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Biomedical subjects

L Lemaitre

Publications and source records attributed to L Lemaitre.

At least 19 recordsLinked to original sources
PubMed1995

Iohexol in patients undergoing urography: a comparison of polypropylene containers (Unique Soft Pack) and glass vials.

The purpose of the present phase IV multicentre trial was to evaluate general patient tolerance to Omnipaque 350 mgI/ml (iohexol) supplied in polypropylene containers compared to that of the same product supplied in routinely used glass vials, with emphasis on allergy-like adverse events. Polypropylene is a pure plastic material with practically no additives, and has been tested in vitro as a contrast medium packaging material for several years. Handling of these containers is easier and safer than handling of glass vials. Iohexol was administered to 1481 patients undergoing urography (741 patients in the glass vial group, 740 in the polypropylene container group), all of whom successfully participated in the trial. Six centres, representing four European countries, participated. Patients were randomized to receive iohexol from either polypropylene containers or traditional glass vials according to a double blind, parallel design. Pre-established inclusion and pre-admission exclusion criteria were followed, as well as routine procedures for preparation of the patients and conduct of the urography examinations at each hospital. Patient tolerance was assessed by recording all adverse events experienced over a period of up to 1 h after the procedure. Allergy-like events were defined as coughing, sneezing, nausea, vomiting, urticaria or itching. No adverse events were experienced by 56.5% of the patients in the glass vial group, nor by 58.0% of those in the polypropylene group. Discomfort (mainly a sensation of warmth) was reported by 39.4% and 38.6% of the patients, and adverse events other than discomfort by 7.4% and 5.9% of the patients, respectively. There seemed to be a correlation between the speed of injection and the frequency of discomfort (an increase with increasing speed), both of which varied a lot between centres. There was no significant difference in the incidence of allergy-like events between the two groups. Such reactions were seen in 2.0% of patients in the glass vial group and 1.9% of those in the polypropylene container group. There was no significant difference between the patients' tolerance to iohexol supplied in traditional glass vials or in polypropylene containers. Therefore, the new polypropylene container can be recommended as a container for Iohexol.

Adolescent↗
PubMed1995

Renal angiomyolipoma: growth followed up with CT and/or US.

PURPOSE: To follow up the growth of renal angiomyolipomas (AMLs). MATERIALS AND METHODS: Patients with known AML (n = 55) were divided into three groups on the basis of initial clinical and computed tomographic (CT) findings: group 1, isolated AML (n = 43); group 2, multiple AMLs without tuberous sclerosis (TS) (n = 6); group 3, multiple AMLs with TS (n = 6). Follow-up ultrasonography (US) and CT were performed in 55 and 31 patients, respectively. Growth of the AMLs (n = 59) was evaluated on the basis of area on initial and follow-up images. RESULTS: Mean percentage growth was 17%, 128%, and 47%, and mean growth rate per year was 5%, 22%, and 18% in groups 1, 2, and 3, respectively. New renal lesions were noted in three patients in groups 1 and 2, but no new lesions were detected in group 3, because of the large number of AMLs. New extrarenal lesions were observed in four, two, and three patients in groups 1, 2, and 3, respectively. No correlation was found between percentage of fatty tissue and growth rate. CONCLUSION: Multiple AMLs show more growth than solitary AMLs.

Adipose Tissue↗
PubMed1995

Congenital cholesteatoma of the temporal bone: MR findings and comparison with CT.

PURPOSE: To describe the MR findings of temporal bone congenital cholesteatoma and MR usefulness in preoperative diagnosis and follow-up, in comparison with CT. METHODS: Seven patients underwent CT and MR studies for facial palsy (n = 3), deafness (n = 3), vertigo (n = 1), tinnitus (n = 1), and otalgia (n = 1). Three patients had for congenital cholesteatoma previously undergone surgery. One of them was free of symptoms and referred for follow-up. Final diagnosis was obtained from surgical data in all the cases but one. RESULTS: Congenital cholesteatoma signal intensity was low or intermediate on T1-weighted images and high on T2-weighted images in all the cases. MR was useful in diagnosis in six cases, helping to differentiate congenital cholesteatoma from other nonenhancing tumors. When temporal bone wall erosion was observed with CT (n = 6), MR ruled out intracranial extension in five cases; in one case, MR found an associated epidermoid cyst of the cerebellopontine angle not identified with CT. However, CT assessed relationships with labyrinthine structures more easily. CONCLUSION: MR and CT are complementary in initial diagnosis and follow-up.

