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PubMed2004

Silver stains distinguish tau-positive structures in corticobasal degeneration/progressive supranuclear palsy and in Alzheimer's disease--comparison between Gallyas and Campbell-Switzer methods.

Possible differences in silver-staining profiles and their relation to tau-like immunoreactivity were investigated on cortical sections from corticobasal degeneration (CBD), progressive supranuclear palsy (PSP), Down's syndrome (DS) and Alzheimer's disease (AD). Pairs of mirror sections were double-fluorolabeled with an anti-PHF tau (AT8) antibody and thiazin red (TR), a fluorochrome that labels fibrillary structures such as neurofibrillary tangles (NFTs). Subsequently, one of the pair was stained with Gallyas method (GAL), and the other with Campbell-Switzer method (CS). Identification of the same structure on the corresponding microscopic fields enabled a comparison of four different profiles of each structure: AT8 immunoreactivity, and affinity to TR, GAL and CS. NFTs of DS/AD, containing three- and four-repeat tau, were positive for TR, GAL and CS. AT8-immunoreactive structures of CBD/PSP, containing mainly four-repeat tau, were positive for GAL, but negative for CS and TR. This discrepancy is explainable if the argyrophilia with GAL is related to deposits containing four-repeat tau, while that with CS is linked to those containing three-repeat tau. The lack of CS labeling may also be related to poor TR staining, possibly representing scarcity of fibrillary structure in CBD/PSP. The absence of CS staining is characteristic of tau-positive structures of CBD/PSP, which is readily distinguishable from NFTs of DS/AD, hence is of potential pathological and diagnostic relevance.

Aged↗

PubMed2005

Silver staining profiles distinguish Pick bodies from neurofibrillary tangles of Alzheimer type: comparison between Gallyas and Campbell-Switzer methods.

Silver staining profiles of Pick bodies (PBs) and their relation to tau-like immunoreactivity were examined on hippocampal sections and compared with those of neurofibrillary tangles of Alzheimer type (NFTs). Pairs of mirror sections were double-fluorolabeled with an anti-paired helical filament tau (AT8) antibody and thiazin red (TR), a fluorochrome that identifies fibrillary structures such as NFTs. One of the paired sections was subsequently stained using the Gallyas method (GAL), and the other using the Campbell-Switzer method (CS). By comparison of the same microscopic field on fluorolabeled sections and on both silver-stained paired sections, four different profiles of each structure could be distinguished: AT8 immunoreactivity, affinity to TR, argyrophilia with GAL or CS staining. PBs, containing mainly three-repeat (3R) tau, were positive for CS but not for GAL and its affinity to TR was, at most, weak. This selective affinity of PBs to CS is in sharp contrast with tau-positive structures of corticobasal degeneration/progressive supranuclear palsy, which are positive for GAL but not for CS, as we reported previously. This contrast is explainable if the argyrophilia with CS is related to deposits containing 3R tau, while that with GAL is linked to those containing four-repeat (4R) tau. Indeed, NFTs, containing both 3R and 4R tau, are positive for both CS and GAL, as expected. Taken together, differences in molecular composition of tau protein in these deposits are linked to their argyrophilic properties that are dependent on the staining method. Although explanations for these empirical differences are not yet available, awareness of this clear distinction is potentially of diagnostic and pathological relevance.

Aged↗

PubMed2005

Argyrophilic grains are not always argyrophilic--distinction from neurofibrillary tangles of diffuse neurofibrillary tangles with calcification revealed by comparison between Gallyas and Campbell-Switzer methods.

