Search PubMed⌕ Search

Biomedical subjects

Y Lefebvre

Publications and source records attributed to Y Lefebvre.

At least 19 recordsLinked to original sources
PubMed2002

[Traumatic bilateral rotatory C1-C2 dislocation in an adult: case report and review of the literature].

Trauma led to bilateral rotatory atlantoaxial dislocation in a 23-year-old woman. Clinical diagnosis of this uncommon dislocation of the cervical spin is generally difficult and often made late. Typical signs include pain in the upper cervical spine and a fixed rotated position of the head. Integrity of the transverse ligament of the atlas is a determining factor for atlantoaxial stability and allows orthopedic treatment after reduction using moderate traction on the head. As for most authors, orthopedic was successful in our patient who totally recovered cervical spine mobility without pain.

Accidents, Traffic↗
PubMed2001

US and CT diagnosis of complete cecocolic intussusception caused by an appendiceal mucocele.

Appendiceal mucoceles are found in only 0.2-0.3% of all appendectomy materials. Colocolic intussusception of the appendix is also very uncommon. We report the very rare association of these two entities in a 40-year-old patient presenting with intermittent right abdominal pain accompanied by a palpable mass in the right flank. The full diagnosis was made preoperatively by ultrasound and confirmed by helical CT by means of unequivocal signs of intussusception associated with a very suggestive "cup-and-ball" aspect of the mucocele induced by a global mucinous cystadenoma of the appendix. A brief review of the available literature on mucocele is given.

Adult↗
PubMed2001

[Bilateral subtotal scapulectomy for chondrosarcoma in Ollier's disease within a 16-year interval].

PURPOSE OF THE STUDY: We report the case of a young man with Ollier's disease who underwent three successive procedures for sarcomatous degeneration of some of his endochondromatous lesions. From the age of twenty, the patient required surgery for resection of a cartilage tumor of the body of L5, amputation of the right index finger, and successive right then left subtotal scapulectomy. At 40 years, the patient presents other stable lesions, mainly located on the right side of the body. We were particularly interested in the functional outcome of the two shoulders in this patient who continues to have normal social and occupational activities.

Adult↗
PubMed2001

[Failure of acetabular cups fixed with cement and thick embedded wire mesh].

PURPOSE OF THE STUDY: We report our experience with the SKH(R) cemented acetabular cup, analyzing the clinical and radiographic consequences of using cement armed with a thick embedded wire mesh. MATERIAL AND METHODS: Between June 1990 and June 1991, 118 total hip arthroplasties (THAs) were performed in 110 patients (8 bilateral cases) using the SKH(R) cemented acetabular cup, a self-blocking cemented femoral stem with anterograde injection made of a Ti-6Al-7Nb alloy and a 28 mm ceramic polyethylene articulation. Mean follow-up for 97 implants (91 patients) was 7.1 years (3 - 9 years). Mean age at implantation was 65 years (36 - 85 years) (43 men and 48 women). THAs were performed for degenerative joint disease (n=79) including 67 cases of primary disease, necrosis (n=11), rheumatoid disease (n=6), and fracture of the femoral neck (n=1). RESULTS: For the 118 procedures, there were 4 complications: 2 dislocations (no revision), one failure of the ceramic head and one implant infection (with revision). As assessed by the Postel-Merle-d'Aubigné score as modified by Charnley for the mobility criterion, clinical outcome was excellent or good in 82% of the cases, fair in 11% and poor in 7%. According to the Massin criteria at last follow-up, there were 13 cup loosenings (13.4%, 10 migrations and 3 total lucent lines > 1 mm); revision procedures were performed in 6 cases. A lucent line postoperatively, observed in 51% of the cases (p=0.025) and involving all or part of zone 1 in 44% (p=0.047), was predictive of acetabular failure. Linear polyethylene wear as measured manually was 0.08 mm/year (average) for non-loosened cups and 0.2 mm/year for loosened cups; the difference was significant (p=0.001). On the contrary, the thickness of the cement, measured at the limits of the three De Lee and Charnley zones, cup tilt and size, age, weight and patient activity level had no effect on failure rate. Actuarial survival of the cup at 9 years was 86.3% taking aseptic loosening (with or without revision) as the failure criterion and 93.8% taking revision for aseptic loosening as the failure criterion. DISCUSSION: These results were rather disappointing. The thick layer of cement reinforced with the wire mesh produces a metal back effect with the known consequences in terms of loosening, cement-bone lucent line, and polyethylene wear. A modification is now undergoing thermal and mechanical assessment. A thinner and tighter mesh would appear to be preferable.

Acetabulum↗
PubMed2001

[Straight femoral taper in cementless primary total hip replacement in less than 65 year-old patients: multicenter study of 115 consecutive implantations at mean 8,2 year follow-up].

