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Biomedical subjects

A Bazin

Publications and source records attributed to A Bazin.

At least 19 recordsLinked to original sources
PubMed2002

[Unsuccessful surgery of Cushing's disease. Role and efficacy of fractionated stereotactic radiotherapy].

BACKGROUND AND PURPOSE: To optimize and reduce the toxicity of pituitary adenoma irradiation, we evaluated the feasibility and effectiveness of fractionated stereotactic radiotherapy (FSR) in 51 patients with functional adenoma; 12 of them had Cushing's disease. PATIENTS AND METHODS: Eleven females and one male, median age: 49 years, 8 of them relapsed and 4 had persistent hormonal secretion after surgery. The delivered dose was 50 grays (Gy) (5 x 1.8 Gy/week) using 5 convergent micro-beams scanning in arc therapy mode. The median planned target volume (PTV) receiving 90 to 100% of the total dose was 2,1 cm(3). We used relocatable non-invasive stereotactic device Brain Lab, and adapted Linac for stereotactic radiotherapy. RESULTS: Nine out of twelve patients (75%) presented with complete remission after a median time of 29 months, 3/12 patients with partial remission. Actuarial probability to have hormonal persistent secretion was 88% at on year, 44% from 3 to 5 years, 22% at 7 years, and 11% to 0% after 7 years. The 12-corticotroph adenomas were significantly (p=0.007) more radiosensitive than 39 non-corticotroph adenomas. Toxicity was significantly lower for corticotrope adenoma, with no radio-induced pituitary deficiency and no neurological or optic injury. CONCLUSIONS: Combined surgery and FSR appears to be safe and effective for treatment of pituitary adenomas. However, long-term follow-up is required to determine the impact in terms of tumor response and hormone deficiency. The focused treated volume obtained by FSR seems more suitable for these benign tumours than standard radiotherapy. In addition to this conformal approach, the use of standard fractionation reduced the risk of severe damage to the optic chiasma, which is sometimes observed after radiosurgery and is inherent in single fraction radiotherapy.

Adenoma↗
PubMed2000

Is There a Genetic Basis for Fluctuating Asymmetry and Does it Predict Fitness in the Plant Lotus corniculatus Grown in Different Environmental Conditions?

Fluctuating asymmetry (FA) is considered to be a good measure of developmental stability. We measured the asymmetry of leaves and flowers of 16 different genotypes of Lotus corniculatus grown in four different experimental environments to estimate the plasticity or developmental stability of asymmetry itself. We found that an index of FA (absolute difference between size of left and right sides, corrected for trait size) differed significantly across environments, with the treatment CO2+/N+ inducing the greatest FA for both flowers and leaves. Genotypes did not differ in FAs. Individual plants showed significantly different FAs only for flowers. At the individual level, we found no significant relationship between flower FA and fitness. Previous work indicates that change in asymmetry in a poor or perturbing environment versus a good environment could reflect the intrinsic quality of a particular genotype. However, in our experiment, genotype effect was significant only for change in asymmetry of leaves, and this last trait was not significantly correlated with our fitness estimate for each genotype in either the most or the least perturbing environment.

Journal Article↗
PubMed2000

Defining the efficiency of fluorescence in situ hybridization on uncultured amniocytes on a retrospective cohort of 27407 prenatal diagnoses.

Rapid prenatal detection of selected numerical chromosomal abnormalities by using fluorescence in situ hybridization (FISH) on uncultured amniotic fluid samples was described six years ago. It allows a very rapid identification of selected aneuploidies. We have indexed the results of our 27407 fetal karyotypes obtained by conventional cytogenetics during the last five years, noting the type of chromosomal abnormality and the reasons for prenatal diagnosis. We have also indexed the chromosomal abnormality regarding the prognosis of the chromosomal aberations to evaluate the real impact of a non-diagnosis. Within the population of bad prognosis abnormalities, the percentage of abnormalities with bad prognosis detectable by FISH is 94.6% for advanced maternal age, 85.3% for ultrasonographic anomalies and 86.4% for positive maternal screening. The use of FISH alone on our cohort is not a suitable method to diagnose the chromosomal abnormalities.

