHODS AND MATERIALS

From January 1981 to September 1993, 91 patients with intracranial meningiomas were treated with fractionated RT. Indications were as follows: (a) incomplete surgical resection, 29 patients; (b) tumor recurrences without considering the amount of the second resection, if performed, 14 patients; (c) completely excised angioblastic, aggressive benign, and anaplastic tumors, 8 patients; (d) medically inoperable and basilar tumors where operation would involve considerable danger or permanent neurological damage, 44 patients. Most patients were irradiated with 6 to 9 MV photon beams. A three- to four-field technique with coned-down portals was used. Doses were calculated on the 95% isodose and were given 5 days a week for a median total dose of 52 Gy (1.80 Gy/fraction).

RESULTS

Median follow-up from radiation therapy was 40 months. Acute tolerance was excellent, but there were six late delayed injuries. Tumor recurrences occurred in six cases. Six patients died from their tumor or RT complications, 19 from nontumoral reasons. Three, 5- and 10-year survival rates were 82, 71, and 40%, respectively. The most significant prognostic factor was age: 5-year survival rate was 86% for patients less than 65 years and 37% for patients more than 65. However, there were no differences in recurrence-free survival rates between patients younger than 65 and the oldest ones. Of 60 symptomatic patients with neurological deficits, 43 had neurological improvement (72%), beginning in some cases within 15 to 20 days after starting RT.

CONCLUSION

These results reassess the role of fractionated RT in the treatment of meningiomas, and stress on its efficacy, especially on cranial nerves palsies, without severe toxicity in most cases.

Fractionated radiation therapy in the treatment of stage III and IV cerebello-pontine angle neurinomas: long-term results in 24 cases

PURPOSE

To reevaluate long-term results of fractionated radiation therapy (RT) in a previously published series of cerebello-pontine angle neurinomas (CPA).

METHODS AND MATERIALS

From January 1986 to May 1992, 24 patients with Stage III and IV CPA neurinomas were treated with external fractionated RT; 7 patients had phacomatosis. One patient was irradiated on both sides and indications for radiotherapy were as follows: (a) poor general condition or old age contraindicating surgery, 14 cases; (b) hearing preservation in bilateral neurinomas after contralateral tumor removal, 5 cases; (c) partial resection or high risk of recurrence after subsequent surgery for relapse, 4 cases; (d) nonsurgical relapse, 2 cases. Most patients were irradiated with 9 MV photons. A three- to four-field technique with coned-down portals was used. Doses were calculated on a 95% isodose and were given 5 days a week for a mean total dose of 51 Gy (1.80 Gy/fraction).

RESULTS

Median follow-up from RT was 60 months (7 to 84); five patients died, two with progressive disease. Two patients underwent total tumor removal after RT (one stable and one growing tumor). On the whole, tumor shrinkage was observed in 9 patients (36%), stable disease in 13 (52%), and tumor progression in 3. Hearing was maintained in 3 out of 5 hearing patients with phacomatosis.

CONCLUSION

Fractionated RT appears to be an effective and well-tolerated treatment for Stage III and IV CPA neurinomas. Hearing can be preserved for a long time.

Dimensions of cervical vertebral bodies according to age and sex

A biometric comparative roentgenological study of the cervical vertebral bodies was performed, according to age and sex, from lateral roentgenograms of 120 adult cervical regions. The sexual dimorphism already described by many authors was confirmed. The vertebral bodies of C2, C3, and C7 have the more variable structure according to age. The results of our measurements are in accordance with clinical findings and provide data on the structural changes of the cervical spine during ageing. In anthropological terms, the vertebral body of C2, in particular its antero-posterior diameter, is the best age indicator, irrespective of individual and exterior variables.