PURPOSE OF THE STUDY: The Swedish Arthroplasty Registry experience with cemented primary total hip arthroplasty (THA) has pointed out age below 65 and high activity level as 2 major factors impairing THA long-term outcome. The aim of this study was to provide intermediate results of cementless femoral replacement in primary THA with use of the Alloclassic-SL grit-blasted titanium stem in "high risk" groups of patients. MATERIAL AND METHODS: From June, 1988 to June, 1992, 127 cementless primary THA's were consecutively performed in<65 year old patients in 2 institutions. Acetabular components were all cementless (threaded cup in 74%) and bearing surfaces were all alumina-ceramic 28mm heads on polyethylene (PE). Five patients (6 hips) died and 6 other hips were lost to follow-up before the 5-year minimum follow-up. Thus, 115 hips in 106 patients could be fully reviewed after a 8.2 year average follow-up period (range, 5 to 12 years). Mean age at surgery of the 62 male and 44 female patients was 52 years (range, 27 to 65 years). RESULTS: Of the index group (127 hips), intra-operative fracture of the greater trochanter and early dislocation were noted in 4.7% and 3.2% of hips, respectively. Of the study group (115 hips), clinical results according to the Merle d'Aubigné and Charnley rating system were graded excellent and good in 94% of hips and fair in 6% (7 hips), with no poor result. Radiologically, early subsidence of more than 2mm could be detected in 8 hips (7%). Calcar atrophy and spot welds were noted in 81% and 89% of hips, respectively. Proximal reactive and lucent lines and mild proximal stress shielding were observed in 10.5% and 4.3% of hips, respectively. Ten-year survivorship with stem revision for any reason as the end point was 99.2% (92.4-99.9) (1 stem exchanged and reoriented for immediate dislocation). One revision is pending for extensive femoral osteolysis due to polyethylene (PE) wear. There was no stem fracture and no ceramic head breakage thus far. Overall PE-wear rate ranging 1-2 mm was detected in 13 hips (9.6%) and femoral osteolysis in 4 hips (3.5%). DISCUSSION: Mid-term results of this cementless straight taper at 10 year are at least equal to those of well performing cemented components, even in "high risk" groups of patients. Conversely, 28mm alumina-ceramic heads can reduce but not prevent the occurrence of PE-wear in such a healthy and active population. CONCLUSION: Press-fitting but not filling the femoral canal with rough titanium straight tapers like the Alloclassic-SL femoral component represent a promising alternative to modern femoral cementing technique in primary THA. Improvement is expected through the use of more wear resistant bearing surfaces.

Adult↗
PubMed2000

Optical Spectroscopy of Diatomic Species: Copper with Group 14 Elements (Si, Ge, Sn, Pb).

Electronic band systems of the gaseous diatomic compounds of copper and various X elements of the 14th column (Si, Ge, Sn, Pb) have been observed by thermal excitation in the red part of the visible spectrum. Vibrational analysis of the two subsystems observed for each of these molecules (except for CuPb with only one system) are reported and assigned as (2)Sigma(+)-(2)Pi(3/2) and (2)Sigma(+)-(2)Pi(1/2) transitions. The variation of the spin-orbit splitting of the (2)Pi lower states from CuSi to CuSn follows closely that of the np shell spin-orbit parameters in the group 14 atoms. This fully corroborates previous ab initio calculations that predict a (2)Pi(r) ground state with the ionic Cu(+) (3d(10))X(-)(pvarsigma(2)ppi) configuration for these molecules. Copyright 2000 Academic Press.

Journal Article↗
PubMed1999

Hazards of laparoscopic adrenalectomy for Conn's adenoma. When enthusiasm turns to tragedy.

A 74-year-old man with primary aldosteronism had a small tumor (27 x 23 mm) of his right adrenal gland successfully removed by a transperitoneal laparoscopy. Despite absence of malignancy in the resected tumor and complete relief of all symptoms in the immediate postoperative period, recurrence occurred 6 months later. The tumor behaved as a carcinoma spread in the peritoneal cavity, and the patient eventually died with peritoneal carcinomatosis. We suggest that the laparoscopic technique coupled with pneumoperitoneum may have favored this recurrence.

Adenoma↗
PubMed1997

Gender sensitivity in medical curricula.

