The response of the different soybean metallothionein isoforms to cadmium intoxication.

Cadmium is a highly toxic heavy metal for both plants and animals. The presence of Cd in agricultural soils is of major concern regarding its entry into the food chain, since Cd compounds are readily taken up by plants, and accumulated in edible parts due to their high solubility. In this study, we first demonstrate the high capacity for Cd concentration of soybean grains. Consequently, we considered the study and characterization of the molecular determinants of Cd accumulation -such as metallothioneins (MT)- to be of major practical importance. We report here the first characterization of the soybean MT system, with the identification of nine genes (one of which is a truncated pseudogene), belonging to the four plant MT types. The most highly expressed of each type was chosen for further function analysis. All of them are expressed at high levels in soybean tissues: GmMT1, GmMT2 and GmMT3 in roots, shoots and seeds, and GmMT4 only in seeds. The corresponding recombinant soybean MTs, synthesized in Escherichia coli cells cultured in metal supplemented media, exhibit greater cadmium than zinc binding capacity. These results suggest a definite role of GmMTs in Cd(II) accumulation as one of the main responses of soybean to an overload of this metal.

Extranodal Rosai-Dorfman disease as a pelvic mass.

Rosai-Dorfman disease (RDD) is a rare histiocytic disorder of unknown cause. RDD most commonly involves the cervical lymph nodes, but extranodal involvement has been described. We report the case of a patient with extranodal RDD that presented as a retroperitoneal mass obstructing the left ureter. The patient underwent surgical resection of the mass, followed by a 5-month course of vinblastine. There was no evidence of progressive disease 22 months after surgery.

Haemodynamic strategy for treatment of diastolic anterograde giacomini varicose veins.

OBJECTIVES: To assess the diagnosis and outcome of a haemodynamic strategy for the treatment of primary varicose veins associated with anterograde diastolic flow (ADF) in the Giacomini vein (GV). METHODS: ADF in the GV, with the escape point located at the saphenopopliteal junction, was demonstrated in 15 patients (15 limbs) by duplex ultrasound. No other escape points were seen in this group. ADF was defined as the flow present in the relaxing phase after isometric contraction of the lower limb, measured in the standing position. Duplex and clinical follow-up was performed prospectively at 1 week, at 1, 3, 6, and 12 months and once per year thereafter, between 1998 and 2001. Surgery consisted of flush division of the GV from the small saphenous vein (SSV) and division of the incompetent collateral veins from the GV. RESULTS: GV diameter showed an average reduction from 6 to 4 mm 33 months after surgery. Fourteen patients (93%) showed no symptoms or varicose veins. GV reconnection and recurrent ADF was demonstrated in two patients (13%). CONCLUSIONS: ADF is a rare condition associated with primary varicose veins. ADF occurs when there is a closed venovenous shunt with recirculation in the muscular diastole. This implies that, although a part of the circuit is ascendant, the re-entry point must be located downstream to the escape point. Accurate duplex assessment is required to distinguish this atypical haemodynamic condition from an abnormal systolic circuit bypassing a deep vein obstruction. Interruption of the GV above its junction with the SSV abolished ADF with an acceptable rate of recurrences.

Durability of reflux-elimination by a minimal invasive CHIVA procedure on patients with varicose veins. A 3-year prospective case study.

OBJECTIVES: to assess the outcome of a conservative and haemodynamic method for insufficient veins on an ambulatory basis (French acronym, "CHIVA") with preservation of the greater saphenous vein (GSV) for treatment of primary varicose veins. METHODS: duplex incompetence of the sapheno-femoral junction (SFJ) and the GSV trunk, with the re-entry perforating point located on a GSV tributary was demonstrated in 58 patients with varices (58 limbs). The re-entry point was defined as the perforator, whose compression of the superficial vein above its opening eliminates reflux in the GSV. Duplex scanning was performed preoperatively and at 7 days, and patients were followed prospectively at 1, 3, 6, 12, 24, and 36 months after CHIVA. Operation consisted in flush ligation and division from the GSV of the tributary containing the re-entry perforating vein (no additional high ligation is included). If reflux returned, SFJ interruption was performed in a second surgical procedure. RESULTS: the GSV diameter showed an average reduction from 6.6 to 3.9 mm 36 months after surgery. Reflux in the GSV system was demonstrated in all but five (8%) patients. Of the 53 patients with recurrent reflux, 46 underwent SFJ interruption. CONCLUSIONS: elimination of reflux in the GSV after the interruption of insufficient collaterals is only temporary.

In vivo copper- and cadmium-binding ability of mammalian metallothionein beta domain.

The beta domain of mouse metallothionein 1 (betaMT) was synthesized in Escherichia coli cells grown in the presence of copper or cadmium. Homogenous preparations of Cu-betaMT and Cd-betaMT were used to characterize the corresponding in vivo-conformed metal-clusters, and to compare them with the species obtained in vitro by metal replacement to a canonical Zn3-betaMT structure. The copper-containing betaMT clusters formed inside the cells were very stable. In contrast, the nascent beta peptide, although it showed cadmium binding ability, produced a highly unstable species, whose stoichiometry depended upon culture conditions. The absence of betaMT protein in E. coli protease-proficient hosts grown in cadmium-supplemented medium pointed to drastic proteolysis of a poorly folded beta peptide, somehow enhanced by the presence of cadmium. Possible functional and evolutionary implications of the bioactivity of mammalian betaMT in the presence of monovalent and divalent metal ions are discussed.