Biomedical subjects
Publications and source records attributed to J L Lamarque.
The meglumine salt of TCA, a piperidinyl nitroxide stable free radical derivative, was tested as an NMR contrast enhancer. This report of its use in animals indicates its usefulness in the enhancement of signal intensity of the kidney and bladder.
A secreted glycoprotein with a molecular weight of 52,000 is induced by estrogen in breast cancer cells and has been purified to prepare monoclonal antibodies. The protein has been detected in some breast cancers but not in normal breast and uterus. In order to study its potential value as a marker, we have tested by immunohistochemistry frozen sections of several normal and malignant tissues and of benign mastopathies. Among different tissues tested, the Mr 52,000 protein was detected only in liver, sweat glands, and some sebaceous glands, and in malignant melanomas and some breast tumors. Other estrogen-responsive tissues (ovary, placenta, endometrium, etc.) gave negative results. Immunoradiometric assay of the Mr 52,000 protein in biological fluid revealed an elevated concentration in cyst fluid (0.5 to 7.4 micrograms/ml), pleural effusions of certain metastatic breast cancer, and sweat. By immunohistochemistry, the Mr 52,000 antigen was also detected in 42% of 129 benign mastopathies. Gynecomastia, fibrous disease, fibroadenoma, and adenosis were mainly negative, whereas ductal hyperplasia and cysts were positive. The Mr 52,000 protein was found mostly in proliferative ducts and in cysts but not in lobular hyperplasia and nonproliferative lesions without cyst. More Mr 52,000 protein was found in postmenopausal patients than in premenopausal patients. We conclude that the Mr 52,000 protein is a marker associated with mammary cysts and proliferative ducts. On the basis of the increased risk of breast cancer in proliferative mastopathies, we suggest that the Mr 52,000 protein is useful for predicting high-risk mastopathies acting as a marker associated with the proliferation of ductal tissue.
Theoretical concepts underlying the principle of nuclear magnetic resonance imaging are defined and the technical basis for its use in medical imaging described (sequences, accumulations, contrast media). Results are presented of a spectrometric study of 23 operative specimens from the bladder, prostate and seminal vesicles with analysis in vitro of relaxation time of the various tissues. Findings confirmed the value of NMR imaging for evaluation of macroscopic extension of tumors within the affected organs, as well as the interrelations of the organs, but the impossibility of identifying histologic structure of tumors and organs explored by this technique. Two groups of subjects were studied: a first group of 20 healthy volunteers to define NMR semeiology of male pelvis and a second group of 40 patients with mainly tumoral lesions of vesicles or prostate. Details are provided of the diagnostic value of NMR imaging with respect to the tumor, local and regional invasion and bone metastases. Excellent images of the tumor were obtained, with the possibility of determining its macroscopic stage, but its histologic nature could not be ascertained. Multiplane examination allowed better assessment of local and regional spread than by a CT scan, particularly for prostatic tumors (bladder, prostate bed or seminal vesicle extension). A negative feature of major importance exists, however, in that early glandular involvement is not detected by NMR imaging, which also fails to identify one case in two with bone metastases. Current research should allow progressive correction of present NMR imaging insufficiencies, notably in the field of tissue characterization.
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Computed tomography was performed in 38 patients with a recent abdominal trauma. Results of this procedure are presented in lesions of the spleen (4 cases), liver (15 cases), pancreas (6 cases), gastrointestinal tract (2 cases), kidney (15 cases). Indications of computed tomography in emergency are only limited by the small number of units. Computed tomography should play an important role in the management of patients with a severe abdominal trauma.
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Changing different parameters involved in imaging procedures, paramagnetic substances provide contrast enhancement in MRI. Contrast agents presently studied in animals and clinical trials, are either salts or complexes of mineral ions either nitroxide stable free radicals. Their development should extend the possibilities of tissular characterization and functional or metabolic evaluation of the MRI.
Since a valid macroscopic investigation fundamentally cannot exist without its basis in microscopy, we are seeking to identify characteristic echo structures by means of acoustical microscopy at frequencies of 600 MHZ and 1 GHZ in order to better understand ultrasonography in everyday practice and to determine reliable and specific imaging characteristics of the different components of breast tissues. We have studied slices of mammary tissue 5-10 microns thick which had been removed during surgery. Acoustical imaging has to be performed in transmission mode as well as reflection mode. The intrinsic acoustic contrast is more than sufficient to obtain good visualization of different tissue components of the mammary gland. We noted, however, that even if the microscopic acoustic images were of good quality--often as good as light microscopy--certain tissue components such as the epithelium are irregularly visualized. It appears that the effective visualization of a structure depends entirely upon this acoustical environment.
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This study reveals the continuing great viability of angiography in the investigation of abdominal masses. It is a fundamentally important procedure within the context of presurgical evaluation. Certain points should be underlined. - The radiological definition of the histological nature of an abdominal mass during angiography remains difficult, practically impossible in certain regions. - Borrowed vascularizations still pose complex diagnostic problems at different levels. - The benefit of angiography should be compared with other modern radiodiagnostic methods, especially the less aggressive ones. - The importance of each of these points has led us to develop them separately: - The diagnostic reliability of angiography in abdominal masses (from anatomico-radiological correlations). To be published - The borrowed vascularisation of abdominal masses. To be published - The tomodensitometry of abdominal masses. To be published - Diagnostic strategy in case of an abdominal mass. To be published.
Using figures from the literature and from our own case material, the diagnostic efficiency of the barium meal, computerized tomography, angiography, ERPC and biopsy have been compared in acute and chronic pancreatitis, pancreatic and papillary carcinoma and islet cell tumour. In acute pancreatitis, CT is the method of choice. In chronic pancreatitis, ERPC has the highest diagnostic accuracy. Furthermore, it is capable of giving an indication for operative intervention, and facilitating the choice of operative method. In pancreatic carcinoma, combination of ERPC, angiography and/or biopsy provides the highest diagnostic accuracy. Angiography and ERPC can provide early diagnosis, and angiography and CT can predict the operability of a tumour. CT is also the most important of the non-invasive diagnostic techniques. Carcinoma of the papilla is easily and reliably recognized by endoscopy. For islet cell tumours, angiography still remains the method of choice.
Many lesions, and particularly hyper-vascularized ones, acquire an aberrant blood supply. These parasitic vascular supplies are defined as tumour vascularizations derived from neighbouring organs or structures, and supplement the normal blood supply of the diseased organ. Their existence is essential for the angiography of abdominal masses. We selected 35 cases of abdominal masses with parasitic vascular networks. Twenty-four belonged to an initial review of 117 angiographic studies of abdominal masses. Eleven have been added in accordance with the theme of this work. Parasitic circulations should be taken into account because of their effects on the angiographic technique, their diagnostic possibilities and limitations, and their importance in the management of the patient.
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During experimental utilization on the dog (per os) of several types of materials capable to be modified by the liver after digestive absorption, sugars appeared naturally opaques in the gastric cavity and so they could substitute in C.T. to the habitual materials of contrast, we also notice some belated modifications on intra hepatic density that might be in relation with the metabolism of intra hepatic glucose.