P-327 The impact of chronic endometritis disease on endometrial receptivity gene expression in women with repeated implantation failure

Study question

Does chronic endometritis (CE) have an impact on the expression of the genes involved in the embryo implantation?

Summary answer

The mRNA expression of genes involved in embryo implantation (HOXA10, HOXA11, BTEB1 and LIF) does not change in patients with and without CE.

What is known already

CE is an inflammatory disorder of the endometrium with a detrimental effect on embryo implantation and its prevalence in women with repeated implantation failure (RIF) is up to 30%. During the implantation window, the expression of some genes plays a key role in determining the success of embryo implantation. The homeobox genes HOXA10, HOXA11 and the basic transcriptional element binding protein 1 (BTEB1) gene are essential for endometrial cells growth regulation and for embryonic development and the leukaemia inhibitory factor (LIF) has a role in the embryo–endometrium interaction.

Study design, size, duration

A single centre-prospective case-control study was conducted at the Women’s and Children’s Health Department at Padua University, on infertile women with RIF from June 2020 to November 2021. 29 women with RIF were prospectively enrolled.

Participants/materials, setting, methods

An endometrial biopsy using a Novak curette was performed for each patient and the obtained tissue samples were divided in two aliquots, one for immunohistochemistry for histological examination (endometrial dating and CE diagnosis) and one for RNA extraction and gene expression analysis that has been performed using RT-PCR. Sample of patients with and without CE were compared using non-parametric Mann–Whitney U-test. A p-value <.05 was considered as statistically significant.

Main results and the role of chance

Enrolled women were divided in two groups according to the histological diagnosis of CE: 13 patients with CE, 16 without CE. In all samples, appropriate histological dating (WOI) was evaluated according to Noyes criteria. After the comparison of all investigated genes (HOXA10, HOXA11, BTEB1 and LIF), no significant difference in mRNA expression was detected between women with and without CE (p value >.05). In the literature, defective endometrial expression of HOXA10, HOXA11 and LIF genes has been associated with abnormal implantation and the reduced expression of BTEB1 gene results in subfertility and progesterone resistance. Although the negative role of CE in altering embryo implantation is known, our results suggest that the CE has no effect on the expression of HOXA10, HOXA11, BTEB1 and LIF genes. Probably the detrimental effect of CE on embryo implantation does not act through HOXA10, HOXA11, BTEB1 and LIF gene expression.

Limitations, reasons for caution

This is a non-randomized observational study with a limited number of patients. Further studies are needed to confirm our data with immunohistochemistry evaluation to define the protein expression levels of the investigated genes.

Wider implications of the findings

Understanding the pathogenic mechanism of CE on endometrial receptivity is crucial for identifying markers that best correlate with possible implantation failure and for identifying the appropriate therapy to treat the disease and restore the embryo implantation capacity.

Trial registration number

not applicable

P–401 Frozen-thawed embryo-transfer adjuvant therapy: one size DOES NOT fit all

Study question

Does adjuvant therapy after frozen-thawed embryo-transfer (FRET) with CardioAspirin and Prednisone enhance clinical pregnancy rate (CPR) and live birth rate (LBR)?

Summary answer

Adjuvant therapy enhanced CPR and LBR in study-group. A significant correlation was found confronting blastocyst FRET in study-group versus controls.

What is known already

Embryo implantation is a rate-limiting step of FRET cycles. It’s a complex process resulting from a balance between inflammation pathways and maternal immune tolerance. Low-dose aspirin unlocks Prostaglandin-F2 synthesis by Cyclooxygenase–1, thus increasing uterine vascular permeability and attachment reaction while reducing vasoconstriction. Pregnancy results from a balance between helper and regulatory T-cells (Treg), the latter protect the embryo from maternal immune attack. Treg cells’ immunosuppressive function is pivotal in pregnancy establishment. Prednisone increases the proportion of Treg cells thus inhibiting inflammation. Many therapy schedules for implantation enhancement are currently used worldwide, although there is no consistent shared evidence.

