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Biomedical subjects

J L Brun

Publications and source records attributed to J L Brun.

At least 37 records · Page 2Linked to original sources

[Does axillary liposuction modify histologic study of excised lymph nodes?].

OBJECTIVE: To determine the pathological features of lymph nodes removed by axillary liposuction. METHODS: A prospective study of 34 axillary dissections performed from July 1995 to September 1996 in patients with breast cancer N0. After lipolysis, the fat was drained from the axillary cavity by means of liposuction (Karman nozzle ch.8; suction pressure of 1 Bar). The remaining nodes were removed by an endoscopic dissection in conservative treatments. The remaining nodes were removed during modified radical mastectomy in non-conservative treatments. Lymph nodes were fixed in formol and examined by the pathologist. RESULTS: An average of 15 lymph nodes (8-35) were removed. 502 lymph nodes were examined: 458 (91%) were not involved and 44 (9%) were involved, including 21 (4%) with rupture of the capsule. No pathological traumatism was seen. CONCLUSION: Axillary liposuction did not alter the pathological features of lymph nodes in our study.

Adult↗

[Uterine malformations. Diagnosis, prognosis and treatment].

Malformations of the uterus result from a variety of anomalies during embryogenesis from the 6th to the 17th week of development. Agenesia (not discussed here) should be distinguished from unicornis, pseudo-unicornis, bicornis, bipartitus and communicating uteri (Musset's classification). Such malformations occur in 3 to 4% of all women. Sonography provides the most useful information for diagnosis and should be used as first intention examination together with a work-up to determine extension. In certain cases, hysterography and laparoscopy may be required. Sterility is not increased in women with a malformation of the uterus, but fecundity is reduced due to a high rate of spontaneous abortions (30 to 40%) and premature births (15 to 45%). Obstetrical prognosis in case of a partitioned uterus can be improved by hysteroscopic resection of the partition. Most authors propose endoscopic treatment when a malformation of the uterus is diagnosed during a sterility work-up.

Congenital Abnormalities↗

[Transient arrhythmia disclosing major glycine poisoning during hysteroscopy].

We report the case of a 41-year-old ASA I patient who experienced during endometrial resection a transient idioventricular cardiac rhythm with hypotension related to a major glycine intoxication. The total volume of absorbed irrigating fluid was over six liters when these clinical signs occurred. The biological data were as following: Na = 89 mmol.L-1, Cl = 60 mmol.L-1 and osmolarity = 215 mOsm.L-1. Simultaneously, the glycine concentration in the plasma was 54.6 mmol.L-1, i.e 160 times higher than the normal value. The clinical course was unremarkable except vomiting. The treatment included only the administration of a diuretic agent, as the correction of the disorder took place spontaneously. The paucity of clinical symptoms when compared to the severity of the biological disorders explain why preventive measures are essential in this type of surgery.

Accelerated Idioventricular Rhythm↗

[Prenatal diagnosis of nuchal edemas and cystic hygromas of the neck. 49 cases].

OBJECTIVES: Determine the pathogenesis of fetal nuchal oedema and cystic hygromas of the neck and establish prenatal prognosis factors. METHODS: Retrospective study of 49 cases including 35 early diagnoses (10 to 14 weeks gestation) and 14 late diagnosis (after 15 weeks). Chorial villosity biopsy was performed for fetal karyotype. RESULTS: The global rate of genetic or chromosomic abnormalities in the fetuses was 47%. The fetuses with nuchal associated with other echographic anomalies had a high risk of chromosomic aberrations (80%). Fetuses with nuchal oedema alone during the first trimester had a higher risk of trisomy 21 proportionally with the age of the mother and paradoxically no trisomy 21 was found in women under 30 years of age. When early nuchal oedema regressed spontaneously in an euploid fetus, echographic surveillance can be proposed to detect possible polymalformation syndromes discovered late. Cystic hygromas of the neck were diagnosed from 15 weeks gestation and were always pathologic. CONCLUSION: Interpreting nuchal images in the fetus must take into account the echographic term at discovery and its isolated or associated nature. Further studies are needed to determine indications for chorial villosity biopsy in mothers under 30 with a fetus with isolated nuchal oedema which regresses spontaneously during the first trimester.

Chromosome Aberrations↗

[Postoperative lymphoceles and lymphatic fistula in gynecologic and breast neoplasms].

The author reports some review articles about post-operative lymphocele in gynecological and breast cancer surgery. Post-operative sonography often shows an increased incidence of this complication which is unsuspected with only physical examination. Curative treatment of the postoperative lymphocele is performed by puncture, drainage or excision if lymphocysts become fibrous. Preventive treatment after lymphadenectomy is performed by padding of the axilla after breast cancer surgery or visceral non-peritonization after extended lymphadeno-colpohysterectomies. There is no real solution to prevent lymphocele after inguinal lymphadenectomy.

Axilla↗

[Prenatal diagnosis of a hydrothorax secondary to an extralobar pulmonary sequestration].

A case of antenatal hydrothorax was observed. The aetiology could not be determined before birth. At birth an extra-lobe lung sequestation was treated surgically after 3 weeks in the intensive care unit. The surgical cure was successful with no sequellae. This favourable outcome is unusual in this type of pathology and can be explained by the fact that the sequestration was isolated in a fetus with only minimal anasarca. Indications for prenatal pleural drainage are discussed.

Adult↗

Physical and biological characteristics of the main biomaterials used in pelvic surgery.

