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PubMed1988

Conversion of IQ, a dietary pyrolysis carcinogen to a direct-acting mutagen by normal intestinal bacteria of humans.

The dietary carcinogen, 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ) is mutagenic in the Salmonella/microsomal mutagenicity assay when activated by microsomal enzymes. IQ is found in many cooked foods, notably fried beef and pork. In laboratory rodents IQ is carcinogenic. We showed that mixed and pure cultures of human intestinal anaerobes, notably Eubacterium spp., metabolized IQ to 2-amino-3,6-dihydro-3-methyl-7H-imidazo[4,5-f]quinoline-7-one (HOIQ). Unlike IQ, both the synthetic and bacterially produced HOIQ were direct-acting mutagens, i.e. active without microsomal activation. This new direct-acting mutagen, from the bacterial metabolism of a dietary pyrolysis carcinogen, raises new concerns about the possible role of this class of genotoxins in the etiology of human cancer.

Biotransformation↗
PubMed1986

Role of the uvr gene in the SOS function inducing activity of two tryptophan pyrolysis products, Trp-P-1 and Trp-P-2, in Escherichia coli K12.

Two tryptophan pyrolysis products, Trp-P-1 and Trp-P-2 were assayed in the SOS-chromotest using PQ 37 (uvr A) and PQ 35 (uvr+) E. coli K12 strains, in the presence of S9 fraction from Aroclor-induced rats. Both compounds were able to induce the expression of SOS functions in uvr A bacteria, in the following order: Trp-P-1 less than Trp-P-2 less than aflatoxin B1, at low concentrations (less than 125 ng/assay). In this range, the induction of SOS functions was significantly decreased in the uvr+ strain. This implies that the uvr gene product plays an important role in the repair of genotoxic damage induced by Trp-P-1 and Trp-P-2. At higher concentrations (125-500 ng/assay), Trp-P-1 became more efficient in inducing SOS functions than Trp-P-2 and excision repair was less efficient than at low concentration.

Aflatoxin B1↗
PubMed1989

Carcinogenic tryptophan pyrolysis products in airborne particles and rain water.

This is the first report that carcinogenic tryptophan pyrolysis products are present in airborne particles and rain water. The airborne particles were collected from August 1988 through October 1988 at 4 locations in Japan. The amounts of 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) in the air were 0.23 +/- 0.17 pg/m3 air (mean +/- SD, n = 18) and 0.16 +/- 0.15 pg/m3 air (n = 18), respectively. Moreover, these carcinogens were detected in rain water. These results indicate that Trp-P-1 and Trp-P-2 are ubiquitous environmental components.

Air Pollutants↗
PubMed1992

Application of pyrolysis mass spectrometry to the investigation of outbreaks of food poisoning and non-gastrointestinal infection associated with Bacillus species and Clostridium perfringens.

Eighteen isolates of Bacillus species and 15 of Clostridium perfringens, all of which had been associated with outbreaks of either food poisoning or non-gastrointestinal infection (NGI), were examined for relatedness by pyrolysis mass spectrometry (PyMS). The PyMS-analysis correctly clustered all the groups of epidemiologically related isolates of both genera, and distinguished all the single, epidemiologically unrelated isolates of the same species. PyMS is a simple, rapid and inexpensive technique which can provide useful and accurate inter-strain comparisons within both the Bacillus and Clostridium genera in complete accord with conventional serological typing results.

Bacillaceae Infections↗
PubMed1991

Strain differentiation of nosocomial isolates of Pseudomonas aeruginosa by pyrolysis mass spectrometry.

Pyrolysis mass spectrometry (PyMS) was used for rapid interstrain comparison of Pseudomonas aeruginosa isolates from a small outbreak of sternal wound infections in a cardiothoracic surgical ward. The PyMS results were compared with those obtained by conventional O-serotyping. All the isolates were phage non-typable. Evidence obtained from PyMS of identity/non-identity between isolates correlated completely with that obtained by O-typing and correctly identified those isolates comprising the epidemic strain, in one instance in advance of O-serotyping. The speed and versatility of PyMS make it an attractive technique for the initial screening of isolates from nosocomial outbreaks of infection with P. aeruginosa and other organisms.

Bacterial Typing Techniques↗
PubMed1991

Inter-strain comparison by pyrolysis mass spectrometry in the investigation of Staphylococcus aureus nosocomial infection.