Study design, size, duration

Retrospective cohort-control study including 237 subjects who underwent FRET after artificial endometrial-preparation from January 2018 to March 2020. Estrogenic stimulation was either oral or transdermic. The study-group received luteal support (vaginal Progesterone 600 mg/die) and adjuvant therapy (CardioAspirin and Prednisone 25–5 mg); the control-group received luteal support only. Pregnancy test (PT) was scheduled 10–14 days post-transfer (blastocysts or cleavage stage embryos). Second PT and ultrasound were performed 7 days later if the first was positive.

Participants/materials, setting, methods

Patients referred to Padua University Hospital’s Human Reproduction Pathophysiology Unit. Exclusion criteria: >50/<18 years, fresh embryo-transfer cycles, oocyte-thawing cycles, natural/natural-modified cycles. Male factor was the prevalent fertility issue. Single embryo-transfer was performed in both groups. Mean endometrial thickness was 9 mm trilaminar in both groups. Statistical analysis were carried out using JMP Pro 14 software. Categorical variables were analyzed using Chi-square test or Fisher’s exact test where appropriate.

Main results and the role of chance

In the study-group, 87 subjects were given luteal support and adjuvant therapy, while in the control-group, 150 subjects received luteal support only. Groups were homogeneous for age, number of embryos transferred, endometrial thickness, endometrial features (trilaminarity) and fertilization tecniques (108 IVF/ 127 ICSI). CPR and LBR were significantly higher in the study-group. CPR was 31.4% in study-group versus 14.8% in controls (p = 0.002), LBR was 27.4% in study-group versus 11.6% in controls (p = 0.002). Since heterogeneity between groups was found regarding the type of embryo transferred (55.3% cleavage-stage versus 44.7% blastocyst, p < 0.01), the groups were split analyzed basing upon the type if embryo transferred. In the cleavage-stage FRET condition no relevant correlation was found between groups. However in blastocyst-FRET group CPR (34.5% study-group versus 18% controls, p = 0.04) and LBR (30.9% study-group versus 12% controls, p = 0.017) were significantly higher in the study-group, thus showing that adjuvant therapy could improve CPR and LBR.

Limitations, reasons for caution

Limited sample size negatively impacts the study’s power. It would be appropriate to expand the sample to obtain more reliable results.

Wider implications of the findings: Although no unanimous consent exists for tout-court adjuvant therapy administration, scientific literature shows that such therapy can help patients with repeated implantation failures or anti-nuclear-antibodies positivity. Assuming that a single-therapy-regimen could perfectly fit all patients is not realistic. We have to move towards patient-tailored adjuvant therapy thinking.

Trial registration number

Not applicable

P–680 Thyroid function in euthyroid women during controlled ovarian stimulation (COH): does the TSH fluctuations have an impact on IVF outcomes?

Study question

TSH blood levels play a role in terms of ovarian stimulation and pregnancy? Do we need to treat patients with TSH out of range?

Summary answer

Euthyroid patients with negative autoantibodies during COS should not be treated even if basal TSH is higher than 2.5 U/L

What is known already

Abnormal thyroid function is associated with adverse pregnancy outcomes, being essential during embryo implantation and early pregnancy. TSH receptors can be found in endometrial and ovarian tissues and during controlled ovarian stimulation TSH levels suffer modifications because of hyperestrogenemia. Subclinical hypothyroidism is defined as a TSH level greater than 4.5 mIU/L with normal FT4 levels. It is controversial whether or not to use first-trimester pregnancy and infertility thresholds for upper limit of 2.5 mIU/L TSH. However, neither American Thyroid Association nor the American Society Reproductive Medicine recommendations have clearly defined how infertile patients need to be treated.

Study design, size, duration

Between April 2016 and December 2019, we performed a retrospective observational study at the University Hospital of Padua, including patients who underwent IVF/ICSI treatments. We included patients with idiopathic or tubal infertility or with poor ovarian reserve, in presence of basal TSH≤ 4,5 U/L and negative anti-TPO Ab and anti-Tg Ab. Exclusion criteria were severe male factor, TSH<0,2 or > 4,5 U/L, BMI higher than 30, oncologic patients, uterine disease.