Adolescent↗
PubMed1995

Ultrasound assessment of ovarian stroma hypertrophy in hyperandrogenism and ovulation disorders: visual analysis versus computerized quantification.

OBJECTIVE: To extend our previous findings on the diagnostic validity of ovarian stroma hypertrophy in women with hyperandrogenic and/or menstrual disorders. DESIGN: Transvaginal ultrasonography was performed in 69 patients complaining of hyperandrogenism and/or menstrual disorders and in 48 normal ovulatory women in early follicular phase. To check the validity of stroma assessment by visual analysis, we used computer-assisted analysis, which allowed selective measurement of the stromal area on a longitudinal ovarian cut. Sensitivity and specificity of each method were estimated by using the normative data from the control group. RESULTS: Stromal area was considered to be increased using visual analysis and computer-assisted analysis in 74% and 61% patients, respectively. Specificity of this sign was 84% and 96% by visual analysis and computer-assisted analysis, respectively. In patients, the increase in stromal area correlated very significantly with the one of total ovarian area, whose upper normal limit was 5.5 cm2 per ovary. CONCLUSION: Visual assessment of stroma may be misleading in some cases, with the risk of overestimating its hypertrophy. An increased total ovarian area > 5.5 cm2 (which can easily be detected by carefully shaping a strict longitudinal ovarian cut) has the same diagnostic value as an increased stromal area by computerized measurement.

Adolescent↗
PubMed1994

Serial anatomy of the auditory tube: correlation to CT and MR imaging.

Serial anatomy of the auditory tube (AT), was studied in nine anatomical specimens, according to transverse, coronal and specific oblique planes and was correlated to computed tomography and magnetic resonance imaging. In order to assess the orientation of the oblique plane, parallel to the AT, 30 AT specimens were catheterized: the mean angle between the AT and the Virchow plane or the bony palate was 34 degrees. The bony portion is better explored with CT, whereas the cartilaginous portion is better studied with MR. The cartilage, posterior and medial, is closed anteriorly and inferiorly by a fibrous membrane (lamina membranacea), which is not seen on CT or MR images. The AT is closely related to the tensor veli palatini muscle (TVPM) anterolaterally, and the levator veli palatini muscle inferiorly (LVPM); both are well imaged on the oblique plane. They are bounded by fascias: the submucosal fascia (tela submucosa) is medial, the pharyngobasilar fascia runs between the TVPM and the LVPM and the auditory tube; the fascia of Weber-Liel is lateral to the TVPM. Fascias are difficult to distinguish from the surrounding fatty tissue and the adjacent muscles. The auditory tube and its muscles, forming the lateral wall of the nasopharynx, are well studied by CT and MR imaging, using the transverse or, preferably oblique plane, together with coronal plane.

Eustachian Tube↗
PubMed1994

Ovarian stromal hypertrophy in hyperandrogenic women.

OBJECTIVE: By using vaginal endosonography, ovarian stromal hypertrophy has been shown to be a strong diagnostic feature of polycystic ovarian syndrome and related states. However, this sign is difficult to quantify and to correlate with other findings because of its subjectivity. We have evaluated the use of computer assisted analysis of ultrasound scans to provide more objective measurements of ovarian structure and size. DESIGN: We used a computer assisted method for the reading of ultrasound scans. It allowed selective calculation of the stromal area by subtraction of the cyst area from the total ovarian area on a longitudinal ovarian section. PATIENTS: A consecutive series of 57 patients with hyperandrogenism (group 1), 17 patients with hypothalamic anovulation (group 2) and 20 normal women (group 3). RESULTS: By computerized measure, 75% patients from group 1 had a bilateral stromal area above the mean +2 SD (700 mm2) of women from group 3. All patients from group 2 were below this threshold. Serum LH level was above the normal range in 45% patients from group 1. The stromal area correlated positively with the serum delta 4-androstenedione (r = 0.47, P < 0.005) and 17 alpha-hydroxyprogesterone (r = 0.39, P < 0.005) levels, exclusively in group 1. It did not correlate with the basal serum testosterone, LH or insulin levels. The cyst area did not correlate with any hormonal parameter. CONCLUSION: Ovarian stromal hypertrophy is a frequent and specific feature of hyperandrogenism. It correlates with the ovarian androgenic dysfunction. Its presence is not always linked with elevated serum immunoreactive LH levels. Further data are needed to elucidate the role of insulin and ovarian growth factors.

