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PubMed1988

The effects of quaternary ammonium chloride (alpha C12 DME AHCl) on enamel hardness and mineral loss under intra oral cariogenicity test conditions.

The effects of a quaternary ammonium compound; 2-hydroxy-ethyl-2-hydroxydodecyl-dimethyl-ammonium chloride (alpha C12 DMEAHCl) on enamel hardness and mineral loss in enamel slabs were studied under intra-oral cariogenicity test conditions. The quaternary ammonium compound without fluoride reduced enamel softening as well as the mineral loss from enamel significantly up to a depth of 100 microns from the surface. Moreover the Ca/P molar ratio of the treated enamel was comparable to untreated enamel controls. These findings suggest that the quaternary ammonium compound itself inhibits mainly demineralisation rather than remineralization under intra-oral cariogenicity test conditions.

Animals↗
PubMed2005

Deuteron NMR spectra of ammonium ion isotopomers at low temperatures.

Partially deuterated ammonium compounds contain ammonium ion isotopomers with relative abundances given by the binomial distribution of protons and deuterons. All isotopomers with deuterons contribute characteristic deuteron NMR spectra at 5K. Experimental NMR spectra were separated and respective contributions of isotopomers were determined. The derived contributions agree with expected values for a given deuteration in the case of ammonium hexafluorophosphate. In ammonium hexachlorotellurate both NH2D2+ and about 50% of NH3D+ ions are rigid, while the remaining NH3D+ perform limited jumps. NHD3+ and ND4+ ions undergo tunnelling rotation, NH3D+ ions perform either jumps about C2 axis or limited jumps, but some stay rigid in ammonium hexachlorostannate. NH2D2+, NHD 3+ and ND4+ undergo rotational tunnelling. In the case of ammonium perchlorate, the NH3D+ ions perform either jumps about C3 axis or limited jumps whilst some remain rigid. Very low values of activation energies were derived for all spectral components from the temperature dependence of their spectra, up to about 20K, which indicates an incoherent tunnelling nature of the observed dynamic processes. The diverse mobility of NH3D+ ions appears to be the most interesting and new feature.

Journal Article↗
PubMedDate not supplied

Involvement of nitrogen-containing compounds in beta-lactam biosynthesis and its control.

Biosynthesis of beta-lactam antibiotics by fungi and actinomycetes is markedly affected by compounds containing nitrogen. The different processes employed by the spectrum of microbes capable of making these valuable compounds are affected differently by particular compounds. Ammonium ions, except at very low concentrations, exert negative effects via nitrogen metabolite repression, sometimes involving the nitrogen regulatory gene nre. Certain amino acids are precursors or inducers, whereas others are involved in repression and, in certain cases, as inhibitors of biosynthetic enzymes and of enzymes supplying precursors. The most important amino acids from the viewpoint of regulation are lysine, methionine, glutamate and valine. Surprisingly, diamines such as diaminopropane, putrescine and cadaverine induce cephamycin production by actinomycetes. In addition to penicillins and cephalosporins made by fungi and cephamycins made by actinomycetes, other beta-lactams are made by actinomycetes and unicellular bacteria. These include clavams (e.g., clavulanic acid), carbapenems (e.g., thienamycin), nocardicins and monobactams. Here also, amino acids are precursors and inhibitors, but only little is known about regulation. In the case of the simplest carbapenem made by unicellular bacteria, i.e., 1-carba-2-em-3-carboxylic acid, quorum sensors containing homoserine lactone are inducers.

Amino Acids↗
PubMed1984

Antacids and anticholinergics in the treatment of duodenal ulcer.