Participants/materials, setting, methods

We enrolled a total of 389 patients. We checked TSH blood levels on the day before starting stimulation (T0). We divided our patients according to TSH level < 2,5U/L (group A) or ≥ 2,5U/L (group B). We then checked TSH on the day of hCG trigger (ThCG). Delta TSH (ThCG-T0) was calculated and correlated to endometrial thickness, number of occytes retrieved, embryos obtained and frozen, Clinical Pregnancy Rate (CPR) and Live Birth Rate (LBR).

Main results and the role of chance

Group A (251) and group B (138) were homogeneous for age, body mass index, AMH levels, antral follicular count. Short ovarian stimulation cycle with GnRH antagonist and long cycle with GnRH agonist proportions were similar in both groups. Also, FSH recombinant and hMG gonadotropin use and total amount were similar for the two groups. No statistically significant difference was found between the groups in terms of endometrial thickness, follicles greater than 14 mm as medium diameter, number of oocytes retrieved, number of mature oocytes (MII), embryos obtained, number of embryos cryopreserved, CPR and LBR. However, when considering the Delta TSH, we found possible correlations in group A. In particular, the number of oocytes retrieved was higher in Delta TSH positive (3.4±2.2) rather than in Delta negative women (2.6±1.7) with a p value of 0.002. Moreover, mature oocytes (MII) were retrieved more frequently in Delta TSH positive (5.7±3.8) rather than in Delta negative women (4.5±3) with a p value of 0.008. Group B Delta TSH did not show any possible statistically significant correlations.

Limitations, reasons for caution

This is a retrospective study and results must be confirmed on a well-designed randomized controlled study. Moreover, since we use strict eligibility criteria, we enrolled few patients. Correlations must be considered with caution since the role of TSH is under study, especially when considering LBR outcome.

Wider implications of the findings: Our results are congruent with previous studies. In particular, we suggest not to treat patients with TSH levels on range (between 0.2mIU/L and 4.5 mIU/L). TSH increase during COS in euthyroid patients could be interpreted as a positive physiological response and it is associate with better COS outcomes.

Trial registration number

N/A

Hyaluronic acid in vulvar and vaginal administration: evidence from a literature systematic review

Vulvovaginal pathology impairs the quality of life of both women in menopause and those who are not. Different therapies have been proposed, mainly related to estrogen therapy in postmenopausal women. However, some contraindications limit its use, and different moisturizers or lubricants have been tested. Hyaluronic acid is a promising and widely used vaginal medical treatment with a moisturizing action and appears to provide a solution. For this reason, we performed a systematic review of the literature. We searched for original articles without date restriction until 30 April 2020. We included all clinical trials which administered local hyaluronic acid in the vulva or vagina. Only English studies and those performed in humans were eligible. Seventeen original studies were included in the review (from randomized controlled trials to longitudinal studies). Hyaluronic acid was generally found to be effective in improving vulvovaginal symptoms (dyspareunia, itching, burning, dryness) and signs (bleeding, atrophy, vaginal pH). In conclusion, hyaluronic acid has the properties to be an efficient moisturizer for women suffering from vulvovaginal atrophy who have contraindications for estrogen therapy and for vulvovaginal signs and symptoms affecting sexual well-being. However, a well-designed randomized controlled trial is needed in order to clarify its efficacy and safety profile.

[Orbital mantle cell lymphoma succesfully treated by Bcl-2 inhibitor: Report of a case]

