Boronic Acid-Mediated Activity Control of Split 10-23 DNAzymes

The 10-23 DNAzyme is an artificially developed Mg2+ -dependent catalytic oligonucleotide that can cleave an RNA substrate in a sequence-specific fashion. In this study, new split 10-23 DNAzymes made of two nonfunctional fragments, one of which carries a boronic acid group at its 5' end, while the other has a ribonucleotide at its 3' end, were designed. Herein it is demonstrated that the addition of Mg2+ ions leads to assembly of the fragments, which in turn induces the formation of a new boronate internucleoside linkage that restores the DNAzyme activity. A systematic evaluation identified the best-performing system. The results highlight key features for efficient control of DNAzyme activity through the formation of boronate linkages.

In situ observation of the percolation threshold in multiphase magma analogues

Magmas vesiculate during ascent, producing complex interconnected pore networks, which can act as outgassing pathways and then deflate or compact to volcanic plugs. Similarly, in-conduit fragmentation events during dome-forming eruptions create open systems transiently, before welding causes pore sealing. The percolation threshold is the first-order transition between closed- and open-system degassing dynamics. Here, we use time-resolved, synchrotron-source X-ray tomography to image synthetic magmas that go through cycles of opening and closing, to constrain the percolation threshold Φ _C at a range of melt crystallinity, viscosity and overpressure pertinent to shallow magma ascent. During vesiculation, we observed different percolative regimes for the same initial bulk crystallinity depending on melt viscosity and gas overpressure. At high viscosity (> 10⁶ Pa s) and high overpressure (~ 1-4 MPa), we found that a brittle-viscous regime dominates in which brittle rupture allows system-spanning coalescence at a low percolation threshold (Φ _C ~0.17) via the formation of fracture-like bubble chains. Percolation was followed by outgassing and bubble collapse causing densification and isolation of the bubble network, resulting in a hysteresis in the evolution of connectivity with porosity. At low melt viscosity and overpressure, we observed a viscous regime with much higher percolation threshold (Φ _C  > 0.37) due to spherical bubble growth and lower degree of crystal connection. Finally, our results also show that sintering of crystal-free and crystal-bearing magma analogues is characterised by low percolation thresholds (Φ _C  = 0.04 - 0.10). We conclude that the presence of crystals lowers the percolation threshold during vesiculation and may promote outgassing in shallow, crystal-rich magma at initial stages of Vulcanian and Strombolian eruptions.

Propagation and localization of electromagnetic waves in quasiperiodic serial loop structures

We study the propagation of electromagnetic waves in one-dimensional quasiperiodic photonic band gap structures made of serial loop structures separated by segments. Different quasiperiodic structures such as Fibonacci, Thue-Morse, Rudin-Shapiro, and double period are investigated with special focus on the Fibonacci structure. Depending on the lengths of the two arms constituting the loops, one can distinguish two particular cases. (i) There are symmetric loop structures, which are shown to be equivalent to impedance-modulated mediums. In this case, it is found that besides the existence of extended and forbidden modes, some narrow frequency bands appear as defect modes in the transmission spectrum inside the gaps. These modes are shown to be localized within only one of the two types of blocks constituting the structure. An analysis of the transmission phase time enables us to derive the group velocity as well as the density of states in these structures. In particular, the stop bands (localized modes) may give rise to unusual (strong normal) dispersion in the gaps, yielding fast (slow) group velocities above (below) the velocity of light. (ii) There are also asymmetric loop structures, where the loops play the role of resonators that may introduce transmission zeros and hence additional gaps unnoticed in the case of simple impedance-modulated mediums. A comparison of the transmission amplitude and phase time of Fibonacci systems with those of other quasiperiodic systems is also outlined. In particular, it was shown that these structures present similar behaviors in the transmission spectra inside the regions of extended modes, whereas they present different localized modes inside the gaps. Experiments and numerical calculations are in very good agreement.

