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Biomedical subjects

G Lemaitre

Publications and source records attributed to G Lemaitre.

At least 19 recordsLinked to original sources
PubMed1994

FGFs and their receptors, in vitro and in vivo studies: new FGF receptor in the brain, FGF-1 in muscle, and the use of functional analogues of low-affinity heparin-binding growth factor receptors in tissue repair.

Several heparin-binding growth factors (HBGFs) are thought to play a key role in the natural processes of tissue homeostasis, regeneration or repair. The HBGFs are active upon release from neighbouring inflammatory or circulating cells, as well as upon release from heparan sulfate proteoglycosaminoglycans that are associated with the extracellular matrix (ECM). To better understand the physiological role of these HBGFs, we have focused our effort on studying a subset of HBGFs, namely FGF-1 and FGF-2 and their receptors. We present the purification and characterisation of a new form of heparin-binding FGF receptor from adult bovine brain (Perderiset et al., 1992). This receptor has now been purified to homogeneity. Ligand blot and cross-linking experiments performed with labeled FGF-1 or FGF-2 revealed 80-kd and 130-kd bands. Preliminary sequence information indicates that receptor is different from the receptors, FGFR-1 to -4, but it may be related the cysteine-rich-FGF receptor (CFR). We have previously shown that FGF-1, but not FGF-2, is specifically expressed in myoblastic satellite cells during the proliferating phase preceding myoblast alignment and fusion. We have now transfected primary cultures of rat myoblastic satellite cells with FGF-1 cDNA and expressed this growth factor constitutively. The transfected cells were no longer able to form myotubes. Transfection with antisense FGF-1 induced myotube formation suggesting that endogenous expression of FGF-1 is associated with myoblastic cell differentiation. Numerous studies have concluded that the ECM represents a natural reservoir for various HBGFs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

[X-ray computed tomographic diagnosis of connective tissue tumors of the stomach of extrinsic development. Apropos of 6 cases].

Computed tomography findings appear to be very useful for the diagnosis of exogastric tumors on the basis of six cases: 4 leiomyosarcomas, 1 leiomyoblastoma and 1 schwannoma. The diagnosis of these usually large tumors arising within the gastric wall is often difficult through baryum opacification of the stomach (U.G.I.) owing to their exogastric growth. In the same way, endoscopy usually fails to evidence these tumors. Computed tomography permits to rule out an extrinsic tumor such as a hepatic or pancreatic one for instance and then to demonstrate the tumor originates within the gastric wall. The hypervascular pattern associated in most cases with central necrosis is demonstrated through contrast medium injection, what is a very typical and relatively constant-finding in these tumors.

Aged↗
PubMed1986

[X-ray computed tomography in pheochromocytoma. Apropos of 20 cases].

Study of 20 pheochromocytomas in 19 patients confirmed the remarkable sensitivity of computed tomography (100%) for the detection of their adrenal and juxtarenal localizations. However, ultrasonography was as effective as the CT scan in these same patients, and even detected latent tumors in several cases. Certain pheochromocytomas in this series presented unusual appearances, particularly two large tumors which were manifest as abdominal masses and a malignant form which provoked a total infarct of the homolateral kidney.

Adrenal Gland Neoplasms↗
PubMed1986

[Sensitivity of bone to parathyroid hormone in type I pseudohypoparathyroidism. 6 cases].

The sensitivity of bone to parathormone in pseudoparathyroidism is not well known. Six patients with Type I pseudohypoparathyroidism (4 with Albright's osteodystrophy) had increased alkaline phosphatase levels (5 patients) and radiological signs of periosteal resorption in the hand in one case. All patients had histological signs of increased surfaces of resorption and periosteocytic lacunae, increased osteoid surfaces and relative osteoid volume with no change of the index of osteoid thickness. These changes are identical to those observed in hyperparathyroidism which leads on to the discussion of the role of the increased parathormone secretion induced by the lack of calcium on the remodeling of bone. Our six cases show that there is no bone resistance to parathormone. The diversity of bone changes in hyperparathyroidism, similar to that of primary hyperparathyroidism, is without doubt dependent on the degree of renal insensitivity to PTH through the inactivation of vitamin D.

Adolescent↗
PubMed1986

[Computerized tomography in evaluating the extension of bladder tumors. 215 cases].

CT scan imaging was used to explore 215 cases of bladder tumor (48 A-B1, 55 B2, 85 C, 27 D), and findings compared with those at operation and on histopathology of specimens after total cystectomy (141 cases), partial cystectomy (13 cases) or endoscopic resection (61 cases). The radiologic technique used was that of natural contrast, evaluating the negative contrast of intravesical urine in relation to the normal or pathologic bladder wall. Analysis of scan sections, assisted by a previous pathologic and radiologic study of 14 transverse sections of pelvis, allowed definition of a certain number of semiologic criteria corresponding to the various stages of the disease. Results showed global reliability to be relatively satisfactory for assessment of local and regional extension (85%): it was obviously a more effective investigation for tumors of low invasion (A-B1: 75%, B2: 81%) than for widely infiltrating tumors (C: 94%, D: 93%). Glandular extension was less reliably evaluated, however, since global efficacy was only 65%. Failures observed can be explained by the frequent small size of the metastatic glands, the poorness in cellular and fatty tissues and, particularly, by the fact that the scanner provides data of size of glands only and not on their internal architecture. The place of the scanner among other paraclinical methods of evaluating tumoral extension has still to be determined.

Humans↗
PubMed1985

Medical treatment of hyperprolactinemia.