Both sex--the biologic aspects of being female or male--and gender--the cultural roles and meanings ascribed to each sex--are determinants of health. Medical education, research and practice have all suffered from a lack of attention to gender and a limited awareness of the effects of the sex-role stereotypes prevalent in our society. The Women's Health Interschool Curriculum Committee of Ontario has developed criteria for assessing the gender sensitivity of medical curricula. In this article, the effects of medicine's historical blindness to gender are explored, as are practical approaches to creating curricula whose content, language and process are gender-sensitive. Specific areas addressed include ensuring that women and men are equally represented, when appropriate, that men are not portrayed as the prototype of normal (and women as deviant), that language is inclusive and that women's health and illness are not limited to reproductive function. By eliminating or at least addressing the subtle and often unintentional gender stereotyping in lecture material, illustrations and problems used in problem-based learning, medical educators can undertake a much-needed transformation of curriculum.

Adult↗
PubMed1996

Teaching Surgical Hysteroscopy with a Computer

Using a hysteroscope can be simulated on a computer. It will improve physician training by measuring basic knowledge and abilities, allow different interventions and anatomic variations, minimize the trauma of surgical intervention, and reduce operative casualties. An integrated questionnaire covers instrumentation, fluid infusion, power source, indications and preparation for endometrial ablation, surgical techniques, and complications to evaluate the user's knowledge. The operation simulation then proceeds. In the endometrial cavity, by virtual simulation, the operating field should appear in real time to allow physicians to adapt the trajectory of the instruments. The computer is an IBM PC compatible. We use a modified joystick with optical encoders to know the instrument position. The simulation can be repeated as desired. An evaluation system is integrated in the software to keep the user informed on the amount of burn area(s) that have been completed. This prototype model is available.

Journal Article↗
PubMed1995

[Prostatic leiomyoma].

Large leiomyomas of the prostate are rare tumors. The authors report the case of a 78-year-old patient with two large prostatic leiomyomas who presented with chronic obstructive urinary symptoms. The US and CT aspects are illustrated; the signs are not specific but rather suggest a benign process. The tumor, probably of embryologic origin, must be distinguished from neoplasms when presenting in association with the classical benign prostatic hypertrophy. The definite diagnosis is obtained histopathologically. Prognosis is good with no evidence of recurrent disease.

Aged↗
PubMed1994

Reactive oxygen species produced from chromate pigments and ascorbate.

The reactions of various chromate pigments and ascorbate were investigated by an ESR spin trapping technique. Production of Cr(V) was detected directly and productions of very electrophilic reactive oxygen species (ROS) was detected via the oxidation of formate. We demonstrated previously that both dissolved oxygen and Cr (V) were essential in the production of ROS in this system, and that ROS production was inhibited by catalase. We studied here the effect of solubility of different chromate pigments: sodium, calcium, strontium, basic zinc, basic lead supported on silica, and lead and barium chromates on the production of ROS in buffered medium and cell culture medium (Dublecco's Modified Eagle medium + fetal calf serum). Sodium, calcium, basic zinc, and basic lead chromates were active in the production of ROS in presence of cell culture medium, whereas lead and barium chromates were inactive.

Ascorbic Acid↗
PubMed1994

[Paratesticular rhabdomyosarcoma].

The observation presented is based on one patient 18 years old who presents a paratesticular rhabdomyosarcoma stage I. A radical orchidectomy through on inguinal incision with high ligation of the spermatic cord was performed. We have omitted retroperitoneal lymph node dissection. The patient was treated by postoperative chemotherapy with V.A.C. during five weeks. Our patient remains disease free one year post-surgery, but after that, he presents suddenly a symptomatic bone metastasis of the thigh-bone and a massive metastatic pulmonary spreading, without retroperitoneal lymph nodes on the CT-scan. A multidisciplinary approach has considerably improved the prognosis of this tumor. Some reports suggest that routine retroperitoneal lymphadenectomy may be unnecessary for patients with no evidence of nodal involvement on CT-scan. The recent literature insists on problems cause by retroperitoneal lymph node involvement, but our clinical caused must induce us not to underestimate the potential of hematogenous spreading of this tumor.

Adolescent↗
PubMed1993

Effects of growth hormone (GH)-releasing factor and somatostatin on GH secretion from early to midgestation human fetal pituitaries.

