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At least 19 recordsLinked to original sources
PubMed1997

Stoichiometric Interconversion of S-Bridged Rh(III)(2)Ag(I)(3) Pentanuclear and Rh(III)(4)Ag(I)(5) Nonanuclear Structures: Synthesis and Structural Characterization of [Ag(3){Rh(aet)(3)}(2)](3+) and [Ag(5){Rh(aet)(3)}(4)](5+) (aet = 2-Aminoethanethiolate).

The reaction of fac(S)-[Rh(aet)(3)] (aet = 2-aminoethanethiolate) with 1.5 molar equiv of AgBF(4) in water gave an S-bridged pentanuclear complex, [Ag(3){Rh(aet)(3)}(2)](BF(4))(3) (1(BF(4))(3)), while the reaction with 1.2 molar equiv of AgBF(4) produced an S-bridged nonanuclear complex, [Ag(5){Rh(aet)(3)}(4)](BF(4))(5) (2(BF(4))(5)). The crystal structures of 1(BF(4))(3) and 2(BF(4))(5) were determined by X-ray crystallography: 1(BF(4))(3).H(2)O crystallizes in the orthorhombic space group Pnma with a = 16.609(3) Å, b = 13.352(4) Å, c = 15.771(3) Å, V = 3497(1) Å(3), Z = 4, and R = 0.056. 2(BF(4))(5).4H(2)O crystallizes in the monoclinic space group P2(1)/c with a = 15.665(5) Å, b = 14.003(2) Å, c = 31.900(9) Å, beta = 94.19(1) degrees, V = 6979(3) Å(3), Z = 4, and R = 0.068. In 1 each of three Ag(I) atoms is linearly coordinated by two thiolato sulfur atoms from two octahedral fac(S)-[Rh(aet)(3)] units. In 2 each of four Ag(I) atoms is trigonally coordinated by three thiolato sulfur atoms from three fac(S)-[Rh(aet)(3)] units, while the remaining Ag(I) atom is linearly coordinated by two thiolato sulfur atoms from two fac(S)-[Rh(aet)(3)] units. 2 was readily converted to 1 by reaction with Ag(+), while the conversion of 1 to 2 was achieved by the reaction with fac(S)-[Rh(aet)(3)].

Journal Article↗
PubMed2005

Two stereoisomers of an S-bridged RhIII2PtII2 tetranuclear complex [{Pt(NH3)2}2{Rh(aet)3}2]4+ that lead to a discrete and a 1D RhIII2PtII2AgI structures by reacting with AgI (aet = 2-aminoethanethiolate).

An S-bridged RhIII2PtII2 tetranuclear complex having two nonbridging thiolato groups, [{Pt(NH3)2}2{Rh(aet)3}2]4+ ([1]4+), in which two fac(S)-[Rh(aet)3] units are linked by two trans-[Pt(NH3)2]2+ moieties, was synthesized by the 1:1 reaction of fac(S)-[Rh(aet)3] (aet = 2-aminoethanethiolate) with trans-[PtCl2(NH3)2] in water. Complex [1]4+ gave both the meso (DeltaLambda) and racemic (DeltaDelta/LambdaLambda) forms, which were separated by fractional crystallization. Of two possible geometries, syn and anti, which arise from the arrangement of two nonbridging thiolato groups, the meso and racemic forms of [1]4+ selectively afforded the anti and syn geometries, respectively. The DeltaLambda-anti and DeltaDelta/LambdaLambda-syn isomers of [1]4+ reacted with Ag+ using two nonbridging thiolato groups to produce a {RhIII2PtII2AgI}n) polymeric complex, {[Ag{Pt(NH3)2}2{Rh(aet)3}2]5+}n) ([2]5+), and a RhIII2PtII2AgI pentanuclear complex, [Ag{Pt2(mu-H2O)(NH3)2}{Rh(aet)3}2]5+ ([3]5+), respectively, which contain octahedral RhIII, square-planar PtII, and linear AgI centers. In [2]5+, each DeltaLambda-anti-[{Pt(NH3)2}2{Rh(aet)3}2]4+ tetranuclear unit is bound to two AgI atoms to form a one-dimensional zigzag chain, indicating the retention of the parental S-bridged structure in DeltaLambda-anti-[1]4+. In [3]5+, two Delta- or Lambda-fac(S)-[Rh(aet)3] units are linked by a [Pt2(mu-H2O)(NH3)2]4+ dinuclear moiety, together with an AgI atom, indicating that two NH3 molecules in [1]4+ have been replaced by a water molecule that bridges two PtII centers, while the parental DeltaDelta/LambdaLambda-syn configuration is retained. The complexes obtained were characterized on the basis of electronic absorption, CD, and NMR spectra, along with single-crystal X-ray analyses.