Anticholinergic agents are most often divided into tertiary and quaternary ammonium compounds. Tertiary ammonium agents are fully and rapidly absorbed. Quaternary ammonium agents are slowly and incompletely absorbed, but do not cross the blood-brain barrier, or do so to a very limited degree, and have a very low rate of central nervous system side-effects. There are probably subclasses of cholinergic receptors, and anticholinergic agents have different affinities for these. Anticholinergics can decrease the basal acid secretion as well as secretion stimulated by histamine, pentagastrin, insulin or food. Combined therapy with antacids and anticholinergics will give a more long-lasting decrease in acidity than with either drug alone. The reported controlled studies with anticholinergic agents suggest that they can induce healing of duodenal ulcer to the same degree as cimetidine but at the cost of more frequent side-effects. Except for the studies on pirenzepine there are, however, too few studies in which anticholinergics have been compared with histamine H2-receptor antagonists; thus the place of anticholinergics in the treatment of an active duodenal ulcer is not clear. In doses of not less than 100 mg daily, pirenzepine is a candidate-drug for the short-term treatment of duodenal ulcer. At these doses, side-effects of dry mouth and visual disturbance are, however, rather frequent, and more serious side-effects such as urinary retention do also occur. More studies with both the conventional anticholinergics and pirenzepine, with emphasis not only on the desired effects but also on side-effects, are needed before anticholinergics can be taken into consideration as alternatives to histamine H2-receptor antagonists for healing and maintenance treatment. There is some evidence that long-term treatment with anticholinergic agents can decrease recurrences and complications of peptic ulcer disease. Even if there are some encouraging reports on the combination of anticholinergics and antacids, we need more such studies with lower doses of antacids and lower doses of anticholinergics before this combination therapy can be regarded as an equally good alternative to histamine H2-receptor antagonists for ulcer healing and symptom relief.

Aluminum Hydroxide↗
PubMed1978

Effects of cholinesterase inhibitors on the spasmogenic action of acetate esters on rat uterus.

Acetate esters, such as phenyl acetate and aspirin, induced atropine-sensitive contractions of isolated uterus only when choline was present. These contractions were selectively and reversibly inhibited by carbamate-type cholinesterase inhibitors, such as neostigmine and eserine, and quaternary ammonium compounds, such as tetraethylammonium and decamethonium. After treatment with organophosphorus cholinesterase inhibitors, such as di-isopropyl fluorophosphate and tetraethyl pyrophosphate, the uterus failed to respond to the acetate esters, even when high concentrations of choline were present. The inhibition of the response of the uterus by organophosphates was effectively removed by pyridine-2-aldoxime methiodide. Pretreatment of the uterus with neostigmine or simultaneous addition of high concentrations of quaternary ammonium compounds prevented the inhibition by organophosphates. The inhibition produced by neostigmine was also reduced by simultaneous addition of quaternary ammonium compounds. These findings suggest that some esterase having an anionic site and an esteratic site, probably cholinesterase, may mediate in the uterine contractions induced by acetate esters in the presence of choline, and that inhibition by organophosphates, carbamates and quaternary ammonium compounds of cholinesterase activity in the preparation may impede the initiation of contractions by the acetate esters in the presence of choline.

Acetates↗
PubMed1985

Binding of drugs with a quaternary ammonium group to alpha-1 acid glycoprotein and asialo alpha-1 acid glycoprotein.

The interaction of eight mono- and four bisquaternary ammonium compounds with alpha-1 acid glycoprotein and its desialylated derivative was investigated. Protein binding was performed in vitro by equilibrium dialysis at 37 degrees C. The simple monoquaternary ammonium compounds tributylmethylammonium, tripropylmethylammonium, triethylmethylammonium and procainethobromide were not appreciably bound (unbound fraction greater than 0.99). Excellent negative correlations of unbound fraction and the log of the octanol/Krebs' partition coefficient were obtained for thiazinamium, N-methylimipramine, N-methyldeptropine and d-tubocurarine, both for alpha-1 acid glycoprotein (r = -0.99) and asialo alpha-1 acid glycoprotein (r = -0.94). Bisquaternary ammonium compounds, with the exception of hexafluorenium, were only poorly bound. Our binding data on N-methyl-deptropine, N-methylimipramine and thiazinamium reveal that these compounds are more avidly bound to alpha-1 acid glycoprotein than to albumin, in spite of their polar character. The interaction of N-methyldeptropine with alpha-1 acid glycoprotein was studied in more detail. Scatchard plots revealed the presence of two classes of binding sites. N-Methyldeptropine could effectively be displaced by imipramine from its high-affinity binding site. This points to the presence of a common high-affinity binding site for tertiary and quaternary ammonium compounds on alpha-1 acid glycoprotein.

