Ovule-specific MADS-box proteins have conserved protein-protein interactions in monocot and dicot plants.

OsMADS13 is a rice MADS-box gene that is specifically expressed in developing ovules. The amino acid sequence of OsMADS13 shows 74% similarity to those of FLORAL BINDING PROTEIN 7 (FBP7) and FBP11, the products of two MADS-box genes that are necessary and sufficient to determine ovule identity in Petunia. To assess whether OsMADS13, the putative rice ortholog of FBP7 and FBP11, has an equivalent function, several analyses were performed. Ectopic expression of FBP7 and FBP11 in Petunia results in ectopic ovule formation on sepals and petals. Here we show that ectopic expression of OsMADS13 in rice and Arabidopsis does not result in the formation of such structures. Furthermore, ectopic expression of FBP7 and FBP11 in Arabidopsis also fails to induce ectopic ovule formation. To determine whether protein-protein interactions involving putative class D MADS-box proteins have been conserved, yeast two-hybrid assays were performed. These experiments resulted in the identification of three putative partners of OsMADS13, all of them encoded by AGL2-like genes. Interestingly the Petunia FBP7 protein also interacts with AGL2-like proteins. The evolutionary conservation of the MADS-box protein partners of these ovule-specific factors was confirmed by exchange experiments which showed that the protein partners of OsMADS13 interact with FBP7 and vice versa.

New combined treatment of hypermelanosis: analytical studies on efficacy and stability improvement.

The aim of this work was to evaluate the synergy between different lightening agents when associated; depigmenting activity was tested in vitro by monitoring the appearance of dopachrome, an intermediate in the melanogenesis process. The results obtained were compared with the depigmenting activity of each single compound, keeping the same global concentration of inhibitor. Our studies showed that the combination of hydroquinone and kojic acid had a synergistic effect, and that the maximum inhibiting action was achieved with an equimolecular mixture. This result could serve in the cosmetics field to prepare skin-lightening formulations that are less irritant. We also investigated the feasibility of complexing hydroquinone with cyclodextrin and evaluated the effectiveness of the complex obtained in the treatment of hyperpigmentation.

Differential effects of acute and short-term lithium administration on dialysate glutamate and GABA levels in the frontal cortex of the conscious rat.

In the present study, we employed in vivo microdialysis in the frontal cortex of the awake rat to investigate the effects of acute and short-term (twice daily, 3 days) lithium chloride administration (1, 2, and 4 meq/kg, s.c.) on local dialysate glutamate and GABA levels. Acute lithium (1 meq/kg) failed to influence cortical glutamate levels while the higher (2 and 4 meq/kg) doses increased (+38 +/- 6% of basal levels) and reduced (-27 +/- 4%) cortical glutamate levels, respectively. Cortical GABA levels were affected by acute lithium only at the highest 4 meq/kg dose (+62 +/- 6%). Furthermore, these effects were prevented by tetrodotoxin (1 microM) and low-calcium (0.2 mM) medium perfusion. Following short-term administration, lithium increased (+58 +/- 4%) cortical dialysate glutamate levels at the 1 meq/kg dose, was ineffective at 2 meq/kg, while the effect of the 4 meq/kg dose was similar to that observed after acute administration. Interestingly, intracortical perfusion with the GABA(B) receptor antagonist CGP 35348 (100 microM) reversed the acute lithium (4 meq/kg)-induced decrease in glutamate levels. Taken together, these findings indicate a differential dose and duration dependent effect of lithium on cortical dialysate glutamate levels involving both a direct enhancement and an indirect inhibition that is mediated via an activation of local GABA(B) receptor. These findings may be relevant for the therapeutic effects of the drug.

Solid-state study of polymorphic drugs: carbamazepine.

Polymorphs of a compound have solid crystalline phases with different internal crystal lattices; in pharmaceuticals, differences due to polymorphism and pseudopolymorphism can affect bioavailability and effective clinical use. The aim of this work was to obtain the different polymorphic modifications of the anticonvulsant drug, carbamazepine, and to characterise them by means of typical structure-sensitive analytical techniques, such as FT-IR spectroscopy, XRPD and DSC. Further investigations were also performed by Hot Stage FT-IR thermomicroscopy, which permitted the visible and spectroscopic characterisation of the polymorphic forms during heating. Our results confirm the existence of three different polymorphic forms for anhydrous carbamazepine: Form III, the commercial one, Form I, obtained by heating Form III and Form II, crystallised from ethanolic solution. Substantial differences were detected among the polymorphs with regard to solid-state properties. Moreover, Hot Stage FT-IR thermomicroscopy proved its analytical potential to characterise the drug's polymorphism.