Silver staining profiles of argyrophilic grains (AGs) and of neurofibrillary tangles (NFTs) of diffuse neurofibrillary tangles with calcification (DNTC, collectively as DNTC-NFTs) were examined for their relation to tau- and ubiquitin-like immunoreactivity (IR). Pairs of mirror sections were triple-fluorolabeled with an anti-PHF tau (AT8) antibody, an anti-ubiquitin antibody and thiazin red (TR), a fluorochrome that identifies fibrillary structures such as NFTs of Alzheimer's disease (AD). One of the paired sections was subsequently stained with Gallyas method (GAL), and the other with Campbell-Switzer method (CS). Comparison of the same microscopic field on the paired fluorolabeled sections, subsequently silver-stained with either GAL or CS enabled the determination of five different profiles of each structure: AT8-IR, ubiquitin-like-IR, affinity to TR, argyrophilia with GAL or CS staining. AGs, mainly composed of four-repeat (4R) tau, were argyrophilic with GAL but not with CS, and their affinity to TR and ubiquitin-like-IR was not intense. This staining profile of AGs is identical with those of tau-positive structures in the cortex of progressive supranuclear palsy/corticobasal degeneration, both composed of 4R tau. This selective affinity of AGs to GAL is in sharp contrast with Pick bodies, composed of three-repeat (3R) tau, that are positive for CS but not for GAL, as we reported previously. This contrast is explainable if the argyrophilia with CS is related to deposits containing 3R tau, while that with GAL is linked to those containing 4R tau. Indeed, DNTC-NFTs, that contain both 3R and 4R tau, were argyrophilic with CS and GAL, and their affinity to TR and ubiquitin-like-IR were consistent, as we reported previously for NFTs of AD and of Down's syndrome, both similarly composed of 3R and 4R tau. Taken together, differences in molecular composition of tau protein in these deposits are linked to their argyrophilic properties dependent on the staining method in these sporadic tauopathies. Although explanations for these empirical differences are not yet available, awareness of this clear distinction is potentially of diagnostic and pathological significance.

Aged↗

PubMed2005

Silver stainings distinguish Lewy bodies and glial cytoplasmic inclusions: comparison between Gallyas-Braak and Campbell-Switzer methods.

Lewy bodies (LBs) of idiopathic Parkinson's disease and glial cytoplasmic inclusions (GCIs) of multiple system atrophy are pathological deposits both composed of phosphorylated alpha-synuclein woven into different filaments. Although both LBs and GCIs are considered to be hallmarks for each independent synucleinopathy, until now they could not be clearly distinguished on the basis of their biochemical or immunohistochemical features. We have examined possible differences in their argyrophilic features and their relation to synuclein-like or ubiquitin-like immunoreactivity (IR). Pairs of mirror sections from different brain areas were triple-fluorolabeled with an anti-alpha-synuclein antibody, an anti-ubiquitin antibody and thiazin red (TR), a fluorochrome that labels fibrillary structures such as Lewy bodies or neurofibrillary tangles. One of the paired sections was subsequently stained using the Campbell-Switzer method (CS), and the other by the Gallyas-Braak method (GB). By comparing of the same microscopic field on the paired fluorolabeled sections, subsequently silver-stained with either CS or GB, five different profiles of each structure could be determined: alpha-synuclein-like IR, ubiquitin-like IR, affinity to TR, argyrophilia with CS or GB. GCIs exhibited argyrophilia with both CS and GB but lacked affinity to TR. In contrast, LBs exhibited argyrophilia with CS but not with GB and some affinity to TR. These disease-specific profiles of argyrophilia were consistent, and were not influenced by areas or cases examined. Although immunohistochemical features of LBs and GCIs were similar in exhibiting IR for alpha-synuclein and ubiquitin, the contrast in their argyrophilic profiles may indicate possible differences in the molecular composition or conformation of alpha-synuclein. Even though these empirical differences still remain to be explained, awareness of this clear distinction is potentially of diagnostic and pathological relevance.

Aged↗

PubMed2005

Progressive accumulation of ubiquitin and disappearance of alpha-synuclein epitope in multiple system atrophy-associated glial cytoplasmic inclusions: triple fluorescence study combined with Gallyas-Braak method.

