A global non-invasive methodology for the phenotyping of potato under water deficit conditions using imaging, physiological and molecular tools.

BACKGROUND: Drought is a major consequence of global heating that has negative impacts on agriculture. Potato is a drought-sensitive crop; tuber growth and dry matter content may both be impacted. Moreover, water deficit can induce physiological disorders such as glassy tubers and internal rust spots. The response of potato plants to drought is complex and can be affected by cultivar type, climatic and soil conditions, and the point at which water stress occurs during growth. The characterization of adaptive responses in plants presents a major phenotyping challenge. There is therefore a demand for the development of non-invasive analytical techniques to improve phenotyping. RESULTS: This project aimed to take advantage of innovative approaches in MRI, phenotyping and molecular biology to evaluate the effects of water stress on potato plants during growth. Plants were cultivated in pots under different water conditions. A control group of plants were cultivated under optimal water uptake conditions. Other groups were cultivated under mild and severe water deficiency conditions (40 and 20% of field capacity, respectively) applied at different tuber growth phases (initiation, filling). Water stress was evaluated by monitoring soil water potential. Two fully-equipped imaging cabinets were set up to characterize plant morphology using high definition color cameras (top and side views) and to measure plant stress using RGB cameras. The response of potato plants to water stress depended on the intensity and duration of the stress. Three-dimensional morphological images of the underground organs of potato plants in pots were recorded using a 1.5 T MRI scanner. A significant difference in growth kinetics was observed at the early growth stages between the control and stressed plants. Quantitative PCR analysis was carried out at molecular level on the expression patterns of selected drought-responsive genes. Variations in stress levels were seen to modulate ABA and drought-responsive ABA-dependent and ABA-independent genes. CONCLUSIONS: This methodology, when applied to the phenotyping of potato under water deficit conditions, provides a quantitative analysis of leaves and tubers properties at microstructural and molecular levels. The approaches thus developed could therefore be effective in the multi-scale characterization of plant response to water stress, from organ development to gene expression.

[Macrovesicular hepatic steatosis revealing pregnancy hemophagocytic lymphohistiocytosis]. / Stéatose hépatique macrovésiculaire majeure révélant un syndrome d'activation lymphohistiocytaire postgravidique.

INTRODUCTION: We report a case of post-partum hemophagocytic lymphohistiocytosis with marked macrovesicular hepatic steatosis. CASE REPORT: A 39-year-old woman was admitted for hemophagocytic lymphohistiocytosis with a serum ferritin level of 103,380 µg/L. Thoracic abdominal and pelvic CT-scan showed hepatomegaly with marked steatosis. Liver biopsy confirmed macrovesicular steatosis. The diagnosis was a primary hemophagocytic lymphohistiocytosis. After treatment failure including corticosteroids, intravenous immunoglobulin, tetracycline, acyclovir, antituberculosis drugs, and anti-IL1R therapy, clinical improvement was obtained with intravenous cyclosporine. At 4-year follow-up, the patient remained asymptomatic. CONCLUSION: Several aspects of this report of primary hemophagocytic lymphohistiocytosis are remarkable and include the association with post-partum, the severe radiologic and histologic macrovesicular steatosis, and the dramatic efficacy of cyclosporine.

Different mechanisms of nucleation and self-organization of droplets in ferroelectric smectic membranes.

New mechanisms of droplet nucleation and self-organization in ferroelectric membranes are described. The droplets may be accompanied by different number of topological defects (zero, one, two) whose location may be on the droplet boundary or in the membrane. Nucleation and self-organization of droplets with total topological charge S = 0 , S = + 1 and S = - 1 were investigated. We found that an S = - 1 topological defect may be the center of both droplet nucleation and chain formation. This mechanism of chaining drastically differs from the droplet self-organization described earlier which is realized by attraction of droplet-defect pairs. Our observations demonstrate new possibilities for manipulating the inclusions and their self-organization in smectic membranes.

Interaction of surfaces in smectic membranes and their instability near thinning transitions.

We report measurements of the interaction between surfaces of the presmectic membrane above the temperature of transition to the phase without layer ordering. Investigations were performed employing cholesteric droplets embedded in the membrane in the temperature range of thinning transitions. Upon heating, the difference between the membrane tension and surface tension of the bulk sample decreases sufficiently, which leads to membrane instability. After the thinning transition, the membrane returns to a stable state with a larger value of surface interaction.

Correlation between dielectric and optical measurements in the smectic-C(*)(alpha) phase.

