Progression after First-Line Cyclin-Dependent Kinase 4/6 Inhibitor Treatment: Analysis of Molecular Mechanisms and Clinical Data

Cyclin-dependent kinase 4/6 inhibitors (CDK4/6iss) are widely used in first-line metastatic breast cancer. For patients with progression under CDK4/6is, there is currently no standard treatment recommended at the category 1 level in international guidelines. The purpose of this article is to review the cellular mechanisms underlying the resistance to CDK4/6is, as well as treatment strategies and the clinical data about the efficacy of subsequent treatments after CDK4/6is-based therapy. In the first part, this review mainly discusses cell-cycle-specific and cell-cycle-non-specific resistance to CDK4/6is, with a focus on early and late progression. In the second part, this review analyzes potential therapeutic approaches and the available clinical data on them: switching to other CDK4/6is, to another single hormonal therapy, to other target therapies (PI3K, mTOR and AKT) and to chemotherapy.

ADHD and eating disorders in childhood and adolescence: An updated minireview

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders with overactivity, inattention, and impulsivity as core characteristics. Recent studies suggest that 20 % of children with ADHD also develop eating disorders (EDs), including anorexia nervosa, bulimia nervosa and binge eating disorder. However, little is still known about the association between ADHD and EDs through childhood and adolescence. Therefore, in the present work, we aimed at summarizing the studies investigating ADHD and EDs in childhood and adolescence over the last 10 years.

METHODS

A bibliographic search on PubMed was performed and only studies that considered participants with a clinical diagnosis of ADHD, patients with an additional diagnosis of EDs and patients under 18 years old were included. A total of 7 studies were retrieved and included in the review.

RESULTS

The majority of the reviewed studies (N = 5) found an association between ADHD and EDs, while the remaining, which focused on EDs symptomatology, reported either lower ED symptoms in ADHD sample or no association between ADHD and EDs.

LIMITATIONS

the majority of studies were cross-sectional and therefore did not allow to explore the longitudinal casual relation between ADHD and EDs in the developmental age range considered.

CONCLUSIONS

This review suggests that children and adolescents with ADHD should be monitored for EDs. However, more work is still needed to better understand the clinical implications of the comorbidity between ADHD and EDs and its prospective impact on the life of children and adolescents with ADHD.

O-074 Whole genome amplification (WGA) of blastocoelic fluid (BF) as an additional criterion for the selection of the most viable embryo

Study question

Is the presence or absence of DNA in the blastocoelic fluid detected by whole genomic amplification (WGA) a valid method to prioritize embryos for transfer?

Summary answer

Blastocysts with DNA in the BF have lower ongoing pregnancy rates compared with blastocysts without DNA, both in PGT-A and in conventional IVF cycles

What is known already

The detection of DNA in BFs from expanded blastocysts has been reported in different studies. After amplification, this DNA can be analyzed to provide information on the blastocyst chromosome condition, but the degree to which it is representative of the corresponding embryo ploidy is still controversial. The reason of this divergence could reside in several factors, including the different status of the studied embryos. A recent study comparing euploid and aneuploid blastocysts reported a significantly higher incidence of failed BF-DNA amplification in euploid blastocysts compared with aneuploid blastocysts suggesting an effect of the embryo ploidy condition on BF content

Study design, size, duration

This prospective study included 142 cycles with PGT-A (Group-1; 24-chromosome analysis was performed on trophectoderm (TE) biopsies) and 121 conventional IVF consecutive cycles (Group-2) treated in the last three years. In both groups, the BF was collected from expanded blastocysts before vitrification, and submitted to WGA. Single blastocyst transfers were performed by selecting blastocysts based on BF-WGA results giving priority to those with failed amplification. In Group-1, only TE-euploid blastocysts were transferred

Participants/materials, setting, methods

Patients in Group-1 had a maternal age higher than in Group-2 (36.8±3 vs 34.1±3.5 years). The same protocol of vitrification was used for all patients, and only expanded blastocysts of high grade were included in the study. Amplification after WGA was evaluated by loading an aliquot of the amplified product onto a 1.5% agarose gel. An ongoing pregnancy was defined as a pregnancy regularly ongoing beyond the 16th week of gestation