Journal Article↗
PubMed2002

Synthesis, characterization, and chiral behavior of S-bridged Co(III)Pt(II)Co(III) trinuclear complexes composed of bis(thiolato)-type octahedral units cis(S)-[Co(aet)(2)(en)](+) and/or trans(N)-[Co(D-pen- N,O,S)(2)](-) (aet = 2-aminoethanethiolate, D-pen = D-penicillaminate).

A series of linear-type Co(III)Pt(II)Co(III) trinuclear complexes composed of C(2)-cis(S)-[Co(aet)(2)(en)](+) (aet = 2-aminoethanethiolate) and/or Lambda(D)-trans(N)-[Co(D-pen-N,O,S)(2)](-) (D-pen = D-penicillaminate) were newly prepared, and their chiral behavior, which is markedly different from that of the corresponding Co(III)Pd(II)Co(III) complexes, is reported. The 1:1 reaction of an S-bridged Co(III)Ni(II)Co(III) trinuclear complex, [Ni[Co(aet)(2)(en)](2)]Cl(4), with K(2)[PtCl(4)] in water gave an S-bridged Co(III)Pt(II)Co(III) trinuclear complex, [Pt[Co(aet)(2)(en)](2)]Cl(4) ([1]Cl(4)), while the corresponding 1:2 reaction produced an S-bridged Co(III)Pt(II) dinuclear complex, [PtCl(2)[Co(aet)(2)(en)]]Cl ([2]Cl). Complex [1](4+) formed both racemic (DeltaDelta/LambdaLambda) and meso (DeltaLambda) forms, which were separated and optically resolved by cation-exchange column chromatography. An optically active S-bridged Co(III)Pt(II)Co(III) trinuclear complex having the pseudo LambdaLambda configuration, Lambda(D)Lambda(D)-[Pt[Co(D-pen-N,O,S)(2)](2)](0) (Lambda(D)Lambda(D)-[3]), was also prepared by reacting Lambda(D)-trans(N)-K[Co(D-pen-N,O,S)(2)] with K(2)[PtCl(4)] in a ratio of 2:1 in water. Treatment of the racemic Delta/Lambda-[2]Cl with Lambda(D)-trans(N)-K[Co(D-pen-N,O,S)(2)] in a ratio of 1:1 in water led to the formation of LambdaLambda(D)- and DeltaLambda(D)-[Pt[Co(aet)(2)(en)][Co(D-pen-N,O,S)(2)]](2+) (LambdaLambda(D)- and DeltaLambda(D)-[4](2+)) and DeltaDelta(D)-[Pt[Co(aet)(2)(en)][Co(D-pen-N,S)(2)(H(2)O)(2)]](2+) (DeltaDelta(D)-[4'](2+)), besides trace amounts of Lambda(D)Lambda(D)-[3] and DeltaDelta- and DeltaLambda-[1](4+). These Co(III)Pt(II)Co(III) complexes were characterized on the basis of electronic absorption, CD, and NMR spectra, along with single-crystal X-ray analyses for DeltaDelta/LambdaLambda-[1]Cl(4), DeltaLambda-[1]Cl(4), and DeltaLambda(D)-[4]Cl(2). Crystal data: DeltaDelta/LambdaLambda-[1]Cl(4).6H(2)O, monoclinic, space group C2/c with a = 14.983(3) A, b = 19.857(4) A, c = 12.949(3) A, beta = 113.51(2) degrees, V = 3532(1) A(3), Z = 4; DeltaLambda-[1]Cl(4).3H(2)O, orthorhombic, space group Pbca with a = 14.872(3) A, b = 14.533(3) A, c = 14.347(2) A, V = 3100(1) A(3), Z = 4; DeltaLambda(D)-[4]Cl(2).6H(2)O, monoclinic, space group P2(1) with a = 7.3836(2) A, b = 20.214(1) A, c = 10.622(2) A, beta = 91.45(1) degrees V = 1682.0(4) A(3), Z = 2.

Journal Article↗
PubMed1979

Rosetting of human T lymphocytes with goat red blood cells: effect of treatment with 2-aminoethylisothiouronium bromide (AET) and comparison with AET treated sheep red blood cells.