We present optical and dielectric measurements in the smectic-C(*)(alpha) (SmC(*)(alpha)) phase of three homologues of an alkoxy benzoate series. Two different behaviors are observed depending on the values and the temperature evolution of the azimuthal angle difference alpha between two adjacent layers. For moderate values of alpha, the Goldstone mode is predominant over the whole SmC(*)(alpha) phase. For large values of alpha, we can distinguish the soft mode near the SmA*-SmC(*)(alpha) phase transition and the Goldstone mode at lower temperatures. In this case, discontinuities are also observed at the SmC(*)(alpha)-SmA* phase transition. These dielectric features are correlated with optical properties using simulations based on the discrete phenomenological "clock model."

Self-organization of N(*) inclusions in SmC(*) free-standing films.

The behaviour of freely suspended smectic-C* ( SmC(*)) films at the bulk SmC(*)-cholesteric ( N(*)) phase transition has been investigated using polarized-reflected-light microscopy. Our experimental observations show that above the bulk SmC(*)- N(*) phase transition the N(*) order appears in different ways according to the film thickness. In thin films, the conventional layer-by-layer thinning occurs. In films of intermediate thickness N(*) inclusions nucleate inside the SmC(*) film. The distortions of the in-plane orientational order of the SmC(*) host phase induce elastic interactions between the inclusions and lead to their self-organization in chain-like structures. Both the dynamic of the chaining and the parameters driving the equilibrium distance between the inclusions in the chain are investigated. In thick films, N(*) fingers grow inside the film. The influence of the experimental conditions on the various processes is analysed.

Molecular characterization of partial trisomy 16q24.1-qter: clinical report and review of the literature.

We describe a 3(1/2)-year-old girl with psychomotor and mental retardation; dysmorphic features, including a high forehead with bitemporal narrowing; a broad nasal bridge and a broadened nose; downslanting palpebral fissures; abnormal ears; vertebral abnormalities; cardiac defect; genital hypoplasia; and anal abnormalities. The karyotype of our patient (550 bands) was normal. Molecular cytogenetic techniques, including comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH), revealed that this girl was a carrier of a de novo derivative chromosome 7 arising from a cryptic t(7;16)(p22.3;q24.1) translocation generating a trisomy 16q24.1-qter and a 7p22.3-pter deletion. FISH with a series of specific chromosome 7p and 16q probes allowed us to delineate the chromosome 7 breakpoint between YAC660G6 (WD7S517) and YAC848A12 (D7S521, D7S31, and WI-4829) and the chromosome 16 breakpoint between BAC457K7 (D42053) and BAC44201 (SGC30711). The comparison of the clinical features of our patient with those of 2 cases of pure terminal 7p deletion and 28 cases of trisomy 16q reported in the literature allowed us to establish the following phenotype-genotype correlation for trisomy of the long arm of chromosome 16: distinctive facies (high/prominent forehead, bitemporal narrowing, periorbital edema in the neonatal period); severe mental retardation; vertebral, genital, and anal abnormalities to 16q24; distal joint contractures and camptodactyly to 16q23; cleft palate and renal anomalies to 16q22; beaked nose and gall bladder agenesis to 16q21; gut malrotation; lung and liver anomalies to 16q13; and behavior abnormalities to band 16q11-q13.

Genetic diversity in european and Argentinian cultivated potatoes (Solanum tuberosum subsp. tuberosum) detected by inter-simple sequence repeats (ISSRs).

In this study, the use of inter-simple sequence repeats (ISSR) to assess genetic diversity between cultivated potatoes (Solanum tuberosum subsp. tuberosum) is reported. ISSR technology rapidly reveals high polymorphic fingerprints and thus determines the genetic diversity among potato cultivars. Nine primers were selected according to the number of amplified markers and the level of polymorphism detected. Three primers (GAG(CAA)5, CTG(AG)8, and (AG)8) were used to cluster the 28 potato accessions and 77 polymorphic markers were sufficient to identify all of the accessions. Among the 15 simple sequence repeat (SSR) motifs tested, the most abundant were CAA and AG. Argentinian- and European-grown potatoes were easily distinguished, with a higher level of genetic diversity among potatoes from Argentina. An ISSR study using a limited number of cultivars and very few primers clearly differentiated between all cultivars, thus ISSR was revealed to be a good tool for the genetic identification of potato and for future germplasm-management programs.

Comparative genomic hybridisation in mentally retarded patients with dysmorphic features and a normal karyotype.

