Effects of calcium and pressure treatment on thermal gelation of soybean protein.

The effect of calcium and high-pressure (HP) treatment on the heat gelation of soybean proteins was investigated. In the presence of calcium (2 to 25 mM), the gelation of dispersions of soybean protein isolate (SPI), a beta-conglycinin-enriched fraction (7SEF), and a glycinin-enriched fraction (11SEF) started with protein having a lower degree of denaturation. The gels from these dispersions had greater stiffness than the samples without added calcium. HP treatment had different effects on heat-induced gelation depending on the presence of calcium and on the nature of the proteins. In the absence of calcium, gels with low stiffness were formed after HP treatment, compared with untreated samples, and regardless of the sample type (SPI, 7SEF, 11SEF). In the presence of calcium, gel stiffness was increased after HP treatment of dispersions containing beta-conglycinin (SPI and 7SEF), while the opposite effect was observed for 11SEF. In the presence of calcium, HP treatment promoted a greater contribution of hydrophobic interactions in SPI and 7SEF. In the dispersions containing beta-conglycinin, these conditions also promoted the appearance of a heterogeneous distribution of molecular sizes, from enormous aggregates to dissociated species. Our results suggest that, in the presence of calcium, HP treatment has an opposite effect on the ability of glycinin and beta-conglycinin to participate in the formation of a 3-dimensional network upon heating.

Identification of in vivo nitrosylated phytochelatins in Arabidopsis thaliana cells by liquid chromatography-direct electrospray-linear ion trap-mass spectrometry.

Reversed-phase liquid chromatography (RPLC) and electrospray (ESI)-linear ion trap (LIT) mass spectrometry was applied to the direct characterization of in vivo S-nitrosylated (SNO) phytochelatins (PCs) expressed in cadmium-stressed Arabidopsis thaliana cells. Cys-nitrosylation is under discussion as in vivo redox-based post-translational modification of proteins and peptides in plants in which the -NO group is involved as signal molecule in different biological functions. The gas-phase ion chemistry of in vivo and in vitro generated SNO-PC(s) was compared with the aim of evaluating NO binding stability and improving MS knowledge about peptide nitrosation. Using RPLC separation and ESI-LIT-MS, mono-nitrosylated PCs were identified in in vivo cadmium treated A. thaliana cells without derivatization. The in vivo binding of the NO group to PC(2), PC(3) and PC(4) resulted to occur selectively on only one cystein residue. The fragmentation pathway energies of the in vitro GSNO-generated NO-PCs with respect to the in vivo NO-PCs were investigated, suggesting the presence of a different internal stability for these molecules. By carrying out MS(2) experiments on these quasi-symmetric peptides, the different stability degree of the NO group was demonstrated to be correlated with the PC chain length. In addition, the data obtained highlight a putative role of the adjacent Glu/Cys motif in the gas-phase stability of the NO-containing molecule.

Genistein effects on Ca2+ handling in human umbilical artery: inhibition of sarcoplasmic reticulum Ca2+ release and of voltage-operated Ca2+ channels.

Isoflavones are a group of natural phytoestrogens including the compound genistein. Health beneficial effects have been attributed to the consumption of this compound, but the fact that it has estrogen-like activity has raised doubts regarding its potential risk in infants, newborns, or in the fetus and placenta during pregnancy. This work is aimed at studying genistein effects on Ca2+ handling by smooth muscle cells of the human umbilical artery (HUA). Using fluorometric techniques, we found that in these cells genistein reduces the intracellular Ca2+ peak produced by serotonin. The same result could be demonstrated in absence of extracellular Ca2+, suggesting that the isoflavone reduces Ca2+ release from the sarcoplasmic reticulum. Force measurement experiments strengthen these results, since genistein reduced the peak force attained by intact HUA rings stimulated by serotonin in a Ca2+-free solution. Moreover, genistein induced the relaxation of HUA rings precontracted either with serotonin or a depolarizing high-extracellular K+ solution, hinting at a reduction of extracellular Ca2+ entry to the cell. This was confirmed by whole-cell patch-clamp experiments where it was shown that the isoflavone inhibits ionic currents through voltage-operated Ca2+ channels. In summary, we show that genistein inhibits two mechanisms that could increase intracellular Ca2+ in human umbilical smooth muscle cells, behaving in this way as a potential vasorelaxing substance of fetal vessels. Taking into account that genistein is able to cross the placental barrier, these data show that isoflavones may have important implications in the regulation of feto-maternal blood flow in pregnant women who consume soy-derived products as part of their meals.

