Biomedical subjects
Publications and source records attributed to B Roger.
Preliminary findings on NMR imaging of 30 soft tissue tumors demonstrated the indispensable value of this examination (particularly when a surface antenna is used) for preoperative investigation and diagnosis of tumoral recurrence when compared with other radiologic techniques. The possible potential of NMR imaging for characterization of tissues, apart from lipoma or liposarcoma, cannot be evaluated at the present time.
The authors have analysed the action of sectioning the transverse carpal ligament by computerised tomography in 19 patients (22 wrists) with carpal tunnel syndrome. Three cuts were studied-proximal, middle and distal, the wrist being either straight, flexed or extended. The study was done pre-operatively and three months after division of the ligament. The study demonstrated the reconstruction of a new ligament which was more lax and expanded anteriorly, despite the fact that the patient wore a plaster cast for two weeks after operation, the wrist being maintained straight. The calibre of the carpal tunnel showed an increase of between 7 p. 100 and 44 p. 100 after the operation and this increase was not related to any alteration in bone topography, which was unchanged. Thus, the role of the ligament in the permanency of shape of the anterior concavity of the wrist skeleton is questionable. The flexor tendons could expand anteriorly, thanks to the laxity of the new ligament.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Thirty-two operations on the common peroneal nerve for leprous neuritis are reported. A combined medical and surgical approach to treatment is recommended, and the technique of operation is described. Recovery of motor power was satisfactory but depended on many factors, including the duration of the neuritis, the extent of the compression, the immunopathological status of the patient and the efficacy of medical treatment. The main indication for neurolysis is hyperalgesic neuritis. The only contraindication is painless long-standing paralysis; in this condition the degree of neural fibrosis prevents any hope of improvement.
Enzymatic dissolution of nucleus pulposus by percutaneous injection of a papain preparation is now used frequently to treat lumbosacral disc hernias responsible for resistant sciatica. Mechanisms of action and techniques are reviewed, and the importance of applying strict criteria for indications for use emphasized. The method should be reserved for nerve root sciatica resistant to medical treatment or physiotherapy, and it constitutes the last stage of conservative treatment. Exclusion criteria are mainly "excluded" disc lesions, major dysfunction or associated spinal vertebral canal stenosis. The optimal indication is represented by the subacute disc hernia in the young. This alternative to open surgery in no way compromises the results in case of failure. Results obtained in a personal series of 150 cases are analyzed comparatively with those reported in the literature.
Percutaneous fine needle puncture of lymph nodes after lymphography with contrast has been performed in 174 patients with urogenital tumors (bladder: 108, prostate: 41, testes: 25). Conducted under direct television screen control the procedure is simple to perform and provokes little discomfort for the patient, since it is painless and relatively non-traumatic. Needle puncture is a reliable technique resulting in no false positives and very few false negatives when carried out using the previously described technique (routine sampling and technical success). Combining lymphography with needle puncture is of undoubted value for detecting extension of tumor and improving choice of therapy.
New prospects are foreseen in CT image processing via mathematical morphology (M.M.). M.M. is a set theory based upon the concept of "structuring elements" and allows texture analysis and pattern recognition by performing sequences of neighborhood transformations. This results in a wide range of quantifications. Mathematical morphology applied to CT densitometry allows obtaining the mean density of an organ after its automatic extraction from the background. This operation eliminates the approximations due to the manual selection of the Region of Interest (ROI). Precision, reliability and reproducibility are therefore improved. In this study, we performed the automatic isolation of a sole vertebral body in thoracic or abdominal CT slices to quantify numerous parameters, among them, density of the vertebral trabecular and cortical bones. On scans of the second and third metacarpals, morphomathematical analysis allowed quantification of the parameters of bone evolution: mean cortical density, directional cortico-diaphyseal index, and medullar area. In a different connection, M.M. has allowed automatic segmentation of lung parenchyma, the measurement of its mean density and the determination of the relative importance of the vascular network.
During a period of eight months thirty-two cases (twenty-two unilateral and five bilateral) of idiopathic carpal tunnel syndrome were studied at the Saint-Louis Hospital, Paris, France. The patients were found to benefit from the use of the preoperative technique, thermography in addition to routine clinical exams and complementary exams such as radiographs and E.M.G. The period of intervention was from the fifteenth day through the second and thirds months. By comparing the clinical and functional results before and after surgical treatment through the use of images from patients in the same condition, it can be concluded that the use of this simple technique can provide valuable information and is harmless in the care of idiopathic carpal tunnel syndrome. It is demonstrated that thermography permits: the ability to foresee the action of treatment; the ability to survey the effects of treatment and therefore obtain a valuable prognosis; and finally, a method of deciding on other acrosyndromes.