Asialoglycoproteins↗
PubMed1977

Potent reversible anticholinesterase agents. Bis- and mono-N-substituted benzoquinolinium halides.

A number of bis- and mono-N-substituted benzoquinolinium salts and their analogues were prepared and evaluated as inhibitors of acetylcholinesterase (AcChE) and butyrylcholinesterase (BuChE). These compounds were also used to help identify some of the morphologic characteristics of the surface at or near the active sites of the cholinesterases. The shape, size, configuration, and conformation of the onium moieties of the quaternary ammonium compounds were found to be the important factors in their anticholinesterase activity. A high concentration of the positive charge of the quaternary ammonium compound is not a critical factor for the cholinesterase inhibitory activity. The order of decreasing potency of cholinesterase inhibition of the benzoquinolinium compounds was found to be acridinium greater than phenanthridinium greater than 5,6-benzoquinolinium greater than 7,8-benzoquinolinium. The inhibitory activity of the monobenzoquinolinium halides against cholinesterases is influenced by the N-substituent. A bis-quaternary ammonium compound with a flexible bridge that links the two nitrogen atoms was found to be more potent in inhibiting AcChE and less potent in inhibiting BuChE than a bis-quaternary ammonium compound with a rigid bridge. The acridinium and phenanthridinium derivatives of the benzoquinolinium compounds are very potent reversible inhibitors against both AcChE and BuChE.

Cholinesterase Inhibitors↗
PubMed1997

Pathogenesis of abnormal keratinization in ichthyosiform cetrimide dermatitis: an ultrastructural study.

We have previously reported 18 cases of an ichthyosiform contact dermatitis caused by antiseptic solutions containing 3% cetrimide and 0.3% chlorhexidine. The reaction was traced to cetrimide, a mixture of quaternary ammonium compounds that are widely used as disinfectants and detergents. Quaternary ammonium compounds are known irritants. To elucidate the pathogenesis of the abnormal keratinization caused by cetrimide, electron microscopy was performed on biopsied lesions from five patients and on specimens from rabbits in which a mild reaction had been induced by closed patch with Savlon, cetrimide, and chlorhexidine. The patients' samples revealed hyperkeratosis with striking vesiculation of lamellar bodies in the granular cells and upper spinous cells, premature secretion of lamellar bodies, and abundant remnants of lamellar bodies and retention of desmosomes between the corneocytes. Similar lamellar bodies changes were induced in rabbit skin after 48 hours of closed patch with Savlon 1:30 and cetrimide 0.1%, but not with chlorhexidine 3%-further indication that cetrimide was the cause of the dermatitis. We conclude that the abnormal keratinization can be attributed, at least in part, to dysfunction of lamellar bodies resulting from the direct effects of cetrimide on the lipids and enzymes of lamellar bodies. Vesiculation with dysfunction of lamellar bodies may be an important pathogenetic mechanism in irritant dermatitis caused by quaternary ammonium compounds.

Animals↗
PubMed1981

The effects of nasal drops on the ciliary beat frequency of chicken embryo tracheas.

The effects of proprietary preparations in the Netherlands and nasal preparations according to the F.N.A. (Formulary of the Netherlands' Pharmacists Association) on the ciliary beat frequency of chicken embryo tracheas have been determined. In general the preservatives, used in the nasal drops, turned out to have a more decisive influence on the ciliary motion than the pharmacologically active constituents. The average time, necessary to decrease the frequency 50% with 1=5 diluted nasal drops (average t 50%(1=5) containing a mercury compound or chlorbutol, is 0.4 h. Quaternary ammonium compounds containing preparations, however, have less influence, average t 50%(1=5) greater than 1.22 h. They are to be used preferably. Nasal drops, used as decongestants, provided that they are preserved with quaternary ammonium compounds, have little influence on the ciliary motion (average t50%(1=5) greater than 1.38 h). Nasal drops containing antihistamines, in contrast, inhibit the ciliary motion largely and almost independently of the preservatives (average t50%(1=5)=0.22 h); the cromoglycate containing preparation, on the contrary, has only little effect in this respect (t50%(1=5) greater than 2 h). Antimicrobial preparations are not preserved and have an intermediate ciliotoxic effect (average t50%(1=5)=0.7 h).