Alpha-synuclein (alphaS) and ubiquitin (Ub) are shared constituents of glial cytoplasmic inclusions (GCIs) and Lewy bodies (LBs), both composed of fibrillary structures. Staining profiles of GCIs were investigated with triple immunofluorescence involving immunostaining for alphaS and Ub, both amplified with catalyzed reporter deposition, and a fluorochrome, thiazin red (TR) that has an affinity to fibrillary structures. After observation for the triple-fluorescent images, the sections were subsequently stained with the Gallyas-Braak method. Sections of putamen, cerebellar white matter and motor cortex from patients suffering from multiple system atrophy (MSA) with varying duration of the disease (4-15 years) were quantified for these staining profiles of Gallyas-positive GCIs. Although most of GCIs were positive for Ub and variably positive for alphaS, they were consistently negative for TR. The result was opposite in LBs in Lewy body disease with variable affinity to TR, suggesting that the construction of GCIs is different from that of LBs. These four staining features (alphaS, Ub, TR and Gallyas) alone failed to exhibit apparent correlation with disease duration, lesion site or severity of degeneration as reported previously. The fraction of alphaS-negative and Ub-positive GCIs, however, linearly increased along the disease progression, while that of alphaS-positive and Ub-negative GCIs decreased in contrast. This reciprocal change suggests that alphaS immunoreactivity in GCIs is being replaced by Ub immunoreactivity during the disease progression, which resulted in the ultimate predominance of alphaS-negative and Ub-positive GCIs in the most advanced case. Interestingly, this predominance of alphaS-negative and Ub-positive GCIs was a feature of motor cortex, where degeneration usually remains mild in spite of robust appearance of Gallyas-positive GCIs. Another fraction, alphaS-positive and Ub-positive GCIs were frequent in cerebellar white matter, suggesting that GCI evolution is heterogeneous and dependent also on area examined. Progressive accumulation of Ub with concomitant disappearance of alphaS epitope and their colocalization, partly shared with LBs, may represent a process of GCI formation, possibly linked to an aspect of degeneration in MSA.

Aged↗

PubMed2001

Therapeutic and prophylactic effects of isometamidium chloride (Samorin) against the hemoflagellate Cryptobia salmositica in chinook salmon (Oncorhynchus tshawytscha) and the effects of the drug on uninfected rainbow trout (O. mykiss).

A series of compounds (triphenylmethanes, thiazines, xanthenes, benzidines, phenanthridiniums, napthalamines, and diamidines) were screened for in vitro toxicity against Cryptobia salmositica. Isometamidium chloride (Samorin) was cryptobiacidal at low concentrations and was examined for therapeutic and prophylactic activities against C. salmositica in chinook salmon (Oncorhynchus tshawytscha). An intramuscular dose (1.0 mg/kg) of Samorin 3 weeks post-infection significantly reduced the parasitemia in adult chinook. A higher dose (2.5 mg/kg) eliminated the infection in 30% of adult fish and parasitemias were significantly reduced in the remaining infected fish. Juvenile chinook treated with 1.0 mg Samorin/kg at 2-3 weeks post-infection survived, while 100% of untreated control fish died from cryptobiosis. The high dose (2.5 mg/kg) was lethal to small fish (98.93 +/- 12.09 g) and 50% died within 24 h of treatment, while all large fish (168.38 +/- 13.87 g) survived. Samorin (1.0 mg/kg) did not affect growth, food consumption, complement, or hematocrit values in uninfected rainbow trout (O. mykiss).

Animals↗

PubMed1984

Continuous spectrophotometric assay of pantetheinase activity.

A continuous spectrophotometric assay for pantetheinase determination using S-pantetheine-3-pyruvate as substrate is described. The enzymatic hydrolysis of this new substrate leads to the formation of S-cysteamine-3-pyruvate, which cyclizes in a non-rate-limiting step to give 2H-1,4-thiazin-5,6-dihydro-3-carboxylic acid (aminoethylcysteine ketimine), a compound exhibiting a strong absorption at 296 nm. The assay is optimized with respect to pH, buffer, and substrate concentration. Prereduction of the enzyme and some properties of the reaction are also studied. The assay is simple, rapid, very sensitive, and specific.

Amidohydrolases↗

PubMed1989

Bioactivation mechanism of L-thiomorpholine-3-carboxylic acid.