In vitro treatment of goat red blood cells (GRBCs) with the sulphydryl compound 2-aminoethylisothiouronium bromide (AET) increases their specific reactivity with human T lymphocytes without affecting the specificity of the reaction. AET-GRBCs bind to only part of T lymphocytes rosetting with AET-sheep red blood cells (SRBCs): the receptors for both types of RBCs are very simular if not identical, but display higher affinity for AET-SRBCs than for AET-GRBCs. Rosetting of T lymphocytes with AET-GRBCs may be useful to enumerate T lymphocyte subsets in patients with abnormality of the immune system and to fractionate T lymphocyte subpopulations.

Animals↗
PubMedDate not supplied

Increased susceptibility of tumor cells and chicken erythrocytes to lysis by antibody and complement after treatment with aminoethylisothiouronium bromide hydrobromide (AET).

After treatment with aminoethylisothiouronium bromide hydrobromide (AET), the ascites forms of the diethylnitrosamine-induced guinea pig hepatomas, line-1 and line-10, were susceptible or more susceptible to killing in vitro by certain combinations of tumor-specific or IgM anti-Forssman antibody and either human or guinea pig complement. Since AET could be toxic to either cell line, conditions of pH, concentration of AET, and duration of exposure of the cells to the reagent were determined that resulted in enhanced susceptibility without significantly affecting cell viability. Chicken erythrocytes (CE) also were tested and AET-treated cells found to be more susceptible to lysis by IgM anti-Forssman antibody and guinea pig complement. The enhancement apparently was not due to increased ability of AET-treated CE to fix antibody. In contrast to CE, the lytic susceptibility of sheep cells was not affected by AET treatment. In addition to AET, several drugs and enzymes that also can affect the susceptibility of the tumor cells to antibody and complement were tested and found to be ineffective against CE. Since AET reputedly acts directly on the cell surface, it seems reasonable to assume that the increased susceptibility of the tumor cells and CE to antibody and complement may result from a modification of the cell surface.

Animals↗
PubMed1979

AET-treated platelets: their usefulness for platelet antibody detection and an examination of their altered sensitivity to immune lysis.

2-Aminoethylisothiouronium bromide (AET) increases the sensitivity of blood cells to complement-mediated immune lysis. We compared the sensitivities of untreated or AET-treated platelets to immune lysis induced by different types of platelet antibody in the 51Cr platelet lysis test. AET platelets were 8-16 times more sensitive to autoantibody and alloantibody, but 8-16 times less sensitive to drug-dependent antibody. AET-platelets bound similar amounts of alloantibody but less drug-dependent antibody, and they lysed at higher complement dilutions than did untreated platelets. AET-platelets detected 10 of 25 autoantibodies, 9 of 9 alloantibodies, and 5 of 8 drug-dependent antibodies. Untreated platelets detected 1 of 25, 6 of 9, and 7 of 8 of these respective platelet antibodies. The use of AET-platelets in the 51Cr platelet lysis test increases its sensitivity for detecting non-drug-dependent platelet antibodies. AET-platelets resemble paroxysmal nocturnal hemoglobinuria (PNH) platelets in their enhanced sensitivity to complement-mediated lysis. They differ from PNH platelets in their insensitivity to immune lysis induced by drug-dependent antibodies and, in this respect, are similar to Bernard-Soulier syndrome platelets.

Autoantibodies↗
PubMed1995

Induction of micronucleated erythrocytes by MEA, AET, WR-2721 and X-rays.

The induction of micronucleated polychromatic erythrocytes (MNPCEs) was assessed in the bone marrow of adult male Swiss mice treated with MEA (cysteamine HCl), AET (2-aminoethylisothiouronium Br.HBr), or WR-2721 (S-2-(3-aminopropylamino)ethyl phosphorothioic acid), at a dose of 200 mg/kg body weight, and/or exposed to 6 Gy X-rays. MEA, AET, or WR-2721 was given alone or 15 min prior to X-ray exposure, and the frequency of MNPCEs was determined 24 h after the aminothiol treatment and X-irradiation of mice. A genotoxic effect was shown for MEA, AET, WR-2721, and X-rays, as well as a protective effect of the aminothiols against X-ray-induced genotoxicity in the mouse erythropoietic system. The aminothiol drugs given alone, without subsequent X-irradiation, elevated the frequency of MNPCEs, and WR-2721 appeared to be less toxic than AET and MEA. After exposure of mice to X-rays, the number of MNPCEs was distinctly increased. MEA, AET, or WR-2721 administration prior to X-irradiation resulted in a reduction of the X-ray-induced elevation of the frequency of micronuclei, but a stronger radioprotective effect was obtained following WR-2721 and AET treatment than after MEA application. So, the genotoxic and radioprotective effect of the aminothiols was dependent on the compound applied.