Properties of the racemic species of verapamil hydrochloride and gallopamil hydrochloride.

It is well known that the stereoselective actions associated with the enantiomeric constituents of a racemic drug can differ markedly in their pharmacodynamic or pharmacokinetic properties. Nevertheless, molecular chirality manifests itself in the solid, that is, crystalline state. The aim of this work was to characterize the solid-state properties of verapamil HCl and gallopamil HCl, two well-known chiral calcium channel antagonists. The characterization of the solid state for the single enantiomers and equimolecular mixtures for both the calcium antagonists was performed by solid-state techniques such as Fourier transform infrared (FT-IR spectroscopy), X-ray powder diffractometry (XRD) and differential scanning calorimetry (DSC). The FT-IR spectra and XRD of the single enantiomers are different from those of the corresponding equimolecular mixture owing to their different crystalline structure. The thermal behavior of the racemates and pure enantiomers were examined by DSC, and the resultant experimental and theoretical binary phase diagrams are discussed. Spectroscopic solid-state techniques, such as FT-IR and XRD, are useful in combination with thermal analysis for characterizing the racemic species of chiral drugs. The data obtained prove that the equimolecular mixtures of both verapmil hydrochloride and gallopamil hydrochloride exist as racemic compounds. Determination of the enantiomeric purity of the enantiomers and racemic compounds of both the calcium antagonists analyzed was performed by DSC.

Determination of azelaic acid in pharmaceuticals and cosmetics by RP-HPLC after pre-column derivatization.

This paper reports a RP-HPLC method for the determination in topics of azelaic acid, a keratolytic and anti-comedogenic agent widely used in the treatment of all types of acne. A derivatization step was needed prior to chromatographic analysis because the analyte is lacking in chromophore. A sample clean-up procedure by solid-phase extraction was also developed to analyse azelaic acid in complex matrices, such as pharmaceutical and cosmetic formulations.

Comparison of [3H]choline and D-[3H]aspartate efflux from guinea pig and human neocortex.

The outflow of [3H]choline ([3H]Ch) evoked by electrical field stimulation and the efflux of D-[3H]Asp induced by 35 mM KCl and 1-10 microM ouabain were studied in human and guinea pig cortical slices, kept under identical experimental conditions. [3H]Ch outflow was significantly lower whereas D-[3H]Asp efflux was significantly higher in humans than in guinea pigs. This suggests a different proportion of the two neuronal systems in these two species. Blockade of muscarinic autoreceptors with atropine increased, whereas stimulation of alpha 2 receptors with norepinephrine (NE) reduced, the evoked [3H]Ch outflow to the same extent in human and guinea pig cortical slices. Conversely, NE did not affect ouabain-induced D-[3H]Asp efflux, suggesting that an alpha 2-mediated control is not operative in the glutamatergic cortical structures. Desmethylimipramine, 2-5 microM, was able to increase [3H]Ch outflow through atropine-like mechanisms only in the human. This drug at 20-50 microM inhibited [3H]Ch and D-[3H]Asp efflux in both species, through mechanisms unrelated to its monoamine reuptake blocking properties. Thus, similarities and differences can be detected between humans and guinea pigs with regard to (a) the relative potency of the cholinergic and acidic amino acidergic signals and (b) the modulation of neurotransmitter outflow by drugs acting on auto- and the heteroreceptors.

[Heteropolycyclic systems. V. 4-alkyl-2,3,3a,4-tetrahydro-1H-pyrro1/2,1-c/ /1,2,4/benzothiadiazin-5,5-dioxide and their bz-substituted derivatives]. / Sistemi eteropoliciclici. Nota V - 4-alchil-2,3,3a,4-tetraidro-1H-pirrolo(2,1-c)(1,2,4)benzotiadiazin-5,5-diossido e loro derivati bz-sostituiti

The preparation of some 4-alkyl derivatives of 2,3,3a,4--tetrahydro-1H-pyrrolo(2,1-c)(1,2,4)benzothiadiazin-5,5-dioxode and bz-substituted derivatives by the action of alkyl iodides on the LiAlH4 reduction products of the corresponding 2,3-dihydro-1H-pyrrolo(2,1-c)(1,2,4)benzothiadiazin-5,5-dioxide is described. It was found that some of the substances synthesized exist in polymorphous forms and it was possible to isolate these.