Main results and the role of chance

In Group-1, a total of 622 blastocysts underwent trophectoderm (TE) biopsy and 261 were euploid. The BF was retrieved from 237 euploid blastocysts and submitted to WGA. Amplification failure resulted in 98 BFs, whereas 139 BF gave a positive amplification. In all, 57 clinical pregnancies resulted, 53 of which were regularly ongoing. 61 transfers were performed with euploid blastocysts with failed BF-WGA, and 81 with positive BF-WGA. When looking at the transfer outcome, the ongoing pregnancy rate was significantly higher for euploid blastocysts with failed BF-WGA (31/61, 50.8%) when compared to those with positive BF-WGA results (22/81, 27.2%, p<0.01). In Group-2, there were 62 clinical pregnancies, 52 of which were ongoing. In relation to the BF-WGA results, the ongoing pregnancy rate showed the same trend of Group-1, and was 20% (52/121) for blastocysts with failed BF-WGA and 59.1% (42/71, p<0.001) for blastocysts with positive BF-WGA

Limitations, reasons for caution

This is a prospective cohort study. The results should be confirmed by a prospectively randomized study

Wider implications of the findings

The presence of DNA in the BF could be indicative of an abnormal embryos that is trying to reach a viable condition. Therefore, failure to detect DNA after BF amplification could represent an additional criterion to select viable embryos for transfer both in PGT-A and in conventional IVF cycles

Trial registration number

Not applicable

NIRS Hemodynamic Response to Methylphenidate in Children with Attention Aeficit Hyperactivity Disorder: First Administration, Titration Phase and Associations with Clinical Severity

Introduction

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by lack of self-regulation and deficits in organizing behaviors in response to emotional stimuli. Methylphenidate (MPH) is one of the most effective psychostimulant drugs for ADHD, however, a possible predictive utility of brain hemodynamic data related to MPH administration and its relation to clinical symptomatology is still not clear. To address these questions, we used Near Infrared Spectroscopy (NIRS) technology, a non-invasive optical technique that allows to investigate the effect of psychopharmacological treatment on cortical hemodynamics.

Methods

Twenty children with ADHD underwent a three-waves study and 25 healthy controls were recruited at W1. At W2 children with ADHD received first MPH administration and at W3 they reached the titration phase. At each phase children performed - during NIRS recording - an emotional continuous performance task with visual stimuli of different emotional content. Clinical data were also collected at W1 and W3. We investigated the relationship among the difference between NIRS activation at W2 and W1 (Delta1) and W3 and W2 (Delta2), for each subject, task condition and brain region. Lastly, we investigated correlations between the Delta1 and clinical symptomatology indexes at W1 and between Delta2 and clinical data at W3.

Conclusions

Our study results suggest that hemodynamic changes in right prefrontal region probably induced by first MPH administration could predict hemodynamic changes related to MPH titration phase. These biological indexes could be associated to clinical evidences related not only to core ADHD symptoms but also to affective correlates.

Disclosure

No significant relationships.

Knowledge and attitudes towards clinical trials among women with ovarian cancer: results of the ACTO study

Background

Despite several initiatives by research groups, regulatory authorities, and scientific associations to engage citizens/patients in clinical research, there are still obstacles to participation. Among the main discouraging aspects are incomplete understanding of the concepts related to a clinical trial, and the scant, sometimes confused, explanations given. This observational, cross-sectional multicenter study investigated knowledge, attitudes and trust in clinical research.

We conducted a survey among women with ovarian cancer at their first follow-up visit or first therapy session, treated in centers belonging to the Mario Negri Gynecologic Oncology (MaNGO) and Multicenter Italian Trials in Ovarian Cancer (MITO) groups. A questionnaire on knowledge, attitudes and experience was assembled ad hoc after a literature review and a validation process involving patients of the Alliance against Ovarian Cancer (ACTO).