L-Thiomorpholine-3-carboxylic acid (L-TMC) is a cyclized analog of S-(2-chloroethyl)-L-cysteine, which is cytotoxic in vitro and nephrotoxic in vivo. To determine whether L-TMC may play a role in S-(2-chloroethyl)-L-cysteine-induced toxicity, the cytotoxicity of L-TMC was studied in isolated rat kidney cells. L-TMC produced time- and concentration-dependent cytotoxicity. Probenecid, an inhibitor of the renal anion transport system, and L-alpha-hydroxyisocaproic acid, a substrate for L-amino acid oxidase, inhibited L-TMC-induced cytotoxicity. Rat kidney cytosol catalyzed the metabolism of L-TMC to a product absorbing at 300 nm. The increase in absorbance at 300 nm was accompanied by an increase in oxygen consumption and was inhibited by L-alpha-hydroxyisocaproic acid; moreover, the absorbance of the metabolite was quenched by addition of potassium cyanide or sodium borohydride, which indicated the formation of an imine. When L-TMC was incubated with rat kidney cytosol and sodium borodeuteride was added at the end of the incubation period, analysis by gas chromatography/mass spectrometry of the tert-butyldimethylsilyl ester of L-TMC showed the formation of [2H]TMC, indicating the intermediate formation of the imine 5,6-dihydro-2H-1,4-thiazine-3-carboxylic acid; chemically synthesized TMC imine showed similar behavior. The enzyme responsible for the metabolism of L-TMC was purified from rat kidney and was identified as L-amino acid oxidase. These observations indicate a role for L-amino acid oxidase in the bioactivation and cytotoxicity of L-TMC.

Amino Acid Oxidoreductases↗

PubMed1990

[35S]Lanthionine ketimine binding to bovine brain membranes.

2H-1,4-Thiazine-5,6-dihydro-3,5-dicarboxylic acid (trivial name: lanthionine ketimine) is a cyclic sulfur-containing imino acid detected in bovine brain extracts. This compound has been synthesized in a heavily labeled form starting from L-[35S]cysteine and purified by high performance liquid chromatography. We demonstrate the existence of a saturable and reversible binding of [35S]lanthionine ketimine to bovine brain membranes. A single population of binding sites with a concentration of 260 +/- 12 fmol/mg protein and a dissociation constant of 58 +/- 14 nM is present. Specific binding is competitively inhibited by other structurally similar imino acids, namely S-aminoethyl-L-cysteine ketimine and cystathionine ketimine. These results suggest a possible functional role for these ketimines in nervous system.

Amino Acids, Sulfur↗

PubMed1994

Synthesis of heterocyclic platelet activating factor analogues.

The synthesis of heterocyclic analogues of the platelet activating factor is described. The preparation starts with acylating rac-tetrahydro-1,3-thiazine-4-carboxylic acid ethyl ester, with palmitoyl chloride to form the amide linkage. Following ester reduction, the phosphocholine part is introduced via 2-chloro-2-oxo-1,3,2-dioxaphospholane and subsequent ring opening with trimethylamine under pressure. Furthermore, the related L-thiazolidine analogue is prepared using the same procedure. In addition the sulfinyl and sulfonyl derivatives of this compound are obtained by oxidation with 3-chloro-perbencoic acid. From one sulfinyl intermediate the diastereomeres are separated and their conformations are determinated by 13C-NMR spectroscopy.

Carbon Isotopes↗

PubMed1995

Synthesis of heterocyclic platelet activating factor analogues.

Magnetic Resonance Spectroscopy↗

PubMed1986

Quality control of azure B preparations by liquid chromatography and standardization with azure B tetrafluoroborate.

A liquid chromatographic procedure for the quantitative determination of the thiazine dye azure B, the principal constituent of Romanowsky stains, is presented. Unlike previous methods relying on peak area normalization, the present approach involves real quantitation through calibration with the reference standard azure B tetrafluoroborate. The method has been used for the quality control of commercial azure B preparations and to study their stability in stock and staining solutions, either or not in the presence of eosin Y. Results suggest that highly pure azure B perchlorate meets the requirements of a reference material, useful for standardization of Romanowsky-Giemsa staining in haematology.