Thyrotropin-releasing hormone and gonadotropin-releasing hormone-associated peptide modulation of [Ca2+]i in human lactotrophs

The effect of thyrotropin-releasing hormone (TRH) and gonadotropin-releasing hormone-associated peptide (GAP) was studied on both secretion and intracellular free Ca2+ concentrations ([Ca2+]i) in human pituitary cells cultured from prolactin (PRL)-secreting tumors. Secretion was measured during a 30-min incubation period and we used a microspectrofluorimetric method in individual cells and indo-1 as the fluorescent probe. TRH (10(-8) M) significantly increased PRL release in five out of the six cell populations. In these five cases, more than 68% of individual cells responded to TRH by an increase in [Ca2+]i. No significant increase in PRL secretion was found in another culture in which TRH increased [Ca2+]i in only 37% of the cells. The effect of GAP (10(-7) M) was studied in five cell populations. In three of them, a decrease of 20% to 51% of the PRL basal secretory rate was observed under GAP. GAP inhibited [Ca2+]i in respectively 59%, 46% and 94% of the cells from these cultures. The inhibitory effect of GAP was blocked by a pertussis toxin (PT) pretreatment which demonstrates the involvement of a PT-sensitive G-protein in GAP action. In two other cultures, GAP did not significantly alter PRL secretion or individual cell [Ca2+]i. These observations suggest that GAP might play a role in the control of PRL secretion in the human.

[Infantile spasms associated with a brain tumor]

BACKGROUND

Infantile spasms are exceptionally associated with a focal cerebral lesion such as a brain tumor.

CASE REPORT

A 15 month-old girl was treated with hydrocortisone and valproic acid for infantile spasms that had appeared a few days earlier. Her psychomotor development was considered normal and the CT scan was normal. Clinical symptoms disappeared within 10 days and the EEG became normal except for a few epileptiform discharges in the frontal areas. The girl developed partial seizures at the age of 5 years. Imaging techniques showed a brain tumor in the right frontal lobe. Surgical excision was followed by radiation therapy. Analysis of the tumor showed an astrocytoma. The girl is normal 18 months after intervention.

CONCLUSION

It is difficult to determine a relationship between the infantile spasms and the brain tumor in this case. The moderately asymmetrical pattern of the EEG after infantile spasms, the fact that these spasms appeared relatively late and the persistence of discharges, lead to repeated specialized investigations.

Anatomical basis of the anterior cervical spine approach: topographic study of the nerve structure

The results of the surgical anterior approach to the cervical spine are marked in a number of cases by dysphagia and dysphonia, especially when the approach is extensive or performed at the upper cervical spine. 35 cadaver dissections were performed to define the topography of the nerve structures during operative exposure at various vertebral levels: superior and recurrent laryngeal nerves, hypoglossal nerve and its superior root of the ansa cervicalis. The authors suggest some technical improvements, for each stage of surgical dissection.

[Study of Beck's hopelessness scale. Validation and factor analysis]

The validation study and factorial analysis of the Beck's hopelessness scale is presented. Two groups were compared including patients suffering from depression (n = 100) and a control group (n = 93). Age and sex were comparable in the two groups. The hopelessness scale is valid, and differentiates depressive patients from control subjects. The scale has a good reliability (test-retest, r = .81) and a good internal consistency (alpha = .97) for depressive subjects and alpha = .79 for control subjects). It also shows a good concurrent validity with other scales assessing depressive cognitions, the automatic thoughts questionnaire, the dysfunctional attitudes scale (form A) and a scale assessing the suicidal risk (ERSD). No concurrent validity is found with scales assessing the intensity of depression, the Beck depression inventory and the Hamilton scale. The factorial analysis elicits a general factor, accounting for 38.15% of the variance, and reflecting negative feelings about the future. The study of all the factorial analysis shows the stability of the factorial structure.

