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Biomedical subjects

B Guyot

Publications and source records attributed to B Guyot.

At least 19 recordsLinked to original sources

[Interest of modern imagery for conservative management of a placenta percreta].

The placenta percreta is a rare form of anomaly of placental insertion threatening the maternal and foetal lives. The incidence of abnormal placental adhesion is correlated to frequency of caesarean sections and advanced maternal age. Patients who are at high risk should be identified during pregnancy by ultrasound examination with Color Doppler looking for characteristic features. The practice of MRI in case of echographic suspicion may be useful, particularly in posterior placentas. A late diagnosis, in an emergency context, leads generally to hysterectomy and even to partial resection of neighbour organs. Thus, we report the case of a conservative management associating uterine embolisation following an elective caesarean delivery at 36 weeks gestation. In postpartum, the placental involution was followed clinically and by imagery. In our case, a total abdominal hysterectomy was performed on the fifth postoperative week because of a severe antibiotics resistant infection. No blood transfusion was required and the postoperative period was uneventful. This clinical case aims to show, through an analysis of the recent data of the literature, the interest of modern imagery to select patients with suspected placenta percreta that would be suitable candidates for conservative management.

Adult↗

[Proposition of a simplified investigation model for adverse outcomes in obstetrics and gynaecology].

Investigation of adverse outcomes in obstetrics and gynaecology requires a systematic and systemically oriented approach. The main objective of these assessments is to decrease their incidence. Lethal complications in obstetrics and gynaecological surgery have become so rare in developed countries that we have to grapple mainly with severe morbidities. A model for such investigation is presented, based on answers to 3 questions: What? How? and Why? These questions correspond to 3 components of quality assurance: Outcome, Process, and Structure, respectively. Aspects of Reason's model of accidents are also included, in the form of "active failures" and "latent conditions." The latter are divided into basic contributory factors, 4 of which are derived from a model of human factors influencing behaviour in anaesthesia or flight-crew environments. To illustrate its basic nature, the model is applied to anonymized cases of surgical complications. Application of the model to the reactive investigation of close calls is discussed, as is application to the proactive interrogation of the care system for the presence and nature of hazards that pose threats to safety.

Adult↗

[Use of prosthetic materials in reconstructive pelvic floor surgery. An evidence-based analysis].

Many surgical procedures for the repair of pelvic organ prolapse are used nowadays. Reconstructive pelvic surgery continues to evolve while surgeons continue to search the definitive surgical cure and have to choose the most appropriate procedures for their patients. Concerning the vaginal approach procedures, there is an increasing interest in the use of synthetic meshes which are at present widely used for surgical repair of pelvic organ prolapse. Prosthetic repair seems to be more reliable, especially when native tissues are of poor quality. The use of synthetic meshes may also simplify surgical procedures and reduce operative duration and morbidity. Material must be inert, permanent and resistant to infection. Based on authors' and other researchers' published experimental and clinical experience, polypropylene is assumed to be the most appropriate material for the vaginal repair of pelvic organ prolapse. However, since no standardized outcome measure is available, it is difficult to compare the results of surgical procedures. Only in recent studies, the subjective cure rates (patient satisfaction and outcome) have been assessed as well as the objective cure rates determined by the investigators. The subjective cure rate is probably more influenced by the functional outcome and sexual activity than by the anatomical result. Continuous evaluation is necessary to study replacement synthetic materials which should improve the rate of prolapse recurrence and reduce the risk of complications. Randomized controlled trials are required to determine which surgical procedures and type of prosthesis are most suitable. This review evaluates the properties of prosthetic materials, their complications and the most common procedures involved in the use of meshes for pelvic reconstructive surgery.

Evidence-Based Medicine↗

[Raloxifene and breast: from the SERMs concept to its place in clinical practice].

Raloxifene is a second generation Selective Estrogen Receptor Modulator. It is indicated in prevention and treatment of post-menopausal osteoporosis. This drug has an estrogen agonistic effect on bone tissue, an estrogen-antagonistic effect in breast and endometrial tissue. It inhibits estrogen induced breast cells proliferation and, in animal studies, it prevents the growth of chemically induced mammary tumors. Raloxifene has a limited effectiveness in women with advanced breast cancers. The effects of raloxifene after treated breast cancer and sequential use of tamoxifene after raloxifene (or the contrary) are not known and should be tested in specific pre-clinical and clinical studies. In osteoporotic women included in the MORE trial, the risk reduction of hormone-dependent breast cancer due to raloxifene raises the issue of some effectiveness of raloxifene in breast cancer prevention. The STAR trial is currently comparing tamoxifene vs raloxifene in breast cancer prevention in women at increased risk of breast cancer. Like tamoxifene, raloxifene increases the risk of venous thrombo-embolic events. On the other hand, in a subgroup of women at increased vascular risk in the MORE trial, the reduction of cardiovascular events raises the issue of an effect of raloxifene in the prevention of coronary events. The ongoing RUTH trial is testing this assumption and it is comparing raloxifene to a placebo in women at increased vascular risk. Today, in clinical practice, before the results of ongoing trail, raloxifene should be used in the setting of osteoporosis prevention and treatment.

