Use Of Benzidine Research Articles

Dye-manufacturing workers and bladder cancer in South Korea

Dear Editor, Manufacturing beta-naphthylamine, which is considered to be a strong carcinogen, was abandoned in European countries from the 1930s to 1950s. Manufacturing benzidine was sustained with preventive measures against health hazards but because tumors continuously occurred despite these eVorts it also was abandoned in the United Kingdom in 1956 (Wallace 1988), in Germany in 1971 (Golka et al 2004), and in the United States in 1973 (Walker and Gerber 1981). The history of dye industry in Korea is closely related with that in Japan. Japanese government banned the manufacture and use of beta-naphthylamine, benzidine, 4-aminobiphenyl and 4-nitrobiphenyl, which turned out to be carcinogenic based on the epidemiological study showing the high prevalence of bladder cancer in workers or ex-workers exposed to aromatic nitrogen compounds (Shinka et al. 1991). Japanese government was forced to shut down dye manufacturing in 1972. On the other hand, Korean dye manufacturers by implementing these technologies from Japan have expanded remarkably since then. There was a lot of controversy over its suspension of production of benzidine or benzidine-based dyes since 1980, but the decision was deferred due to the importance of the dye industry. In 1990s, there were one factory manufacturing benzidine illegally and also manufacturing benzidine chlorides and eight factories using benzidine chlorides in Korea. However, Wnally even manufacturing benzidine-based dyes and benzidine dichlorides were legally prohibited in 2000 in Korea. The latent period of bladder cancer due to benzidine is generally known to be 20 years or more, though it varies with the exposure level and duration. Considering that the peak use of benzidine was in 1980s in Korea, the outbreak of bladder cancer due to benzidine is highly expected in early 2000s. Hence, the authors intend to examine bladder cancer incidence of those who were exposed to benzidine or benzidine chlorides. The subjects in our study were factories and its workers that manufactured benzidine or benzidinebased dyes in Korea (see Table 1).

The first examples of benzidinium cations templated low-dimensional molybdates

For the first time, use of benzidine as a structure-directing agent has resulted in the crystallization of two novel organic/inorganic hybrid molybdates under hydrothermal condition (180 °C and autogenous pressure). The presence of monoprotonated benzidinium ions in aqueous molybdate solution appears to engineer two new hybrid solids: one-dimensional chains in [H 2NC 12H 8NH 3] 2Mo 2O 7, 1 ( a = 5.9686, b = 7.0761 and c = 14.3293 Å, α = 77.17°, β = 85.25° and γ = 88.56°; P 1 ¯ and Z = 2) and two-dimensional step-wise layered molybdate [H 2NC 12H 8NH 3] 2Mo 5O 16, 2 ( a = 5.6843, b = 14.3024 and c = 19.4787Å, α = 108.1°, β = 98.4° and γ = 90.0°; P 1 ¯ , Z = 2). 1 is an unusual solid wherein the anionic chains are charge compensated by counter cations which also act as ligands to the metal and 2 is a new layered molybdate built of MoO 5 square pyramids and MoO 6 octahedra.

Benzidine Stain for the Histochemical Detection of Hemoglobin in Splinter Hemorrhage (Subungual Hematoma) and Black Heel

Minor nail trauma may cause bluish discoloration of the nail, while tangential skin trauma on the heel can result in a so-called black heel. To rule out melanoma in such clinical situations, a biopsy is needed to reveal homogeneous eosinophilic masses deposited under the nail plate or within it (transepidermal elimination). Most dermatopathologists attempt to demonstrate the presence of hemoglobin in these eosinophilic masses with Prussian blue stain, which typically remains negative. In our experience, these traumatically induced blood deposits are always situated in avascular spaces, devoid of degrading phagocytes. Consequently, a histochemical stain for these deposits should be directed specifically toward hemoglobin, not hemosiderin. In the dermatopathologic literature, the various techniques to detect hemoglobin deposits in tissue sections are not well-known. We would like to emphasize benzidine stain, a highly selective and efficient method to demonstrate the presence of hemoglobin deposits in histologic sections. To date, benzidine stain has not been utilized to characterize splinter hemorrhage (subungual hematoma). Of concern, the use of benzidine in histopathology laboratories is restricted because this agent is a known carcinogen, while the non-mutagenic derivative, 3,3',5,5'-tetramethylbenzidine, does not stain histologic sections. Patent blue V, a completely different and less specific agent, stains hemoglobin an intense blue-green.

Use of benzidine for histological demonstration of haemoglobin in human bite marks.

Macroscopic evidence of bruising from human bite marks may be inconclusive and routine histochemical methods of showing extravasated erythrocytes can be unreliable. Leuco patent blue staining, for the presence of peroxidase, Amido black B, a tinctorial staining method for haemoglobin, Perls's reaction for ferric iron (haemosiderin), Masson-Fontana for melanin, Masson's trichrome, a connective tissue strain, and the benzidine reaction for haemoglobin peroxidase were carried out in three forensic cases and one experimental case. A modified benzidine method was the most reliable indicator of haemoglobin activity, especially where dispersion into extra-cellular tissues had occurred. The resilience of the erythrocyte peroxidase enzyme to temperature changes and fixation supports the concept of a "pseudo-peroxidase" in those cells. It is concluded that free haemoglobin from bite marks, or indeed other forms of blunt trauma, may best be shown by the benzidine reaction and that exemption certificates for use of this prohibited substance may be worth pursuing.