Azure Stains↗

PubMed1984

Differential effects of trifluoperazine on arachidonate liberation, secretion and myosin phosphorylation in intact platelets.

Gel-filtered platelets prelabeled with [3H]-arachidonate and [14C]-adenine or [32P]-orthophosphate were stimulated with thrombin in the presence of various concentrations of trifluoperazine (TFP). Based on the presence of [14C]- or [32P]-labeled extracellular adenine nucleotides, TFP, above 50 microM, caused platelet lysis which reached 30-40% at 100 microM. In the non-lytic range (0-50 microM) TFP caused marked inhibition of [3H]-arachidonic acid liberation and [3H]-phosphatidylcholine breakdown which was complete at 25 microM. Breakdown of [3H]-phosphatidylinositol was partially (about 50%) inhibited at 25 microM TFP and little further inhibition occurred above this concentration. These results show that thrombin-induced liberation of [3H]-arachidonic acid occurs entirely by a TFP-sensitive mechanism, and suggest that the major portion of the arachidonate is liberated from phosphatidylcholine with a possible contribution from phosphatidylinositol. Dense granule secretion and acid hydrolase secretion were progressively inhibited by TFP, while the thiazine had only a small effect on phosphorylation of myosin. These results indicate that the inhibition of the secretory processes by TFP is not caused by action of TFP on myosin light chain kinase. It is suggested that the profound effect of TFP on arachidonic acid liberation but not myosin phosphorylation is due to different subcellular localization of these calmodulin-requiring enzymes: phospholipase A2 and myosin light chain kinase. The lipophilic TFP dissolves preferentially in the membranes where it has access to phospholipase A2 but not to myosin light chain kinase.

Adenosine Diphosphate↗

PubMed1988

Study on the mutagenicity of nifurtimox and eight derivatives with the L-arabinose resistance test of Salmonella typhimurium.

The mutagenicity of nifurtimox (nfx) and 8 nfx analogues has been investigated with the L-arabinose forward-mutation assay of Salmonella typhimurium. The nfx analogues tested were obtained by replacing the 3-methyl-4-yl-tetrahydro-1,4-thiazine-1,1-dioxide group of the parent compound with the following other groups: indazol-1-yl (1); pyrazol-1-yl (2); benzimidazol-1-yl (3); 1,2,4-triazol-4-yl (4); 1-methyl-3-methylthio-1,2,4-triazol-4-yl-5-thione (5); 3,5-bis(methylthio)-1,2,4-triazol-4-yl (6); 1-adamantyl (7); 4,6-diphenylpyridin-1-yl-2-one (8). The mutagenic activity of each chemical was determined by the standard plate-incorporation test, in the presence or absence of the S9 activation mixture. The 9 compounds were mutagenic and exhibited linear dose-mutagenic response relationships. They were direct-acting mutagens and showed a nearly 1000-fold range in mutagenic potency from chemical 1 to nfx. In most cases, the addition of S9 mixture to the test plates decreased the mutagenicity of compounds. This effect was particularly noticeable in the case of chemicals 1-3, 5 and 7 where a more than 70% decrease in mutagenic activity was observed in the presence of the S9 mixture. The mutagenic potency of compounds in the Ara test showed a negative linear correlation with previously reported antitrypanosomal activity. Thus, chemicals 6 and 8 with in vitro activities against Trypanosoma cruzi clearly superior to that of nfx showed 2 of the lowest mutagenic potencies in the Ara test and these were only somewhat higher than the mutagenicity of the reference drug.

Animals↗

PubMed1992

Mutagenic potential of toluidine blue evaluated in the Ames test.