Aged↗

Impact of the Coffea canephora gene introgression on beverage quality of C. arabica.

Lines of Coffea arabica derived from the Timor Hybrid (hybrid between C. arabica and C. canephora) are resistant to coffee leaf rust (Hemileia vastatrix) and to the nematode Meloidogyne exigua. The introgression of C. canephora resistance genes is suspected of causing a drop in beverage quality. Coffee samples from pure lines, compared in a Trial 1, and from F1 hybrids and parental lines from a half-diallel trial in a Trial 2, were studied for beverage quality, chemical composition and amount of introgressed genetic material. Chemical analyses (caffeine, chlorogenic acids, fat, trigonelline, sucrose) were carried out with near-infrared spectrometry by reflectance of green coffee. The number of amplified fragment length polymorphic (AFLP) markers introgressed from the Timor Hybrid varied from 1 to 37 for the lines studied. There were significant differences between lines for all of the biochemical compounds analysed and for the acidity and the overall standard of the beverage. Two lines (T17927, T17924) were significantly poorer than the controls for sucrose and beverage acidity. T17924 also had more chlorogenic acids and was poorer for the overall standard. However, two highly introgressed lines, T17934 and T17931 (25 and 30 AFLP markers, respectively), did not differ from the non-introgressed controls. There were no correlations between the number of AFLP markers and the chemical contents or beverage attributes. Significant correlations were found between the performance of the parents and their general combining ability for beverage quality. It was concluded that it should be possible to find lines with both the desired resistance genes and good beverage quality. Selection can avoid accompanying the introgression of resistance genes with a drop in beverage quality.

Coffea↗

[Ovarian choriocarcinoma: about one case].

We report the case of a woman, 43 years old, presenting with an ovarian choriocarcinoma. This patient, addressed for a right-side suspicious pelvic mass, had an exploratory laparotomy. Frozen section found an ovarian cancer. The patient had total hysterectomy, left annexectomy and a complete staging surgery. Histology concluded to an ovarian gestational choriocarcinoma. It is a rare germinal tumour, the treatment of which was medical, with radical exeresis and complete staging surgery associated with polychemotherapy.

Adult↗

Characterization of promoter elements directing Mona/Gads molecular adapter expression in T and myelomonocytic cells: involvement of the AML-1 transcription factor.

Monocytic adaptor (Mona, also called Gads) is a molecular adaptor implicated in T cell activation and macrophage differentiation. The objective of this study was to identify elements regulating specific expression of Mona/Gads in human T cell and myelomonocytic cell lines. We first confirmed that the -2000 to +150 genomic region relative to the Mona gene transcription start site is sufficient to direct specific reporter gene expression in T cell lines, Jurkat, and MOLT-4 and in the immature myeloid cell lines, KG1a and RC2A. Deletion analysis and electrophoresis mobility shift assay identified several cis regulatory elements: overlapping initiator sequences, one interferon response factor-2 (IRF-2)-binding site at position -154, one GC box recognized by Sp1 and Sp3 at position -52, and two acute myeloid leukemia (AML)-1 binding sites at positions -70 and -13. Site-directed mutagenesis experiments indicated a key role of AML-1 for driving Mona expression in T cells and myeloid cells, and involvement of Sp1/Sp3 and IRF-2 transcription factors to modulate Mona expression in a cell-specific manner.

5' Flanking Region↗

Genomic organization and restricted expression of the human Mona/Gads gene suggests regulation by two specific promoters.

Monocytic adaptor (Mona) also known as Gads is a Grb2-related adaptor whose expression is restricted to hematopoietic cells. It plays an important role in intracellular signaling in T cells, monocytic cells, and platelets. Here we investigated the regulatory aspects of Mona expression in human hematopoietic cells. This was carried out by combining nucleotide sequence analyzes and experimental approaches. We confirmed that Mona expression is restricted to T-cell, myeloid and platelet lineages. In the various cells examined, we detected two major Mona transcripts (1.9 and 4 kb), likely resulting from the alternative use of two polyadenylation sites. Consequently, Mona transcripts of the same size have identical 3' untranslated region (UTR), irrespective of the cell type. In contrast, Mona transcripts contain either 5' UTR-1A or -1B exons, that were detected in a cell-lineage specific manner. Thus, T cells and several myeloid cell lines express 5' UTR-1A-containing transcripts, whereas platelets and cell lines exhibiting megakaryocytic potential express 5' UTR-1B-containing transcripts. Interestingly, 5' UTR-1A is generated from an exon located approximately 45 kb upstream of exon 1B. This suggested that lineage-restricted transcription of the Mona gene is controlled by specific promoters. Indeed, 2-kb genomic fragments upstream of each 5'-UTR showed lineage-restricted ability to drive expression of luc reporter gene.