Adult↗
PubMed2000

[Research notes].

Explore the source record for details and available documents.

Data Collection↗
PubMed1998

[Starling resister and stability of sleep ventilation].

The upper airway can be described as a collapsible segment (the pharynx) interposed between two rigid bony (the cavum) or cartilaginous (the trachea) segments. Due to this structure, the pharynx behaves as a collapsible tube, in which airflow does not depend on the downstream pressure, but is limited to a maximum value which depends only on the upstream pressure and on the pressure surrounding the collapsible segment; this behavior, known as a Starling resistor can be modeled by the waterfall effect. Thus, the upper airways can be in three different conditions: an occluded condition, in which no flow is possible, a patent condition, in which flow depends on the difference between upstream and downstream pressures (according to Poiseuille's law), and a situation in which flow is limited. The behavior of the upper airway is largely dependent on its anatomic structure, but functional factors play a critical role. Among these sleep state is both a determinant of the collapsibility of the pharynx, and determined by the simulation of upper airway mechanoreceptors whose activity depends on the activity of respiratory muscles. Thus the interplay of three factors: ventilatory drive, upper airway collapsibility, and arousal threshold can predict most of the situations of stable and unstable ventilatory behavior during sleep. The level of the arousal threshold governs the stability of the ventilatory pattern, as it determines whether a combination of slow, respiratory effort, and blood gases can be maintained or is interrupted by an arousal.

Airway Resistance↗
PubMed1997

[Post-radiotherapy multifocal meningioma].

We report one case of radio-induced meningiomas revealed by an intracranial hypertension in an 46 year-old woman. A history of cephalic irradiation during infancy for a vascular nevus, not spontaneously reported by the patient, had been discovered because of the association with a radio-induced cataract. Meningiomas are a rare, severe and late complication of cephalic radiotherapy. The history of irradiation is not always spontaneously reported by the patient.

Female↗
PubMed1997

[Postoperative spinal extradural hematomas. 14 cases].

We report 14 cases of post-operative spinal epidural hematoma and compare them with 17 cases reported in the literature. These 14 cases have been drawn from a continuous series of 7950 patients operated on at our institution by the posterior route for a non-traumatic spinal pathology. The symptom-free period after initial surgery was shorter than 5 hours in 13 cases out of 14. The clinical picture was characteristic 11 times. It started with a stabbing pain in the operated site, followed by paresthesia, radicular pain and neurologic palsy which were always bilateral even when the operation had been unilateral. The diagnosis was always established rapidly when the compression was cervical or thoracic and with some delay when the lumbar area was concerned. All patients, except one, have been reoperated without any radiological investigation. The source of bleeding was found 12 time out of 14. Full recovery was obtained in all 14 patients but delayed recovery of a few weeks occurred in 3 patients for whom reoperation was delayed. None of the potentiating factors studied in this work were found to be decisive. Post-operative spinal epidural hematoma is a rather uncommon complication of spinal surgery occurring at a rate of 1 to 2 per thousand. The diagnosis is more often obvious because its clinical picture is similar to that of spontaneous spinal epidural hematoma. Early reoperation allows a full recovery. Special attention during the first six post-operative hours for all patients after spinal surgery is essential for early detection of such a complication.

Adult↗
PubMed1996

Lhermitte-Duclos disease associated with syringomyelia.

A 23-year-old man presented with a 2-week history of intracranial hypertension. CT showed a large, nonenhancing cerebellar mass with surrounding calcification and displacement of the fourth ventricle. MRI revealed a septate lesion, with low signal on T1-weighted and high signal on T2-weighted images. The cerebellar tonsils were displaced below the foramen magnum and there was associated syringomyelia. The MRI features were characteristic of Lhermitte-Duclos (LD) disease (dysplastic gangliocytoma) and the diagnosis was confirmed following surgery. In this case, we emphasise the usefulness of MRI in the diagnosis of LD disease and consider the possible pathogenesis of the associated syringomyelia.

Adult↗
PubMed1994

[Prone position and operative posture in neurosurgery].