Lymphoma is the most common orbital malignancy in adults. Among the types of lymphoma, mantle cell lymphoma is a particularly aggressive form, often discovered through systemic involvement, with a dismal prognosis due to frequent recurrences. It is secondary to a t (11 ; 14) (q13; q32) chromosomal translocation resulting in an anti-apoptotic signal via overexpression of Bcl-2. Treatment is based on R-CHOP poly-chemotherapy. We describe the case of a patient with an orbital recurrence of mantle cell lymphoma successfully treated with oral Bcl-2 inhibitor monotherapy. A 58-year-old man who was treated with R-CHOP 8 years ago for mantle cell lymphoma, in remission for 5 years, presented with progressive decreased visual acuity in the left eye, along with binocular diplopia. Clinical examination revealed a decrease in visual acuity in the left eye to 1/20 Parinaud 20 and a relative afferent pupillary defect on the left. External examination revealed a left cranial nerve VI palsy, 2mm of painless proptosis, and hypesthesia of the left V1 territory, leading to a diagnosis of left orbital apex syndrome. The disc and macular OCT were normal. The visual field showed enlargement of the left blind spot. An emergency CT scan and MRI revealed an apical extraconal tissue mass infiltrating the medial rectus muscle, extending to the superior orbital fissure, optic canal and left cavernous sinus, hyperintense on T2 weighted images and isointense on T1. The morphological appearance was strongly suggestive of an infiltrative lymphomatous process. An 18 FDG PET-scan identified the orbital lesion as well as enhancing lesions in the axilla and colon; given the clinical features and test results, the diagnosis of recurrent mantle cell lymphoma was made without biopsy. Treatment with Venetoclax (Bcl-2 inhibitor) was initiated. At one month of treatment, the orbital apex syndrome had entirely resolved, with visual acuity increased to 8/10 Parinaud 4 and a metabolic return to normal on PET scan. The PET scanner and clinical examination at 3 months were entirely normal. At the one-year follow-up visit, the patient was still on Venetoclax, the clinical examination was unchanged, and the PET-scan still showed a complete metabolic response.

Is corifollitropin alfa effective in controlled ovarian stimulation among all poor ovarian responders? A retrospective comparative study

Several studies have compared the effectiveness of corifollitropin alfa versus daily gonadotropins in poor ovarian responders (PORs) undergoing controlled ovarian stimulation (COS), showing conflicting results in terms of IVF outcomes. Given the heterogeneity of patients included in the classification of POR according to 'Bologna criteria', the aim of this study was to evaluate the impact of corifollitropin alfa in two different categories of POR distinguished according to patients' antral follicle count (AFC). We retrospectively evaluated 104 infertile POR, split into two groups according to AFC (Group A ≤ 5; Group B > 5) and subgroups according to the ovarian stimulation regimen (corifollitropin alfa plus daily gonadotropins (Subgroup 1) versus daily gonadotropins alone (Subgroup 2)). Outcome measures were total oocytes, MII oocytes, total embryos, follicular output rate (FORT), implantation rate (IR), clinical pregnancy rate (CPR), miscarriage rate (MR), and live birth rate (LBR). Subgroup A1 experienced a lower number of total oocytes, MII oocytes, total embryos, and FORT (p < .05) in comparison to Subgroup A2, while no difference was found when comparing Subgroups B1 and B2. No difference was found between subgroups even in terms of IR, CPR, MR, and LBR. In conclusion, corifollitropin alfa may be as effective as daily gonadotropins in POR with AFC > 5 undergoing COS, while it might be inferior to daily gonadotropins in POR with AFC ≤ 5.

[Anatomical description of the retro-caruncular approach and its application in oculoplastics: A cadaveric study]

PURPOSE

To describe the anatomical landmarks of the retro-caruncular approach and its clinical applications based on a cadaveric study.

PATIENTS AND METHOD

A dissection of 8 orbits providing from 4 fresh cadavers was carried out at the anatomical laboratory of the University Hospital of Nice, France between October 2018 and January 2019.

RESULTS

Main anatomical relationships encountered are anteriorly the Duverney-Horner muscle and the lacrimal sac, posteriorly the anterior and posterior ethmoidal arteries, superiorly the pulley of the superior oblique muscle, inferiorly the lacrimonasal duct and the tendon of the inferior oblique muscle. The retro-caruncular approach allows a safe surgical access behind the lacrimal sac and Duverney-Horner muscle. Many oculoplastic surgical procedures can be performed through this approach: dacryocystorhinostomy, medial orbital fractures repair, "médial" orbital "décompression", biopsy of medial and extraconal tumours, medial periosteal fixation in third-nerve palsy.

CONCLUSION

The retro-caruncular approach is a safe procedure avoiding skin incision. It allows a wide surgical space even if it is reduced compared to a more conventional skin route. It requires a great anatomical knowledge and a longer surgical learning curve.