3' Untranslated Regions↗

Microbiological and biochemical study of coffee fermentation.

The coffee fermentation microflora were rich and mainly constituted of aerobic Gram-negative bacilli, with Erwinia and Klebsiella genuses at the highest frequencies. The best population increase was observed with lactic acid bacteria and yeasts, whereas those microorganisms that counted on a pectin medium remained constant during the fermentation step. Qualitatively, lactic acid bacteria belonged mainly to Leuconostoc mesenteroides species but the others microflora were relatively heterogeneous. The microorganisms isolated on pectin medium were Enterobacteriaceae, identified as Erwinia herbicola and Klebsiella pneumoniae, not reported as strong pectolytic strains. Throughout coffee fermentation, 60% of the simple sugars were degraded by the total microflora and not specifically by pectolytic microorganisms.

Carbohydrates↗

Fate of mucilage cell wall polysaccharides during coffee fermentation.

Effects of a 20-h fermentation on cell wall polysaccharides from the mucilage of pulped coffee beans were examined and compared to those of unfermented beans, on alcohol insoluble residues (AIRs), their hot-water-soluble crude pectic substances (PECTs), and their hot-water-insoluble residues (RESs). Yields and compositions were very similar: AIRs, which consisted of approximately 30% highly methylated pectic substances, approximately 9% cellulose, and approximately 15% neutral noncellulosic polysaccharides, exhibited no apparent degradation. However, PECTs from fermented beans were shown to have undergone a slight reduction of their intrinsic viscosity and weight-average molecular weight by capillary viscosimetry and high-performance size-exclusion chromatography. After fermentation, hot-water-insoluble pectic substances of RES exhibited partial de-esterification. Removal of coffee bean mucilage by natural fermentation seems to result from a restricted pectolysis, the mechanism of which remains to be elucidated.

Cell Wall↗

[Nancy medicines for hospices and prisons in 1805].

The chemist François Mandel, past author of Pharmcopée de Nancy, writes a list of medicines for civil hospices and a formulary for prisons. To take care of these adult, poor sick, drugs and medicines are chosen simple, at little expense, but adequate to treat everyday diseases. The prison formulary holds many novel preparations. The two manuscripts have never been published.

France↗

Chemoenzymatic synthesis of glucose fatty esters.

D-Glucose fatty esters at C-6 were obtained by chemoenzymatic synthesis involving 1,2-O-cyclohexylidene-alpha-D-glucofuranose (1) followed by hydrolysis of the cyclohexylidene protecting group. The enzymatic esterification of 1 was performed with fatty acids of variable chain lengths (C8:0 to C18:0). The kinetic of the reaction was studied for each fatty acid and the structure of the octanoyl ester was determined by 1H and 13C NMR spectroscopy.

Esters↗

[Endoscopic gynecologic surgery in Africa. Luxury of necessity?].

Per- and postoperative mortality remain high in black Africa, with rates of the order of 30 to 40% according to teams. Three essential causes are generally reported: infection, hemorrhage and anesthetic complications. There can be no doubt as to the advantages of celiosurgery over open surgery: low postoperative morbidity, less than 1% serious complications, real savings in treatment costs by shortening of average hospital stay and time off work. Celio-surgery is technology-dependent and operator-dependent. The cost of equipment remains prohibitive and its maintenance delicate and expensive, potentially hampering the implantation and spread of this new technique in Africa, which also lacks specifically trained staff as well as an appropriate technical infrastructure. Nevertheless, the experience of teams in Cameroon and Gabon are encouraging with 110 and 220 patients respectively treated by celio-surgery without complications. A veritable journeyman-apprentice approach is necessary for the learning of these new techniques by teams in developing countries, in several possible ways (locally or abroad), in order that the population as a whole can enjoy the benefits of the reproducible therapeutic and diagnostic advances of new techniques (celio-surgery, MAP, antenatal diagnosis, medical imaging).

Africa↗

Operative laparoscopy for ectopic pregnancy: how experienced should the surgeon be?

The purpose of this study was to assess the efficacy of laparoscopic surgery for ectopic pregnancy in a general hospital in Paris, where most of the surgeons are still in training. During a period of 20 months, 100 cases of ectopic pregnancy were diagnosed and treated by the attending residents. Nine cases required a laparotomy due to heavy bleeding or interstitial ectopic pregnancy. Most of the other cases were treated laparoscopically, with either salpingectomy (70 cases) or linear salpingostomy (19 cases). Complications of the laparoscopic surgical procedures were rare. There was one failure of linear salpingostomy that required a second intervention (5.3% failure rate); there was one case of urinary retention that resolved after 48 h; and one case of fever above 38 degrees C that responded well to antimicrobial therapy. In conclusion, we have shown that the current notion that laparoscopic surgery is preferred to conventional abdominal surgery for the treatment of ectopic pregnancy, can be applied to a public gynaecological centre with young inexperienced residents, supervised by experienced gynaecologists.

Adolescent↗