Using explant cultures of human anterior pituitary glands (9-19 weeks fetal age) and an acute (3-h) test protocol, we investigated fetal somatotrope responsiveness to human GH-releasing factor [hGRF-(1-44)] and somatostatin [SRIF-(1-14) and SRIF-(1-28)] as a function of age. Ontogenic data were analyzed using three age groups: 9-10, 12-13, and 15-19 weeks fetal age. Both daily (24-h) and acute test (3-h) basal GH secretion increases as a function of fetal age, with the greatest increase occurring after 12-13 weeks; however, the 3 h/24 h secretion ratio remains unchanged, at approximately 12%. GRF (0.1-10 nM) stimulates GH release in a dose-related fashion, regardless of fetal age; there is a significant increase in the response to both 1 nM (P < 0.05) and 10 nM (P < 0.01) GRF between 9-10 and 15-19 weeks fetal age and to 10 nM GRF (P < 0.05) between 12-13 and 15-19 weeks. Pretreatment of cultures (9-19 weeks) with 1 or 10 nM GRF for 24 h does not alter basal 3-h GH secretion, but significantly decreases subsequent responses to 1 or 10 nM GRF, respectively (P < 0.01). Pretreatment with 1 nM GRF does not alter a subsequent 3-h response to 10 nM GRF. SRIF-(1-14) (1-100 nM) causes a dose-related inhibition of basal GH secretion from as early as the ninth week of fetal life; there is a small age-related increase in the somatotrope response to 100 nM SRIF-(1-14) between 12-13 and 15-19 weeks fetal age (P < 0.05). In a group of 11- to 14-week-old fetal pituitaries, SRIF-(1-28) had a significantly (P < 0.05) greater inhibitory effect than SRIF-(1-14) at both 1 and 10 nM; the two peptides decreased basal GH secretion to a similar extent at 100 nM (52.8 +/- 4.0% of control value; P < 0.01). SRIF-(1-14) (10 and 100 nM) does not significantly alter 10 nM GRF-stimulated GH release from 9- to 10-week-old fetal pituitaries. However, by 12-13 weeks, 10 nM SRIF-(1-14) reduces GRF-stimulated GH secretion by 60% (P < 0.01), while 100 nM SRIF-(1-14) decreases it by 80% (P < 0.01); similar inhibitory effects are observed with 15- to 19-week-old fetal somatotropes.(ABSTRACT TRUNCATED AT 400 WORDS)

Cells, Cultured↗
PubMed1993

In vitro modulation of growth hormone (GH) secretion from early to midgestation human fetal pituitaries by GH-releasing factor and somatostatin: role of Gs-adenylate cyclase-Gi complex and Ca2+ channels.

Using explant cultures of human fetal anterior pituitary glands (9-19 weeks fetal age) and an acute (3-h) test protocol, we investigated the role of two signal transduction pathways (Gs-adenylate cyclase-Gi, Ca2+ channels) in GH-releasing factor (GRF)/somatostatin (SRIF) regulation of GH secretion during the first half of gestation. Data have been analyzed for ontogenic changes using three age groups: 9-10, 12-13, and 15-19 weeks fetal age. The fetal somatotrope shows dose-related responses to forskolin (0.1-10 microM), dibutyryl cAMP (dBcAMP; 0.1-1 mM), and theophylline (0.01-1 mM), all factors that increase intracellular concentrations of cAMP; there is a significant age-related increase in the stimulatory effects of 1 mM dBcAMP and 1 mM theophylline. When any one of these three factors is added with 10 nM GRF, there are no significant additive or synergistic effects on GH secretion. Although 10 nM SRIF has no effect at 9-10 weeks, it is inhibitory in the 12-13 and 15-19 week groups, significantly suppressing the stimulatory effect of 1 microM forskolin and completely blocking the effects of 1 mM dBcAMP or theophylline. Pretreatment of cultures with pertussis toxin completely blocks SRIF inhibition of both basal and GRF-stimulated GH release. KCl (5-50 mM) and Bay K 8644 (0.1-10 microM), both activators of Ca2+ channels, have dose-related stimulatory effects on GH release; 50 mM KCl shows an age-related increase in stimulatory activity. If 10 nM GRF, 1 microM forskolin, 1 mM theophylline or 1 mM dBcAMP is added with either 50 mM KCl or 1 microM Bay K 8644, there is an additive response. SRIF (10 nM) completely blocks the stimulatory effects of 1 microM Bay K 8644 and markedly inhibits the effects of 50 mM KCl from as early as the ninth week of fetal age. The Ca2+ channel blocker nifedipine (1-10 microM) significantly inhibits basal as well as stimulated (GRF, forskolin, dBcAMP, theophylline, KCl, and Bay K) GH release from as early as 9 weeks fetal age; in contrast, the calmodulin blocker trifluoperazine (0.01-10 microM) has no effects on basal GH secretion and only slightly inhibits the stimulatory effects of KCl. Pretreatment with 10 nM GRF for 24 h significantly decreases a subsequent 3-h response to 10 nM GRF, but does not alter the subsequent response to 1 mM theophylline or 50 mM KCl.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenylyl Cyclases↗
PubMed1993

[Infected urachal cyst].

There is a wide variety of pathologies associated with the presence of urachal remnants. We describe a case of infected urachal cyst in a young adult male, with classical symptoms of dysuria, lower abdominal pain, and fever. Ultrasound, cystography and CT are described, ultrasound being often the modality of choice. Differential diagnosis of acute abdominal and pelvic pain or a midline lower abdominal mass at this age should include infection of an urachal remnant.

Adult↗