Amifostine↗
PubMed1994

Late protective effects against CCl4-induced liver necrosis by the radioprotective agent 2-aminoethyl-isothiouronium bromide hydrobromide (AET).

Administration of the radioprotective agent 2-aminoethyl-isothiouronium bromide hydrobromide (AET) (240 mg/kg, i.p. in saline 30 min before or 6 or 10 h after CCl4 (1 ml/kg i.p. as a 20% v/v solution in olive oil) significantly prevented the necrogenic effect of the hepatotoxin at 24 h. Protection was more intense when the drug was given 6 h after CCl4 than when administered 30 min before. CCl4-induced fat accumulation was prevented only when AET was given 30 min before. AET did not prevent the CCl4-induced initiation of a lipid peroxidation (LP) process as evidenced by diene hyperconjugation of microsomal lipids. AET pretreatment 30 min before CCl4 did not significantly modify the CCl4 levels reaching the liver and only exerted a transient significant effect on the covalent binding of [14C]Cl4 reactive metabolites to microsomal lipids (CB) at 1 h but not at 3 h. The markedly intense protective effects of AET when given 6 or 10 h after CCl4 can not be attributed to decreased amounts of CCl4 reaching the liver or to decreasing effects in CB or to chain breaking effects in LP. Really, protection might be due to a favorable modulation of late events occurring after CB or LP, events that remain to be elucidated.

Animals↗
PubMed2006

A scanning electron microscopic study of debris and smear layer remaining following use of AET instruments and K-flexofiles.

AIM: To compare in vitro the cleanliness of root canal walls following automated or manual instrumentation. METHODOLOGY: Thirty extracted human maxillary central incisors, maxillary and mandibular canines and premolars with single root canals were used in this study. The teeth were divided into two groups. In group 1 (20 teeth) automated canal preparation was performed using Anatomic Endodontic Technology (AET). In group 2 (10 teeth) manual instrumentation was performed with K-Flexofiles. Irrigation was performed using alternately 3.00% NaOCl and 18% EDTA, followed by rinsing with saline. The roots were split longitudinally into halves and the canals examined using a scanning electron microscope. The presence of debris and smear layer was recorded at coronal, middle and apical thirds of root canals using a four-step scoring scale. Mean scores for debris and smear layer were calculated and statistically analysed for significance (P<0.05) between and within groups, using the Mann-Whitney-Wilcoxon and Friedman nonparametric tests. RESULTS: At coronal and middle thirds the root canals prepared with manual instrumentation had significantly less surface debris on the canal walls compared with canals prepared with AET (p<0.05). At apical third root canals prepared with manual instrumentation had significantly more debris compared with AET group. The amount of smear layer was greater in the apical than in the coronal and middle thirds of the root and significantly less amount was in the AET group (P<0.05). CONCLUSIONS: Complete cleanliness was not achieved by any of the techniques and instruments investigated. It may be inferred that the choice between AET and hand instrumentation should be based on factors other than the amount of root canal debridement, which does not vary high significantly according to the instruments used.

Chelating Agents↗
PubMed1991

[Estimation of physical exertion by the AET ergonomic job description].

The study has been aimed at showing the advantages of using the AET ergonomic job description for estimation of physical workload, as compared to the traditional methods in which the estimates are made on the basis of the value of energy expenditure, static load and motion monotypicity. From tests on employees at 28 workposts it has been found that by analysing 17 factors involved in the overall estimate of physical workload according to AET, it is possible to characterize the work more precisely. The results of the tests indicate that AET estimates of heavy dynamic work are strongly correlated with the size of energy expenditure, whereas the estimation of body position--with the estimate of static load and the frequency estimate--with the estimate of motion monotypicity. New possibilities, with regard to the traditional method of physical workload estimation, are opened up by the AET method in relation to light dynamic work and static effort. The physical workload rate, calculated according to the AET method as the total of 17 elements estimated, does not differentiate the values of the workloads at individual workposts and, therefore, requires physiological verification.

