Simultaneous bilateral total knee arthroplasty. A multicenter feasibility study.

Introduction: The value and risk of simultaneous total knee arthroplasty (TKA) in patients with bilateral knee arthritis is a subject of debate.

Hypotheses: The risk of complications following simultaneous bilateral TKA will be increased compared to the rates published in the literature for unilateral TKA, and the clinical and functional outcomes will be poorer in this particular group.

Materials And Methods: One hundred and twenty-three patients who underwent simultaneous bilateral TKA between 2005 and 2011 in five specialized, high volume centers were evaluated.

Dorsally displaced distal radius fractures treated by fixed-angle volar plating: Grip and pronosupination strength recovery. A prospective study.

Introduction: Malunion following open reduction and internal fixation of distal radius fracture threatens wrist function. Fixed-angle palmar plates provide rigid fixation that is stable over time; however, the pronator quadratus sectioning required by the anterior approach entails a risk of pronation strength loss and of distal radioulnar joint destabilization. The present study assessed recovery of grip, pronation and supination strength following such internal fixation.

Grafts of ovaries in males and females of Pleurodeles waltl (urodele amphibia): evidence of a long-term tolerance of allografts; application following a space biology experiment.

Ovary grafts were investigated in the salamander Pleurodeles using juveniles and adults as donors and hosts. Ovaries were provided by standard or histo-compatible strains and by standard females which had been submitted to a space flight. Laparotomy of the hosts was used to control viability of grafts.

Insights into pigmentary phenomena provided by grafting and chimera formation in the axolotl.

The expression of pigmentation patterns in axolotl pigmentary mutants was observed following three types of experimental manipulations including chimera formation, reciprocal neural crest grafts, of gonadal primordia. Three pigmentary genes were utilized including the wild type (D), white (d), and albino (a). In chimeras between white and albino embryos, melanoblasts from the white half crossed the graft interface to differentiate in albino skin.

Fate of the grafted ovaries from female salamander Pleurodeles waltl embarked on the Cosmos 2229 flight.

The flight procedure of "Experience Triton" on Cosmos 2229 made necessary to sacrifice the embarked females just after landing. In order to detect genetic abnormalities in the progency of these adult females, we have performed a surgical procedure based on the transplantation of an ovarian piece on a recipient animal. One year later, as observed after laparotomy, the grafted ovaries exhibit oogonies and some growing oocytes.

Differential stability of Xenopus c-myc RNA during oogenesis in axolotl Involvement of the 3' untranslated region in vivo.

We have used the axolotl oocyte (Ambystoma mexicanum Shaw) to study the stability of exogenously injected Xenopus RNAs. Three different cellular developmental stages have been analysed: (1) the growing oocyte (stage III-IV of vitellogenesis), (2) the full-grown oocyte at the end of vitellogenesis (stage VI) and (3) the progesterone-matured stage VI oocyte. Three exogenous RNAs have been synthesized in vitro from a c-myc Xenopus cDNA clone.

In vivo fertilization and development in microgravity using pleurodele ("ZEUS" project).

The objectives of this experiment are to perform natural fertilization and to achieve embryonic development in microgravity. Pleurodeles waltl, an urodele amphibian, is considered by CNES and NASA to be suitable experimental material for achieving in vivo fertilization in space. Previously inseminated females can be embarked in the Frog Environmental Unit (FEU) developed by NASA.

Melanin as a natural germ cell marker for intraspecific transplantation experiments in Ambystoma mexicanum (Urodela, Amphibia).

In urodele amphibians, the lack of a reliable germ cell marker restricts the experimental study of the germ lineage. In the present work, we conducted genetic and histological analyses in order to demonstrate that melanin from oocytes constitutes a germ cell marker available for intraspecific experiments in Ambystoma mexicanum. Then, using this marker, we implanted germ cells from undifferentiated gonads (stage 48) into the blastocoel of host embryos and investigated their fate and determined state.

Temperature sex-reversal in amphibians and reptiles.

The sexual differentiation of gonads has been shown to be temperature-sensitive in many species of amphibians and reptiles. In two close species of salamanders, Pleurodeles poireti and P. waltl, both displaying a ZZ/ZW mechanism of genotypic sex determination (GSD), the rearing of larvae at high temperatures (30 degrees-32 degrees C) produces opposite effects: ZZ genotypic males of Pleurodeles poireti become phenotypic females whereas ZW genotypic females of P.

Evidence for a change in expression of DNA ligase genes in the Pleurodeles waltlii germ line during gonadogenesis.

The expression of DNA ligase genes was studied using the nuclear transplantation approach in the germ line of Pleurodeles waltlii (P. waltlii) just before and during gonadogenesis. Germ cell (GC) nuclei were isolated from larvae of P.

[Experimental teratomas from xenogenic embryonic implants in the urodele amphibian, Pleurodeles waltlii Michah].

Ambystoma mexicanum embryos in stages 5 to 32 were implanted into the coelomic cavity of larvae or metamorphosing larvae of Pleurodeles waltlii. Out of 76 experimental animals, 43 presented teratomas a few months later. In another series of experiments, Ambystoma embryos together with Pleurodeles embryos were implanted in 18 Pleurodeles larvae.

[Development of the urogenital tract in double-bodied pleurodele chimeras. Effect of position on interactions between the genital glands of different sex].

Chimeric grafts of the embryos of the urodele amphibian (Pleurodeles waltlii Michah.) produced viable, double-bodied animals having two pairs of genital glands of the same sex [homosexual chimeras: anterior testes--posterior testes (male----male) and anterior ovaries--posterior ovaries (female----female)] or of different sex [(heterosexual chimeras: anterior ovaries--posterior testes (female----male) and anterior testes--posterior ovaries (male----female)]. 115 chimeras aged 5 months to 15 years were analysed.

Control of DNA ligase molecular forms in nucleocytoplasmic combinations of axolotl and Pleurodeles.

A light form of DNA ligase (EC 6.5.1.

[Genetic determination of sex: demonstration in animals of a phenotypic sexual inversion by temperature in the amphibian urodeles, Pleurodeles waltlii Michah].

Phenotypic males of the newt Pleurodeles waltlii were obtained from larvae of ZW genotypic females reared at 30 degrees C. They were subsequently bred with standard ZW females, and the sex-ratio of the offspring were analysed. It was found to be identical to the theoretical sex-ratio.

Concanavalin A binding to amphibian embryo and effect on morphogenesis.

The effect of Concanavalin A (Con A) on morphogenesis in Pleurodeles waltlii has been studied. Embryos were incubated with various concentrations of the lectin for a period of 6 days. Three stages of development were examined, late blastula, young gastrula and late gastrula.

[Inversion of the female sexual phenotype at high temperature in the urodelian amphibian, Pleurodeles waltii Michah].

Breeding of Pleurodeles waltii larvae with female gentotype was carried out in 29,5-30 degrees C tap water within 4 months after hatching. 11 out of 15, 1 year old animals, exhibited all the characteristics of male sexual maturity. Mating one of the neo-males (ZW) thus obtained, with a standard female (ZW) results in a sex-ratio of the offspring consistent with theoretical expectation.

[Evolution of xenografts of embryonic gonads and juvenile ovaries from Ambystoma mexicanum Shaw, transplanted into Triturus alpestris Laur].

Gonad primordium of Ambystoma mexicanum when grafted at tail-bud stage on Triturus alpestris is indefinately tolerated. Testis or ovaries derived from those grafted embryonic gonads follow their differentiaion and reach sexual maturity. Axolotl juvenile ovaries transplanted in Triturus alpestris are also tolerated; the ovocytes achieve the entire vitellogenesis but are not able to be laid.