Results

From 25 centers 348 questionnaire were collected; 73.5% of responders were 56 years or older, 54.8% had a high level of education, more than 80% had no experience of trial participation. Among participants 59% knew what clinical trials were and 71% what informed consent was. However, more than half did not know the meaning of the term randomization. More than half (56%) were in favor of participating in a clinical trial, but 35% were not certain. Almost all responders acknowledged the doctor’s importance in decision-making. Patients’ associations were recognized as having a powerful role in the design and planning of clinical trials.

Conclusions

This study helps depict the knowledge and attitudes of women with ovarian cancer in relation to clinical trials, suggesting measures aimed at improving trial “culture”, literacy and compliance, and fresh ways of communication between doctors and patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-022-00970-w.

Laboratory evidence that dinotefuran, pyriproxyfen and permethrin combination abrogates Leishmania infantum transmissibility by sick dogs

Dogs are reservoir hosts of leishmaniasis caused by Leishmania infantum and transmitted by phlebotomine vectors. The effect of dinotefuran, pyriproxyfen and permethrin spot-on solution (Vectra®3D, Ceva Santé Animale, Libourne, France) on Leishmania transmissibility by naturally infected dogs via reared Phlebotomus perniciosus, was assessed. Dogs affected by leishmaniasis were submitted to xenodiagnosis and 6 infecting >10% of insects were treated topically on day 0. Antifeeding, insecticidal and anti-transmissibility effects were evaluated through xenodiagnoses performed on days 1, 7 and 28, using individual pre-treatment parameters as control. Feeding and mortality rates were assessed at 24 h, whereas promastigote infection, maturation and burden were assessed up to 96 h post blood meal (potentially infectious rate). On day 1, the anti-feeding efficacy was >95% in 4 dogs, insecticidal efficacy 100% in 4 dogs, and anti-transmissibility effect 100% in 6 dogs. Efficacy rates recorded on day 7 were very similar to day 1. On day 28, anti-feeding and insecticidal efficacy values were much broader, ranging 32.6-100% and 7.7-94.4%, respectively. Potentially infectious insects were recorded from two dogs, with sharp decrease in transmissibility rate as compared with pre-treatment condition. Altogether, Vectra®3D abrogated by >98% the potential Leishmania transmissibility by the examined pool of infected dogs over 1 month.

Permanence of de novo segmental aneuploidy in sequential embryo biopsies

STUDY QUESTION

Is de novo segmental aneuploidy (SA) a biological event or an artifact that is erroneously interpreted as partial chromosome imbalance?

SUMMARY ANSWER

The detection of de novo SA in sequential biopsies of preimplantation embryos supports the biological nature of SA.

WHAT IS KNOWN ALREADY

Although some SAs are detected in oocytes and in blastocysts, the highest incidence is observed in cleavage-stage embryos. Based on these findings, we can postulate that the majority of cells affected by SAs are eliminated by apoptosis or that affected embryos mainly undergo developmental arrest.

STUDY DESIGN, SIZE, DURATION

This retrospective study includes 342 preimplantation genetic testing for aneuploidy (PGT-A) cycles performed between January 2014 and December 2018. Chromosome analysis was performed on 331 oocytes, 886 cleavage-stage embryos and 570 blastocysts (n = 1787). From 268 expanded blastocysts, the blastocoelic fluid (BF) was also analyzed (resulting in 2025 samples in total). In cases of SAs involving loss or gain in excess of 15 Mb, embryos were not considered for transfer and sequential biopsies were performed at following stages. This resulted in 66 sets where the initial diagnosis of SAs (4 made in polar bodies, 25 in blastomeres and 37 in trophectoderm (TE) cells) was followed up.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 2082 samples (2025 + 27 whole embryos) were processed by whole genome amplification followed by array comparative genomic hybridization.