17-alpha-Hydroxyprogesterone↗
PubMed1991

Compressive strength of some polyalkenoates with or without dental amalgam alloy incorporation.

The present study compares the compressive strength after one week of some conventional glass-ionomer restorative materials with that of glass ionomers reinforced by the addition of ceramic-coated silver or dental amalgam alloy particles to the aluminosilicate glass powder. Apart from the commercially available Ketac Silver and Miracle Mix, experimental mixtures of Fuji II glass-ionomer powder, the old as well as the new version, with various amounts of either a spherical or lathe-cut amalgam alloy were investigated. For the conventional glass ionomers, the mean compressive strength based on all measurements amounts to 159.9 +/- 4.5 MPa. Both formulations of Fuji II have a comparable strength after one-week maturation. The compressive strength of Ketac Silver does not differ significantly from that of Ketac Fill or from that of the conventional glass ionomers investigated. The effect of admixing amalgam alloy on the compressive strength is found to be determined by the shape and the amount of the alloy particles. Moreover, both parameters are interactive with the formulation of the Fuji glass ionomer used for preparation of the mixture. The results indicate that when dental amalgam alloy is added to the glass ionomer, lathe-cut particles are to be preferred but only in an amount up to 20% by weight.

Analysis of Variance↗
PubMed1991

Polycystic ovarian disease: contribution of vaginal endosonography and reassessment of ultrasonic diagnosis.

OBJECTIVE: We evaluated the superiority of vaginal ultrasonography (US) on the abdominal US for the diagnosis of polycystic ovarian disease (PCOD). DESIGN: The US pattern of ovaries was prospectively investigated by abdominal US and, whenever possible, by vaginal US. SETTING: Primary care, institutional. PATIENTS: One hundred forty-four women in whom PCOD was suspected on endocrine grounds and 62 other patients presenting with primary hyperprolactinemia (n = 23) or hypothalamic anovulation (n = 39). MAIN OUTCOME MEASURE: Vaginal US allowed a better analysis of the ovarian stroma. RESULTS: The external ovarian features of PCOD were observed by both routes in less than one third of the 144 patients with PCOD. The internal ovarian features of PCOD were much more frequently observed by vaginal US than by abdominal US (polycystic pattern: 66.7% versus 38.1%, P less than 0.05; increased ovarian stroma: 57.1% versus 4.8%, P less than 0.001). In the 62 patients without PCOD, US features of PCOD were observed in less than 10% of them, except for the uterine width/ovarian length ratio less than 1 and the polycystic pattern (abdominal US: 17% and 34%; vaginal US: 11% and 50%, respectively). CONCLUSIONS: An increased ovarian stroma seems to be the most sensitive and specific US sign of PCOD, providing that it can be investigated by vaginal US.

Abdomen↗
PubMed1991

[Normal imaging of facial sinuses].

The high spatial resolution of computed tomography allows visualisation of the fine structures of the facial skeleton and gives precise information about the anatomy of the nasal cavity, the paranasal sinuses and their relations with adjacent structures. A detailed knowledge of the normal anatomy, particularly of the nasal cavity and ethmoid, is very useful to provide to the surgeon with a precise pre operative surgical map, before transnasal endoscopic ethmoidectomy or management of paranasal sinuses tumors.

Humans↗
PubMed1990

[Computed tomography of the abdomen in 8 cases of pancreatic trauma].