The current treatment of choice for primary hyperprolactinemia is medical. This is true not only for idiopathic forms, but also for micro- and macroprolactinomas, which are the most frequent causes of this pathology. Although questioned by some authors, the slow evolution of the illness, the rarity of transformation of a microadenoma into a macroadenoma, and the possibility of spontaneous cure cause most authors to favor medical treatment, with which they observe both normalization of gonadal function and tumor regression. By retrospective analysis of 95 hyperprolactinemic patients (72 women and 23 men including 26 cases of suspected microadenoma and 44 macroadenomas) treated with 3 dopamine agonists (bromocriptine, metergoline and CU 32085) between 1975 and 1983, and with the help of large series published in the literature, we have tried to review the present knowledge of this subject. After a quick review of different medications, we will consider their prolactin-suppressing effects, their influences upon gonadal and gonadotropic functions, and their antitumoral action. More specific problems will then be discussed: side effects, resistance, possibility of cure, the evolution of the prolactinoma, the place of medical therapy relative to surgery, and contraception in association with dopaminergics.

Adenoma↗
PubMed1985

Treatment of human hyperprolactinaemia with a new dopamine agonist: CU 32085 (mesulergin).

CU 38085 (mesulergin) was given at doses ranging from 0.5 to 5 mg/day to 37 patients with pathological hyperprolactinaemia of varying aetiology. The effectiveness of this drug on the suppression of hyperprolactinaemia and on the recovery of gonadal functions was equivalent to that of bromocriptine previously given to a different group of 83 hyperprolactinaemic patients. Tumour shrinkage during treatment with CU 32085 was ascertained in two cases of macroprolactinoma. Histological examination after adenomectomy revealed extensive peri-vascular fibrosis in both cases. In most patients, the efficient doses of CU 32085 were 5-fold lower than those of bromocriptine. After acute oral administration in 10 previously untreated patients, 0.5 mg of CU 32085 had a more prolonged suppressive effect on Prl levels than 2.5 mg of bromocriptine (approximately 18 vs 12 h). According to this, 0.5 mg CU 32085 once a day was sufficient to maintain Prl levels within the normal range in 16 patients. Side-effects were similar in nature and frequency to those induced by bromocriptine and seemed to be dose-dependent. They can be avoided by slowly increases of dose at initiation of treatment.

Administration, Oral↗
PubMed1985

[Efficacy of modern imaging technics in the diagnosis of isolated angiomyolipoma of the kidney. Apropos of 11 cases].

Ultrasound and computed tomography imaging techniques are very reliable methods of detection and diagnosis of renal angiomyolipoma not associated with the tuberous sclerosis of Bourneville's disease: results are considerably improved when compared with conventional investigations (IVU, arteriography). The series reported included 6 patients with large angiomyolipomas and 5 with lesions less than 2 cm in diameter discovered fortuitously on ultrasonography: all tumors were partially or totally hyperechogenic. The fatty tissue was detected in 9 of the 11 cases by computed tomography imaging.

Adult↗
PubMed1984

[X-ray computed tomography in the diagnosis of non-advanced stages of renal polycystosis in adults].

At early of non-advanced stages, the diagnosis of adult type polycystic disease may be very difficult using standard morphological techniques: IVU, echotomography. The CT scan is sometimes a decisive diagnostic feature when it shows diffuse invasion of parenchymal tissues by large numbers of cysts, certain measuring only millimetres. Its contribution is emphasised in five cases where the diagnosis was only suspected or envisaged by IVU and echotomography. In 4 of these cases the diagnosis of polycystic disease was confirmed by CT scan.

Adult↗
PubMed1984

[X-ray computed tomography and echography in the diagnosis of subcapsular hematoma of the kidney].

Results and diagnostic value of computed tomography and ultrasound imaging in subcapsular hematoma of the kidney are discussed in relation to data from 9 cases. A positive diagnosis could be made in each case from CT scan images, but results of ultrasonography were less evident. An etiological diagnosis is difficult to establish and extreme caution is recommended before excluding a tumoral lesion, even in patients developing hematomas during anticoagulant treatment. Arteriography remains a valid examination since analysis of a large subcapsular hematoma by a CT scan is often risky, and a small cortical tumor may remain undetected.

Adult↗
PubMed1984

[Pyelomanometry in obstructions of the upper urinary tract. Apropos of 26 cases].

Pyelomanometry can be used in cases of ambiguous dilatation, to measure the pressure in the upper urinary tract during constant-flow perfusion through a percutaneous catheter (Whitaker's test). After recalling the principles of this method, and the technical procedure, the authors go on to discuss twenty six cases, analyzing the results, and comparing the advantages of this procedure with other methods of exploration.

Adolescent↗
PubMed1982

[Agnathia, apropos of a case].

A male 32 weeks still-born with agnathia is reported. Other malformations are pointed out: microstomia, microglossia, type III microtia and meatal atresia. There are vertebral clefts of D7 et D10. Probands and parents chromosomal analysis are normal. Mother is 28 years old, gravida 7, para 3 and father is 46 years old. They are algerian, healthy, non related. A single one male child is alive and in good health.

Abnormalities, Multiple↗
PubMed1982

[Normal intrahepatic vessels. Remarks on their echographic image].

The sonographic appearances of intrahepatic vessels are demonstrated by the basic principles of ultrasonography. All intrahepatic vessels have a sonolucent lumen which may be blurred because of the slice-thickness effects. The vascular walls are detected only when they are perpendicularly struck by the ultrasound beam. The portal branches are visualized with satellite echoes which are reflections from the intraparenchymal hepatic arteries and/or biliary ducts, and from the collegenous sheath of the portal triad. These echoes are blended with the wall-echoes of the portal veins as to the major branches. For smaller branches they remain visible when the incidence of the ultrasound beam becomes less accurate, whereas the echoes from the portal veins tend to disappear. The echoes related to the hepatic veins only come from the walls of the veins, which are usually of medium size.

Bile Ducts, Intrahepatic↗