MAIN RESULTS AND THE ROLE OF CHANCE

The incidence of SAs was 6.3% in oocytes, increased to 16.6% in cleavage-stage embryos (P < 0.001) and decreased to 11.2% in blastocysts (P < 0.025 versus oocytes; P < 0.01 versus cleavage-stage embryos). The highest incidence of SAs was found in BFs (26.1%, P < 0.001). The analysis of 66 sets of sequential biopsies revealed that the initial finding was confirmed in all following samples from 39 sets (59.1% full concordance). In 12 additional sets, SAs were detected in some samples while in others the interested chromosome had full aneuploidy (18.2%). In three more sets, there was a partial concordance with the initial diagnosis in some samples, but in all TE samples the interested chromosome was clearly euploid (4.5%). In the remaining 12 sets, the initial SA was not confirmed at any stage and the corresponding chromosomes were euploid (18.2% no concordance). The pattern of concordance was not affected by the number of SAs in the original biopsy (single, double or complex) or by the absence or presence of concomitant aneuploidies for full chromosomes.

LIMITATIONS, REASONS FOR CAUTION

Chromosome analyses were performed on biopsies that might not be representative of the true constitution of the embryo itself due to the occurrence of mosaicism.

WIDER IMPLICATIONS OF THE FINDINGS

The permanence of SAs throughout the following stages of embryo development in more than half of the analyzed sets suggests for this dataset a very early origin of this type of chromosome imbalance, either at meiosis or at the first mitotic divisions. Since SAs remained in full concordance with the initial diagnosis until the blastocyst stage, a corrective mechanism seems not to be in place. In the remaining cases, it is likely that, as for full chromosome aneuploidy, mosaicism derived from mitotic errors could have occurred. In following cell divisions, euploid cell lines could prevail preserving the embryo chances of implantation. Due to the scarcity of data available, the transfer of embryos with SAs should be strictly followed up to establish possible clinical consequences related to this condition.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was obtained. There are no conflicts of interest.

Gate-reflectometry dispersive readout and coherent control of a spin qubit in silicon

Silicon spin qubits have emerged as a promising path to large-scale quantum processors. In this prospect, the development of scalable qubit readout schemes involving a minimal device overhead is a compelling step. Here we report the implementation of gate-coupled rf reflectometry for the dispersive readout of a fully functional spin qubit device. We use a p-type double-gate transistor made using industry-standard silicon technology. The first gate confines a hole quantum dot encoding the spin qubit, the second one a helper dot enabling readout. The qubit state is measured through the phase response of a lumped-element resonator to spin-selective interdot tunneling. The demonstrated qubit readout scheme requires no coupling to a Fermi reservoir, thereby offering a compact and potentially scalable solution whose operation may be extended above 1 K.

Extracellular enzymatic activities of 32 fungal species

Se investigó en 32 especies fúngicas, la producción de enzimas extracelulares y ms determinaciones cualitativas (amilasa, celulosa, caseinasa, fosfatasa, lipasa, pectinasa y ureasa). La detección de los enzimas en los cultivos fúngicos en agar varió ampliamente.En la mayoría de los cultivos fúngicos se detectaron: amilasas, ureasas, y fosfatasas. Las celulosas se pesquizaron particularmente en cultivo de Aspergillus flavus, A. fumigatus, Cladosporium cladosporioides Penicillium brevicompactum, Rhizopus stolonifer, Scopulariopsis flava y Trichothecium roseum. Penicillium digitatum y P.duclauxi fueron productores de caseinasa en un alto grado. La actividad lipolítica se detectó en cultivos con grasas sintéticas tweens 20, 40, 60, y 80 como sustrato para lipasa. Indicaron actividad lipolítico para estos sustratos A. flavus, Aureobasidium pullulans, C. cladosporioides, Gliocladium roseum, Mycothypha microspora, Microsporum gypseum, P. brevicompactum y Scopulariopsis brumptii. Productores de pectinasas fueron las cepas de A. flavus, C. cladosporioides y Fusarium oxysporum, P. brevicompoctum y Ulocladium atrum

Chemoprevention of Breast Cancer with Fenretinide (4-HPR): Study of Long-Term Visual and Ophthalmologic Tolerability

Background

Fenretinide (4-HPR) is a synthetic retinoid being clinically tested in the chemoprevention of different tumors and precancerous lesions. Though safer than many other retinoids in experimental models, in humans 4-HPR may induce adverse effects that mainly affect the eye and visual function. Such effects are thought to be caused by the reduction of plasma retinol levels, which occurs after administration of the retinoid.

