Effect of glicentin, oxyntomodulin and related peptides on isolated gastric smooth muscle cells

Glicentin (proglucagon 1-69 GLIC) and oxyntomodulin (proglucagon 33-69 or OXM) are two peptide hormones that are co-released from ileum and large intestine during digestion. They modulate in vivo gastric acid secretion and the gastro-pyloro-duodenal activity. The specificity of their effects is linked to the presence of their C-terminal octapepide. As yet, no isolated target cell that responds specifically to this family of peptides has been described. The present report describes the in vitro effect of human synthetic GLIC, OXM and octapeptide-bearing fragments on smooth muscle cells isolated from the rabbit antrum. GLIC or OXM decreased the mean length of the cells by: 13.9 +/- 0.8% and 15.5 +/- 0.9%, respectively - GLIC being 16 times more potent than OXM (respective EC50 values: 5 and 83 pM). The C-terminal fragments OXM(19-37) and OXM(30-37) were as efficient as GLIC or OXM. Their potencies were OXM = OXM(19-37)>>OXM(30-37). Glucagon, which corresponds to OXM without the C-terminal octapeptide, or glucagon-like peptide-1 (7-36 amide) did not have any effect. The response to OXM was not influenced by antagonists to muscarinic, cholecystokinin or substance P receptors. In conclusion, our studies demonstrate for the first time an isolated target cell that responds specifically to GLIC, OXM and other octapeptide-bearing peptides.

Characterization of new polyclonal antibodies specific for 40 and 42 amino acid-long amyloid beta peptides: their use to examine the cell biology of presenilins and the immunohistochemistry of sporadic Alzheimer's disease and cerebral amyloid angiopathy cases

BACKGROUND

In Alzheimer's disease (AD), the main histological lesion is a proteinaceous deposit, the senile plaque, which is mainly composed of a peptide called A beta. The aggregation process is thought to occur through enhanced concentration of A beta 40 or increased production of the more readily aggregating 42 amino acid-long A beta 42 species.

MATERIALS AND METHODS

Specificity of the antibodies was assessed by dot blot, Western blot, ELISA, and immunoprecipitation procedures on synthetic and endogenous A beta produced by secreted HK293 cells. A beta and p3 production by wild-type and mutated presenilin 1-expressing cells transiently transfected with beta APP751 was monitored after metabolic labeling and immunoprecipitation procedures. Immunohistochemical analysis was performed on brains of sporadic and typical cerebrovascular amyloid angiopathy (CAA) cases.

RESULTS

Dot and Western blot analyses indicate that IgG-purified fractions of antisera recognize native and denaturated A beta s. FCA3340 and FCA 3542 display full specificity for A beta 40 and A beta 42, respectively. Antibodies immunoprecipitate their respective synthetic A beta species but also A beta s and their related p3 counterparts endogenously secreted by transfected human kidney 293 cells. This allowed us to show that mutations on presenilin 1 triggered similar increased ratios of A beta 42 and its p 342 counterpart over total A beta and p3. ELISA assays allow detection of about 25-50 pg/ml of A beta s and remain linear up to 750 to 1500 pg/ml without any cross-reactivity. FCA18 and FCA3542 label diffuse and mature plaques of a sporadic AD case whereas FCA3340 only reveals the mature lesions and particularly labels their central dense core. In a CAA case, FCA18 and FCA3340 reveal leptomeningeal and cortical arterioles whereas FCA3542 only faintly labels such structures.

CONCLUSIONS

Polyclonal antibodies exclusively recognizing A beta 40 (FCA 3340) or A beta 42 (FCA3542) were obtained. These demonstrated that FAD-linked presenilins similarly affect both p342 and A beta 42, suggesting that these mutations misroute the beta APP to a compartment where gamma-secretase, but not alpha-secretase, cleavages are modified. Overall, these antibodies should prove useful for fundamental and diagnostic approaches, as suggested by their usefulness for biochemical, cell biological, and immunohistochemical techniques.