The influence of thyroid autoimmunity on embryo quality in women undergoing assisted reproductive technology

The influence of thyroid autoimmunity in assisted reproductive technology (ART) outcome in euthyroid women is still controversial. In this study, we retrospectively evaluated embryo quality in 123 euthyroid women undergoing ART with or without thyroid autoantibodies (TAA). Embryo quality was assessed in 119 embryos of 29 infertile patients with TAA and in 394 embryos of 94 infertile patients without TAA. Our results showed not statistically significant differences in age, body mass index, anti-Müllerian hormone, follicle stimulating hormone, free triiodothyronine, and free thyroxine levels between cases and controls. Thyroid stimulating hormone was within the normal range, but significantly higher in TAA patients compared with the controls (2.4 ± 0.8 vs. 2 ± 0.9 mIU/L, respectively, p < .01). The number of oocytes picked up and fertilized was comparable between the two groups. Embryo quality was significantly impaired in women with at least one autoantibody (p < .001). Implantation rate, pregnancy rate, and ongoing pregnancy rate were comparable in the two groups. These results suggest a negative impact of thyroid autoimmunity in embryo quality in women undergoing ART even when thyroid function is normal.

A diversity-oriented synthesis of cyclopenta[b]pyrroles and related compounds through a calcium(ii)/copper(ii) catalytic sequence

A sequential bicatalytic route relying on calcium(ii) and copper(ii) salts is described to provide access to original nitrogen-containing heterocycles.

Subtalar distraction arthrodesis using a ramp cage

Subtalar distraction bone block arthrodesis has been described to treat late complications of displaced calcaneal fractures. A "ramp cage" can be used to restore the talocalcaneal relationship by providing stable correction in the coronal and sagittal dimensions.

Impact of HLA-C on acute rejection in liver transplantation

Although liver transplants show a special tolerogenic behaviour, rejection remains an important problem that involves several immunological mechanisms, some of which are unknown. Our study sought to analyze the influence of HLA-C polymorphism on short-term liver graft acceptance by HLA-C genotyping of 100 orthotopic liver transplant recipient-donor pairs. Recipients were statified according to the occurrence of acute rejection. HLA-Cw*06 allele appeared to be underrepresented among recipients without versus those with acute rejection or those in control groups. With regard to HLA-C allelic compatibility, the frequency of acute rejection or those in episodes decreased with fewer HLA-C mismatches. These findings suggest the participation of HLA-C molecules in liver graft alloresponses, involving HLA-C genotyping, as well as compatibility.

Report of recombinations between HLA loci within two families: utility of high resolution typing

We have analysed two Caucasian families in which recombinant individuals have been identified. In both families, initial low resolution typing of class I and II antigens of possible patients referred for bone marrow transplantation and their respective potential donors (based on inherited haplotypes analysis) revealed them to be HLA identical and supposedly inheriting-non-recombinant haplotypes. The mothers were found to be DRB1*04 generic allele homozygous, but possessing two DRB1*04 specific alleles, DRB1*0403 and DRB1*0404 (family A) and DRB1*0401 and DRB1*0402 (family B). In both cases the patients inherited a maternal haplotype that is the result of a recombination event between the mother's HLA-DRB1 and -B genes on their chromosomes. Based on linkage disequilibrium it is likely that the recombinant haplotypes are present in the patients rather than their brothers. In both families, the results of the MLC in terms of relative response was positive. Thus, these cases illustrate the importance of high resolution DNA class II typing when assignment of MHC antigens is of extreme importance (i.e. bone marrow transplantation).

Polymorphism in the upstream regulatory region of the HLA-DQB1 gene in liver graft recipients

HLA-DQB1*0302 allele frequency is increased in liver graft recipients with acute rejection. We investigated polymorphism in the upstream regulatory regions (URRs) of the DQB1 gene to determine whether polymorphism in the DQB1 promoter region influences liver graft acceptance. A combination of typing protocols based on the polymerase chain reaction were used in 103 first-time liver transplants and 108 healthy Spanish controls. The QBP3.21 allele frequency and QBP3.21-DQB1*0302 haplotype were significantly different in recipients with acute rejection compared to those with good graft acceptance and to controls. Of major interest for acute rejection development are the promoter "splits" of DQB1*0302 (QBP3.21, QBP3.22, and QBP3.3 alleles), which are in linkage disequilibrium with DQB1*0302. The promoter splits were equally distributed in all groups. Thus, although there are significant differences in the frequencies of the QBP alleles and QBP-DQB1 haplotypes between recipients with and without acute rejection and controls, the composition of these haplotypes is essentially the same in all groups. In conclusion, our data show that the polymorphism in the DQB1 promoter region does not clearly influence liver graft acceptance, and, as occurs in other populations, QBP alleles exhibit strong linkage disequilibrium with the DQB1 locus.