The most satisfactory method of prone positioning for the posterior approach to the spine and posterior fossa has been influenced by the necessity of providing good operating condition: prone position without abdominal and thoracic compression with a patient's head in the neutral position. Communication between the cava veins and the vertebral venous plexus explain that induce positioning can produce an excessive venous intraoperative bleeding with decreased surgical visibility. Furthermore venous return to the heart decreased resulting in some degree of impaired cardiac output. Hemodynamic disturbances of cerebral or spinal cord bloods flows can occurred.

Cerebrovascular Circulation↗
PubMed1993

[Comparison of 2 consecutive series of aneurysmal subarachnoid hemorrhage with or without nimodipine and study of the temperature curve].

A total of 210 consecutive patients with aneurysmal subarachnoid hemorrhage (S.A.H.) of any clinical grade admitted from January 1985 through May 1990 were retrospectively studied to determine the effect of intravenous Nimodipine on survival and functional results and to analyse temperature curve as a prognosis factor. The 106 patients admitted from January 1985 through November 1987 constituted the reference series termed G1. The 104 patients admitted from December 1987 through May 1990 and treated with intravenous Nimodipine constituted the series termed G2. Of the 210 patients, 172 (82%) could be operated on with a similar mean operative delay in both series (G1 = 9.5 days, G2 = 9.8 days). Of the 210 patients, 153 (73%) survived with an average follow-up of 111 weeks for G1 and of 64 weeks for G2. Nimodipine treatment was associated with a significant increase of survival (11.8%, P = 0.05) which was not the result of improved operative technique but of a lower incidence of deaths caused by postoperative vasospasm (G1 = 5 deaths, G2 = 0 deaths, P = 0.05) and by rebleeding (G1 = 15 deaths, G2 = 5 deaths, P = 0.03). No significant difference between the two series G1 and G2 was observed regarding functional results in the 153 survivors, frequency and seriousness of clinical signs of vasospasm during the waiting phase for surgery, radiologic signs of vasospasm on initial and second angiography, cerebral infarctus on second C.T.-Scan. Analysis of temperature curves of the 210 patients revealed that a delayed fever with a plateau pattern was associated with a higher incidence of vasospasm, rebleeding, and deaths.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Frontal sinus injuries: apropos of 67 cases].

The authors report their experience in the treatment of frontal sinus fractures, between 1979 and 1987, about 67 cases. 52% of these trauma involve alone, the anterior and/or posterior wall of the frontal sinus, with or without cerebrospinal fluid rhinorrhea. The sinus surgery was composed of cranialization in 20 cases (30%) and open reduction with reconstruction, with or without tube to stent the nasofrontal duct, in 30 cases (48%). Two points appear to them, essential to guide the treatment, osteomeningeal tear and naso-frontal duct injury.

Adolescent↗
PubMed1990

[Injuries of the frontal sinus].

The authors report their experience in the treatment of frontal sinus fractures, between 1979 and 1987, about 67 cases. --52% of these trauma involve alone, the anterior and/or posterior wall of the frontal sinus, with or without cerebrospinal fluid rhinorrhea; --the sinus surgery was composed of cranialization in 20 cases (30%) and open reduction with reconstruction, with or without tube to stent the nasofrontal duct, in 30 cases (48%). Two points appear to them, essential to guide the treatment: --osteomeningeal tear, --naso-frontal duct injury.

Adolescent↗
PubMed1989

[Synovial cysts and synovialomas of the lumbar spine. Histo-pathologic and neuro-surgical aspects apropos of 8 cases].

Based on 8 personal cases and a 81-cases review of literature, it's authors' opinion that cystic or solid masses issued form posterior lumbar articular process and called according to the cases synovial cyst, ganglion cyst, benign synovialoma, pigmented villonodular synovitis, are a single variety of benign degeneration of soft articular tissues. The cystic or solid feature of these masses depends upon the extent of their histiocytic granulomatous proliferation. They may be asymptomatic, accompany chronic lumbar pain or cause sciatica, seldom cauda equina syndrome. In case of sciatica, clinical picture rather consists of a narrow lateral recess than a discal protrusion. CT scan is the best investigation to get a right preoperative diagnosis. Postoperative prognosis is excellent and no anatomical recurrence has been reported.

Adult↗