Biomedical subjects
Publications and source records attributed to P Castan.
The cloverleaf skull is a rare and due to complex craniosynostosis. This malformation can be isolated or associated with extracranial skeletal anomalies. This anomaly has a poor prognosis both in terms of neurological outcome and esthetic appearance. Our report underscores the need to obtain a global study of the skull, the brain and the cerebral vessels with 3D reconstructions and MRI prior to early surgery.
Ethidium bromide was used to study perturbations induced in salmon sperm DNA complexed with a series of platinum and palladium compounds obtained from chloro and orotic acid derivatives as leaving ligands. The antitumoral activity of these compounds against Sarcoma 180 cells grafted intraperitoneally into mice is correlated with their capacity to interact with DNA in vitro and to perturb its secondary structure. Nevertheless, among these compounds, [Pt(Dach)(3-methyl-orot)] and [Pt(Dach)(5-fluoro-orot)] do not interact with DNA in vitro and are inactive against Sarcoma 180 cells. This lack of activity originates from the fact that strong chelating properties of the ligand prevent hydrolysis of the compounds which are unable to give rise to aquo species which are the reactive ones. On the other hand, the interaction with DNA is not the only prerequisite in order that a compound be active towards tumour cells. In fact, cis-[Pd(NH3)2Cl2] and cis[Pd(Dach)Cl2] are not antitumoral. It is well known that the former undergoes an inactive trans-conformation and that the two compounds hydrolyse very fast assuming that they interact in vivo with a lot of molecules particularly proteins preventing them to reach the DNA, their pharmacological target. By contrast, [Pd(Dach)(3-methyl-orot)] (T/C = 267%) and [Pd(Dach)(5-fluoro-orot)] (T/C = 270%) display significant antitumour activity.
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A meningoencephalitis Behçet's disease revealing is reported. Magnetic resonance imaging is more sensitive than computerized tomography in detecting encephalitic lesions. However, no specific pattern may be retained. This exploration is non invasive and can be used to monitor the evolution after treatment.
From a series of eleven children aged from 4 months to eight years presenting with a parieto-occipital flattening that was unilateral in nine and bilateral in two, we attempted to determine a 3D-CT semeiology able to demonstrate the presence of a lambdoid suture synostosis, as well as the participation of coronal and lambdoid sutures in the genesis of complex cranial malformations. Pure isolated forms of lambdoid synostosis are rare and justify a surgical treatment for cosmetic purposes if the deformation is severe and progressive.
The MRI exploration of a woman suspected, on clinical grounds, of having Hallervorden-Spatz disease (or rather syndrome) revealed, on T2-weighted sequences, the "tiger's eye" or "target" image of the pallidum described by previous authors: i.e. a high-intensity signal in the centre of a distinct low-intensity signal; it also showed an abnormal low-intensity signal of the substantia nigra. These changes are related to the iron deposits and neuro-axonal lesions which characterize the disease. The MRI semeiology of Hallervorden-Spatz disease has been analyzed in the literature. The images we obtained in this patient with the echo-gradient technique using T1-weighted sequences were unusual, showing a low-intensity signal of the globi pallidi surrounded by central and peripheral low-intensity signal areas, whereas the images obtained with spin-echo T1-weighted sequences were normal.
Three dimensional computed tomography was performed in 150 children suffering from a bone lesion of the base of the skull and face. These lesions were either malformative, neoplastic, infectious or traumatic. 3D CT provided an essential anatomical approach to the lesions facilitating the choice of the most appropriate treatment. 3D CT is also indicated in the follow-up of these operated children, particularly of the growth of the operated bone segment and its relations with adjacent structures.
Three-dimensional (3D) imaging was performed on 150 children with craniofacial malformations divided into three groups: craniostenosis, craniofacial dysraphism and labio-maxillo-palatine clefts arbitrarily included in a corpus of constitutional and acquired abnormalities. The authors believe that this technique is of interest not only for the management of these children, but also to understand the pathogenesis of their malformations.
In order to design and develop potential anticancer drugs involving the same structural pattern as platinum(II) antitumor complexes, complexes of palladium and platinum with 3-methyl-orotic acid as the leaving ligand have been synthesized. The study of the anticancer activity of these compounds toward L1210 leukemia and sarcoma 180 in mice is presented and discussed in terms of the nature of the ligand and the metal involved. The (3-methylorotato)(1,2-diamino-cyclohexane) palladium(II) has an activity (sarcoma 180) similar to that for cis-DDP itself. The crystal structure of (3-methylorotato)(dl-trans-1,2-diaminocyclohexane) platinum(II) is described.
The authors report a prospective and comparative study of the pre-operative staging of 90 laryngeal carcinomas by CT and MRI, with blind analysis of each examination. The radio-anatomic correlations and the inter-method correlations (CT versus MRI) are reported. According to the authors MRI seems to be the method of choice because of its capabilities in soft tissues differentiation and because of its multiplanar representation. The motion artefacts are resolved by the fast imaging technique and the spatial resolution is optimized by special surface coils.
The results of magnetic resonance imaging (MRI) performed in 67 patients with cerebral vascular malformations (35 arteriovenous malformations [AVM], 29 cryptic malformations, 11 venous angiomas and 2 associated lesions) were studied retrospectively after the patient population was divided into epileptics [25] and non-epileptics [42]. Several criteria were determined for each type of malformation in the two groups. They included patient's age, site of the malformation in relation to the cortex, size of the malformation, presence of a perilesional high-intensity signal on T2-weighted sequences and evidence of recent haemorrhage. Epileptogenic AVMs seemed to be more superficial and more often associated with a perilesional parenchymatous high-intensity signal on T2-weighted sequences than non-epileptogenic malformations. Epileptogenic cryptic malformations were closer to the cortex, larger, and specifically but rarely associated with changes in signal of the adjacent brain tissue on T2-weighted sequences. The few angiomas associated with epilepsy were, paradoxically, located in the cerebellum.