Our study compared mechanical and biological properties of four materials classically used in surgery: polyethylene terephtalate (Mersilene), polypropylene (Marlex), polytetrafluoroethylene (Teflon) and expanded one (Gore-Tex) and polyaramide (Kevlar). No deterioration for polytetrafluoroethylene and polypropylene under irradiation was observed when materials were treated by physical means. Mechanical tests showed that all these materials could bear more than 50 N. Such a high tensile strength is never reached in visceral physiology. Results of graft elongation during tensile strength test shows two classes: a first one that includes high elongation grafts (Gore-Tex and Marlex) and a second one that includes low elongation grafts (Mersilene and Kevlar). As these materials have many potential uses in surgery, we have performed cytotoxicity tests. Material extracts were obtained under standardized conditions, and we have looked at a potentially toxic effect of substances eventually leached from the materials towards cells cultured in vitro. None of the material extracts listed above were cytotoxic except for untreated Kevlar. Toxicity disappeared when Kevlar was treated with methanol. As suspected, untreated Kevlar contains toxic additives introduced during the manufacture of this textile. Thus, in spite of good mechanical properties, Kevlar should not be used in pelvic surgery on account of its lower bicompatibility. These results shows that the choice of the grafts by surgeons must be relevant in a given application.

Drug Screening Assays, Antitumor↗

Inhibition of the post-translational processing of microvillar hydrolases is associated with a specific decreased expression of sucrase-isomaltase and an increased turnover of glucose in Caco-2 cells treated with monensin.

The biosynthesis and post-translational processing of sucrase-isomaltase and dipeptidylpeptidase IV were studied by L-[35S]methionine labeling, immunoisolation with monoclonal antibodies and SDS-PAGE in post-confluent Caco-2 cells treated with monensin (10 microM, 48 h). In addition to its classical effect on the post-translational processing of both hydrolases, i.e. an inhibition of the conversion of the high-mannose to the complex glycosylated form of the enzymes, monensin was found to have two other effects: a marked decrease of sucrase-isomaltase expression, but not of dipeptidylpeptidase IV; an increased turnover of glucose, as substantiated by increased rates of glucose consumption and lactic acid production and a decreased glycogen content. Whether these two effects are related to the particular differentiation and metabolic status of Caco-2 cells is discussed, as well as a possible role for the drug-induced modifications of glucose turnover on the decreased expression of sucrase-isomaltase.

Cell Line↗

Enterocytic differentiation of a subpopulation of the human colon tumor cell line HT-29 selected for growth in sugar-free medium and its inhibition by glucose.

In order to study the effect of glucose on the differentiation of cultured human colon cancer cells, a subpopulation of HT-29 cells was selected for its capacity to grow in the total absence of sugar. These cells (Glc-cells) exhibit, after confluency, an enterocytic differentiation, in contrast to cells grown with glucose (Glc+ cells), which always remain undifferentiated. The differentiation is characterized by a polarization of the cell layer with apical brush borders and tight junctions, and by the presence of sucrase-isomaltase. The differentiation of Glc- cells is reversible: the addition of glucose to postconfluent cultures of Glc- cells results in an inhibiting effect on the expression of sucrase-isomaltase; switching growing cultures of Glc- cells to the Glc+ medium for several passages results in a progressive reversion to the undifferentiated state, which is completed after seven passages. The dedifferentiation process is associated with a parallel, passage-related, increase in the rates of glucose consumption and lactic acid production, and decreases of intracellular glycogen content, which return to the values of the undifferentiated original Glc+ cells. The values of these metabolic parameters are correlated, at each passage, with the degree of dedifferentiation of the cells. When these dedifferentiated cells, after having been cultured in Glc+ medium for 20 passages, are switched back to the Glc- medium, they readily grow without mortality, and reexpress the same enterocytic differentiation as the parent Glc- cells. These results show that the capacity of this subpopulation to grow and differentiate in the absence of sugar is a stable characteristic. They further suggest that glucose metabolism interferes with the program of differentiation of HT-29 cells.

Cell Differentiation↗

Enterocytic differentiation and glucose utilization in the human colon tumor cell line Caco-2: modulation by forskolin.

The human colon cancer line Caco-2 exhibits after confluency a concomitant increase of glycogen accumulation and an enterocytic differentiation. The purpose of this work was to investigate whether forskolin (FK), an activator of adenylate cyclase, would induce a permanent glycogenolysis and, if so, whether it would result in modifications of the differentiation pattern of the cells. FK activates adenylate cyclase in Caco-2 cells with an ED50 of 7 X 10(-6)M. Three different treatment protocols with FK (10(-5)M) were applied: 1) the cells were treated during all the time in culture (20 days); 2) the treatment was started after confluency; 3) the treatment was interrupted after confluency. The presence of FK results in a permanent stimulation of cAMP accumulation (10 to 20 fold the basal values) and in a permanently reduced glycogen content (30 or 50% of the control values). The rates of glucose consumption are increased three and five fold in protocols 1 and 3 respectively. These metabolic changes are associated with morphological changes (tightening of the intercellular spaces and shortening of the brush border microvilli) and with a dual inhibition of the activities of brush border hydrolases: a) an inhibition of the post-confluent increase of activity of sucrase, aminopeptidase N and alkaline phosphatase in the brush border enriched fraction; b) an inhibition of the post-confluent increase of activity of sucrase in the cell homogenate. A comparison of the results obtained in each protocol shows that the morphological modifications and the decrease of the enzyme activities in the brush border fraction are regularly associated with an increased cAMP accumulation, whereas the inhibition of the differentiation of sucrase is a direct consequence of the increase in glucose consumption and decrease in glycogen stores.

Cell Line↗