A new way to monitor external ventricular drainage

External ventricular drainage is prone to mechanical complications and monitoring the system is not easy. It requires repeated checking of the drip or the level of the drained cerebrospinal fluid (CSF) in the bag. It was thus proposed that an efficient method by which to monitor the complete external ventricular drainage system would be by continuously weighing the drained CSF. Using weighing scales, a converter, and a recorder, the CSF weight was displayed as a function of time (i.e., flow, if the specific gravity of the CSF is 1, which is usually the case as an approximation). This system was used in 16 comatose patients (11 with subarachnoid hemorrhages and 5 with hydrocephaly during 204 recorded periods of 22.7 +/- 2.8 hours (mean +/- standard deviation). The mean flow was 0.17 +/- 0.05 ml/min. A cessation of CSF flow was seen graphically as a plateau. This occurred 18 times because of obstruction, which was relieved before clinical worsening by making minor adjustments in 15 patients and by reinsertion of a drain in 3 patients. Nociceptive stimuli like tracheal suctioning were also clearly visible on the graph (increased slope, i.e., increased CSF flow). This type of external ventricular drainage monitoring appears to be safe and reliable, giving indications before changes in medical condition. The observed flow, however, is not equal to its rate of secretion but rather to the difference between CSF secretion and reabsorption.

Experimental evaluation of a collagen-coated vicryl mesh as a dural substitute

Dural substitutes must provide immediate restitution of a membranous covering for the brain without inducing any adverse reaction in the host or provoking adhesions to underlying nervous tissues. Ideally, the material should disappear completely and be replaced by tissues similar to the dura mater. In this study, parietal dural defects were created in 12 beagle dogs and closed with a vicryl mesh prosthesis made watertight by a film of bovine collagen. Clinical and biological tolerances were satisfactory. There was one case of early local infection. Gross and microscopic examinations performed between 7 days and 9 months after implantation showed degradation of the prosthetic mesh and connective tissue growth into the implant mimicking dura mater as early as 15 days after implantation. There was no attendant inflammatory reaction or cortical adhesions or other adverse reactions. The authors conclude that collagen-embedded vicryl mesh provides satisfactory biological function and compatibility when used as a substitute for dura mater in the dog.

Cerebral arterial fenestrations associated with intracranial saccular aneurysms

Fenestrations of cerebral arteries other than the anterior communicating artery are rare congenital anomalies, which may be associated with saccular aneurysms. In such cases, the aneurysms may be located at the fenestration itself or may involve other intracranial vessels. This kind of association is not infrequently the cause of angiographic diagnostic problems, as well as surgical difficulties, and consequently needs to be well known to physicians. Four recent cases of rare fenestrations of cerebral arteries associated with intracranial aneurysms are reported in this study and discussed together with a review of the literature.

Fractionated radiation therapy in the treatment of stage III and IV cerebello-pontine angle neurinomas: preliminary results in 20 cases

From January 1986 to March 1989, 20 patients with stage III and IV cerebello-pontine angle neurinomas were treated with external fractionated radiation therapy; seven patients had phacomatosis. Indications for radiation therapy were as follows: (a) poor general condition or old age contraindicating surgery, 10 patients; (b) hearing preservation in bilateral neurinomas after contralateral tumor removal, 5 patients; (c) partial resection or high risk of recurrence after subsequent surgery for relapse, 4 patients; (d) non-surgical relapse, 1 patient. Most patients were irradiated with a 9 MV linear accelerator. A 3 to 4-field technique with 5 x 5 cm portals was used. Doses were calculated on a 95% isodose and were given 5 days a week for a mean total dose of 5140 cGy (180 cGy/fraction). Median follow-up from radiation therapy was 30 months (7 to 46); 4 patients died, 2 with progressive disease. Two patients underwent total tumor removal after radiation therapy (1 stable and 1 growing tumor). On the whole, 14 tumors remained stable, 3 decreased in size, and 3 progressed. CT scan or NMR tumor changes consistent with partial tumor necrosis appeared in four cases. Hearing preservation was obtained in 3/5 hearing patients with phacomatosis. When surgery is not indicated or incomplete, fractionated radiation therapy appears to be an effective and well-tolerated treatment for stage III and IV neurinomas. Hearing can be preserved.