Methods

A series of 826 women treated with 4-HPR was studied to quantify the incidence and temporal pattern of occurrence of visual (dark adaptation) and ophthalmologic complaints (ocular dryness, lacrimation, conjunctivitis or photophobia) and to investigate the possible association between their occurrence and plasma retinol levels.

Results

The cumulative incidence of visual complaints reached nearly 20% at 5 years. The occurrence of these symptoms was more frequent at the start of treatment. The probability of developing visual complaints was significantly higher in patients with lower plasma retinol concentrations following 4-HPR treatment. The cumulative incidence of ophthalmologic complaints was 8% at 5 years. The occurrence of these complaints was evenly distributed during treatment. Ophthalmologic complaints were not associated with a greater degree of reduction of plasma retinol concentrations, but rather with the patient's age, since symptomatic patients were generally older than asymptomatic patients.

Conclusions

Visual and ophthalmologic complaints are common during 4-HPR treatment: their estimated 5-year cumulative incidence is close to 20% and 8%, respectively. However, the pattern of occurrence over time and the underlying mechanisms of these two types of complaints seem different.

First Report of a Successful Pregnancy in an Everolimus-Treated Heart-Transplanted Patient: Neonatal Disappearance of Immunosuppressive Drugs

The use of everolimus (EVL) as primary immunosuppression is steadily increasing in heart transplantation (HTx) patients. Limited data currently exist in kidney transplantation, but there is no report of EVL use during pregnancy after HTx and its pharmacokinetics in the newborn. We report a case of an unplanned pregnancy discovered at 21 weeks of gestation in a female HTx patient aged 40 years treated with EVL and cyclosporine (CyA). Because pregnancy was advanced, immunosuppression therapy was left unchanged. At 36 weeks, a healthy infant was delivered. At birth, CyA blood levels were lower in the neonate, but EVL concentrations in maternal and neonatal umbilical blood were similar. Amniotic fluid concentrations were undetectable for both drugs. In the newborn, EVL was measurable at 5 days after birth, whereas CyA disappeared within 2 days. Cord blood displayed a normal count of B and T cells and CD4, CD8 and natural killer cell populations. At birth, both mother and newborn displayed the same blood levels of EVL; therefore, a filter effect of the placenta may be hypothesized for CyA but not for EVL. No immediate complications were observed with this pregnancy.

In vivo engineering of oncogenic chromosomal rearrangements with the CRISPR/Cas9 system

Chromosomal rearrangements play a central role in the pathogenesis of human cancers and often result in the expression of therapeutically actionable gene fusions¹. A recently discovered example is a fusion between the Echinoderm Microtubule-associated Protein-like 4 (EML4) and the Anaplastic Lymphoma Kinase (ALK) genes, generated by an inversion on the short arm of chromosome 2: inv(2)(p21p23). The EML4-ALK oncogene is detected in a subset of human non-small cell lung cancers (NSCLC)² and is clinically relevant because it confers sensitivity to ALK inhibitors³. Despite their importance, modeling such genetic events in mice has proven challenging and requires complex manipulation of the germline. Here we describe an efficient method to induce specific chromosomal rearrangements in vivo using viral-mediated delivery of the CRISPR/Cas9 system to somatic cells of adult animals. We apply it to generate a mouse model of Eml4-Alk-driven lung cancer. The resulting tumors invariably harbor the Eml4-Alkinversion, express the Eml4-Alk fusion gene, display histo-pathologic and molecular features typical of ALK+ human NSCLCs, and respond to treatment with ALK-inhibitors. The general strategy described here substantially expands our ability to model human cancers in mice and potentially in other organisms.