Segmental aneusomy for small chromosomal regions has been shown to be a common cause of mental retardation and multiple congenital anomalies. A screening method for such chromosome aberrations that are not detected using standard cytogenetic techniques is needed. Recent studies have focused on detection of subtle terminal chromosome aberrations using subtelomeric probes. This approach however excludes significant regions of the genome where submicroscopic rearrangements are also liable to occur. The aim of the present study was to evaluate the efficiency of comparative genomic hybridisation (CGH) for screening of submicroscopic chromosomal rearrangements. CGH was performed in a cohort of 17 patients (14 families) with mental retardation, dysmorphic features and a normal karyotype. Five subtle unbalanced rearrangements were identified in 7 patients. Subsequent FISH studies confirmed these results. Although no interstitial submicroscopic rearrangement was detected in this small series, the study emphasises the value of CGH as a screening approach to detect subtle chromosome rearrangements in mentally retarded patients with dysmorphic features and a normal karyotype.

Interactions between colloidal inclusions in two-dimensional smectic-C* films.

We report an experimental study of colloidal inclusions in free-standing films of smectic-C* liquid crystal. The inclusions are cholesteric droplets that form above the bulk smectic-C*-7cholesteric transition temperature. Each droplet confined in a two-dimensional (2D) system, is accompanied by a topological defect. The distortions of the in-plane orientational order of the smectic-C* film induce elastic interactions between the droplets. As in 3D water nematic emulsions, a short-range repulsion and a long-range dipolar attraction govern the stability of the inclusions and lead to their organization in chainlike structures. Our results are in agreement with recent theoretical predictions.

Formation of string defects at thinning transitions in smectic-C* free-standing films

The layer thinning transitions in freely suspended smectic-C* films have been investigated. The defect structure formed by stringlike lines was observed just before the thinning transitions. The string defects disappear after the thinning transition and appear again near the temperature of the next thinning transition. These results clearly indicate that thin free-standing films at the thinning transitions are slightly below the melting temperature of the interior layers.

Multicritical behaviors and an induced twist grain boundary phase in a binary liquid crystalline mixture

We report here the composition-temperature phase diagram of a mixture between n=9 and n=16 terms of a chiral tolans series shortly noted nF(2)BTFO1M7. This diagram constitutes an experimental illustration of one of the three theoretical phase diagrams predicted by the Renn and Lubensky's model. The pure compounds n=9 and n=16 exhibit, respectively, the phase sequences Cry-Sm-C*-Sm-A-TGB(A)-N*-BP-I and Cry-Sm-C*-N*-BP-I, where TGB refers to a twist grain boundary phase. Phases identification and transition temperatures, at atmospheric pressure, have been determined by both optical microscopy and photothermal methods. The experimental phase diagram shows the disappearance of Sm-A and TGB(A) mesophases and the appearance of a TGB(C) phase when the n=16 composition increases. Four of the five multicritical points theoretically anticipated by Renn and Lubensky are pointed out.

A randomized, multicenter, controlled trial using intravenous pulses of methylprednisolone in the initial treatment of simple forms of giant cell arteritis: a one year followup study of 164 patients.

OBJECTIVE: (1) To evaluate the corticosteroid sparing effect of an initial intravenous (i.v.) pulse of methylprednisolone (MP) in the treatment of simple forms of giant cell arteritis (GCA). (2) To analyze corticosteroid response, steroid related side effects, and GCA complications. METHODS: Patients received a 240 mg i.v. pulse of MP followed by 0.7 mg/kg/day oral prednisone (Group 1) or 0.7 mg/kg/day prednisone without an i.v. pulse (Group 2, controls), or a 240 mg i.v. pulse of MP followed by 0.5 mg/kg/day prednisone (Group 3). Corticosteroid dosage was reduced after normalization of 2 biological inflammatory variables to obtain half-dosage after 4 weeks in Groups 1 and 2 and 20 mg/day after 2 weeks in Group 3. Tapering was systematically attempted from the 6th month of treatment. RESULTS: One hundred sixty-four patients were included in the trial (1992-96). Cumulative doses of corticosteroids after one year were identical for all groups (p = 0.39). No significant differences were observed in the time required for normalization of C-reactive protein, corticosteroid resistance (13.5%), and corticosteroid related side effects (39% of patients; p = 0.37). Corticosteroid resistant patients received larger doses and showed a high risk of GCA related complications (p = 0.02). CONCLUSION: MP pulses have no significant longterm, corticosteroid sparing effects in the treatment of simple forms of GCA and should be limited to complicated forms. Moreover, corticosteroid resistance is a real risk factor for GCA complications.