Incidence and predisposing factors for incisional hernia in patients with liver transplantation

BACKGROUND

Cirrhotic patients who are transplanted have a high risk of developing incisional hernia (IH).

MATERIALS AND METHODS

We have analysed the incidence and treatment of IH in 465 patients with liver transplantation (LT). In order to find predisposing factors, we compared these patients with a similar group of patients with LT without IH. Fifty-four patients (11.6%) developed an IH. Forty-six of these (85%) were males, and in 37% the entire laparotomy incision was involved. Forty patients have been operated on for the hernia, three by primary repair and 37 (92.5%) with a polypropylene mesh. After a follow-up of 42 months, 6 (15%) IHs recurred. Comparing groups, IH patients were older (P<0.05), of male gender (P<0.001), and received more steroids (P<0.01). The IH rate was not related to suture material.

CONCLUSIONS

Our rate of IH is perhaps reasonable in these high risk patients. It appears that IH can be reduced if steroids are reduced or avoided. We recommend a large mesh for repair.

Effects of gymnastics expertise on the perception of body orientation in the pitch dimension

The purpose of this study was to investigate how experts in motor skills requiring a fine postural control perceive their body orientation with few gravity based sensory cues. In Experiment 1, expert gymnasts and controls had to detect their body tilt when pitching at a velocity of 0.05 deg.s(-1), in two conditions of body restriction (strapped and body cast altering the somatosensory cues). Contrary to the experts, the controls exhibited a larger body tilt when totally restrained in the body cast. In Experiment 2, subjects had to estimate their Subjective Postural Vertical (SPV) starting from different angles of pitch tilt. The controls exhibited significant errors of SPV judgement whereas the experts were very precise. These results suggest that 1) somatosensory cues are more informative than otolithic cues for the perception of body orientation, and 2) the efficiency of otolithic and/or interoceptive inputs can be improved through a specific training to compensate for the lack of somatosensory cues.

The effect of expertise in gymnastics on postural control

The goal of this paper was (1) to investigate if gymnasts have a more stable standing posture than experts in other sports, and (2) to determine how much gymnasts are affected by the removal of vision in different postural tasks. Six expert gymnasts and six experts in other non-gymnastic sports were asked to maintain balance in three standing postures of increasing difficulty: bipedal, unipedal, and unipedal + unstable support (i.e. 7 cm thick foam surface). Each posture was tested successively with and without vision. Based on the displacement of the center of pressure (range and mean average speed), the results showed that when visual cues were available, postural sway increased with the difficulty of the task, but both groups had comparable performance in all the tasks. When vision was removed, although both groups demonstrated larger postural sway in the unipedal tasks, this effect was less accentuated for the gymnasts. We concluded that gymnasts are able to use the remaining sensory modalities to compensate for the lack of vision in unstable postures.

Fludarabine, arabinosyl cytosine and idarubicin (FLAI) for remission induction in poor-risk acute myeloid leukemia

Progress in treatment of acute myeloid leukemia (AML) is slow and treatment intensification alone has limited effects, particularly in poor-risk cases. Poor-risk cases, that are identified mainly by prior history, leukemic cell mass and cytogenetic abnormalities, share multiple mechanisms of drug resistance that are responsible for treatment failure. Since Pgp-mediated resistance to anthracycline can be reduced with Idarubicin (IDA) and resistance to arabinosyl cytosine (AC) can be reduced with Fludarabine (FLUDA), we tested a combination of high dose AC (2000 mg/sqm, 5 doses), FLUDA (30 mg/sqm, 5 doses) and IDA (12 mg/sqm, 3 doses) for remission induction and consolidation in 45 consecutive cases of poor-risk AML. The complete remission (CR) rate was 71% after the first course and 82% overall, with a projected 2-year survival and relapse-free survival of 44% and 50% respectively. Non-hematologic toxicity was very mild, that is very important in elderly patients, but hemopoietic toxicity was substantial, with a time to hematologic recovery of 3 to 4 weeks and two cases of death in CR. Peripheral blood stem cells (PBSC) could be mobilized and collected successfully only in 11 cases. This three-drug combination is effective and has a limited non-hematologic toxicity, but FLUDA may increase the difficulty of obtaining PBSC early after remission induction.