Animals↗
PubMedDate not supplied

Occupational allergic contact dermatitis from alkylammonium amidobenzoate.

Quaternary ammonium compounds are water-soluble antimicrobials which are widely used in disinfectants, sterilizers, skin cleansers and antiseptic creams. One quaternary ammonium compound, alkylammonium amidobenzoate (Osmaron B) has for decades been used in udder ointments. Here we present a ship technician with occupationally induced sensitization to alkylammonium amidobenzoate. The diagnosis was reached only when it emerged, after careful questioning, that the patient was exposed to a substance peculiar to his workplace but not to his occupation and was then patch tested for it. It turned out that an udder ointment had been used at the patient's workplace as a hand ointment. Patch testing was positive to the patient's hand ointment, and Osmaron B at 0.1-0.01% in petrolatum. Other sensitizing quaternary ammonium compounds, namely benzalkonium chloride, benzethonium chloride, benzoxonium chloride, N-benzyl-N,N-dihydroxyethyl-N-cocosalkyl-ammonium chloride, cetalkonium chloride, cetylpyridinium chloride, cetrimonium bromide, chloroallylhexaminium chloride, dequalinium chloride, domiphen bromide, methylbenzethonium chloride and 2,3-epoxypropyl trimethyl ammonium chloride are reviewed briefly. The importance of patch testing to all materials in use by the patient is emphasized. It is also important to select non-allergenic hand creams for use at work places.

Benzoates↗
PubMed1999

Routine disinfection of patients' environmental surfaces. Myth or reality?

We have evaluated the need for daily disinfection of environmental surfaces not contaminated by biological fluids, in patient areas of a medical unit with two wings [North (N) and South (S)] at the University Hospitals of Geneva, Switzerland. Weekly bacteriological monitoring of surfaces was carried out at random (N = 1356 samples). In the S wing (control), we used detergent/disinfectant for daily cleaning of the floors and furniture. In the N wing we began by using a detergent for floors and furniture; after four weeks the results suggested changing to a rotation of detergent, dust attracting disposable dry mops and disinfectant. During this period the furniture was cleaned with an active oxygen-based compound. The average differences in contamination before and after cleaning floors were (mean reduction in bacterial counts and 95% confidence intervals; CI95): disposable mops: 92.7 cfu/24 cm2 (CI95; 74-112), active oxygen based compound 111.1 (90-133), and quaternary ammonium compound -0.6 (-27-26). Use of detergent alone was associated with a significant increase in bacterial colony counts: on average by 103.6 cfu (CI95 73-134). The quaternary ammonium compound was inadequate for disinfecting bathrooms and toilets but the active oxygen based compound was satisfactory. For furniture, there was a significant reduction in bacterial counts with both the methods using disinfectants. As the detergent was contaminated, by using it alone for cleaning, we were actually seeding surfaces with bacteria. A total of 1117 patients was studied and we observed no change in the incidence of nosocomial infections during the four months of the trial. In conclusion, uncontrolled routine disinfection of environmental surfaces does not necessarily make it safe for the patient and could seed the environment with potential pathogens.

Analysis of Variance↗
PubMed2002

Mechanistic investigation of the interaction between bisquaternary antimicrobial agents and phospholipids by liquid secondary ion mass spectrometry and differential scanning calorimetry.

Mechanisms of interaction between the antimicrobial drugs decamethoxinum and aethonium, which are based on bisquaternary ammonium compounds, and a phospholipid component of biological membranes, dipalmitoylphosphatidylcholine, were studied by means of liquid secondary ion mass spectrometry (LSIMS) and differential scanning calorimetry (DSC). Supramolecular complexes of the drugs with this phospholipid were recorded under secondary ion mass spectrometric conditions. The dependence of the structures of these complexes on structural parameters of the dications of the bisquaternary ammonium compounds was demonstrated. Tandem mass spectrometric investigations of the metastable decay of doubly charged ions of decamethoxinum and aethonium complexes with dipalmitoylphosphatidylcholine allowed estimation of structural parameters of these complexes in the gas phase. Interactions of decamethoxinum and aethonium with model membrane assemblies built from hydrated dipalmitoylphosphatidylcholine were studied using DSC. It was shown that while both drugs can interact with model membranes, the mechanisms of such interactions for decamethoxinum and aethonium differ. The correlation between the nature of these interactions and structural and electronic parameters of the dications of the two bisquaternary agents is discussed. Interpretation of combined mass spectrometric and calorimetric experimental data led to proposals that the molecular mechanisms of antimicrobial action of bisquaternary ammonium compounds are related to their effect on the membrane phospholipid components of microbial cells.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed2002