Prothèse acoustique et bruiteur conjoint pour des sujets hypoacousiques et acouphéniques

INTRODUCTION

Sound therapy has been studied in a group of 30 patients experiencing hearing loss and tinnitus.

MATERIAL AND METHODS

Patients wore a BTE hearing-aid (TCI-COMBI by Siemens), which, in addition to acoustic amplification, can generate a broadband noise. Comparison of self-questionnaires completed by the patients during a 12 week period with amplification alone to a 12 week period with amplification and noise.

RESULTS AND CONCLUSIONS

His study demonstrates that the level of suffering is significantly reduced during the period with added noise.

Hawthorn extracts inhibit LDL oxidation

Polyphenol-rich diet decreases cardiovascular risk. LDL oxidation is the primary event in atherosclerosis plaque formation and antioxidants such as polyphenols were shown to inhibit LDL oxidation and atherosclerosis development. Hawthorn (Crataegus) and derived pharmaceuticals are rich in polyphenols and already prescribed to treat moderate heart failure, nervousness and sleep disorders. Extracts either from fresh plant parts (flower buds, flowers, young leaves or green fruits) or from dried pharmaceutical parts (flowers and flowering tops) were previously shown to be effective inhibitors of lipoperoxidation and scavengers of oxygen species. In this study, the capacity of total and ethyl-acetate extracts from dried pharmaceutical flowers, tops and fruits to inhibit Cu(2+)-induced LDL oxidation was tested. This capacity was positively linked to their content in total polyphenols, proanthocyanidins (global and oligomeric forms), as well as to their content in two individual phenolics: a flavanol, the dimeric procyanidin B2 and a flavonol glycoside, hyperoside. Flavanol-type phenolics showed to be higher active than the majority of the flavonoids tested in inhibiting Cu(2+)-induced LDL peroxidation. This study suggests that hawthorn could be a source of polyphenols able to inhibit LDL oxidation.

InsP(3)-mediated calcium release induced by heterologous expression of total chicory Leaf RNA

A calcium dependent-chloride current (I(ni)) was recorded in Xenopus oocytes injected with total RNA from chicory leaf tissues, following depolarization from -35 to +60 mV. However, the signal transduction mechanism mediating I(ni) is unknown. The development of this current was mimicked by intracellular injection of the second messenger InsP(3) in control (non-injected) oocytes. Moreover, InsP(3) injection after I(ni) rundown did not reinitiate the current. The same phenomenon was observed following a second injection into control oocytes. Measurement of InsP(3) production in injected oocytes showed a net increase in the InsP(3) level on depolarization. Moreover, extracellular application of caffeine (5 mM) significantly reduced the number of oocytes displaying I(ni). Also, extracellular application of U-73122, a potent PLC inhibitor, clearly reduced the occurrence of I(ni). These data provide the first evidence that the calcium homeostasis mechanism induced by heterologous expression of total RNA from chicory leaves involves the InsP(3) signaling pathway.

A glutathione S-transferase cDNA identified by mRNA differential display is upregulated during somatic embryogenesis in Cichorium

CHI-GST1, a cDNA encoding a glutathione S-transferase, was isolated by differential display in leaf tissues of chicory, during the early stages of somatic embryogenesis. Expression analysis of the gene by Northern blot indicated that the transcript accumulation is specific of the leaf developing somatic embryogenesis and is not observed in leaf tissue of the non-embryogenic cultivar.

Management of male osteoporosis

The objective of this study was to evaluate the efficacy of treatments for male osteoporosis selected based on the cause of the disease.

METHODS

Sixty-three men with osteoporosis (T-score at the lumbar spine and/or femoral neck lower than -2.5) with a mean age of 53+/-11 years were studied. Forty-three (68.3%) had a history of fracturing without trauma (vertebral fractures, 37 patients, 57%). Treatments were as follows: idiopathic osteoporosis: calcium and vitamin D supplements (N = 10) or cyclical etidronate for 2 weeks followed by calcium and vitamin D supplements for 76 days (N = 29); moderate idiopathic phosphate diabetes: calcitriol and phosphate (N = 15); idiopathic hypercalciuria: hydrochlorothiazide (N = 6); and hypogonadism: testosterone (N = 3).

