Comparison of four decontamination methods for recovery of Mycobacterium avium complex from stools

The presence of Mycobacterium avium complex (MAC) in stool specimens may be a predictor of disseminated MAC infection, yet the methods for decontaminating stools have not been evaluated for their usefulness in recovering MAC organisms. In the present study, four decontamination methods commonly used to recover acid-fast bacteria from respiratory specimens were compared for their utility in recovering MAC from stool specimens. Ten strains of MAC were used at a level of 10(4) to 10(6) CFU to seed the stool specimens. Specimens were divided into four portions and were decontaminated by using the following treatments: (i) N-acetyl-L-cysteine-sodium hydroxide (NALC-NaOH), (ii) cetylpyridinium chloride-sodium chloride (CPC-NaCl), (iii) oxalic acid, or (iv) benzalkonium chloride-trisodium phosphate (BC-TSP). The specimens were then plated onto a total of five pieces of selective and nonselective egg- and agar-based media. The oxalic acid method yielded the greatest number of MAC CFU from seeded stool samples; this was followed by NALC-NaOH, BC-TSP, and CPC-NaCl. The difference between the oxalic acid method and each of the other methods was statistically significant (analysis of variance at the 95% significance level). Although more MAC CFU was recovered from seeded stool samples by using oxalic acid than NALC-NaOH, no difference in culture positivity rates was observed when the two methods were used to test 368 clinical stool specimens processed with either oxalic acid (164 specimens) or NALC-NaOH (204 specimens) (P = 0.07) or 67 specimens processed by both methods (P = 0.77). The oxalic acid and NALC-NaOH decontamination methods both appear to be useful for the recovery of MAC organisms from stool specimens.

Kurloff cell ultrastructure after combined formaldehyde-cetylpyridinium chloride fixation and high-iron diamine staining

This study deals with the ultrastructure of the chondroitin sulphate proteoglycans of the Kurloff body, a large lysosomal organelle that stains metachromatically with Toluidine Blue and which is present in Kurloff cells (a blood cell unique to the guinea pig). Splenic tissues were fixed with 1% cetylpyridinium chloride (CPC) added to 4% paraformaldehyde and examined either after Spicer's high-iron diamine staining for sulphated anionic sites followed by post-fixation with ferrocyanide-osmium tetroxide or after a simple post-fixation with ferrocyanide-osmium tetroxide. CPC-precipitated sulphated sites were preferentially located at the periphery of the Kurloff body but, unexpectedly, were absent in the central matrix. Although their electron opacity was lower, these anionic sites were readily observable in the absence of HID-staining after sole post-fixation by ferrocyanide-reduced osmium. CPC-precipitated sulphated anionic sites were either associated with the myelin figures or constituted unexpected structures. They contained (i) tightly-stacked lamellae, with a very regular 4 nm periodicity, and (ii) groups of 2, 3, 4 short dense lines with a 3-5 nm periodicity. By taking into account the susceptibility of these HID-reactive structures towards chondroitinase ABC, these different sulphated components were assumed to be related to the proteochondroitin-4-sulphate previously characterized as the only major sulphated glycoconjugate of the Kurloff cell. Their colocalization with phospholipidic structures was suggested following observation of sections treated by a chloroform-methanol mixture.

Structural variations of different oral basement membranes revealed by cationic dyes and detergent added to aldehyde fixative solution

The ultrastructural appearance of different types of basement membrane was studied using histochemical methods for visualizing glycosaminoglycans. Samples of rat gingiva and mouse molar germ tissue were fixed either with glutaraldehyde, glutaraldehyde-ruthenium hexammine trichloride (RHT), glutaraldehyde-Cuprolinic Blue (CB) or cetylpyridinium chloride-glutaraldehyde (CPC). Ultrathin sections were stained with uranyl acetate and lead citrate. The results showed that the conventional trilaminar structure of the basement membrane was observed after glutaraldehyde and CB fixation. In contrast, after CPC or RHT fixation, the appearance of the basement membrane was homogeneous without any evidence of a lamina lucida. Furthermore, after single fixation with CPC, the ultrastructure of different basement membranes from oral tissues showed some differences in appearance which were related to their localizations, functions, or both.

Collagen-associated sulphated proteoglycans. Ultrastructure after formaldehyde-cetylpyridinium chloride fixation

In the course of an ultrastructural cytochemical study of intracellular sulphated proteoglycans involving the addition of cetylpyridinium chloride in the primary aldehyde fixative, a remarkable ultrastructural preservation of the collagen-associated sulphated proteoglycans was observed. Together with the preservation of their localization among the collagen fibrils (with, for some of them, a 50 nm periodic association with d-bands) and of their native elongated shape, previously observed under similar technical conditions, these stick-shaped and chondroitinase ABC-sensitive proteoglycans exhibited a typical pattern with several dense longitudinal parallel tracks (periodicity: 3-4 nm) not described as yet. Readily observable without high iron diamine-staining, the morphology of these cetylpyridinium chloride-precipitated and collagen-associated polyanions was particularly enhanced after incubation in the diamine solution which ascertained their sulphate content. Such a common ultrastructural organization with parallel tracks for both intracellular (i.e., in eosinophilic polymorphonuclear cells and Kurloff cells) and extracellular CPC-precipitated sulphated proteoglycans could correspond to intrinsic properties of the complexed molecules and could be related to 'double track' proteoglycans observed under other technical conditions in basement membranes.