Pyrolysis mass spectrometry (PyMS) was used to examine isolates of Staphylococcus aureus from an outbreak of wound infections on a cardiothoracic surgical unit, some of which were thought to have been related to a point-source in the operating theatre. The PyMS results were compared with the results of phage typing. Both methods suggested that a single strain of S. aureus, of phage pattern 29/52/52A/79/80/81, was responsible for some of the wound infections, but PyMS also identified two patients with phage non-typable isolates. Phage typing indicated four staff members as possible carriers of the epidemic strain, but PyMS indicated only two. Epidemiological enquiry confirmed that one of the two members of staff identified by both methods was likely to have been the source of the theatre-based infection. PyMS is a rapid and relatively inexpensive technique for the investigation of nosocomial S. aureus infection and was more discriminatory than phage typing in this instance.

Carrier State↗
PubMed1995

Pyrolysis mass spectrometry of cephalosporin-resistant Enterobacter cloacae.

Thirteen clinical and four environmental isolates of third-generation cephalosporin-resistant Enterobacter cloacae (CREC) together with single isolates from the hands of a nurse and from a blood gas analyser were associated with two clusters of nosocomial infection. With an unrelated CREC isolate they had been typed by serotype, biotype, ribotype and phage-type and were examined by pyrolysis mass spectrometry (PYMS) as described here. PYMS data yielded two clusters, major and minor. All except one isolate in the major cluster corresponded to type group identity (serotype 07, biotype 62, ribotype D) which had caused neonatal sepsis and colonization. Multivariate analysis showed a homogeneous group consisting of this strain plus two outliers. The minor cluster included four different strains, one of which, serotype 03, biotype 62, ribotype C had caused excoriation of the buttocks and colonization.

Cephalosporin Resistance↗
PubMed1980

Metabolic activation of mutagenic tryptophan pyrolysis products (Trp-P-1 and Trp-P-2) by a purified cytochrome P-450-dependent monooxygenase system.

Tryptophan pyrolysis products, Trp-P-1 and Trp-P-2, were activated to metabolites mutagenic to Salmonella typhimurium by cotychorome P-450 purified from rat liver microsomes. Of the four purified cytochrome P-450 preparations tested, PCB P-448 and MC P-448 showed high activity, while PCB P-450 and PB P-450 were less active. The number of revertants was proportional to the amount of cytochrome PCB P-448 added under the conditions used.

Animals↗
PubMed1981

Carcinogenic activity of 3-amino-1-methyl-5H-pyrido [4,3-b]indole (Trp-P-2), a pyrolysis product of tryptophan.

The carcinogenic activity of 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2), a pyrolysis product of tryptophan, was studied in inbred strain ACI rats. Twenty rats received a diet containing 0.01% Trp-P-2 for 870 days. Nineteen rats survived for more than 400 days after the start of feeding, 1 rat developed a hemangioendothelial sarcoma of the liver, and 6 rats developed neoplastic liver nodules. These liver tumors were found only in female rats that died 666--870 days after the start of feeding. No liver tumors were found in control animals.

Animals↗
PubMed1981

Metabolic activation of a tryptophan pyrolysis product, 3-amino-1-methyl-5H-pyrido[4,3-b]indole(TRP-P-2) by isolated rat liver nuclei.

The metabolic activation of a tryptophan pyrolysis product, 3-amino-1-methyl-5H-pyrido[4,3-b]indole(Trp-P-2), by rat liver nuclei was studied. Nuclei from the livers of rats treated with polychlorinated biphenyl (PCB) or 3-methylcholanthrene (MC) showed high mutagenic activity with Trp-P-2 in the Ames test, but activities with nuclei of untreated or phenobarbital (PB)-treated rat livers were quite low. The formation of N-hydroxy-Trp-P-2 by nuclei of PCB- or MC-treated rat livers was greater than that by nuclei of untreated or PB-treated rat livers. Similar results were observed with microsomes, which suggests that Trp-P-2 is metabolized by the same type of monoxygenase system in nuclei as in microsomes.

Animals↗
PubMed1988

Comparative carcinogenicity of the food pyrolysis product, 2-amino-5-phenylpyridine, and the known human carcinogen, 4-aminobiphenyl, in the neonatal B6C3F1 mouse.