Differential targeting of nicotinic acetylcholine receptors by novel alphaA-conotoxins

We describe the isolation and characterization of two peptide toxins from Conus ermineus venom targeted to nicotinic acetylcholine receptors (nAChRs). The peptide structures have been confirmed by mass spectrometry and chemical synthesis. In contrast to the 12-18 residue, 4 Cys-containing alpha-conotoxins, the new toxins have 30 residues and 6 Cys residues. The toxins, named alphaA-conotoxins EIVA and EIVB, block both Torpedo and mouse alpha1-containing muscle subtype nAChRs expressed in Xenopus oocytes at low nanomolar concentrations. In contrast to alpha-bungarotoxin, alphaA-EIVA is inactive at alpha7-containing nAChRs even at micromolar concentrations. In this regard, alphaA-EIVA is similar to the previously described alpha-conotoxins (e.g. alpha-MI and alpha-GI) which also selectively target alpha1- versus alpha7-containing nAChRs. However, alpha-MI and alpha-GI discriminate between the alpha/delta versus alpha/gamma subunit interfaces of the mouse muscle nAChR with 10,000-fold selectivity. In contrast, alphaA-conotoxin EIVA blocks both the alpha/gamma site and alpha/delta site with equally high affinity but with distinct kinetics. The alphaA-conotoxins thus represent novel probes for the alpha/gamma as well as the alpha/delta binding sites of the nAChR.

Congenital dysfibrinogenemia

Fibrinogen abnormalities can be classified as congenital or acquired. Each class manifests quantitative or qualitative alterations; the latter are known as dysfibrinogenemias. In dysfibrinogenemias, structural defects cause alterations in the conversion of fibrinogen to fibrin. Approximately 300 abnormal fibrinogens have been reported, and about 83 structural defects have been identified. The most common structural defect involve the fibrinopeptides and their cleavage sites, and the second most common involves the gamma-chain polymerization region. Approximately half of the mutants are clinically silent, whereas hemorrhage and thrombosis occur in almost equal numbers of cases. Study of the abnormal fibrinogens has provided insight into fibrinogen structure and fibrin formation and dissolution. Some of the structural abnormalities exhibit defective assembly and activation of components of the fibrinolytic system on the abnormal fibrin, resulting in impaired dissolution of fibrin, clinically associated with thrombosis.

CholecystokininB receptor from human Jurkat lymphoblastic T cells is involved in activator protein-1-responsive gene activation

The aim of this study was to analyze the role of cholecystokinin (CCK(B)) receptor in human lymphoblastic Jurkat T cells. We investigated the trophic effect resulting from activation of such a receptor by using the reporter gene strategy. For this purpose, we transiently transfected Jurkat T cells with the reporter plasmid p[(TRE)3-tk-Luc] and found that CCK-8 was able to dose-dependently induce luciferase expression related to activator protein-1 (AP-1) activation with a maximal response identical to that obtained with compounds known to activate AP-1 complex (quantitatively, the same level of induction was obtained with 1 nM 12-O-tetradecanoylphorbol-13-acetate, 100 microM diacylglycerol, or 4 nM epidermal growth factor). The involvement of the CCK(B) receptor in such a stimulation was demonstrated by the inhibiting effect of the selective CCK(B) receptor antagonist PD-135,158. This effect was confirmed in COS-7 cells transfected with the cDNA of CCK(B) receptor cloned from Jurkat T cells. To better understand the AP-1-dependent luciferase expression in Jurkat T cells, we tested two specific inhibitors of serine/threonine phosphatases-1 and -2A: okadaic acid and calyculin A. These compounds strongly increased the phorbol-12-myristate-13-acetate response, whereas we have not observed a contribution of phosphatase inhibitors on a CCK-8-induced luciferase activity. To confirm that CCK(B) receptors are involved in AP-1 response, we investigated the CCK-8 effect on interleukin-2 expression, a natural endogenous gene regulated by several factors, including AP-1. In Jurkat T cells activated by phorbol-12-myristate-13-acetate and phytohemagglutinin, CCK-8 induced IL-2 expression. This induction was abolished by PD-135,158. Our results indicate that CCK-8 exerts a trophic effect in Jurkat T cells through stimulation of CCK(B) receptors by modulation of expression of AP-1-regulated genes.

Clinical improvement with fluoxetine therapy and noradrenergic function in patients with panic disorder

BACKGROUND

Central noradrenergic (NA) dysregulation has provided a major theoretical framework for understanding the pathogenesis of panic disorder (PD). Using clonidine, an alpha 2-adrenergic receptor agonist, as a probe of NA function, we investigated the hypothesis that the antipanic efficacy of the selective serotonin reuptake inhibitors may be associated with normalization of a putatively dysregulated NA system.