Efectos de la genisteína en los niveles del Ca2+ citosólico en células musculares de arteria umbilical humana / Genistein effects on Ca2+ handling in human umbilical artery: inhibition of sarcoplasmic reticulum Ca2+ release and of voltage-operated Ca2+ channels

Isoflavones are a group of natural phytoestrogens including the compound genistein.Health beneficial effects have been attributed to the consumption of this compound,but the fact that it has estrogen-like activity has raised doubts regarding itspotential risk in infants, newborns, or in the fetus and placenta during pregnancy.This work is aimed at studying genistein effects on Ca2+ handling by smooth musclecells of the human umbilical artery (HUA). Using fluorometric techniques, we foundthat in these cells genistein reduces the intracellular Ca2+ peak produced by serotonin.The same result could be demonstrated in absence of extracellular Ca2+, suggestingthat the isoflavone reduces Ca2+ release from the sarcoplasmic reticulum.Force measurement experiments strengthen these results, since genistein reduced thepeak force attained by intact HUA rings stimulated by serotonin in a Ca2+-free solution.Moreover, genistein induced the relaxation of HUA rings precontracted eitherwith serotonin or a depolarizing high-extracellular K+ solution, hinting at a reductionof extracellular Ca2+ entry to the cell. This was confirmed by whole-cell patchclampexperiments where it was shown that the isoflavone inhibits ionic currentsthrough voltage-operated Ca2+ channels. In summary, we show that genisteininhibits two mechanisms that could increase intracellular Ca2+ in human umbilical smooth muscle cells, behaving in this way as a potential vasorelaxing substance offetal vessels. Taking into account that genistein is able to cross the placental barrier,these data show that isoflavones may have important implications in the regulationof feto-maternal blood flow in pregnant women who consume soy-derived productsas part of their meals(AU)

Las isoflavonas son un grupo de fitoestrógenosnaturales que incluyen la genisteína. Alconsumo de este compuesto se le han atribuidoefectos beneficiosos para la salud, pero su actividadsimilar a los estrógenos permite pensaren efectos indeseados en niños o en el feto o laplacenta durante el embarazo. En este trabajose estudian los efectos de la genisteína sobre elmanejo de Ca2+ por las células de músculo lisode la arteria umbilical humana (AUH).Mediante la utilización de técnicas fluorométricasse observó que la genisteína reduce elpico de Ca2+ intracelular producido por la serotonina en estas células incluso en ausenciade Ca2+ extracelular, lo que sugiere que la isoflavonareduce la liberación de Ca2+ a partir delretículo sarcoplásmico. Los experimentos demedida de fuerza refuerzan estos resultados, yaque la genisteína redujo la fuerza pico desarrolladapor serotonina en anillos intactos deAUH en una solución libre de Ca2+. Además,la genisteína indujo la relajación de anillos deAUH precontraídos con serotonina o con unasolución despolarizante de alto K+ extracelular,lo que apunta a una reducción de la entradade Ca2+ desde el exterior de la célula. Con latécnica de “patch-clamp” en configuración decélula entera, los resultados confirmaron que laisoflavona inhibe corrientes iónicas a través decanales de Ca2+ operados por el voltaje. Enresumen, mostramos que la genisteína inhibedos mecanismos que incrementan el Ca2+intracelular en células de músculo liso deAUH, comportándose de esta manera comoun potencial vasorrelajante de los vasos fetales.Dado que la genisteína atraviesa la barrera placentaria,estos datos muestran que las isoflavonaspodrían tener consecuencias en la regulacióndel flujo materno-fetal en mujeres embarazadasque incluyan productos derivados de lasoja como parte de sus dietas(AU)

Genistein inhibits contractile force, intracellular Ca2+ increase and Ca2+ oscillations induced by serotonin in rat aortic smooth muscle.

The soy-derived isoflavones genistein and daidzein affect the contractile state of different kinds of smooth muscle. We describe acute effects of genistein and daidzein on contractile force and intracellular Ca2+ concentration ([Ca2+]i) in in situ smooth muscle of rat aorta. Serotonin (5-HT) (2 microM) or a depolarizing high K+ solution produced the contraction of aortic rings, which were immediately relaxed by 20 microM genistein and by 20 microM daidzein. Accordingly, both 5-HT and a high K+ solution increased the [Ca2+]i in in situ smooth muscle cells. Genistein strongly inhibited the [Ca2+]i increase evoked by 5-HT (74.0 +/- 7.3%, n = 11, p < 0.05), and had a smaller effect on high K+ induced [Ca2+]i increase (19.9 +/- 4.0%, n = 7, p < 0.05). The K+ channels blocker tetraethylammonium (TEA) (0.5 mM) diminished genistein effects on 5-HT-induced [Ca2+]i increase. Interestingly, during prolonged application of 5-HT, the [Ca2+]i oscillated and a short (90 s) preincubation with genistein (20 microM) significantly diminished the frequency of the oscillations. This effect was totally abolished by TEA. In conclusion, in rat aortic smooth muscle, genistein is capable of diminishing the increase in [Ca2+]i and in force evoked by 5-HT and high K+ solution, and of decreasing the frequency of [Ca2+]i oscillations induced by 5-HT. The short time required by genistein, and the relaxing effect of daidzein suggest that tyrosine kinases inhibition is not involved. The small inhibiting effect of genistein on the [Ca2+]i increase evoked by high K+ and the effect of TEA point to the activation by genistein of calcium-activated K+ channels.