Assessment of sex chromosome aneuploidy in sperm nuclei from 47,XXY and 46,XY/47,XXY males: comparison with fertile and infertile males with normal karyotype.

Sex chromosome aneuploidy was assessed in spermatozoa from a 47,XXY male and a 46,XY/47,XXY male using three colour fluorescence in-situ hybridization (FISH) and compared with two control groups. The first group included subjects of proven fertility and the second infertile males with normal constitutional karyotype. The frequencies of XX and YY disomic, XY hyperhaploid and diploid spermatozoa were significantly increased in the 47,XXY male compared to subjects from the two control groups (P < 0.0001). For the 46,XY/47,XXY sample, the same results were observed, except that the incidence of YY disomic spermatozoa did not differ significantly from the rate obtained in infertile patients. The frequency of sex chromosome aneuploidy did not differ significantly between the 47,XXY and the 46,XY/47,XXY males, except for XX disomic sperm nuclei which was higher in the 47,XXY patient. The frequency of chromosome 12 disomy was also increased in the two XXY individuals (0.42 and 0.49% respectively; P < 0.0001). The meiotic abnormalities observed in the two XXY patients arose through segregation errors in XY germ cells. The increased number of meiotic non-disjunctions observed in the germ cells of infertile males may be a common feature of the deficient oligo- or azoospermic testis. Patients with Klinefelter's syndrome with oligozoospermia have an increased risk of both sex chromosome and autosome aneuploidy in their progeny.

[Microdeletion of 22q11 and conotruncal cardiopathies: contribution of prenatal diagnosis]. / Microdélétion 22q11 et cardiopathies conotroncales: apport du diagnostic prénatal.

OBJECTIVE: We report our experience on prenatal diagnosis of 22q11 deletion by fluorescent in situ hybridation (FISH). PATIENTS AND METHODS: From February 1997 to April 1998, prenatal diagnosis of 22q11 deletion was performed in 13 cases of congenital conotruncal heart defects. FISH was carried out using D22S75 DiGeorge's chromosome region probe. RESULTS: Microdeletions of 22q11 were detected in 4 fetuses with tetralogy of Fallot (3 cases) and pulmonary atresia with ventricular septal defect (1 case). Termination of pregnancy was performed in two cases for severe congenital heart defect. A third malformed fetus died immediately after a blood sampling procedure. The last fetus, with a tetralogy of Fallot malformation, was born and underwent corrective cardiac surgery. The dysmorphic features of this fetus was suggestive of DiGeorge's syndrome, and the development status was normal. CONCLUSION: Prenatal detection of 22q11 only played a minor role in the decision to terminate the pregnancy in our study.

Fluorescence in situ hybridization with chromosome paint probes: a novel approach to assess aneuploidy in human sperm nuclei.

PURPOSE: Fluorescence in situ hybridization (FISH) using whole-chromosome paint probes was performed to evaluate disomy and diploidy frequency for chromosomes 1, 18, 19, and 22 in human sperm nuclei. METHODS: Ten subjects of proven fertility and normal spermatic parameters were included in the study. A dual-color FISH method was carried out. RESULTS: A total of 157,896 spermatozoa was scored. The mean frequencies of disomic sperm for chromosomes 1, 18, 19, and 22 were 0.22% (range, 0.19 to 0.28%), 0.24% (range, 0.14 to 0.37%), 0.22% (range, 0.17 to 0.30%), and 0.25% (range, 0.21 to 0.29%), respectively. The mean frequency of diploidy was 0.14% (range, 0.09 to 0.18%). No interindividual and interchromosomal variations in the aneuploidy frequency were observed between the different subjects. CONCLUSIONS: FISH with whole-chromosome paint probes provides a novel and efficient approach for disomy assessment in human sperm nuclei.

Relationship between clinical phenotype, semen parameters and aneuploidy frequency in sperm nuclei of 50 infertile males.

The purpose of this study was to analyse the frequency of disomy for chromosomes 1, 13, 14, 18, 21, 22, X and Y in sperm nuclei of 50 infertile men and 10 healthy probands of proven fertility. Semen parameters (sperm count, global motility and morphology), urological clinical examination, genital ultrasound and lymphocyte karyotyping were performed for each patient. Disomy frequency was established by fluorescence in situ hybridization by using whole chromosome paint probes. The mean rate of disomy for the various autosomes studied was higher in infertile males than in subjects of proven fertility. Interchromosomal and interindividual differences in the disomy frequency were observed between the 50 patients. The mean frequency of homodisomy YY and heterodisomy XY was increased in spermatozoa of patients with low semen quality parameters (0.24% and 0.54%, respectively). The disomy frequency in infertile males was directly correlated with the severity of oligospermia. However, no relationship was established between aneuploidy rate, sperm motility, morphology or clinical phenotype. These results support the hypothesis that, during spermatogenesis of males with sperm parameter alterations, a decreased frequency of meiotic chromosome pairing and crossing over may lead to spermatogenesis arrest at the meiosis stage and/or to an increase of meiotic nondisjunctions. Meiotic arrest in some germ cells may be responsible for oligospermia and nondisjunctions in other cells for aneuploidy in mature male gametes.