RESULTS

Percentage change in bone mineral density (mean +/- standard error of the mean) after 18 months: calcium and vitamin D (lumbar spine: 0.6+/-2; femoral neck: 2.2+/-2.2); etidronate (lumbar spine: 3.6+/-1.4*; femoral neck: 0.5+/-1); calcitriol (lumbar spine: 7.0+/-3.5*; femoral neck: 0.0+/-1.4); thiazide diuretic (lumbar spine: 1+/-3.2; femoral neck: -2.3+/-3.7); and testosterone (lumbar spine: 6.8+/-6.4; femoral neck: 2.5+/-2.7), where *P < 0.05 versus baseline. Gastrointestinal side effects occurred in three patients (4.8%), including two on calcitriol-phosphate therapy and one on etidronate therapy. Of the six (9.5%) patients who experienced incident fractures, four were on etidronate, one on calcitriol-phosphate, and one on calcium-vitamin D. No patients discontinued their treatment because of side effects.

CONCLUSION

Etidronate and the combination of calcitriol-phosphate produce a significant increase in lumbar spine bone mass in men with idiopathic osteoporosis or moderate idiopathic phosphate diabetes.

Phenolic compounds and antioxidant activities of buckwheat (Fagopyrum esculentum Moench) hulls and flour

The interest of polyphenolics as therapeutic agents against diseases involving radical damage is growing. The phenolic contents of the hulls and flour from the seeds of Fagopyrum esculentum (French variety 'La Harpe') (total phenols, flavonoids, total flavanols, oligomeric proanthocyanidins) are compared with the antioxidative effects of the extracts against reactive oxygen species: hydrogen peroxide, hypochlorous acid, superoxide anion. The higher efficiency of the flour extract can be related to its higher flavanolic content rather than to flavonoids which are predominant in the hull extract.

Changes in lipid composition during somatic embryogenesis in leaves of Cichorium

The present studies were conducted to investigate the changes in lipid and fatty acid composition during the earliest stages of somatic embryogenesis in leaf tissues of the Cichorium hybrid '474'. The presence of glycerol in the culture medium during the induction step allowed to separate two phases in the embryogenic process. Firstly, cells are induced for morphogenetic competence (induction phase) and secondly, they express an embryogenic competence (expression phase). The analysis of fatty acid composition of total lipids showed that the percentage of linolenic acid (18:3) decreased while that of linoleic acid (18:2) increased throughout the culture period. A comparison with a non-embryogenic genotype of Cichorium indicated a higher increase of linoleate content in embryogenic genotype. The incorporation of [14C] glycerol into lipid classes was studied in leaf tissues. During the induction step, label was confined almost exclusively in polar lipids, particularly in phosphatidylcholine (PC). An important increase of labeled triacylglycerols (TAG) amounts was noted during the expression step. The accumulation of 18:2 was observed in PC and also in TAG. These results show that the early stages of somatic embryogenesis are associated with the increase of PC and TAG which are mainly enriched in 18:2.

Arabinogalactan-proteins in Cichorium somatic embryogenesis: effect of beta-glucosyl Yariv reagent and epitope localisation during embryo development

Direct somatic embryogenesis was induced in root tissues of the Cichorium hybrid '474' (C. intybus L. var. sativum x C. endivia L. var. latifolia). Addition of beta-D-glucosyl Yariv reagent (betaGlcY), a synthetic phenylglycoside that specifically binds arabinogalactan-proteins (AGPs), to the culture medium blocked somatic embryogenesis in a concentration-dependent manner with complete inhibition of induction occurring at 250 microM betaGlcY. The AGP-unreactive alpha-D-galactosyl Yariv reagent had no biological activity in this system. Upon transfer of 250 microM betaGlcY-treated roots to control conditions, somatic embryogenesis was recovered with a time course similar to that of control roots. The betaGlcY penetrated roots and bound abundantly to developing somatic embryos, to the root epidermis and the stele. Immunofluorescence and immunogold labelling using monoclonal antibodies (JIM13, JIM16 and LM2) revealed that AGPs were localised in the outer cell walls peripheral cells of the globular embryo. A spatio-temporal expression of AGPs appeared to be associated with differentiation events in the somatic embryo during the transition from the globular stage to the torpedo stage. To verify betaGlcY specificity, molecules that bound betaGlcY were extracted from treated conditioned medium and identified as AGPs by using the same monoclonal antibodies. In addition, AGPs were found to be abundantly present in the medium during embryogenic culture. All of these results establish the implication of AGPs in embryo development, and their putative role in somatic embryogenesis is discussed.