METHODS

We report further analyses on data from 17 subjects with PD and 16 healthy volunteers who underwent measurement of the plasma NA metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) immediately before and after oral clonidine administration. Thirteen patients with PD were rechallenged after 12 weeks during open fluoxetine hydrochloride treatment using the same clonidine paradigm; 13 healthy volunteers were rechallenged at 12 weeks, not having received treatment between challenges.

RESULTS

Patients with PD, compared with healthy volunteers, have markedly elevated plasma MHPG volatility during the first clonidine challenge. Volatility describes the magnitude of within-subject plasma MHPG oscillatory activity as assessed by the root of the mean square successive difference. A greater degree of clinical global improvement was predicted by a greater magnitude of basal MHPG reduction with fluoxetine treatment. Antipanic response to fluoxetine was accompanied by a significant decrease of MHPG volatility to volunteer levels. Volunteer MHPG volatility remained unchanged from the first to second clonidine challenge.

CONCLUSIONS

Further evidence is provided for the hypothesis of NA dysregulation in PD as reflected by elevations of within-subjects plasma MHPG volatility during clonidine challenge. Effective selective serotonin reuptake inhibitor-antipanic treatment in this clinical sample was paralleled by normalization of dysregulated NA function.

Interactions between calcipotriene and ultraviolet light

BACKGROUND

Calcipotriene is often used with UVB or PUVA, but interactions between UV radiation and calcipotriene have not been examined extensively.

OBJECTIVE

Our purpose was to examine interactions between calcipotriene and UV light.

METHODS

Minimal erythema doses (MEDs) were determined with UVB and immediate pigment darkening was measured for UVA. The effect of calcipotriene ointment applied before phototesting was examined. Thick and thin applications of calcipotrience were compared. Calcipotriene ointment was applied to a small area on the skin before phototherapy. Patients received either UVB, PUVA, UVA, or no phototherapy. After phototherapy, the ointment was collected and assayed by reverse-phase, high-performance liquid chromatography.

RESULTS

MEDs for UVB and immediate pigment darkening for UVA were unaffected by calcipotriene. Thick application of calcipotriene, however, increased the MED, UVA caused substantial reductions in the concentration of detectable calcipotriene.

CONCLUSION

When used in conjunction with PUVA, calcipotriene should be applied after exposure to UVA.

Detection and characterization of enterohaemorrhagic Escherichia coli in slaughtered cattle

Fecal samples from slaughtered cattle were studied for enterohaemorrhagic Escherichia coli (EHEC) by DNA hybridization with biotin-labelled DNA probes specific for the EHEC virulence plasmid, Shiga-like toxin I (SLT I), Shiga-like toxin II (SLT II) and eae gene. Among 136 animals analysed, 47 (34.5%) were found to carry EHEC. The cytotoxic genotypes observed for EHEC strains were: 60.4% SLT I, 12.5% SLT II and 10.4% SLT I + SLT II; 16.7% resulted SLT I and SLT II negative. A total of 14 out of 48EHEC strains (29.2%) hybridized with a fimbrial probe and 14 of 48 strains with an sas probe. An important number of strains (18 out of 48) belonged to serogroups O157, O26 and O111, serogroups also commonly isolated from haemolytic uremic syndrome cases in Chile. While EHEC isolates from the same animal were usually of the same serogroup, one animal was found to carry two EHEC strains of different serogroups. A total of 50% of EHEC strains were sorbitol negative, irrespective of the O serogroup or EHEC genotypic profile. Results obtained in this study strongly suggest that cattle in Chile are a reservoir of EHEC associated with disease in humans.