Assessment of autosome and gonosome disomy in human sperm nuclei by chromosome painting.

Disomy and diploidy frequencies for autosomes 1-22 and the gonosomes were assessed in 299,442 sperm nuclei from four normal fertile men by chromosome painting. This novel approach allowed us to perform a specific and sensitive detection of each chromosome. A minimum of 5000 sperm nuclei per subject were evaluated for each chromosome by dual colour fluorescence in situ hybridization. The disomy rate proved to be similar for all the autosomes (0.24%) and the diploidy rate varied from 0.12% to 0.15%. No interchromosomal or interindividual differences in the frequency of disomic and diploid sperm nuclei were observed between the four subjects. The mean frequency of XX-, YY- and XY-bearing spermatozoa was estimated to 0.17%, 0.17% and 0.32%, respectively. This strategy constitutes a new approach for detecting aneuploidy in human sperm nuclei and suggests an equal repartition of non-disjunction among chromosomes in male gametes.

Drug-induced vasodilation: in vitro and in vivo study on the effects of lidocaine and papaverine on rabbit carotid artery.

Flap ischemia is often encountered during pedicled and free tissue transfer. In this study, the vascular effects of varying doses of lidocaine, papaverine, and a combination of the two agents were evaluated and compared in an in vitro and in vivo model in the rabbit carotid artery. In the in vitro study, 14 rings from the rabbit carotid artery were bathed in Krebs-Ringers solution and stretched progressively to an optimal tension of 3.7-4.2 grams. Their isometric contractile activity was measured. The specimens were precontracted with norepinephrine (1 microM), and a dose response curve was established by adding cumulatively either lidocaine (to 7 arterial rings) or papaverine (to 7 arterial rings) at increasing concentrations. In the in vivo study, microvascular anastomoses were performed bilaterally in the rabbit carotid artery in 30 animals using 9-0 nylon suture and standard microsurgical techniques. In each animal, one side was treated with heparinized sodium chloride and served as the control. The other side was treated blindly, during and after the anastomoses, with a topical application of 1 ml of either lidocaine 2% (n = 5), lidocaine 20% (n = 5), papaverine (30 mg/ml, n = 5), lidocaine 2% combined with papaverine (30 mg/ml, n = 5), or lidocaine 20% combined with papaverine (30 mg/ml, n = 5). For 30-60 minutes after the procedure, blood flow changes in the vessels were continuously monitored with a transonic doppler applied to both carotid arteries. The 20% lidocaine group was flushed with saline at the end of the first hour and monitored for an additional 60 minutes. Papaverine elicited a concentration-dependent relaxation of norepinephrine precontracted carotid artery rings in vitro. Lidocaine elicited a biphasic response, with low concentrations (10(-6)-10(-4) M) increasing the norepinephrine-induced contraction and high concentrations (10(-4)-10(-2) M) relieving this contraction. Microsurgical anastomosis produced a significant decrease of blood flow through the rabbit carotid artery as measured by the transonic doppler. Drug application did not alter the systemic blood pressure of the animals. Topical application of lidocaine 2% did not significantly change the blood flow after microvascular anastomosis. Topical application of lidocaine 20%, papaverine (30 mg/ml), or lidocaine (2% or 20%) combined with papaverine significantly increased the blood flow in the rabbit carotid artery. In the lidocaine 20% group, the blood flow remained significantly increased after the drug was flushed with heparinized saline solution. These results demonstrate that topical lidocaine 20%, papaverine, and lidocaine 2% or 20% combined with papaverine significantly increase blood flow in the rabbit carotid artery after microvascular anastomosis. The data confirm the use of papaverine and lidocaine 20%, alone or in combination, as spasmolytics during clinical microsurgery. This suggests that lidocaine 2% alone is not the ideal drug to relieve vascular constriction, and further studies on the clinical use of low concentrations of topical lidocaine in microsurgery is warranted.