Histological analysis of indirect somatic embryogenesis in the Marsh clubmoss Lycopodiella inundata (L.) Holub (Pteridophytes)

An efficient in vitro plant regeneration method was developed for Lycopodiella inundata (L.) Holub, an endangered medicinal Lycopod (Pteridophytes). Vegetative apices were used as explant material. Nodular calluses were established after three cycles (13 weeks each) on a medium containing a few minerals and organic compounds and supplemented with 0.05 µM 3-indolebutyric acid (IBA) and 1.4 µM kinetin (Kin). Propagation was achieved every 13 weeks on this callus medium (CM). When nodular calluses were transferred on a medium supplemented with 2.5 µM IBA and 0.33 µM gibberellic acid (GA(3)) designated as embryogenic medium (EM), organized structures appeared and developed into plantlets. Development phases were characterized by histological studies. Some phases of zygotic embryogenesis previously described for Lycopods were observed in L. inundata. Histological analyses established that an indirect somatic embryo was derived from a single embryogenic cell by following the zygotic developmental pathway. As this phenomenon has not previously been reported in Lycopods, a comparison between somatic and zygotic embryos is discussed based upon morphology and histology.

Three major somatic embryogenesis related proteins in Cichorium identified as PR proteins

In Cichorium hybrid clone '474' (C. intybus L., var. sativum x C. endivia L., var. latifolia), the direct somatic embryogenesis process in leaf tissues is accompanied by an overall increase in the amount of proteins secreted into the culture medium. Amongst these, three major protein bands of 38 kDa, 32 kDa and 25 kDa were found in the conditioned media. These extracellular protein bands accumulated in the medium of the embryogenic Cichorium hybrid up to 8-fold compared with those in the medium of a nonembryogenic variety. 32 and 25 kDa proteins were purified from the medium and their identities were determined as already described for 38 kDa beta-1,3-glucanases. To investigate their possible function in somatic embryogenesis, peptide sequences, serological relationships or biochemical properties revealed that there were at least two acidic chitinases of 32 kDa and one glycosylated osmotin-like protein of 25 kDa in the embryogenic culture medium. Comparing the amounts of the 38 kDa glucanases, the 32 kDa chitinases, and the 25 kDa osmotin-like protein present in the conditioned media of the embryogenic '474' hybrid and of a non-embryogenic variety, a 2-8-fold higher accumulation of these proteins was observed in the embryogenic hybrid culture medium. This may suggest that part of the accumulation of these three pathogenesis-related (PR) proteins could be correlated with the somatic embryogenesis process. Their possible involvement in this developmental process is discussed.

[Assessment of perilymphatic pressure using the MMS-10 tympanic membrane displacement analyzer (Marchbanks' test) in patients with Meniere's disease: preliminary report]

OBJECTIVES

The aim of this study was to investigate non-invasive measurement of perilymphatic pressure using the MMS-10 tympanic displacement analyzer (Marchbanks' test) in patients with Meniere's disease.

METHODS

We performed measurements in 20 patients with Meniere's disease and in 9 normal subjects with normal hearing. Data were collected in three groups: healthy ears of normal-hearing patients, healthy and affected ears in patients with Meniere's disease.