Occupational allergy in saffron workers

Sensitization to the flower of saffron, a plant commonly grown in Spain for commercial purposes, and its clinical significance as an occupational allergen were studied. The prick test and RAST, with saffron pollen, stamen, and pistil extracts, were used to evaluate the cutaneous and specific antibody responses in the studied population. Provocation tests in patients with clinical findings were used to verify the implication of saffron components in these symptoms. Fifty saffron workers were evaluated. Three of them were sensitized to saffron pollen and stamen proteins, giving prick and RAST positive values. One patient presented asthma, showing a positive bronchial provocation test, and two patients rhinoconjunctivitis, showing positive conjunctival provocation tests. Of a general allergic population of 237, 10 patients also presented cutaneous test and IgE positive to saffron. Saffron allergens (from pollen and stamens) were characterized by SDS-PAGE immunoblotting. A relevant allergen of 15.5 kDa with profilinic nature was detected and further purified by high-resolution gel filtration chromatography. No allergenic components were demonstrated in pistils. Cross-reactivity of saffron extracts was evaluated by RAST inhibition with respect to other pollen species commonly causing sensitization in the same area of study. A significant degree of cross-reactivity was demonstrated between saffron and Lolium, Salsola, or Olea. The identification of the protein components involved in the cross-reactions was investigated by blot inhibition.

PTCA procedure for Shepherd's Crook right coronary artery lesion with a new long soft-tip 6F guiding catheter

A new Cordis Long Brite Tip 6F guiding catheter (I.D. .064") is described. Because of its technical characteristics, this product provides greater balloon catheter support by means of deeper intubation of the right coronary artery (RCA). We present our experience with a Shepherd's Crook RCA lesion PTCA procedure.

Cathepsin D displays in vitro beta-secretase-like specificity

The formation of A beta and A beta-containing fragments is likely a key event in the process of neural degeneration in Alzheimer's disease. The N-terminal residue (Asp-1) of A beta and its C-terminally extended sequences is liberated from the beta-amyloid precursor protein (beta APP) by beta-secretase(s). This activity appears highly increased by the presence (N-terminally to Asp-1) of a double-mutation (KM-->NL) found in several Swedish families affected by early onset Alzheimer's disease. By means of synthetic peptides encompassing the "normal' (N peptide) and mutated (delta NL peptide) sequences targeted by beta-secretase(s), we have detected a human brain protease displaying preferred efficiency for the delta NL peptide than for the non-mutated analog. This activity is sensitive to pepstatin, maximally active at acidic pH and hydrolyses the two peptides at the expected M/D or L/D cleavage sites. Such acidic activity is also detected in rat brain, PC12 cells and primary cultured astrocytes. The pepstatin sensitivity and pH maximum of the brain activity that appeared reminiscent of those displayed by the acidic protease cathepsin D led us to examine this enzyme as a putative beta-secretase-like candidate. Purified cathepsin D displays higher catalytic parameters for the delta NL peptide than for the non-mutated peptide, cleaves these two substrates at the expected M/D or L/D sites, and is maximally active at acidic pH. However, cathepsin D does not cleave peptides bearing mutations that were previously shown to drastically lower or fully block A beta secretion by transfected cells. Furthermore, cathepsin D hydrolyses recombinant baculoviral delta NL beta APP751 at a 6-fold higher rate than beta APP751 and gives rise to a 12-kDa C-terminal product that is recognized by antibodies fully specific of the N-terminus of A beta. Altogether, our study indicates that cathepsin D displays several in vitro beta-secretase-like properties that suggests that this protease could fulfill such a role, at least in the Swedish genetic form of Alzheimer's disease.

Colocalization of tissue transglutaminase and stress fibers in human vascular smooth muscle cells and human umbilical vein endothelial cells

The subcellular distribution of tissue transglutaminase in human umbilical vein endothelial cells and human arterial and venous smooth muscle cells was examined. Double-immunofluorescence staining of smooth muscle cells and endothelial cells with anti-transglutaminase antisera and rhodamine-tagged phalloidin revealed codistribution of transglutaminase with the stress fibers, with endothelial cells also containing a cytoplasmic pool. This pattern of distribution was confirmed by confocal microscopy. Immunoprecipitation experiments demonstrated that transglutaminase co-immunoprecipitated with myosin in high-molecular-weight complexes, but not with actin, suggesting that the association of transglutaminase with the stress fibers was due to its cross-linking to myosin. About 97% of endothelial cell transglutaminase activity was present in the cytosolic fraction and 3% in the particulate fraction. The detergent-insoluble fraction was practically devoid of activity as measured by the putrescine assay, but was active as evidenced by the covalent cross-linking of 125I-fibronectin. Western blotting with a polyclonal rabbit antiserum raised against human erythrocyte transglutaminase detected high levels of enzyme in endothelial cell cytosol and both detergent-soluble and detergent-insoluble membrane fractions. In contrast, smooth muscle cells contained much less cytosolic transglutaminase, as determined either functionally or antigenically. Furthermore, within the particulate fraction of the smooth muscle cells, most of the enzyme was located in the detergent-insoluble fraction, as assessed by Western blot analysis. Retinoic acid increased the levels of enzyme in the cytosol of all cell types and the increases were correlated with increases in mRNA. Thus, tissue transglutaminase is present in various particulate fractions of vascular smooth muscle cells and endothelial cells and may be present in this cellular fraction by virtue of autocross-linking of the enzyme itself to stress fiber-associated myosin.