Energy Metabolism↗
PubMed1983

Effect of aminoethyl-isothiuronium (AET) treatment on intestinal cell proliferation during ageing.

To establish whether aminoethyl-isothiuronium X bromide X hydrobromide (AET) treatment influenced intestinal cell proliferation during ageing, juvenile and aged female rats were treated with AET for a period of 20 days. Subsequent incorporation of 3H-thymidine was studied in the epithelial cells of the duodenal and jejunal crypts. It was found that after AET administration the major changes occurred in the duodenum, i.e. the number of the villous epithelial columnar cells were found to be elevated during senescence with a markedly higher level of mitotic numbers in the crypts. Changes were less in the ageing jejunum, here neither the cells nor the number of mitoses were as altered as those of the duodenal region. In general, the labelling indices of crypt cells increased in young ages after AET treatment. The findings can be explained by the role of AET with respect to nuclear metabolism.

Aging↗
PubMed1981

Absence of AET protection against fast neutrons: cellular effects.

A series of experiments has been undertaken in order to test the biological properties of neutrons produced in the cyclotron of the Institute "Ruder Bosković" (IRB) in Zagreb. Protective effect of AET (2-amino ethylisothiuronium bromide hydrobromide) on survival of L cells irradiated by fast neutrons generated in the IRB cyclotron were studied by employing the single cell clonal growth method. For comparison the protective effect of AET after gamma irradiation has also been studied. The most important findings that have emerged from these experiments can be summarized as follows: (1) Protective effect of AET was present after gamma irradiation only. (2) The degree of protection was dependent on AET concentration in the growth medium. (3) No protective effect was found after neutron irradiation. These findings are in agreement with the generally less efficient protection of this compounds after high-LET irradiation.

Animals↗
PubMed2005

Root canal preparation with Endo-Eze AET: changes in root canal shape assessed by micro-computed tomography.

AIM: To evaluate the relative performance of Endo-Eze Anatomic Endodontic Technology (AET) stainless steel instruments when shaping maxillary molar root canals in vitro. Methodology Extracted human maxillary molars were scanned, before and after root canal shaping with Endo-Eze AET, employing micro-computed tomography (muCT) at an isotropic resolution of 34 microm. Three-dimensional root canal models were reconstructed and evaluated for volume, surface area, 'thickness' (diameter), canal transportation and prepared surface. Preparation errors such as apical zips, perforations and fractured instruments were visually determined from those models. Means were contrasted using anova and Scheffé post-hoc tests. RESULTS: Volume and surface area increased significantly and similarly in mesiobuccal (mb), distobuccal (db) and palatal (p) canals and gross preparation errors (n = 17) were found. Mean root canal diameters, 5 mm coronal to the apex, increased from 0.31 to 0.52, 0.35 to 0.50 and 0.50 to 0.70 mm for mb, db and p canals, respectively. Mean canal transportation ranged from 0.15 to 0.29, 0.15 to 0.27 and 0.21 to 0.33 mm for apical, middle and coronal root canal levels, respectively, with highest values found for mb canals (P < 0.003). Root canals were significantly straightened during preparation (P < 0.002). CONCLUSIONS: In summary, Endo-Eze AET instruments shaped root canals in maxillary molars with substantial canal transportation, particularly in mesiobuccal root canals. Preparation with this instrument removed high volumes of dentine, even though apical preparation was size 30. Based on the current results, Endo-Eze AET cannot be recommended for the preparation of teeth with curved root canals.

Analysis of Variance↗
PubMed1971

Electron microscope study of PNH red cells and AET-treated normal red cells (PNH-like cells).

The morphology of red cells damaged by 2-aminoethylisothiouronium bromide (AET) has been compared to that of PNH cells by transmission and scanning electron microscopy. The main features of the effect of AET as demonstrated by the scanning electron microscope were spherical and deformed cells, with surface craters and relatively large pits. The transmission electron microscope revealed loss of surface structure, an unusual amount of irregularly shaped electrondense material and fine pits in the cell membranes. The paroxysmal nocturnal haemoglobinuria cells showed, by transmission electron microscope, electron-dense material scattered over the cell and fine pitting; by scanning electron microscope, larger craters were seen and swellings protruded from the cell surface. Although the AET changes were not identical with the natural abnormality of paroxysmal nocturnal haemoglobinuria, the two types of cells were sufficiently similar to each other to support the proposition that AET cells have many of the characteristics of paroxysmal nocturnal haemoglobinuria.

Cell Membrane↗