Determination of alkyl benzyl and dialkyl dimethyl quaternary ammonium biocides in occupational hygiene and environmental media by liquid chromatography with electrospray ionisation mass spectrometry and tandem mass spectrometry.

A new method for the simultaneous qualitative and quantitative determination of alkyl benzyl and dialkyl quaternary ammonium compounds (QACs) has been developed. Analysis is by reversed-phase high-performance liquid chromatography coupled with electrospray ionisation mass spectrometry. QACs are extremely amenable to the electrospray ionisation technique (limit of detection of BAC C12 homologue 3 ng ml(-1)). The selectivity of mass spectrometric detection allows simultaneous determination of benzyl and dialkyl dimethyl ammonium compounds. The method was successfully applied to the analysis of real samples (occupational hygiene sampling devices, products and swimming pool water). Structural information was obtained by MS-MS and cone voltage ion dissociation techniques. Ion dissociation enabled the structural elucidation of an unknown quaternary ammonium compound present in a commercial formulation.

Chromatography, High Pressure Liquid↗
PubMed1990

Antimicrobial activity of betaine esters, quaternary ammonium amphiphiles which spontaneously hydrolyze into nontoxic components.

A series of quaternary ammonium compounds that are esters of betaine and fatty alcohols with hydrocarbon chain lengths of 10 to 18 carbon atoms were tested with respect to antimicrobial activities and rates of hydrolysis. When the tetradecyl derivative was tested against some selected microorganisms, the killing effect was comparable to that of the stable quaternary ammonium compound cetyltrimethylammonium bromide. At higher pH values, both the antimicrobial effect and the rate of hydrolysis of the esters increased. However, whereas at pH 6 greater than 99.99% killing of Salmonella typhimurium was achieved with 5 micrograms/ml in 3 min, the rate of hydrolysis was less than 20% in 18 h. At pH 7, a similar killing effect was achieved in 2 min and 50% hydrolysis occurred in ca. 5 h. Thus, it is possible to exploit the rapid microbicidal effect of the compounds before they hydrolyze. The rate of hydrolysis was reduced by the presence of salt. The bactericidal effect of the betaine esters increased with the length of the hydrocarbon chain of the fatty alcohol moiety up to 18 carbon atoms. Since the hydrolysis products are normal human metabolites, the hydrolysis property may extend the use of these quaternary ammonium compounds as disinfectants and antiseptics for food and body surfaces.

Bacteria↗
PubMed2006

Efficacy of hospital germicides against adenovirus 8, a common cause of epidemic keratoconjunctivitis in health care facilities.

The inactivation of virus-contaminated nonporous inanimate surfaces was investigated using adenovirus type 8, a common cause of epidemic keratoconjunctivitis. A 10-microl inoculum of adenovirus was placed onto each stainless steel disk (1-cm diameter), and the inoculum was allowed to air dry for 40 min. Twenty-one different germicides (including disinfectants and antiseptics) were selected for this study based on their current uses in health care. After a 1- or 5-minute exposure to 50 microl of the germicide, the virus-germicide test mixture was neutralized and assayed for infectivity. Using an efficacy criterion of a 3-log10 reduction in the titer of virus infectivity and regardless of the virus suspending medium (i.e., hard water, sterile water, and hard water with 5% fetal calf serum), only five disinfectants proved to be effective against the test virus at 1 min: 0.55% ortho-phthalaldehyde, 2.4% glutaraldehyde, 2.65% glutaraldehyde, approximately 6,000 ppm chlorine, and approximately 1,900 ppm chlorine. Four other disinfectants showed effectiveness under four of the five testing conditions: 70% ethanol, 65% ethanol with 0.63% quaternary ammonium compound, 79.6% ethanol with 0.1% quaternary ammonium compound, and 0.2% peracetic acid. Of the germicides suitable for use as an antiseptic, 70% ethanol achieved a 3-log10 reduction under four of the five test conditions. These results emphasize the need for proper selection of germicides for use in disinfecting noncritical surfaces and semicritical medical devices, such as applanation tonometers, in order to prevent outbreaks of epidemic keratoconjunctivitis.