Isolation of two flavonoids from Tanacetum microphyllum as PMA-induced ear edema inhibitors

The CH2Cl2 extract of Tanacetum microphyllum exhibited antiinflammatory activity on PMA-mouse ear model. Two antiinflammatory flavonoids, 5,7-dihydroxy-3,6,4'-trimethoxyflavone (santin) (1) and 5,7-dihydroxy-3,4'-dimethoxyflavone (ermanin) (2), were isolated.

A role for tissue transglutaminase in hepatic injury and fibrogenesis, and its regulation by NF-kappaB

This study was undertaken to delineate a possible role for tissue transglutaminase (tTG), an enzyme that catalyzes protein cross-linking, in hepatic fibrogenesis. Rats were treated with CCl4 solution and then killed at different stages of liver injury and fibrogenesis. Liver tTG mRNA levels were markedly increased as early as 6 h after the first injection, peaked at 4 days and 1 wk, and remained increased for 8 wk. The enzymatic activity of tTG was increased in livers of rats treated with CCl4, in a fashion that paralleled the Northern blot results. Cell isolation experiments indicated that all hepatic cell types synthesize tTG mRNA. Increased binding to the nuclear factor-kappaB (NF-kappaB) motif of the tTG promoter was found in the nuclear extracts prepared from CCl4-treated samples. These data demonstrate an increase in tTG gene expression during hepatic injury and fibrosis, suggesting a possible role for this enzyme in stabilizing the fibrotic bands during hepatic fibrogenesis. Moreover, increased NF-kappaB binding to the tTG promoter may represent one of the mechanisms by which cell injury induces tTG transcription and thus potentiates the process of fibrogenesis.

Identification of two amino acids of the human cholecystokinin-A receptor that interact with the N-terminal moiety of cholecystokinin

A region between residues 38 and 42 of the human cholecystokinin-A (CCK-A) receptor was shown to be involved in the binding of CCK but not in that of JMV 179 and JMV 180, two peptides closely related to CCK (Kennedy, K., Escrieut, C., Dufresne, M., Clerc, P., Vaysse, N., and Fourmy, D. (1995) Biochem. Biophys. Res. Commun. 213, 845-852). In the present study, we have identified the residues of both the receptor and the ligand responsible for this differential binding. Residues Trp-39 and Gln-40 of the receptor were crucial for binding of the C-terminal nonapeptide of CCK as W39F and Q40N mutants demonstrated parallel decreases in both affinity and potency to induce accumulation of inositol phosphates (12.9- and 20.9-fold). The W39F and Q40N mutant receptors bound CCK analogues modified at their C-terminal end, including JMV 179 and JMV 180, as well as the C-terminal amidated heptapeptide of CCK, with identical affinities to the wild-type receptor. In contrast, W39F and Q40N mutants bound CCK octapeptide with the same decreased affinity as the CCK nonapeptide. The modeling of the CCK-A receptor and the docking of the peptide agonists [Thr,Nle]CCK9 and CCK-8 indicated that their N terminus was connected to the receptor through a strong bond network involving Trp-39 and Gln-40 thus confirming experimental data. These first molecular data identifying the agonist binding site of the human CCK-A receptor represent an important step toward the complete delineation of the agonist binding site and the understanding of the molecular mechanisms that govern differential activation of this receptor by CCK-related peptides.