Wilms' tumor gene 1 transcript levels in leukapheresis of peripheral blood hematopoietic cells predict relapse risk in patients autografted for acute myeloid leukemia

Autologous hematopoietic stem cell transplantation (ASCT) is a curative option alternative to allogeneic transplantation for patients with acute myeloid leukemia (AML). Relapse after ASCT can be due to contamination with leukemic blasts of autologous peripheral blood stem cells (PBSCs) collected by leukapheresis (LK). Identification and quantification of a minimal residual disease (MRD) marker in PBSCs could be relevant in determining the relapse risk after ASCT. High levels of the WT1 gene transcript in bone marrow of AML patients after treatment completion predict disease relapse. We evaluated WT1 transcript levels in autologous PBSC from LK used for ASCT in 30 consecutive AML patients in complete remission (CR) and established a correlation with clinical outcome. At diagnosis, all patients had WT1 overexpression. All patients were in morphological and genetic CR at the time of PBSC collection and before ASCT. Real-time quantitative PCR of WT1 was performed in samples of each LK, using TaqMan technology on RNA from mononucleated cells. The median WT1 transcript level in the PBSC graft (WT1-LK) of patients who relapsed was significantly higher than of those who did not relapse after transplantation (P <.0001). We defined a cut-off level of 80 WT1-LK copies/ABL 10e4 copies to discriminate between positive and negative PBSC grafts. The cut-off level was strongly associated with disease recurrence, DFS and OS. Our study represents the largest series of patients evaluating WT1 as a marker of MRD in PBSC LK products using a completely standardized real-time WT1-reverse transcriptase-PCR based assay. These data, if confirmed by prospective study, will help to determine an individual patient's adapted postremission allocation strategy.

Predicting aneuploidy in human oocytes: key factors which affect the meiotic process

BACKGROUND

To estimate the incidence of aneuploidy in relation to patients' characteristics, the type of hormonal stimulation and their response to induction of multiple follicular growth, 4163 first polar bodies (PB1s) were analyzed.

METHODS

Five hundred and forty four infertile couples underwent 706 assisted conception cycles (640 with poor prognosis indications and 66 controls) in which chromosomal analysis of PB1 for the chromosomes 13, 15, 16, 18, 21 and 22 was performed. Results were evaluated in a multivariate analysis.

RESULTS

The proportion of normal oocytes was directly correlated (P < 0.01) with (i) the number of mature oocytes and (ii) the establishment of a clinical pregnancy; and inversely correlated (P < 0.01) with (i) female age, (ii) causes of female infertility (endometriosis, abortions, ovulatory factor), (iii) poor prognosis indications (female age, number of previous cycles, multiple poor prognosis indications), (iv) number of FSH units per oocyte and (v) number of FSH units per metaphase II oocyte. There was a weak significance of frequency (P < 0.05) between type of abnormality (originated by chromatid predivision, chromosome non-disjunction or combined mechanisms in the same oocyte) and groups of the studied variables, rather than to a specific abnormality or a specific chromosome.

CONCLUSIONS

The type of infertility had a significant effect on errors derived from the first meiotic division, whose incidence was significantly higher in the presence of endometriosis or of an ovulatory factor, and in women that experienced repeated abortions. Each aneuploidy event was found to be dependent not on a specific variable, but on groups of variables. In addition, the tendency of chromosomal abnormalities to occur simultaneously implies that the deriving aneuploidies can be of any type.

Capillary blood viscosity in microcirculation

As known, at the arteriolar level there is the highest resistance to the flow due to the section and to the velocity with an average pressure fall of 50 mmHg (from 85 to 35 mmHg). This resistance is expressed in sec(-1) by the ratio W/2r. This ratio is very high with an average value of 332 sec(-1) and viscosity at this high shear-rate is negligible. At the capillary level the pressure fall is 11.5 mmHg but the vascular resistance W/2r is much lower, on average 32 sec(-1). We can say that if a resistance of 333 sec(-1) corresponds with a pressure fall of 50 mmHg, then a resistance of 32 sec(-1) should correspond with a pressure fall of 4.8 mmHg. The highest pressure fall is due to another kind of resistance which we can define as "Capillary Blood Viscosity" because it depends on the rheological and structural characteristics of the blood. Our instrument reproduces the structure of the capillary district in an experimental model and measures the General Blood Viscosity (GBV) and the Capillary Blood Viscosity (CBV) at the same shear-rate and in particular at the low shear-rate when in non-Newtonian fluids the highest increase in viscosity appears. Consequently, at the capillary, viscosity is dominant with respect to the other geometric and physical resistances. Moreover, the percentage ratio between the GBV and the CBV gives a physical measure of erythrocyte deformability. Knowing viscosity at shear-rate present in the circulatory system, we can obtain the size of RBCs aggregates in the different circulatory districts and their characteristics expressed like "aggregation bond". Changes in CBV are the only possibility in clinical practice to improve the circulatory flow in the capillary district because it is not sure that changes in the arteriolar section can improve the capillary flow or rather open arterio-venous anastomosis. Moreover, in the systemic circulation the aggregate size allows us to point out the phenomenon of cell adhesion because the presence of several receptors involves also the other blood cells. Finally the size and the stability of the RBCs aggregates can modify the endothelial thrombo-resistance.