Computed tomography (CT) is an accurate method for detecting pancreatic trauma. There are two pitfalls to its use: the indication of CT and the risk of misinterpretation. The purpose of this study was to evaluate these 2 difficulties. We report our experience and results obtained in 8 patients with pancreatic trauma (7 closed, 1 open). Peritoneal lavage demonstrated an increased amylase level in the fluid in 2 of our patients. Computed tomography was performed as an emergency diagnostic test for 2 patients and secondarily in 6 patients. In 5 patients, the pancreatic injury was considered to be deep with suspicion of a major pancreatic duct lesion and in 3 patients, the lesion was superficial. Six patients had operative confirmation of the CT results. Pancreatic injuries were classified according to Hervé and Arrighis. Four were grade III, 1 grade II, 1 grade I, while CT showed 5 deep injuries and 1 superficial injury in these patients. Two patients with CT signs of superficial injury were not operated. When there is a clinical suspicion and/or a high amylase level in serum, urine or fluid collected from peritoneal lavage, CT must be carried out as part of in the overall strategy of management of isolated pancreatic trauma. We believe that CT is a valuable tool to evaluate the extent of the injury to the pancreatic parenchyma.

Adolescent↗
PubMed1990

[A superior vena cava syndrome of unusual etiology: compression syndrome of the innominate veins].

A 65-year-old hypertensive and atheromatous presented with "unilateral superior vena cava syndrome". Venography and computed tomography scan with hemodynamic studies demonstrated an intermittent compression of the left innominate vein by the supra-aortic trunks, mainly due to the left subclavian artery, during expiration. The late development of symptoms might be due to arterial atheroma coupled with a narrow superior mediastinum. The case described here is a thoracic equivalent of Cockett's syndrome and so can be called "innominate vein compression syndrome".

Aged↗
PubMed1989

A model for the corrosion behavior of dental amalgams.

At high frequencies, electrochemical impedance behavior for corroding dental amalgams cannot be interpreted in terms of a simple Randles equivalent circuit. This may often be ascribed to the imperfect cell geometry resulting in a nonuniform current distribution. However, the insertion of a constant phase element (CPE) in the non-faradaic branch of the equivalent circuit offers a new scope for interpretation as the circuit provides an m-parameter corresponding to the degree of distortion. The decrease of m as a function of time was explained by a mathematical model reflecting an increasing number of pores. Moreover, that same model allows a better understanding of the passivating effect of NaHCO3 and of the differences between conventional and Cu-rich dental amalgams.

Biocompatible Materials↗
PubMed1989

A mechanistic study of the electrochemical corrosion of the gamma 2 phase in dental amalgams. I. Evaluation of the measurements.

Conventional dental amalgams are prone to corrosion of the gamma 2 phase. In an anodic polarization experiment the presence of gamma 2 causes a current peak in the proximity of -250mV vs. SCE. Electrochemical impedance measurements carried out at this potential indicate the occurrence of an impedance curve in two parts. The high frequency part is a semi-circle with its centre below the real axis. Apart from the faradaic impedance and the double layer capacitance, the high frequency part is dominated by the behaviour of the corrosion products layer on the amalgam surface. The low frequency part has the form of a diffusion-like curve. However, since the phase angle is smaller for the above-mentioned case than for a free diffusion, this phenomenon is ascribed to diffusion in a porous layer at the interface between amalgam solution.

Corrosion↗
PubMed1989

A mechanistic study of the electrochemical corrosion of the gamma 2 phase in dental amalgams. II. Introduction of a model.

Electrochemical impedance measurements on conventional dental amalgams at an anodic polarization potential of -250 mV vs. SCE were performed. An initial evaluation was given in part I of this study; in the second part the results are interpreted in terms of a model. The latter, characterized by an equivalent circuit, is a parallel combination of a flat surface and a pore. The selection of appropriate values for the elements of the equivalent circuit leads to a better insight into the corrosion process. Although no simple relationship exists between the circuit elements and the impedance curves, an explanation was found for some typical features of these curves. As an application, the influence of the anodic polarization potential on the impedance curves was studied. Evaluation by means of the model demonstrated the importance of the characteristics of the corrosion products.

Corrosion↗