Expression of amiloride-sensitive sodium channel: a strategy for the coexpression of multimeric membrane protein in Sf9 insect cells.

The amiloride-sensitive epithelial sodium channel (ENaC) mediates Na(+) reabsorption in many epithelial tissues including the distal nephron, colon, lung, and secretory glands and plays an important role in pathophysiology of hypertension and cystic fibrosis. The ENaC is a multimeric integral membrane protein formed by the association of highly homologous,alpha-, beta-, and gamma-ENaC subunits. Here we explored the Sf9 insect cell-baculovirus expression system as a source to obtain high yields of recombinant ENaC for functional and structural studies. Although this expression system is widely used, coexpression of ENaC subunits could not be accomplished by the conventional procedures. We thus developed a protocol in which the alpha- and gamma-ENaC cDNA's were first fused individually with polyhedrin promoters at their 5'-ends and then inserted in the multiple cloning sites of pVL1393 transfer vector carrying the beta-ENaC cDNA. Utilizing this transfer vector, a recombinant baculovirus carrying all of the three ENaC cDNA's was prepared. Infection of Sf9 insect cells with this recombinant baculovirus resulted in the expression all of the three ENaC subunits in high yield. Planar lipid bilayer reconstitution procedure revealed the presence of approximately 6 pS sodium channels that are amiloride-sensitive. The results presented point out certain underlying rules for the expression of multiple genes in Sf9 cells, which may be useful in the expression other multimeric proteins and in the studies of protein-protein interactions as well.

[Peroperative echography in neurosurgery. Its value and applications 10 years later]. / L'échographie peropératoire en neurochirurgie. Son intérêt et ses applications dix ans après.

Intraoperative ultrasound imaging has many advantages over other imaging methods. The authors present their experience from hundred patients over ultrasound scanning. A large iconography is exposed. Not only the intracerebral lesions such as gliomas or metastases but also abscess or cysts can be controlled or biopsied directly. Per-operative ultrasonography is interesting for spinal cord lesions and spinal traumas. Ten years from the first utilisation in neurosurgery, the method is always used, its cost is low and its practice is very easy.

[Intramedullary neurinoma. Apropos of a case. Review of the literature]. / Neurinome intramédullaire. A propos d'un cas. Revue de la littérature.

The authors present a case of intramedullary neurinoma. A 44 years old patient was admitted for lumbar pain and bilateral sciatica. Neurological examination was normal except for dysuria and diminution of Achilles tendon reflexes. Lumbar spine X-rays and spinal cord angiogram were normal, but myelogram and myelo-scan revealed a fusiform enlargement of the conus medullaris. MRI confirmed this aspect. Total removal of an intramedullary tumor was done, using ultrasonography, operating microscope and ultrasonic aspiration. The post-operative course was uneventful, with, as sequelae a perineal hypoesthesia. Histological examination of the excised tumor revealed a neurinoma. The epidemiology, clinical features, radiology, and surgical treatment of such rare intramedullary tumors are discussed.

[Cervical osteoid osteoma. Report of a case and review of the literature]. / Ostéome ostéoïde somatique cervical. Présentation d'un cas et étude de la littérature.

One case of a cervical osteoid osteoma is presented and compared with infrequent similar cases from the literature. The authors recall the diagnosis difficulties, facing a long standing not explained neck pain due to poor neurological and current radiological informations. The interest of the bone scintigraphy, CT scan and M.R.I. are emphasized. Like in other cases, the pain disappeared after surgical removal of the tumor. The eventually associated scoliosis often rectify too.

[Solitary plasmacytoma simulating pituitary adenoma]. / Plasmocytome solitaire simulant un adénome hypophysaire.

A case of solitary plasmocytoma of the sphenoid is reported, masquerading as pituitary adenoma. At the time of surgery, the patient had no findings of multiple myeloma. The tumor was removed by trans-sphenoidal route and radiotherapy delivered. The post-operative course was uneventful, and two years later, there is no sign of recurrency or extension of multiple myeloma.

[Cauda equina syndrome complicating cutaneous T-cell lymphoma (mycosis fungoides)]. / Compression de la queue de cheval compliquant un lymphome cutané à cellules T (mycosis fongoïde).

Authors present a case of a cutaneous T. cell lymphoma (mycosis fungoides) complicated by a cauda equina syndrome. Crural and sciatic radicular pain were due to epidural lumbar involvement by tumoral process. After surgical decompression completed by chemotherapy the evolution was uneventful. This case is the second one reported in the literature.

Spinal subdural hematoma.

The authors report a case of spinal subdural hematoma in a 51-year-old man who experienced a sudden onset of back pain accompanied by vomiting and headache without paralysis or paraparesis. CT Scan, myelography and MRI revealed a subdural hematoma at the levels of 6th, 7th and 8th thoracic vertebrales. Laminectomy allowed the removal of an encapsulated cyst formation filled with xanthochromic fluid and some blood clots. The follow-up was uneventful.

[Intervertebral biopolymer implant for arthrodesis. A study of 45 cases]. / Implant intervertébral au biocopolymère (B.O.P.) pour arthrodèse. Etude de 45 cas.

The B.O.P. biocopolymer is a bioresorbable, biocompatible product which can ossify. It has been used in 45 spinal arthrodesis, 42 times in cervical region but three in lumbar spine. The authors report their results after a follow-up period of 8 to 28 months. Persistent cervical pain has been noted in 9 cases. This was the most important postoperative complaint. Graft ossification has nevertheless been observed only in 40% of cases, as proved by simple X rays or/and scanner examination over a 26 months period. An osseous overproduction with posterior osteophytes could otherwise be observed. The authors remains cautious about using moreover this kind of graft, at least in its actual presentation, though the clinical results can be compared with these obtained with osseous autograft.