Do static or dynamic AFOs improve balance?

OBJECTIVE

To verify if partial or total limitation of degrees of freedom at ankle joints could help patients with balance disorders in standing and walking.

DESIGN

A cross-over design was chosen. Patients with multiple sclerosis (MS) were tested in three experimental conditions: barefooted, wearing ankle foot orthoses (AFOs), and wearing AFOs that allowed plantar flexion.

SETTING

Neurorehabilitation unit in a rehabilitation centre.

SUBJECTS

Fourteen patients suffering from MS with mild strength problems and balance disorders that required them to use walking aids outside.

MAIN OUTCOME MEASURES

Tests inferring static and dynamic skills were carried out in the three experimental conditions described above.

RESULTS

Improvements were obtained in static balance tests especially wearing dynamic AFOs; the number of patients who were able to pass tasks on balance in upright position such as 'standing with feet together, head extended' increased from three to nine. Dynamic balance was impaired especially with static AFOs; the time spent walking 10 metres with these orthoses increased by 172% with respect to barefoot; less difference (113%) has been reported wearing dynamic AFOs.

CONCLUSION

Static and dynamic AFOs improved static balance, while dynamic balance was impaired especially by static AFOs; less negative influence on dynamic balance has been found while wearing dynamic AFOs.

Possible interchromosomal effect in embryos generated by gametes from translocation carriers

BACKGROUND

The incidence of abnormal pregnancies in carriers of balanced translocations depends strictly on the chromosomes involved in the translocations. The aim of this study was to verify whether conventional aneuploidy screening could be advantageously combined with preimplantation genetic diagnosis (PGD) for translocations.

METHODS

Twenty-eight carriers of Robertsonian and reciprocal translocations underwent 43 PGD cycles; specific probes were used to screen the translocation in 172 embryos generated by 35 cycles; most of these embryos were also screened for chromosomes 13, 16, 18, 21, 22 (n = 166), XY (n = 107), 1 (n = 17) and 15 (n = 88). For the remaining eight cycles (carriers of reciprocal translocations) only the chromosomes involved in common aneuploidy screening were investigated on the 40 embryos generated in vitro.

RESULTS

In Robertsonian translocations, the proportion of embryos with abnormalities due to the translocation was 21%, common aneuploidies contributed 31% of total abnormalities, whereas the remaining 36% of embryos had abnormalities due to both types of chromosome. For reciprocal translocations, the chromosomes involved in the translocation were responsible for 65% of total abnormalities; only 6% of the embryos were abnormal for common aneuploidies and 16% carried abnormalities due to both the chromosomes involved in the translocation and those not related to the translocation.

CONCLUSIONS

An interchromosomal effect seems to play a role in the case of Robertsonian translocations, where the relevant contribution of aneuploidy exposes the couple to an additional risk of abnormal pregnancy.

Nonpeptidomimetic farnesyltransferase inhibitor RPR-115135 increases cytotoxicity of 5-fluorouracil: role of p53

A new nonpeptidic farnesyltransferase inhibitor, RPR-115135, in combination with 5-fluorouracil (5-FU) was studied in an isogenic cell line model system consisting of human colon cancer HCT-116 cells. HCT-116 cells were transfected with an empty control pCMV vector and with a dominant-negative mutated p53 transgene (248R/W). We found that, relative to control transfectants, there was a slight tendency for the p53 inactivated cells to be less sensitive to 5-FU after 6 days of continuous treatment. Simultaneous administration of RPR-115135 and 5-FU, at equitoxic concentrations, resulted in an enhancement of 5-FU cytotoxicity, especially in the CMV-2 clone. Growth inhibition could be accounted for on the basis of a specific cell cycle arrest phenotype (G(2)-M arrest in CMV-2 and S arrest in mutated clones), as assayed by flow cytometry. The combination RPR-115135 + 5-FU increases apoptotic events only in the CMV-2 clone.

