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Biomedical subjects

F Arnal

Publications and source records attributed to F Arnal.

66 records · Page 4Linked to original sources
PubMed1985

[Biology of micro-vascularized cartilaginous transplantation in the growing dog].

Epiphyseal bone transplantations including growth area have been extensively studied experimentally in different animals and applied in children for several decades. Results were unpredictable and the amount of growth obtained with the graft could get 50 per cent of the normal. Development of microsurgical techniques has determined new possibilities of epiphyseal transfer with the respect of the epiphyseal vascularization. Growth plate germinal cell division is directly related to the epiphyseal vascular respect. In a large multifacetted program we could successively determine the vascular patterns of the donor site areas and then utilized different grafts in some experimental situations reproducing the clinical pathology in children, like hip dysplasia or epiphyseal defects after resection for tumor or infection. Results demonstrate that the main problem, in epiphyseal transplantation, is not vascular but mechanical. Further studies have to be done in this direction.

Aging↗
PubMed1985

[Principle and practice of in vitro fertilization. Role in the treatment of female sterility].

In vitro fertilization (IVF) and embryo transfer (ET) appear to constitute a revolution in the reproductive sciences rather than merely a new technique in the treatment of sterility. Principle of IVF: IVF accomplishes in vitro the process than normally occurs in the oviduct between the ovulation of oocyte II and embryo implantation in the endometrium. This 4 day period (under normal conditions in the woman) involves 4 steps: recovery, fertilization, segmentation and transport. Performance of IVF: Recovery of the oocytes: The oocytes are recovered under celioscopic or echographic observation when they have completed cytoplasmic maturation and their first meiosis. A precise monitoring of ovulation (spontaneous or induced) should be performed using estrogen and LH assays. IVF provides an opportunity for evaluating the methods of ovulation induction and monitoring, as a function of the maturation of the oocytes recovered. Fertilization: When the oocyte has achieved maturing after several hours of incubation, fertilization is obtained 15 h contact with washed and capacitated spermatozoa (100 000/ml). This step is highly dependent on gametocyte quality: oocyte maturity and fecundity of spermatozoa, which can be estimated from the percentage of survival in the insemination medium. Segmentation occurs in culture at pH 7.28 in the presence of 5 per cent CO2 at 37 degrees C (pronucleus 15th, 2 blastomeres 26 h, 4-8 blastomeres 52 h). Embryo transfer is carried out when an embryo is present at 52 h. Only 1/10 of the embryo transfers result in successful implantation, which depends on the quality of the embryo; the quality can only be indirect criteria.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Division↗
PubMed1984

Developmental regulation of production of an aggregation-stimulating factor from the cellular slime mold Polysphondylium violaceum.

An excreted, dialyzable component(s) produced during development of wild-type Polysphondylium violaceum has been previously shown to stimulate aggregation of aggregateless mutants in the complementation group aggA. Production of this aggregation-stimulating factor, called D factor, is greater during development in liquid culture than during development on a surface. after partial purification of crude D factor using high performance liquid chromatography, multiple species are found that retain the ability to stimulate aggregation of the aggA mutants. The three major components (DfA, DfB, and DfC) show decreasing polarity based on purification using reverse-phase chromatography. The proportion of each component secreted varies, depending on the developmental conditions (surface versus liquid) and the time after starvation when the factors are isolated. Preliminary physical and chemical characterization of the three D factor components suggests that they are related.

Cell Adhesion Molecules↗
PubMed1983

[Selection of motile spermatozoa from human sperm by migration in follicular fluid].

Using the property of human follicular fluid activation or "attraction" of human spermatozoa, a number of motile and active sperm was isolated from a sample of generally deficient sperm. The objective was to improve the success of artificial insemination of the conjoint. It was shown that it is possible to collect a much higher number of spermatozoa in the follicular fluid than in Menezzo's fluid. Taking into account the known toxicity of follicular fluid, the best results, based on number and motility were obtained with an mixture of follicular fluid and Menezzo's fluid in the ratio of 1:1.

Body Fluids↗
PubMed1983

[In vitro effects of preovulatory human follicular liquid on migration of human spermatozoa].

In vitro measurements of spermatozoa migration in different media showed a 75% increase in the number of spermatozoa migrating into preovulatory human follicular fluid versus Menezo's fluid. However after 4 h storage in either medium, total and progressive motility of the spermatozoa was lower in follicular fluid than in Menezo's fluid. A positive correlation was evident between the spermatozoa migration in follicular fluid and the concentration or motility of spermatozoa in fresh sperm.

Ejaculation↗
PubMed1983

[Failures at in vitro fertilization: electron microscopic studies of unfertilized oocytes and undivided ova].

We have examined by electron microscopy the non fertilized oocytes and the non divided eggs after assay of in vitro fertilization. We have observed three blocking points; 1) absence of fusion of the gametes, either because of oocyte immaturity or over-maturity, either because of spermatozoa phagocytosis by follicle cells transformed in phagocytic cells, in presence of intra or extra-cellular bacteria; 2) fusion of the gametes but absence of spermatic nucleus decondensation; 3) fusion of the gametes and pronuclei formation but absence of amphimixy. Two causes are evident: failure of oocyte maturation in vivo or in vitro, and bacterial contamination problems after female or male infra-clinical infections.

Cleavage Stage, Ovum↗
PubMed1977

Calculation of the cross sections of electron interaction with matter.

Electron scattering cross sections have been calculated and measured for aluminium, copper, silver and gold samples. The energy of the incident electrons ranges from 300 to 1200 keV. We have developed a theory similar to that of Lenz using a modified form of the Wentzel potential. The theoritical results give a good representation of the measurements.

Electrons↗
PubMedDate not supplied

[Obesity and assisted reproduction techniques].

Obesity was defined by a body mass index more than 30 kg/m2. Many risks were related to this pathology, and sometimes, menstrual disorders or infertility. In order to obtain an adequate response to ovarian stimulation during IVF cycles, higher doses of menotropins are necessary in the group of obese patients. The mechanism of this phenomenon is still unclear. Leptin is one of the main hypothesis, and could act on obesity and reproductive system simultaneously. The likelihood to have an ongoing pregnancy after IVF treatment is less in the group of obese patients because of the increased risk of miscarriage and obstetrical complications. Weight loss prior IVF remains the main advice in order to decrease the risks of the procedure and to treat successfully these patients.

Body Mass Index↗