Clinical deterioration during or after brain irradiation may be due to progression of neoplasm or radiation induced necrosis of the neoplasm and/or of normal brain tissues, or a combination of all. Eight patients with histologically documented radiation induced lesions of the brain are included in this study. The radiation therapy included the fractional schedule, group A, who received 280 to 300 rads daily, to a total dose of 4500 to 5000 rads and weekly exposure did not exceed 900 rads. Group B patients were exposed to 850 rads, daily dose on day 1, 3, 21 and 23 to a total dose of 3400 rads. The incidence of radiation induced lesions of brain was 3.4% in patients group A and 8.7% in group B patients (without statistical significance). The median time of onset of these lesions after completion of radiation therapy was significantly shorter in group B patients (8.5 months) as opposed to group A patients (21 months).
Recurrent symptoms or signs during or after therapeutic brain irradiation may be due to the progression of the irradiated tumour, necrosis of normal brain tissue, necrosis of tumour, or all three of these. We have studied 12 patients with pathologically proven radiation-induced damage of normal brain tissue. All patients were exposed to a therapeutic range of radiation for an intra or extracranial tumour. Seven patients were exposed to 280 to 300 rads per day, three times weekly to a total dose of 4500 to 6000 rads (fractionated). Five patients received 750 to 850 rads per day, on days 1, 3, 21 and 23 (split-course). The diagnosis of radiation-induced brain lesions is difficult. CT scan is the most informative diagnostic procedure. The various patterns of radiation-induced brain lesions on CT are nonspecific. However where there is sufficient clinical data suggesting radiation-induced brain lesions, and a good correlation between CT abnormalities and the maximum delivered dose, on dose distribution maps of the brain exposed to a high cumulative radiation dose, the diagnosis may be accepted. The time interval between the end of radiation therapy and the occurrence of radiation-induced lesions was shorter in the patient group exposed to a split-course therapy (median time: 9.6 months) as opposed to the patient group exposed to a fractionated radiation (median time: 45 months). Pathologically the lesions corresponded to either a demyelinated area within the white matter with minimal vasculopathy or an area of coagulation necrosis with varying degrees of necrosis, delamination or hyalinosis of small blood vessels.(ABSTRACT TRUNCATED AT 250 WORDS)
A case of histologically proven benign choroid plexus papilloma of the third ventricle in a 4-month-old male child is reported. The clinical symptoms and the neuroradiologic findings were those of a supratentorial hydrocephalus. A shunting procedure was performed after refusal by the family of a direct surgical approach. Subsequently there was a four- to fivefold increase in volume of this tumor in less than 4 months under decreased cerebrospinal fluid pressure. The purpose of this report is first to add a case to 27 cases of papilloma of the choroid plexus of third ventricle reported in the medical literature. Secondly to underline a possible influence of intraventricular pressure on the growth of a histologically benign intraventricular papilloma. Subsequently, the question of radiation therapy may be raised, if total removal of the papilloma is not obtained, especially in view of decreased cerebrospinal fluid pressure provided by the previous shunting procedure.
Described by Chance (1948) this fracture is induced by a mechanism of flexion distraction (seat belt fracture). The injury is characterized by the following (W.S. Smith, 1969): A disruption of the vertebral body by an horizontal splitting of this formation and neural arches through the pedicles, nor, or a minimum decrease in the anterior height of the involved vertebral body, no forward or lateral displacements of the superior vertebra, location of the disruption between the first and third lumbar vertebra in the majority of cases. Four patterns of Chance's fracture are isolated in this paper: First pattern: The osseous disruption cross the posterior arches, pedicles and vertebra. The fracture is unstable. Second pattern: horizontal fracture involves both pedicles with extension anteriorly through inferior third of the vertebral body (unstable). Third pattern: Chance's fracture with anterior vertebral extension through superior third of vertebra (unstable). Fourth pattern: fracture with anterior horizontal vertebral disruption in the posterior half of the body (stable).
A 9-year-old boy developed ataxia, right transient hemiparesis, left transient hemichorea, dysarthria and swallowing difficulties with left velar paralysis following two transient episodes of vomiting, headache and dizziness. Angiography demonstrated an occlusion of the distal part of the basilar artery. Thirty-six previously reported cases of vertebro-basilar arterial occlusion in children were reviewed, with particular regard to possible etiologies.
Since the original description by Schneider (1956), the tear drop fracture is designated as a flexion fracture. The C.A.T. investigation proves the coexistence of two lines of fractures: a frontal fracture (by mechanism of flexion), a sagittal fracture (by compression). The sagittal fracture affects the body and the posterior arch in 48% of Lee's cases (1982) as Jefferson's fracture. The tear drop fracture is a fracture by mechanism of flexion-compression with sagittal sprain of the inter vertebral cervical disk. --In our experiences C5 is the level of the most frequent lesion. --4 types of tear drop fractures are described: an occult form (C.A.T. diagnosis), tear drop without displacement, tear drop with moderate displacement, tear drop with posterior dislocation and kyphosis greater than 20 degrees. --The spinal cord damage corresponds to displacement of the two half vertebral bodies and posterior dislocation. --In case with posterior dislocation and kyphosis greater than 20 degrees complete tetraplegia or anterior spinal cord injury are often presents. --In case with asymmetrical posterior displacement of an half vertebral body the syndrom of Brown Sequard is constant. --The tear drop fracture is unstable and cervical spine fusion necessary.
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