Genistein inhibits contractile force, intracellular Ca2+ increase and Ca2+ oscillations induced by serotonin in rat aortic smooth muscle

The soy-derived isoflavones genistein and daidzein affect the contractile state ofdifferent kinds of smooth muscle. We describe acute effects of genistein and daidzeinon contractile force and intracellular Ca2+ concentration ([Ca2+]i) in in situ smoothmuscle of rat aorta. Serotonin (5-HT) (2 ìM) or a depolarizing high K+ solution producedthe contraction of aortic rings, which were immediately relaxed by 20 ìMgenistein and by 20 ìM daidzein. Accordingly, both 5-HT and a high K+ solutionincreased the [Ca2+]i in in situ smooth muscle cells. Genistein strongly inhibited the[Ca2+]i increase evoked by 5-HT (74.0 ± 7.3%, n=11, p<0.05), and had a smallereffect on high K+ induced [Ca2+]i increase (19.9 ± 4.0%, n=7, p<0.05). The K+ channelsblocker tetraethylammonium (TEA) (0.5 mM) diminished genistein effects on 5-HT-induced [Ca2+]i increase. Interestingly, during prolonged application of 5-HT,the [Ca2+]i oscillated and a short (90 s) preincubation with genistein (20 ìM) significantlydiminished the frequency of the oscillations. This effect was totally abolishedby TEA. In conclusion, in rat aortic smooth muscle, genistein is capable of diminishingthe increase in [Ca2+]i and in force evoked by 5-HT and high K+ solution, andof decreasing the frequency of [Ca2+]i oscillations induced by 5-HT. The short timerequired by genistein, and the relaxing effect of daidzein suggest that tyrosine kinasesinhibition is not involved. The small inhibiting effect of genistein on the [Ca2+]iincrease evoked by high K+ and the effect of TEA point to the activation by genisteinof calcium-activated K+ channels (AU)

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Genistein inhibits contractile force, intracellularCa2+ increase and Ca2+ oscillations induced byserotonin in rat aortic smooth muscle

The soy-derived isoflavones genistein and daidzein affect the contractile state ofdifferent kinds of smooth muscle. We describe acute effects of genistein and daidzeinon contractile force and intracellular Ca2+ concentration ([Ca2+]i) in in situ smoothmuscle of rat aorta. Serotonin (5-HT) (2 ìM) or a depolarizing high K+ solution producedthe contraction of aortic rings, which were immediately relaxed by 20 ìMgenistein and by 20 ìM daidzein. Accordingly, both 5-HT and a high K+ solutionincreased the [Ca2+]i in in situ smooth muscle cells. Genistein strongly inhibited the[Ca2+]i increase evoked by 5-HT (74.0 ± 7.3%, n=11, p<0.05), and had a smallereffect on high K+ induced [Ca2+]i increase (19.9 ± 4.0%, n=7, p<0.05). The K+ channelsblocker tetraethylammonium (TEA) (0.5 mM) diminished genistein effects on 5-HT-induced [Ca2+]i increase. Interestingly, during prolonged application of 5-HT,the [Ca2+]i oscillated and a short (90 s) preincubation with genistein (20 ìM) significantlydiminished the frequency of the oscillations. This effect was totally abolishedby TEA. In conclusion, in rat aortic smooth muscle, genistein is capable of diminishingthe increase in [Ca2+]i and in force evoked by 5-HT and high K+ solution, andof decreasing the frequency of [Ca2+]i oscillations induced by 5-HT. The short timerequired by genistein, and the relaxing effect of daidzein suggest that tyrosine kinasesinhibition is not involved. The small inhibiting effect of genistein on the [Ca2+]iincrease evoked by high K+ and the effect of TEA point to the activation by genisteinof calcium-activated K+ channels (AU)

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The Na+/Ca2+ exchanger is active and working in the reverse mode in human umbilical artery smooth muscle cells.

The data presented in this work suggest that in human umbilical artery (HUA) smooth muscle cells, the Na(+)/Ca(2+) exchanger (NCX) is active and working in the reverse mode. This supposition is based on the following results: (i) microfluorimetry in HUA smooth muscle cells in situ showed that a Ca(2+)-free extracellular solution diminished intracellular Ca(2+) ([Ca(2+)](i)), and KB-R7943 (5microM), a specific inhibitor of the Ca(2+) entry mode of the exchanger, also decreased [Ca(2+)](i) (40.6+/-4.5% of Ca(2+)-free effect); (ii) KB-R7943 produced the relaxation of HUA rings (-24.7+/-7.3gF/gW, n=8, p<0.05); (iii) stimulation of the NCX by lowering extracellular Na(+) increases basal [Ca(2+)](i) proportionally to Na(+) reduction (Delta fluorescence ratio=0.593+/-0.141 for Na(+)-free solution, n=8) and HUA rings' contraction (peak force=181.5+/-39.7 for 130mM reduction, n=8), both inhibited by KB-R7943 and a Ca(2+)-free extracellular solution. In conclusion, the NCX represents an important Ca(2+) entry route in HUA smooth muscle cells.