RESULTS

We found no significant differences between the 3 groups for the types of the graph. Measurements of the tympanic membrane displacement test variables (Vi and Vm) showed large inter-subject variations. No significant difference was found between the 3 groups for cochlear aqueduct patency.

CONCLUSION

Preliminary results of this short series show that assessment of perilymphatic pressure using the MMS-10 procedure does not seem to be useful in Meniere's disease.

Cloning of beta-1,3-glucanases expressed during Cichorium somatic embryogenesis

Three different beta-1,3-glucanase cDNA fragments, CG1, CG2 and CG3, were obtained by RT-PCR from RNA isolated from Cichorium hybrid '474' leaf fragments cultured for 11 days under somatic embryogenesis-inducing conditions. When expressed in Escherichia coli the proteins encoded by the three cDNAs were recognized by antibodies raised against 38 kDa extracellular beta-1,3-glucanases studied previously (Helleboid et al., Planta 205 (1998) 56-63). The CG2 and CG3 cDNAs may represent expressed alleles of one gene because their sequences showed a very high identity (98.5%) and are only 70% identical with CG1. Southern blot analysis revealed the presence of 3-4 genes coding for beta-1,3-glucanases in the Cichorium genome. Expression analysis of the genes corresponding to the three clones analysed by semi-quantitative RT-PCR indicated that CG1 mRNAs were only detectable in Cichorium hybrid '474' leaf fragments from day 3 of somatic embryogenesis induction, whereas CG2-CG3 mRNAs were already present in non-induced leaf tissue of both the embryogenic hybrid '474' and a non-embryogenic genotype. The level of CG1 mRNAs was particularly high when embryogenic cells were dividing to produce embryos, and when the amount of callose deposited in cell walls surrounding embryogenic cells and young embryos decreased. These results indicate that expression of the CG1 gene is correlated to the somatic embryogenesis process and that it encodes a 38 kDa beta-1,3-glucanase protein that may be involved in the degradation of callose localized around embryogenic cells and young embryos. A full-length CG1 cDNA clone was obtained using 3' and 5' RACE-PCR, and its sequence revealed that it encodes a beta-1,3-glucanase that is equally homologous to both class III and class IV plant beta-1,3-glucanases.

Effects of glycerol on somatic embryogenesis in Cichorium leaves

 Direct somatic embryogenesis was induced in leaf cells of a Cichorium hybrid (Cichorium intybus L var. sativum×Cichorium endivia L. var. latifolia) through a two-step procedure. Leaf tissue explants were cultured for 5 days in M17 liquid medium supplemented with 30 mM sucrose and 330 mM glycerol (M17S30Gly330 medium). Synchronised divisions of embryogenic cells occurred after transfer for 7 days onto glycerol free-medium (M17S30). By doubling the sucrose concentration (60 mM) in the presence of glycerol (M17S60Gly330) during the induction step, embryogenesis increased and the length of the induction step was reduced from 5 to 4 days. Compared to sucrose, glycerol as carbon source during the induction and the expression steps had an inhibitory effect on the embryogenic response. During culture, glycerol was not detected in M17S60 medium and was at a low level in leaf fragments incubated in this medium. Initially supplied as an osmoticum, glycerol disappeared from M17S60Gly330 medium during the 4-day induction period and penetrated into the tissues where most of was metabolised. Furthermore, glycerol modified it carbohydrate metabolism, particularly during the induction period of embryogenesis. Sucrose hydrolysis was affected in the medium and sucrose and hexose contents in tissues were higher than in glycerol-free medium. The effects of glycerol as osmoticum and as a molecule itself are discussed.