Explore the source record for details and available documents.
Interpretable cytologic data were obtained in 63% of a series of 68 punctures, for biopsy of hematologic affections, guided by CT scanning. The frequency of puncture of post-therapy residual masses (44 cases) explains the high incidence of non-significant examination results after lymph node puncture. The technique was most effective (78% of punctures exploitable) when used for thoracic masses and visceral localizations. The method is very safe: lack of serious incidents and minor reactions, mainly during thoracic puncture, in only 4.4%. The method is simple in use and should be employed, within certain limits that should be recognized, very widely in hematologic diseases.
Results of cervical myelography by the lumbar approach were compared with those of CT scan imaging after subarachnoid metrizamide by the lumbar route, in 16 patients operated upon for post-traumatic cervical spine lesions. Examination in each patient included the last four cervical and first thoracic roots on the injured side, making a total of 80 roots. Lesions detected by myelography and CT scanning are described, comparison of semiologic data with gross findings at operation showing poorer diagnostic accuracy for myelography (86%) than for myelography and a CT scan combined (97%). Sensitivity of the former varied between 70 and 90%, depending on whether doubtful forms were classed as normal or pathologic, but was lower than that of the CT scan (96%). This also applied to specificity (90% as against 96%) and diagnostic accuracy (86% to 90% as against 97%). Combining myelography with a CT scan after subarachnoid contrast injection provides complementary very precise data allowing improved therapeutic results.
Computed tomography analysis was conducted in 29 patients with 34 carpal canal syndromes to determine structural modifications of the wrist during the immediate preoperative period and two and three months after operation. The carpus was analyzed at 3 levels of the section: proximal at the entrance orifice of the canal, median and distal at the orifice of exit, with the wrist at rest and then in maximum active flexion and extension. Results showed that the increase of canal caliber (and therefore the decrease in local increase in pressure) continued during the second and third postoperative months, at rest as well as in flexion or extension. It appears, further, that opening of the canal does not alter structural organization of wrist bones or ligaments, the increases in caliber obtained varying in the same sense whatever the position of the wrist or the level of the section.
The influence of the fat content in the cancellous bone on CT densitometry was measured on the excised vertebrae from 42 elderly human subjects. Using single energy CT, the decrease of the measured mineral content was 12% for a fat content of 10% by volume at a mean mineral content of 100-110 mg/cm3. Using a dual calibration at 85 and 130 kVp with reference to K2HPO4 for mineral and to alcohol for fat, our experiment showed that the mineral content of the vertebra can be measured with an accuracy of 6% referred to the ash-weight.
An experimental study of the reproducibility and exactitude of densitometric measurements obtained by CT scanning showed: 1) the existence of marked variations due to factors related to the apparatus: beam energy, filtration, electronics, direction of rotation, reconstruction software; 2) that the structure of the object was also an influencing factor: variations in tissues surrounding the vertebra, and variations in bone density as a function of the plane in the vertebral body, and in fat content in the spongy tissue. Any measurement by CT scan of the mineral density of the vertebral body requires the use of a calibration phantom, strict definition of the volume to be measured, and routine correction for hypodensity induced by fat when necessary. Results under these conditions are reproducible and useful for the diagnosis of rarefying osteopathies.
The Queen Substance 1, a pheromone of the queen Honeybee Apis mellifica is an in vitro inhibitor of E. coli B tRNA methylations. This activity is not specific of the methylase source, as inhibitions have been observed with preparations from queen honeybee ovaries, Rat liver or a Mouse plasmocytoma 1-adenine methylase. These results, together with preceding ones concerning t, t-farnesyl-acetone 3, are discussed.
Explore the source record for details and available documents.
We measured the amount of 9-oxodec-2-enoic acid in virgin Honeybee queens 1 to 50 days old. We chose 4 age ranges: from 1 to 6, from 16 to 20, from 26 to 30, from 40 to 50 days. Queens 16 to 20 days old contain most 9-oxodec-2-enoic acid (average : 1 107 mug). The observed variations in amounts should partly depend on the physiology of attending workers. The authors discuss the mechanisms responsible for the action of 9-oxodec-2-enoic-acid.