The Determination of Free Benzidine in Dyes

Methods for the quantitative determination of benzidine have been assessed and a convenient method for the analysis of trace amounts of this compound in dyes has been developed. The method of analysis has been applied to some forty dyes all of which require the use of benzidine in their manufacture. Results are discussed in terms of possible future regulations.

Mutagenicity of the urine of rats treated with benzidine dyes (author's transl)

Today industrial use of benzidine is restricted in many countries. However, little attention is paid to those substances which may decompose themselves in the body and release benzidine or benzidine-like substances. I investigated the mutagenicity of urinary ingredients of rats to which benzidine and three kinds of azo dyes were separately administered through the alimentary tract. The azo dyes were Direct Black EX(EX), Direct Green BK(BK), and Direct Bordeaux BK(BK), all having 4,4'-diazobiphenyl group in each structure. The mutagenicity of the urine extract with ether was tested on Salmonella typhimurium TA 98 and TA 100. Urinary metabolites of benzidine showed stronger mutagenicity than benzidine itself on both TA 98 and TA 100 in the presence of S9 mix. EX itself showed mutagenicity only on TA 98, whereas B and BK were nonmutagens. Nevertheless, the urine extract of each azo dye showed strong mutagenicity of the same pattern as benzidine. As a result it is suggested that benzidine might be released in the intestine of experimental animals after the administration of each azo dye. Mutagenic activity of urine sample is important and full of suggestions from the viewpoint of carcinogenicity of aromatic amines.

A Warning against the Use of Benzidine

A Warning against the Use of Benzidine

Benzidine as a Substrate for Measuring Phenoloxidase Activity in Crude Cellfree Extracts ofSchizophyllum Commune

Benzidine, p-diaminodiphenyl, has been used as an in situ test for fungal phenoloxidase and peroxidases (Lyr, 1958). The application of the colorless benzidine solution directly to fungal colonies, or to the underside of the agar bearing the colony, produces bright blue coloration within minutes in the presence of phenoloxidases. This simple test has a number of advantages over the more tedious, although more popular, Bavendamm reaction (Lyr, 1958). The present study examines the use of benzidine as a measure of phenoloxidase activity in crude cell-free extracts of Schizophyllum commune Fr. and characterizes, to some extent, optimal conditions for in vitro studies.

Benzidine revisited: a review of the literature and problems associated with the use of benzidine and its congeners.

Benzidine revisited: a review of the literature and problems associated with the use of benzidine and its congeners.

Anti-Protein Plaque-Forming Cells Detected with High Efficiency by the Use of Red Cells Coupled to Bovine Serum Globulin through Bis-diazo-benzidine

Abstract It has been known for many years that sheep red cells coupled to proteins through diazotized benzidine can be hemolyzed by anti-protein sera (1). However, early attempts to use protein-coupled cells in the hemolytic plaque assay to detect cells producing anti-protein antibodies were unsuccessful (2). The first successful experiments were done with red cells coupled to protein by means of 1-ethyl-3-(3-dimethylamino propyl) carbodiimide HCl (ECDI) (3, 4), but this method has drawbacks in that ECDI is an expensive reagent, and large amounts of protein are required to obtain coupled cells with useful sensitivity. We have now re-investigated the use of benzidine and have found that we can obtain sheep red cells coupled with bovine γ globulin (BGG-SRBC) which are more efficient in detecting anti-BGG plaque-forming cells (PFC) than were any of the preparations we obtained after detailed investigation of the ECDI technique (5).

Determination of small amounts of sulphur as sulphates in biological fluids

THREE main forms of sulphur are usually recognized in biological fluids: (a) inorganic sulphates, (b) ethereal sulphates and (c) neutral sulphur. The determination of these different forms of sulphur is usually made as sulphate. Several methods have been proposed but none of them is free from errors. The earliest gravimetric methods depending on barium precipitation can only be used when large samples are available, as with urine. For blood sulphates barium precipitation has also been used, the precipitate being measured volumetrically [Hamburger, 1916; De Boer, 1917], or nephelometrically [Denis, 1921; Denis & Reed, 1926]. In other methods barium chromate is added and the liberated chromate estimated colorimetrically with diphenylcarbazide [Lang, 1929], or volumetrically [Klinke, 1924; Morgulis & Hemphill, 1932]. 0llgard [1934] estimated sulphates using an adsorption indicator (sodium rhodizonate). An important advance was the use of benzidine proposed by Rosenheim & Drummond [1914] and applied by Raiziss & Dubin [1914] to the determination of sulphates in urine, and later to blood estimations by Fiske [1921]. Benzidine sulphate has been estimated by alkalimetric [Pohorecka-Lelesz, 1927; Cope, 1931; De Meio, 1933], iodimetric [Wakefield et al. 1931], manganimetric [Hoffman & Cardon, 1935] and colorimetric methods, the latter being based bn conjugation reactions [Cuthbertson & Tompsett, 1931; Letonoff & Reinhold, 1936], or oxidation [Yoshimatsu, 1926; Hubbard, 1930; Wakefield, 1929]. All these methods are subject to error due to non-quantitative precipitation of benzidine sulphate and to the imperfection of the colour reactions employed. We therefore started the study of a new method, based on the use of benzidine as a precipitant but modifying the technique of precipitation so that complete removal of interfering substances was obtained. The benzidine sulphate is determined colorimetrically, using the weak reducing power of benzidine on phosphotungstomolybdic acid (Folin's phenol reagent). The Pulfrich photometer is employed for the final matching.

On the Micro-Volumeteric Method of determining Sulfuric Acid by the Use of Benzidine

On the Micro-Volumeteric Method of determining Sulfuric Acid by the Use of Benzidine