A calcium homeostasis mechanism induced by heterologous expression of total RNA from chicory leaves in Xenopus oocytes

Xenopus oocytes were injected with total RNA from chicory leaf tissues and then examined by the voltage-clamp technique. A double-step voltage protocol was used, with an initial hyperpolarization step from the holding potential of -35 to -140 mV followed by a second depolarization step to +60 mV. Two different outward currents were observed, one noninactivating (Ini), and one inactivating (Ii). Only the noninactivating outward current (Ini) could be induced by depolarization from -35 to +60 mV. The mean amplitude of Ini was 2915 +/- 848 nA (n = 11). This current, carried by chloride ions, declined nearly to the baseline in 153 +/- 64 sec (n = 13), and was highly dependent on intracellular calcium. After the rundown of Ini, the same oocyte was depolarized from -140 to +60 mV. This protocol induced an inactivating outward current (Ii) with a mean amplitude of 4461 +/- 1605 nA (n = 13). Ii was also carried by chloride ions and dependent on extracellular calcium. Ii was strongly inhibited by 100 micron extracellular La3+. These two types of chloride currents were also observed after IP3 injection in control oocytes. Ini and Ii were not observed in noninjected oocytes or water-injected oocytes. We suggest that the expression of total chicory leaf tissue RNA in Xenopus oocytes reveals a calcium homeostasis mechanism responsible for calcium mobilization from internal stores and subsequent calcium entry.

A nonsymbiotic hemoglobin gene is expressed during somatic embryogenesis in Cichorium

After differential screening of a cDNA library corresponding to genes expressed during the early stages of somatic embryogenesis in leaf tissue from the Cichorium hybrid '474' (C. intybus L., var. sativumxC. endivia L., var. latifolia) a nonsymbiotic hemoglobin cDNA was obtained. Studies of the expression of the gene corresponding to this clone by Northern blot analysis suggest that in Cichorium a nonsymbiotic hemoglobin gene is specifically expressed under somatic embryogenesis-inducing conditions, and that its expression is not related to stress caused by wounding or tissue culture conditions.

Extracellular beta-1,3-glucanases are induced during early somatic embryogenesis in Cichorium

In leaf tissues of the Cichorium hybrid clone '474' (C. intybus L. var. sativum x C. endivia L. var. latifolia), the acquisition and expression of embryogenic competence was characterised by the appearance of 15 polypeptides (Boyer et al., 1993, Plant Sci 93: 41-53). The 38-kDa proteins were found to be abundantly present in conditioned embryogenic medium after the first division of the induced cells. These proteins seemed to be glycosylated as indicated by general carbohydrate detection methods. Internal amino-acid sequences obtained after microsequencing tryptic peptides appeared to be 36-57% homologous with plant beta-1,3-endoglucanases. In addition, these 38-kDa proteins were recognised by antibodies raised against the pathogenesis-related tobacco glucanase PR2a and their beta-1,3-glucanase activity was demonstrated by direct detection in polyacrylamide gels after electrophoresis. These results strongly suggested that the 38-kDa somatic-embryogenesis-related (SER) polypeptides are beta-1,3-glucanases. Moreover, the level of glucanase activity was nearly three times higher in the medium of the embryogenic '474' line than in the medium of a non-embryogenic line. The possible involvement of the extracellular 38-kDa proteins in callose degradation during somatic embryogenesis is discussed.

Antioxidant activities of polyphenolic extracts from flowers, in vitro callus and cell suspension cultures of Crataegus monogyna

Numerous plants synthesize among their secondary metabolites phenolic compounds which possess antioxidant effects. The aim of the present work was to assay the antioxidant activities of phenolics from Crataegus monogyna Jacq. flowers and in vitro tissue culture (calli and cell suspensions) extracts. In the case of tissue culture extracts, the phenolic production is studied at three different stages of one subculture period (initial growth period, increasing and maximal phenolic synthesis phases). Attention was paid to the main categories: flavonoids and proanthocyanidins, and to the principal individual components. Total phenolic amounts decrease in the order: fresh flowers > cell suspension cultures > callus cultures. The antioxidant activities of these different extracts against H2O2 and HOCl, have been determined in vitro. All the extracts are efficient and the scavenging capacity is clearly related to the total phenol content. The scavenging effects of the cell suspension extracts are similar to those of the flowers. Among individual compounds, the flavanol-type derivatives, specially the proanthocyanidin B2, are more efficient. Thus, in vitro plant tissues could be an interesting source of bioactive molecules.