Toluidine blue is a vital, metachromatic thiazine dye which is used as an adjunct in clinical examination for the early detection of asymptomatic recurrent or secondary primary carcinoma in individuals who are at high risk for developing oral cancer. Because available data on the mutagenicity of toluidine blue was limited and contradictory, this study was conducted to evaluate the mutagenic potential of toluidine blue in the in vitro Ames Salmonella test. Tester strains TA97a, TA98, TA100 and TA102 were used. Toluidine blue was tested at concentrations of 0.1, 1.0, 10, 50, 100, 250 and 500 micrograms/plate, with and without S9 microsomal activation, and positive and negative controls were included. Results from tests without S9 showed a significant increase (p less than 0.05) in number of revertants in TA102 and in TA97a with 50 and 100 micrograms toluidine blue/plate, respectively. In tests with S9 activation, doses of toluidine blue ranging from 10 to 250 micrograms/plate induced dose-related increases in the number of revertants in all 4 strains. The results of this study indicate that toluidine blue has a mutagenic effect in the Ames test.

Analysis of Variance↗

PubMed1984

Cell cycle related phenothiazine effects on adriamycin transport.

In P388 murine leukemic cells, the pheno-thiazine tranquilizer, chlorpromazine, causes a marked increase in intracellular drug retention. Laser excited flow cytometry shows that in log phase cultures this increase in drug retention is not uniform but confined to a sub-population. In cell cycle phase enriched populations of P388 cells obtained by centrifugal elutriation, the phenothiazine enhanced adriamycin retention is seen predominantly in cells in the late S, G2/M part of the cell cycle.

Animals↗

PubMed2006

Topo-optical visualization reactions of carbohydrate-containing amyloid deposits in the respiratory tract.

Staining with Congo red according to is the most commonly used method for the demonstration of amyloid, but structures other than amyloid can give false-positive results. To overcome this problem, introduced an aqueous Congo red staining with gum arabic as the mounting medium, which we have used in this and previous publications. Most histochemical studies on amyloid deposits to date have concentrated on conventional methods including staining with thioflavine, sirius red, alcian blue, methyl and crystal violet. In this study, we used topo-optical reactions with thiazine dyes on both the light and polarization microscopic level to establish the structure, distribution and location of carbohydrate components that occur within amyloid deposits, especially in the respiratory tract. Topo-optical staining reactions for the qualitative analysis of carbohydrate components in amyloid deposits included (1) reactions that identify the carbohydrate residues, (2) reactions that detect sialic acids and, (3) methods that visualize glycosaminoglycans. In conclusion, a comparison of consecutive serial sections stained with Congo red, aldehyde bisulfite toluidine blue reaction, sialic acid-specific topo-optical reaction, toluidine blue topo-optical reaction and chemically intensified basophilic reaction showed correlative staining patterns and anisotropic effects, corresponding to a close pathomorphological relationship between amyloid fibrils, periodate reactive carbohydrates, including sialic acids, and glycosaminoglycans.

Adult↗

PubMed2006

Antiviral properties of new arylsulfone derivatives with activity against human betaherpesviruses.

Based on our previous experience with arylsulfone derivatives displaying antiherpetic activity, we synthesized several analogues in which the sulfonyl group is part of a bicyclic structure. The benzene-fused derivative 2H-3-(4-chlorophenyl)-3,4-dihydro-1,4-benzo-thiazine-2-carbonitrile 1,1-dioxide and its thiophene-fused analogue were shown to have favorable activity and selectivity against the betaherpesviruses human cytomegalovirus (HCMV) and human herpesvirus 6 (HHV-6) and 7 (HHV-7). The benzene-fused derivative retained its anti-HCMV activity when evaluated against virus strains resistant to foscarnet, ganciclovir, and/or cidofovir. The compound conferred >or=95% inhibition of viral DNA synthesis in HHV-6-infected cells. RT-PCR analysis of immediate-early, early and late gene products revealed that this arylsulfone compound acts at a step preceding late gene expression, and coinciding with the inhibition exerted by foscarnet. No inhibitory effect was seen in an enzyme assay for DNA elongation catalyzed by the HCMV or HHV-6 DNA polymerase catalytic subunit. The arylsulfone derivatives had no effect on the functional interaction between the catalytic subunit of HCMV DNA polymerase and its accessory protein, nor did they disrupt the physical interaction between the two proteins. We conclude that these arylsulfone derivatives represent new betaherpesvirus inhibitors with a novel mode of action that results in indirect inhibition of viral DNA synthesis.

Antiviral Agents↗