High-pressure induced physicochemical and functional modifications of low-density lipoproteins from hen egg yolk.

High-pressure treatment represents a potential method to stabilize microbiologically agricultural raw materials that are sensitive to heat treatments. Low-density lipoproteins (LDL), the main contributors to the exceptional emulsifying properties of yolk, are particularly sensitive to heat treatment. In this study, high-pressure treatments have been performed on LDL, and their impact on LDL physicochemical and emulsifying properties has been assessed. LDL dispersions at two pH levels (pH 3 and 8) were treated at different pressure levels: 200, 400, and 600 MPa at 20 degrees C. LDL dispersion characteristics (solubility, aggregation, and protein denaturation) and LDL emulsifying properties (o/w 30:70 emulsions: droplet size, flocculation, and protein adsorption) of nontreated and high-pressure treated dispersions were compared. Solubility is not altered by high-pressure treatment whatever the pH, whereas aggregation and protein denaturation are drastically enhanced, in particular at pH 8. The effects of these modifications on LDL emulsifying properties are mainly a diminution of the flocculation (depletion and bridging) at this same pH. Finally, it seems that high-pressure treatment combined with an alkaline pH decreases droplet flocculation of LDL dispersions.

Foliar uptake of 134Cs and 85Sr in strawberry as function by leaf age.

In this paper a study of the foliar uptake and translocation of 134Cs and 85Sr in a herbaceous fruit plant is presented. In particular, absorption, translocation and loss of these radionuclides in strawberry plants have been studied in relation to the age of contaminated leaves. Strawberry plants were contaminated by distributing droplets of an aqueous solution containing 134CsCl and 85SrCl2 on the surface of two leaves per plant. One half of the plants was contaminated through two young leaves, a second half through two old leaves. Sets of plants were collected 1 day, 7 days and 15 days after contamination. One half of them was rinsed with double distilled water before gamma analysis. Rinsing contaminated leaves removes on average 55% of the applied 134Cs and 45% of 85Sr. The activity removed decreases during the 15 days of the experimental study, both for 134Cs and for 85Sr, suggesting an increase in foliar absorption during this period. The activity removed does not differ between old and young leaves. "External loss" is lower for young than old contaminated leaves. "Internal loss" through translocation occurs mainly for 134Cs. Translocation coefficients from contaminated leaves to fruits are two orders of magnitude higher for 134Cs (4.0%), than for 85Sr (0.05%). Leaf to fruit translocation coefficients for 134Cs are higher from young leaves (5.8%), than from old leaves (2.3%).

[Isolated straddling tricuspid valve. Presentation of 2 cases operated on successfully]. / Valvola tricuspide a cavaliere isolata. Presentazione di due casi operati con successo.

During the period May 1977-September 1983 in the Department of Cardiac Surgery of Massa Hospital two patients with isolated straddling tricuspid valve were studied with cardiac catheterization and selective angiocardiography and subsequently underwent surgical correction. The first patient, a 38-month-old white boy presented with "complete straddling" according to Bharati and Lev classification; the second, a 39-month-old white boy presented with "peripheral straddling". In both cases at surgery the ventricular septal defect was closed with a Teflon patch, sparing the chordae tendinae and the "straddling" papillary muscle. Both patients survived operation. The first one developed a complete atrioventricular (A-V) block with a ventricular rate which never was below 80 beats/min, during the 30 days of in-hospital observation. No permanent pacemaker was therefore inserted. The follow-up controls (39 and 79 months respectively) shows both patients to be hemodynamically and functionally well.

Post-traumatic mitral regurgitation and ventricular septal defect in absence of left pericardium.

A six-year-old boy was hospitalized following a car accident. Cardiac catheterization demonstrated acute post-traumatic mitral regurgitation (MR) and ventricular septal defect (VSD). The patient was operated on for mitral valve replacement and closure of the VSD. On opening the chest absence of the left pericardium was noted. Cardiac catheterization performed in the postoperative period demonstrated a residual left-to-right shunt at ventricular level. The patient was reoperated on 10 months later for closure of the residual VSD. Six months after the last operation the patient is in good condition. The congenital absence of the pericardium is considered as favoring both the post-traumatic cardiac lesions and the postoperative pulmonary problems on the left side.