[Arachnoid cysts of the cerebellopontine angle]

The authors report two cases of arachnoid cysts of the cerebello-pontine angle. The otologic symptoms were unsteadiness, hearing fall and tinnitus. In the first case, the patient who presented a cerebellar syndrome was operated. Afterwards the hearing felt and he developed a transient hydrocephalus. The symptoms disappeared in 9 months. In the second cas, the patient was not operated. She was treated medically and supervised. Then the symptoms disappeared too. The authors review the paraclinic exams especially MR, relevant to the diagnosis and discuss the opportunity of a surgical operation.

Use of ketoconazole in the treatment of Cushing's disease and ectopic ACTH syndrome

Ketoconazole, an imidazole derivative which inhibits adrenal steroidogenesis, has been used with success for the metabolic control of Cushing's disease. Few data are available about the use of ketoconazole in the management of the ectopic ACTH syndrome. We have used ketoconazole in eight patients: four patients with Cushing's disease, two patients with overt and two with occult ectopic ACTH syndrome. Among patients with Cushing's disease, reversible hypoadrenalism occurred once. All had full clinical and biochemical regression of the disease for more than 6 months with 400-1200 mg ketoconazole per day. Patients with ectopic ACTH syndrome received 1200 mg ketoconazole per day for at least 2 months. Partial biochemical regression was observed in two and a secondary escape to adrenal blockade in two others. These findings further indicate that ketoconazole is a valuable tool for the metabolic control of Cushing's disease. On the contrary, in ectopic ACTH syndrome, this aim can be impossible to reach with ketoconazole although the reasons for its ineffectiveness remain to be determined.

[Value of the corticoliberine test in the etiologic diagnosis of Cushing's syndrome]

Several studies have demonstrated that the corticotropin-releasing factor test (CRF) is useful for the aetiological diagnosis of Cushing's syndrome: in Cushing's disease, as opposed to ectopic ACTH secretion syndrome, the hypothalamus-pituitary-adrenal (HPA) axis can still be stimulated by CRF. In the present study, we compared the CRF test with the reinforced dexamethasone suppression test in 18 patients: 11 with Cushing's disease, 6 with ectopic ACTH secretion and 1 with adrenal gland adenoma. We obtained 2 false-negative results with the CRF test and 1 false-positive result with the dexamethasone suppression test. Our study, together with published data, suggests that the CRF test is useful in the exploration of Cushing's syndromes of uncertain origin. However, the results obtained with this test must be compared with those of other methods used to explore the HPA axis and which are still necessary.

Anatomical basis of the extended subtemporal approach to the cerebellopontine angle: its value and limitations

The cerebellopontine angle is an anatomic region situated deeply at the anterolateral aspect of the brainstem, access to which is complicated by the presence of neurovascular bundles. The functional importance of these cranial n. (trigeminal, facial, vestibulo = cochlear, glossopharyngeal, vagus and accessory) calls for the use of special surgical routes of access in certain cases. In particular, tumors situated between the vestibulocochlear-facial bundle behind and the trigeminal n. in front are difficult to reach by the suboccipital and subtemporal transmeatal routes. The endeavor to preserve hearing in particular situations, where the side opposite the tumor is no longer functional, justifies the use of a subtemporal transmeatal route extended by opening the tentorium cerebelli. This anatomic and experimental surgical study deals with the possibilities of this route of approach.

[Preliminary study of a list of obsessional thoughts. Validation and factorial analysis]

The validation study and factorial analysis of a list of obsessive thoughts is presented. Four groups were compared. They included patients suffering from obsessive compulsive disorders (n = 22), depression (n = 21), phobias (n = 16) and a control group (n = 21). The four groups were comparable as far as age, sex, and educational level were concerned. The list of obsessive thoughts is valid, reliable, and has a good internal consistency. The factorial analysis showed a first factor (accounting for 37.22% of the variance) reflecting perfectionism, and a second factor (accounting for 12.10% of the variance) reflecting a pathological sense of responsibility.