Oxygen species scavenging activity of phenolic extracts from hawthorn fresh plant organs and pharmaceutical preparations

Different extracts of fresh vegetative and reproductive organs from Crataegus monogyna harvested during a whole season and from some pharmaceutical hawthorn preparations exhibit in vitro antioxidant activities using three different models of oxygen reactive species generation (superoxide anion, hydrogen peroxide and hypochlorous acid). All the tested samples show low IC50 values, the most efficient being fresh young leaves, fresh floral buds and pharmaceutical dried flowers. The activities seem to be especially bound to the total phenolic proanthocyanidin and flavonoid contents.

Antioxidant activities of Crataegus monogyna extracts

Interesting antioxidant activities of extracts from different vegetative and reproductive organs of Crataegus monogyna harvested at different stages of growth have been determined by the malondialdehyde-thiobarbituric acid (MDA) test on hepatic microsomal preparations and compared to the contents in total phenolics, proanthocyanidins, catechins, flavonoids, and phenolic acids. The best correlations were established with total phenols while activities in leaves seem to be influenced by flavonoids and in flowers and fruits by proanthocyanidins and catechins.

Male-sterile chicory cybrids obtained by intergeneric protoplast fusion

Male-sterile chicory plants were obtained by fusion of chicory mesophyll protoplasts and hypocotyl protoplasts derived from male-sterile sunflower plants. The protoplasts of both species were fused by the PEG method and the products were selected manually and cultivated at very low density in a liquid medium. Three to twenty percent of the heterokaryocytes divided and evolved into microcalli, then into calli where budding could be induced. The mitochondrial genome of ten male-sterile or totally sterile plants was studied. Restriction endonuclease profiles of mitochondrial DNA and molecular hybridization with specific genes of the mitochondrial genome used as probes indicated that mitochondrial DNA rearrangement had occurred between sunflower and chicory and the intensity of the rearrangements correlated with the degree of sterility of the different plants.

Procyanidin Production by Fagopyrum esculentum Callus Culture

FAGOPYRUM ESCULENTUM CALLUS cultures grown on B5 medium synthesize procyanidins B2 (0.6-1.8 mg/g dry wt) and B2-3'- O-gallate (3.5-6.0 mg/g dry wt). Sucrose is a better source than other carbohydrates and moderate concentrations (3-4%) stimulate both growth and procyanidin synthesis. While darkness was not a limiting factor, light induced faster growth and increased procyanidin contents. Treatment with gallic acid strongly stimulated the procyanidin B2-3'- O-gallate production, but drastically inhibited growth, leading to a two-step-culture experiment combining convenient growth and increased galloylated dimer synthesis (up to 45 mg/g dry wt).

Participation du métabolisme glucidique à l'orientation organogène de tissus du Cichorium intybus cultivés in vitro

6-Benzylaminopurine and α-naphthaleneacetic acid each stimulate inulase and invertase activities in Cichorium intybus, although these two hormones induce different organ formations. Unlike auxin, however, cytokinin allows a partial elaboration of sucrose reserves without changing callus growth. Furthermore, addition of an external source of glucose inhibits inulase and invertase activities, which results in an increase in sugar reserves (sucrose and starch) in the bulky callus. This activity differs from that observed with α-naphthaleneacetic acid, which is characterized by an increase in protein synthesis and water absorption in the tissues. Root initiation also requires additional sugars with α-naphthaleneacetic acid; gibberellic acid improves these results by promoting the catabolism of external sugars rather than a conversion into tissue reserves. Key words: organogenesis, Cichorium intybus, carbohydrates, in vitro cultures.

The supernumerary muscles of the leg: a report of two cases

Two cases of supernumerary muscles of the leg reported, which were both inserted on the sides of the calcaneus. The accessory soleus m., adductor of the fore-foot, is a variation of the triceps surae which through hypertrophy on the medial side of the leg can become particularly problematic in athletes. The fourth peroneal m. abductor of the fore-foot, is considered to increase the stability of the ankle and is asymptomatic.