Control of locomotion in expert gymnasts in the absence of vision

The main aim of this study was to determine how gymnasts are affected by the removal of vision when executing simple moves. A secondary aim was to establish whether crucial sensory cues exist for blindfolded gymnasts. Eight expert gymnasts were asked to maintain a straight displacement during three types of blindfolded locomotion: walking, steering a wheelchair and verbally ordering a second person pushing their wheelchair. In the first two conditions, active displacement made proprioceptive cues available to update the body trajectory. In the last condition, however, proprioceptive cues were greatly reduced, since the gymnasts displaced passively. The performance of the gymnasts was compared to that of eight experts in other non-gymnastic sports (control group). The results showed that the participants veered in all conditions. However, except in the verbal condition, the gymnasts departed less from linearity than the controls. We conclude that: (1) even for a simple motor task, gymnasts' performance is altered by eliminating vision; (2) compared with other sportsmen and women, gymnasts are better able to deal with the absence of vision when proprioceptive cues are available. These findings suggest two possible explanations: (1) gymnasts are more able to 'pick up' crucial information and (2) a gymnast's proprioceptive system is more sensitive.

P-Element repression in Drosophila melanogaster by a naturally occurring defective telomeric P copy

In Drosophila melanogaster, hybrid dysgenesis occurs in progeny from crosses between females lacking P elements and males carrying P elements scattered throughout the genome. We have genetically isolated a naturally occurring P insertion at cytological location 1A, from a Tunisian population. The Nasr'Allah-P(1A) element [NA-P(1A)] has a deletion of the first 871 bp including the P promoter. It is flanked at the 3' end by telomeric associated sequences and at the 5' end by a HeT-A element sequence. The NA-P(1A) element strongly represses dysgenic sterility and P transposition. However, when testing P-promoter repression, NA-P(1A) was unable to repress a germinally expressed P-lacZ construct bearing no 5'-homology with it. Conversely, a second P-lacZ construct, in which the fusion with lacZ takes place in exon 3 of P, was successfully repressed by NA-P(1A). This suggests that NA-P(1A) repression involves a homology-dependent component.

Postural coordination modes considered as emergent phenomena

The coordination of multiple body segments (torso and legs) in the control of standing posture during a suprapostural task was studied. The analysis was motivated by dynamical theories of motor coordination. In 2 experiments it was found that multisegment postural coordination could be described by the relative phase of rotations around the hip and ankle joints. The effective length of the feet, the height of the center of mass, and the amplitude of head motions in a visual tracking task were varied. Across these variations, 2 modes of hip-ankle coordination were observed: in-phase and anti-phase. The emergence of these modes was influenced by constraints imposed by the suprapostural tracking task, supporting the idea that such tasks influence postural control in an adaptive manner. Results are interpreted in terms of a dynamical approach to coordination in which postural coordination modes can be viewed as emergent phenomena.

Postural coordination modes considered as emergent phenomena

The coordination of multiple body segments (torso and legs) in the control of standing posture during a suprapostural task was studied. The analysis was motivated by dynamical theories of motor coordination. In 2 experiments it was found that multisegment postural coordination could be described by the relative phase of rotations around the hip and ankle joints. The effective length of the feet, the height of the center of mass, and the amplitude of head motions in a visual tracking task were varied. Across these variations, 2 modes of hip-ankle coordination were observed: in-phase and anti-phase. The emergence of these modes was influenced by constraints imposed by the suprapostural tracking task, supporting the idea that such tasks influence postural control in an adaptive manner. Results are interpreted in terms of a dynamical approach to coordination in which postural coordination modes can be viewed as emergent phenomena.