High temperature increases the masculinization rate of the all-female (XX) rainbow trout "Mal" population.

Salmonids are generally considered to have a robust genetic sex determination system with a simple male heterogamety (XX/XY). However, spontaneous masculinization of XX females has been found in a rainbow trout population of gynogenetic doubled haploid individuals. The analysis of this masculinization phenotype transmission supported the hypothesis of the involvement of a recessive mutation (termed mal). As temperature effect on sex differentiation has been reported in some salmonid species, in this study we investigated in detail the potential implication of temperature on masculinization in this XX mal-carrying population. Seven families issued from XX mal-carrying parents were exposed from the time of hatching to different rearing water temperatures ((8, 12 and 18°C), and the resulting sex-ratios were confirmed by histological analysis of both gonads. Our results demonstrate that masculinization rates are strongly increased (up to nearly two fold) at the highest temperature treatment (18°C). Interestingly, we also found clear differences between temperatures on the masculinization of the left versus the right gonads with the right gonad consistently more often masculinized than the left one at lower temperatures (8 and 12°C). However, the masculinization rate is also strongly dependent on the genetic background of the XX mal-carrying families. Thus, masculinization in XX mal-carrying rainbow trout is potentially triggered by an interaction between the temperature treatment and a complex genetic background potentially involving some part of the genetic sex differentiation regulatory cascade along with some minor sex-influencing loci. These results indicate that despite its rather strict genetic sex determinism system, rainbow trout sex differentiation can be modulated by temperature, as described in many other fish species.

Self-specific memory regulatory T cells protect embryos at implantation in mice.

Regulatory T cells (Tregs) play crucial roles in both fetal and tumor development. We recently showed that immunosurveillance by pre-existing CD44(high)CD62L(low) activated/memory Tregs (amTregs) specific for self-Ags protects emergent tumor cells in mice. This Treg response of a memory type is more rapid than and dominates the antitumor response of tumor-specific effector T cells. In this study, we report striking similarities between the early Treg responses to embryo and tumor implantation. Tregs are rapidly recruited to uterus-draining lymph nodes and activated in the first days after embryo implantation in both syngeneic and allogeneic matings; express the markers of the amTreg subset; and are at least in part self-Ag specific, as seen in tumor emergence. Unlike in the tumor emergence setting, however, for which preimmunization against tumor Ags is sufficient for complete tumor eradication even in the presence of Tregs, Treg depletion is additionally required for high frequencies of fetus loss after preimmunization against paternal tissue Ags. Thus, amTregs play a major role in protecting embryos in both naive and preimmune settings. This role and the ensuing therapeutic potential are further highlighted by showing that Treg stimulation, directly by low-dose IL-2 or indirectly by Fms-related tyrosine kinase 3 ligand, led to normal pregnancy rates in a spontaneous abortion-prone model.

Early regulators in abortion and implications for a preeclampsia model.

This paper reports a summary of our comparative analysis of the uterine expression of interleukin-23 (IL-23), IL-27 and TWEAK in the CBA/J femalexDBA/2 male mouse mating combination, a model of immune-mediated early pregnancy loss. Compared with the MHC-identical CBA/JxBALB/c mating combination, which yields successful pregnancies, immunohistochemistry and qPCR in uterine tissue showed an immediate post-mating IL-27 hyper-expression after mating with DBA/2 males. Intra-uterine TWEAK expression was present in females mated with DBA/2 or Balb/c males from days 0.5 to 4.5 post-coitum (pc), peaking on day 0.5 pc together with uterine TNFalpha. In uteri of DBA/2 mated mice, TWEAK declined to almost undetectable levels on days 6.5-9.5 pc, a steeper drop than in BALB/c mated mice where TWEAK remained detectable. In both mating combinations, neutralisation of TWEAK by antibodies increased resorption rates, but surprisingly, so did IL-27 neutralisation. The complement regulator mannan binding lectin-A (MBL-A), but not MBL-C, was present on day 4.5 pc especially after mating with DBA/2 males. High levels of MBL are present in the uterine luminal fluid of sterile women, and possible functions for TWEAK and MBL in human implantation are indicated by their protein and mRNA expression in uterine biopsies from infertile and fertile individuals. Consistent with the results in mice, increased MBL expression is linked with pregnancy failure. Serum and uterine VEGF and VEGF receptor levels are also different between fertile and sterile patients. The implications of these findings for utilising the CBA/JxDBA/2 mating combination as an early onset model of preeclampsia are discussed.

Evaluación del enterotest modificado en el diagnóstico de la giardiasis / Evaluation of modified enterotest diagnosis of giardiasis

Durante 1991-92, aplicamos simultáneamente el enterotest modificado (cápsula preparada por uno de nosotros) y el examen de heces seriado (3 en 1) a 108 personas, de ambos sexos, entre 5 y 36 años de edad, procedentes del distrito de Hunter, vecino de la ciudad de Arequipa (2,340 metros de altitud). Mediante del enterotest diagnosticamos 53 (49%) personas con Giardia Lamblia y con el examen de heces, 17 (15.74%) (p<0.001). Hallamos coincidencia de resultados positivos por ambos métodos en 16 personas y de negativos en 54. El enterotest permitió diagnosticar 37 casos que no lo fueron al examen de heces; y el examen de heces un caso que no lo fue al enterotest. El enterotest fue aceptado favorablemente por los niños y los adultos.

During the 1991-92 period we compared the use of an enterotest technique as modified by us and serial stool examinations (3) for ova a parasites in 108 patients of both sexes between 5 and 36 years in age, from the neighbourdhood (district) of Hunter close to Arequipa, Perú, at 2.340 meters above sea level. The enterotest detected Giardia lamblia in 53 patients (49%), while the stool examinations revealed this parasite in only 17 patients (15.74%) )(p0.001). There was agreement between both tests in 16 cases and disagreement in 54. The enterotest was positive in 37 who patients failed to show the parasite on stool examination, while the latter was positive in only one case found negative by the enterotest. Enterotest is a procedure favorably accepted by both children and adults and we advise its use in the investigations of giardiasis.