Induction of micronuclei by a new non-peptidic mimetic farnesyltransferase inhibitor RPR-115135: role of gene mutations

To investigate the relationship between oncogene activation and induction of micronuclei by a new non-peptidic mimetic farnesyltransferase inhibitor, RPR-115135, two isogenic cell lines, human colon cancer line HCT-116, which harbors a K-ras mutation, and spontaneously immortalized human breast epithelial cell line MCF-10A, were utilized. HCT-116 cells were transfected with an empty control pCMV vector (clone CMV-2) or with a dominant negative mutated p53 transgene (clone Mu-p53-2) to disrupt p53 function. In both clones RPR-115135 induced a significant increase in the frequency of micronucleation at concentrations that did not affect cell membrane integrity. RPR-115135 produced a significant increase in the ratio of CREST+ to CREST- micronuclei. MCF-10A cells were stably transfected with either c-Ha-ras or c-erbB-2 or both H-ras + c-erbB-2. No induction of micronuclei was observed. No induction of micronuclei was reported in human lymphocytes and in primary spinal cells obtained from 7-day chick embryos. In conclusion, RPR-115135 acts as an aneugenic agent in a complex manner, dependent upon the complement of mutations in cell regulatory genes in tumour cells and this activity may be independent of ras genotype.

RPR-115135, a new non peptidomimetic farnesyltransferase inhibitor, induces G0/G1 arrest only in serum starved cells

A new non peptidomimetic farnesyltransferase inhibitor, RPR-115135, was studied in an isogenic cell model system consisting of human colon cancer HCT-116 line. HCT-116 cells were transfected with an empty control pCMV vector or with a dominant-negative mutated p53 transgene to disrupt p53 function. Growth inhibitory effects of RPR-115135 were evaluated on cells growing under different conditions (serum starvation, serum starvation and recovery, nocodazole treatment). The cytotoxic activity of RPR-115135 was independent of the cell cycle status of the target cells. Addition of RPR-115135 only to cells exposed to reduced serum conditions (0.1% FCS) resulted in an enhanced ability of HCT-116 cells to arrest in the G0/G1 phase. This arrest response appeared independent of p53/p21cip1/waf-1 function. A reduction of Cyclin A protein amount by RPR-115135 was observed in both clones. These latter results suggest that RPR-115135 might down-regulate the cell cycle factor that would normally impede G0/G1 arrest.

[Rheologic modifications induced by heparin therapy. Capillary blood viscosity, erythrocyte deformability, aggregation index]

BACKGROUND

The most important problem with which doctors have to deal every day in their practice, is occlusive vascular disease, at the basis of which there is commonly a process of thrombosis. For this reason, it is very important to define early the subjects at thrombosis risk and an appropriate therapeutic strategy.

METHODS

We considered 13 inpatients at thrombosis risk, c/o sezione di Clinica Medica I, dipartimento di Medicina Interna e Terapia Medica, Università di Pavia, IRCCS Policlinico S. Matteo, and 12 healthy volunteers, between March and June 1998, evaluating age, sex, weight, diseases and ongoing therapy, hemocytological, hemocoagulational and hemorheological tests before and after heparinic therapy.

RESULTS

General blood viscosity, measured by the rotational and double-filtration method, presented no significant changes; on the contrary, capillary blood viscosity and erythrocyte deformability, measured by our new double-filtration method, showed respectively an increase and a decrease.

CONCLUSIONS

Calcium heparin is the most frequently used antithrombotic drug in thrombotic diseases and their prevention, but its action on the hemorheological profile is not clear. This study showed that it increases erythrocyte aggregation rate and decreases erythrocyte deformability, having a negative effect on the microcirculation.