2-Amino-5-phenylpyridine (2-APP) is a mutagenic heterocyclic aromatic amine that is formed by pyrolysis of phenylalanine in proteins. Since this mutagen is structurally similar to the multipotent carcinogen, 4-aminobiphenyl (4-ABP), we compared their relative tumorigenic activity in the neonatal male B6C3F1 mouse. After determinations of the maximum tolerated dose (MTD), both aromatic amines were administered i.p. at 2 dose levels (MTD and MTD/2) on days 1, 8, 15 and 22 after birth. Groups were killed at 9 and 12 months and examined for histopathologic changes. No treatment-related neoplastic lesions were observed for 2-APP. In contrast, 4-ABP was strongly carcinogenic and induced a high incidence of multiple hepatocellular adenomas and carcinomas.

Aminobiphenyl Compounds↗
PubMed1977

Identification of acetylcholine and propionylcholine in bull spermatozoa by integrated pyrolysis, gas chromatography and mass spectrometry.

Acetylcholine was identified in fertile bull spermatozoa using combined pyrolysis gas-chromatography and mass spectrometry. Bull spermatozoa contain other minor choline esters in smaller quantities than acetylcholine. One of the minor choline esters is possibly propionylcholine. The spermatozoa from infertile bulls exhibited low motility and very low levels of acetylcholine.

Acetylcholine↗
PubMed1983

Mutagenesis of amino acid pyrolysis products in Chinese hamster V79 cells.

The mutagenic effects of Trp-P-1, Trp-P-2, Glu-P-1, Glu-P-2, Lys-P-1, MeA alpha C, A alpha C, MeIQ and IQ on Chinese hamster V79 cells with or without X-irradiated Syrian hamster embryo cells were examined. Of these products, only Trp-P-2 and Lys-P-1 induced ouabain-resistant mutants of Chinese hamster V79 cells in a dose-related fashion; X-irradiated Syrian hamster embryo cells were required for the mutagenicity of Lys-P-1, but not for that of Trp-P-2. None of the other pyrolysis products examined was mutagenic with or without X-irradiated Syrian hamster embryo cells.

Amino Acids↗
PubMed1984

Analytical pyrolysis of Streptococcus salivarius as an aid to identification in bite-mark investigation.

The use of pyrolysis mass spectrometry (Py-MS) and statistical analysis of mass spectra is introduced as a method for "finger-printing" strains of Streptococcus salivarius. The objective is to provide correlative evidence regarding the identity of suspects in cases of assault or rape involving bite-marks. The results of the analysis of isolates from two individuals are presented, illustrating the differentiation of S. salivarius at strain level according to the origin of the isolate.

Bites and Stings↗
PubMed2004

The fuel properties of pyrolysis liquid derived from urban solid wastes in Bangladesh.

Urban solid wastes in the form of scrap tyre, waste plastic and waste paper, were pyrolyzed in an externally heated fixed bed reactor. The condensed liquids were analyzed for their properties as fuels and compared with petroleum-derived products. The properties were physical properties, higher heating value, elemental (CHNOS) analysis and chemical composition using Fourier transform infra-red (FTIR) spectroscopy. The results showed that the pyrolysis of urban solid wastes may be a potential source of liquid hydrocarbon fuel.

Bangladesh↗
PubMed2006

Polycyclic aromatic hydrocarbons (PAHs) in bio-crudes from induction-heating pyrolysis of biomass wastes.

The aim of this work was to prepare the bio-crudes from agricultural wastes (i.e., rice straw, rice husk, sugarcane bagasse and coconut shell) by using induction-heating pyrolysis at specified conditions. The quantitative analysis of 21 priority pollutant polycyclic aromatic hydrocarbons (PAHs) in bio-crudes examined using gas chromatography/mass spectrometry (GC/MS) revealed that the PAHs in bio-crudes were primarily dominant in the low molecular weight (LMW) PAHs, including naphthalene (1.10-2.45 mg/L) and acenaphthene (0.72-7.61 mg/L). However, by considering carcinogenic potency, the bio-crudes from rice husk and sugarcane bagasse contained higher contents of benzo[a]pyrene (BaP) (0.52 and 0.92 mg/L, respectively) as compared to those from rice straw and coconut shell.

Agriculture↗