[Chronic subdural hematoma in the elderly and computerized tomography. Study of 80 cases]. / Hématome sous-dural chronique des personnes âgées et scanner. Etude de 80 cas.

The pathogenesis of chronic subdural hematoma, especially the reason why it becomes chronic is still under discussion. A series of 80 patients older than 60 years (47% older than 75 years) were studied clinically and by CT. As compared with angiography, CT allows the subdural hematoma to be detected earlier. In some cases the subdural hematoma might have been missed without CT. The indication for surgery remains unchanged and surgical techniques too. In 80% of the patients good results from the clinical point of view could be achieved. There was no correlation between clinical signs and the findings obtained by CT. Postoperatively it usually took 60 to 70 days for CT findings to disappear. The prognosis of subdural hematoma in the elderly remains guarded. The mortality rate in our series was 11% possibly as a consequence of age.

[Cervical chordoma. Apropos of a case]. / Chordome cervical. A propos d'un cas.

The chordomas are malignant tumors arising from the remnants of the posterior spinal chord. The chordomas of the cervical spine are rare (5% of the spinal chordomas). A new case of spine chordoma at C5 level in a 76 years old woman is reported. The diagnosis depends on the results of the histological studies and especially the studies of the labelled elements as Protein S100 or Cytokeratin. Firstly a double osteosynthesis was realized by an anterior and posterior approach. There was no radiotherapy after this operation. A new operation for a fracture of odontoid process was necessary one year later. There was no recurrence. The patient was complaining from pains, two years after the first operation in relation to lateral recurrence. A third operation by an anterior approach was realized. A radiotherapy of 50 Gy was applied on the same level. The first osteosynthesis was with acrylic cement and the second one with an autologous bone graft and a plate after removing the cement without problem. Actually she is in good health, 78 years old.

[Cerebrospinal fluid fistula--indications for treatment with lumbar puncture and drainage. Report of 66 cases]. / Die Liquorfistel--Indikationen zur Behandlung mit Lumbalpunktion und Drainage. Bericht über 66 Fälle.

The authors present a series of 66 cases of cerebrospinal fluid fistulas. Ways of localizing the fistula as well as different therapeutic methods are studied. They insist on the efficiency of external lumbar drainage of the cerebro-spinal fluid which permits a fair number of patients to recover without surgery.

[Glioblastoma of the cerebellum in a child. Apropos of a case. A review of the literature]. / Glioblastome du cervelet chez un enfant. A propos d'un cas. Revue de la littérature.

Authors present a case of glioblastoma of cerebellum in a 11-year old child. Symptoms and signs are those of other tumors of posterior fossa. Diagnosis was made by CT Scan and pathologist. In spite of radiotherapy, he died one year after craniotomy. Only twenty cases of glioblastoma of cerebellum in childhood were described in the literature.

[The injured cervical spine with and without lesions of the nerve structures. Clinical results of surgical therapy]. / Die verletzte Halswirbelsäule mit und ohne Läsionen nervaler Strukturen. Klinische Ergebnisse nach operativer Therapie.

The operative treatment of the cervical spine injuries with and without neurological deficit was active developed in the last 25 years. The surgical management has been determined by the type of deformity, and also by the anatomical and functional specialties. The indication, the diagnostical and therapeutical strategy and the results of surgical treatment of 304 cases are discussed.

[Rupture of neoplastic intracranial aneurysm caused by metastatic uterine choriocarcinoma]. / Rupture d'anévrisme intracrânien néoplasique dû à une métastase de choriocarcinome utérin.

Authors report a case of 18 years old woman with intracranial neoplastic aneurysm. Its rupture occurred one month after delivery, and the diagnosis of metastatic aneurysm from choriocarcinoma was made by pathologist. The craniotomy has allowed to remove the hematoma and the aneurysm with good immediate follow-up. In spite of X-ray-therapy and chemotherapy, the patient died one year after the outset from choriocarcinoma dissemination, in a comatose state. The review of the literature shows that this form of aneurysm is very exceptional. It is resulting from the invasion of the arterial wall by metastatic cells, by a neighbouring metastatic tumor or by another type of brain-tumor. In some cases, the aneurysmal rupture was the first symptom, before any gynecologic manifestation of the choriocarcinoma. The prognosis has been bad in such cases in spite of a commonly good response after chemotherapy.

[Hand-Schüller-Christian disease with tumor localization in the posterior fossa]. / Maladie de Hand-Schüller-Christian avec localisation tumorale dans la fosse postérieure.

A 19-year-old girl had been suffering since the age of 4 from Hand-Schüller-Christian disease. The condition was diagnosed by biopsy of a cranial bone lacuna. Later on, she developed diabetes insipidus and bilateral exophthalmos, both being typical signs of Hand-Schüller-Christian disease. At the age of 14, an intracranial tumour in the posterior cerebral fossa was discovered by computerized tomography, but in view of her parent's refusal of surgery, she was operated upon only 4 years later for obstructive hydrocephalus with intracranial hypertension. Two years after this operation, she presented with neurological signs of compression of the medulla oblongata, including tetraparesis and respiratory disorders, and the tumour was resected. Following a brief improvement she died of major hydroelectrolytic disorders due to her irreducible unstable diabetes insipidus. A review of the literature on Hand-Schüller-Christian disease and its rare association with intracranial tumours is analysed. The occurrence of such tumours raise important therapeutic problems and make the prognosis considerably worse.