Adenoviridae↗
PubMed1997

Bronchial hyperresponsiveness and exposure in pig farmers.

OBJECTIVE: To study the effect of exposure on bronchial responsiveness in pig farmers. METHOD: A group of 196 pig farmers were tested for lung function and bronchial responsiveness to histamine in the summer of 1992. To achieve sufficient contrast in respiratory morbidity and exposure, 96 of the farmers were selected because they had chronic respiratory symptoms and the remaining 100 because they were free from any respiratory symptoms. Personal exposure to dust, endotoxins and ammonia was measured during 1 working day in the summer of 1991 and 1 day in the winter of 1992. Data on farm characteristics were gathered in the same period. RESULTS: After adjusting for age and smoking behaviour, mild bronchial responsiveness, defined as PC10 < or = 16 mg/ml, was associated with the use of quaternary ammonium compounds as disinfectant [prevalence odds ratio (POR) 6.7, 95% confidence interval (CI) 1.4-32.8], use of wood-shavings as bedding (POR 13.3, CI 1.3-136.7), use of automated dry feeding (POR 2.8, CI 1.0-7.8), use of pellets as feeding material (POR 4.8, CI 1.1-21.1) and location of air exhaust via pit or roof in the confinement units (POR 2.7, CI 1.2-6.3). The association with the use of disinfectants other than quaternary ammonium compounds was not significant (POR 2.4, CI 0.7-8.4). No associations between bronchial responsiveness and measured exposure to dust, endotoxins or ammonia were discernible. CONCLUSION: Protective measures, designed to prevent airway disease in confinement farming, should be based on information about the operational and other characteristics of farms that are related to high exposure and health effects. Specifically, the use of quaternary ammonium compounds as disinfectant, the use of wood-shavings as bedding and the use of automated dry feeding should be discouraged.

Adult↗
PubMed2003

Heme binding contributes to antimalarial activity of bis-quaternary ammoniums.

Quaternary ammonium compounds have received recent attention due to their potent in vivo antimalarial activity based on their ability to inhibit de novo phosphatidylcholine synthesis. Here we show that in addition to this, heme binding significantly contributes to the antimalarial activity of these compounds. For the study, we used a recently synthesized bis-quaternary ammonium compound, T16 (1,12-dodecanemethylene bis[4-methyl-5-ethylthiazolium] diodide), which exhibits potent antimalarial activity (50% inhibitory concentration, approximately 25 nM). Accumulation assays reveal that this compound is readily concentrated several hundredfold (cellular accumulation ratio, approximately 500) into parasitized erythrocytes. Approximately 80% of the drug was shown to be distributed within the parasite, approximately 50% of which was located in the parasite food vacuoles. T16 uptake was affected by anion substitution (permeation increasing in the order Cl(-) < Br(-) = NO(3)(-) < I(-) < SCN(-)) and was sensitive to furosemide-properties similar to substrates of the induced new permeability pathway in infected erythrocytes. Scatchard plot analysis of in situ T16 binding revealed high-affinity and low-affinity binding sites. The high-affinity binding site K(d) was similar to that measured in vitro for T16 and ferriprotoporphyrin IX (FPIX) binding. Significantly, the capacity but not the K(d) of the high-affinity binding site was decreased by reducing the concentration of parasite FPIX. Decreasing the parasite FPIX pool also caused a marked antagonism of T16 antimalarial activity. In addition, T16 was also observed to associate with parasite hemozoin. Binding of T16 to FPIX in the digestive food vacuole is shown to be critical for drug accumulation and antimalarial activity. These data provide additional new mechanisms of antimalarial activity for this promising new class of antimalarial compounds.

Animals↗