Tissue-specific inhibition of apolipoprotein B mRNA editing in the liver by adenovirus-mediated transfer of a dominant negative mutant APOBEC-1 leads to increased low density lipoprotein in mice

APOBEC-1 is a catalytic subunit of an apolipoprotein B (apoB) mRNA editing enzyme complex. In humans it is expressed only in the intestine, whereas in mice it is expressed in both the liver and intestine. APOBEC-1 exists as a spontaneous homodimer (Lau, P. P., Zhu, H.-J., Baldini, A., Charnsangavej, C., and Chan, L. (1994) Proc. Natl. Acad. Sci. U. S. A. 91, 8522-8526). We tested the editing activity and dimerization potential of three different mouse APOBEC-1 mutants using in vitro editing activity assay and immunoprecipitation in the presence of epitope-tagged APOBEC-1. One catalytically inactive mutant, mu1 (H61K/C93S/C96S), that retains its capacity to dimerize with wild-type APOBEC-1 was found to inhibit the editing activity of the latter and was thus a dominant negative mutant. Two other inactive mutants that dimerized poorly with APOBEC-1 failed to inhibit its activity. Intravenous injection of a mu1 adenovirus, Admu1, in C57BL/6J mice in vivo resulted in liver-specific expression of mu1 mRNA. On days 4 and 9 after virus injection, endogenous hepatic apoB mRNA editing was 23.3 +/- 5.0 and 36.8 +/- 5.7%, respectively, compared with 65.3 +/- 11 and 71.3 +/- 5.2%, respectively, for luciferase adenovirus-treated animals. Plasma apoB-100 accounted for 95 and 93% of total plasma apoB in Admu1 animals on days 4 and 9, respectively, compared with 78 and 72% in luciferase adenovirus animals. Plasma cholesterol on day 9 was 98 +/- 17 mg/dl in the mu1-treated animals, substantially higher than phosphate-buffered saline-treated (57 +/- 9 mg/dl) or luciferase-treated (71 +/- 12 mg/dl) controls. Fast protein liquid chromatography analysis of mouse plasma showed that the intermediate density/low density lipoprotein fractions in the animals treated with the dominant negative mutant adenovirus were much higher than those in controls. We conclude that active APOBEC-1 functions as a dimer and its activity is inhibited by a dominant negative mutant. Furthermore, apoB mRNA editing determines the availability of apoB-100, which in turn limits the amount of intermediate density/low density lipoprotein that can be formed in mice. Liver-specific inhibition of apoB mRNA editing is an important component of any strategy to enhance the value of mice as a model for human lipoprotein metabolism.

Normalization of plasma factor X levels in amyloidosis after plasma exchange

Some patients with systemic light chain amyloidosis develop bleeding complications that can be caused by vascular infiltration with amyloid or by alterations of the coagulation or fibrinolytic systems. Factor X deficiency is the most common cause of bleeding manifestations, although deficiencies of other clotting factors, a disruption in the conversion of fibrinogen to fibrin, and circulating heparin-like anticoagulants have also been reported. Deficiency of factor X is a well-recognized cause of bleeding manifestations in patients with light chain amyloidosis. This acquired disorder appears to be secondary to adsorption of factor X to the amyloid fibrils. Previous studies have shown that infusion of plasma into patients with acquired factor X deficiency and amyloidosis induces a transitory improvement of the coagulation tests. However, there is a rapid return to pretransfusion levels. In this manuscript we report the clinical application of plasma exchange in the management of a patient with systemic light chain amyloidosis with acquired factor X deficiency.

Behaviour of metals following intensive pig slurry applications to a natural field treatment process in Brittany (France)

It is well-known that heavy metals brought by intensive pig slurry applications accumulate in the soil; because of their potential impact on the environment, studying their behaviour is of utmost interest. The Solepur process has been developed in Brittany (France) where pig farming causes serious environmental problems; it enables the soil to be used as a treatment medium to process pig slurry. Numerous pig slurry applications were performed from 1991 to 1995 on an experimental hydrologically-isolated field specially equipped to recover all the leachate. These applications approximately corresponded to the amount which might have been spread over one century. The Solepur process can be considered as a simulation model for what happens to metals in pig slurry under normal field conditions over a long period of time. This work measured the concentrations of Cu, Zn, Mn, Co, Fe and Cd in pig slurry, in soil and in drainage water, and the results are discussed. Total concentrations and speciation data within the three different compartments were analysed and showed that Cu and Zn accumulate in the surface layer, whereas other metals, such as Mn and Co, dissolve and are washed away in the leachate. The increase in the bioavailability and toxicity of these metals as well as their impact on the environment are discussed.