Immunogold electron microscopy of soluble proteins: localization of Bet v I major allergen in ultra-thin sections of birch pollen after anhydrous fixation techniques

To localize the highly water-soluble major allergen Bet v I in ultra-thin sections of birch pollen, pollen grains were cracked, air-dried, and processed for electron microscopy using one of the following preparation techniques: fixation in aqueous p-formaldehyde + cetylpyridinium chloride; fixation in p-formaldehyde vapor; fixation in benzoquinone vapor; inert dehydration; or no fixation. Afterwards the pollen grains were embedded in Lowicryl K4M resin at low temperature. Ultra-thin sections were cut and incubated with a monoclonal antibody against Bet v I, followed by a gold-labeled secondary antibody. In some experiments, commercial rabbit IgG antibodies against birth pollen allergens were also used, followed by incubation with the protein A-gold complex. Bet v I could be localized only after vapor fixation and in the inert dehydrated specimens. Best preservation of ultrastructure and antigenicity was obtained after p-formaldehyde vapor fixation. Bet v I antibody binding sites were detected only in the cytoplasmic matrix of the pollen grain, never in the pollen wall. Commercial rabbit antibodies bound to cytoplasm and wall of all prepared specimens, even after aqueous fixation. This might be explained by the assumption that these antibodies recognize a variety of antigenic and allergenic structures, not all of which are so highly soluble as Bet v I.

Determination of nabam fungicide in crops by liquid chromatography with postcolumn reaction detection

The ethylenebisdithiocarbamate (EBDC) fungicide, nabam, was determined in several crop matrixes using liquid chromatography with postcolumn reaction detection. After separation by micellar liquid chromatography, nabam (EBDC sodium salt) was acid hydrolyzed to ethylenediamine and fluorigenically labeled with o-phthalaldehyde-mercaptoethanol (OPA-MERC). Standard curves were linear from the detection limit of ca 1 ng to 1000 ng. Nabam was recovered in high yield (89 plus or minus 7.7%) over a range of concentrations (0.1 to 20 ppm) from fortified samples of papaya, lettuce, cucumber, spinach, and applesauce using a simple extraction method. Efforts to convert the more popular EBDC fungicides, maneb and mancozeb, to nabam are discussed.

Chemical control of plaque

Plaque is generally accepted as the prime agent in the aetiology of gingivitis and caries. However, it has been estimated that the oral microbial load must be reduced by some 99.9% in order to produce a significant effect on plaque formation--and mechanical tooth cleaning alone is unlikely to achieve this. Considerable effort has therefore been put into researching chemical means of controlling plaque. In the final article of this eight-part series, the author reviews the efficacy and modes of action of the chemical agents currently available.

Mechanical devices versus antimicrobial rinses in plaque and gingivitis reduction

The effectiveness of mechanical oral cleaning and oral antimicrobial rinses was compared for gingivitis and bacterial plaque control in 158 subjects. Teeth were brushed ad lib throughout; four of the five groups used either an interdental cleaner, dental floss, an essential oil mouthwash or a cetypyridinium mouthwash. Gingival bleeding (EIBI), visual inflammation (VGI), and tooth plaque coverage were evaluated at zero, six and 12 weeks of product use. After six weeks, bleeding reduction was 42% greater for the interdental cleaner and 21% greater for the dental floss than for the control. All groups showed a further decrease after 12 weeks, but only the 49% reduction of the interdental cleaner was significantly greater than the control. The rinses showed no more reduction in bleeding sites than the control throughout the study. VGI scores were no different from the control for any of the groups. However, the EIBI proved much more sensitive than the visual method finding three times as many inflamed sites. Plaque was reduced by both antimicrobial rinses 27% more than the control over 12 weeks; the interdental cleaner and dental floss groups showed no significant incremental plaque reductions. The results suggest antimicrobial rinses reduce plaque on visible tooth surfaces, but do not penetrate sufficiently between teeth to affect interdental plaque and thus interdental inflammation. However, by disturbing interdental plaque, both dental floss and the interdental cleaner have little effect on visible tooth surface plaque accumulation, yet produce a significant reduction in gingival inflammation.

Visualization of glycosaminoglycans in rat incisor predentin and dentin with cetylpyridinium chloride-glutaraldehyde as fixative

Using cetylpyridinium chloride (CPC) in glutaraldehyde as fixative, we observed sinuous fiber-like structures 300-500 nm long and 7-14 nm thick in the spaces between the collagen fibers of rat incisor predentin. Small granules and fibrils were also detected. Electron-dense vesicles were seen inside the odontoblast processes. The plasma membrane was irregularly stained with material that adhered to its surface. In demineralized dentin, needle-like structures were seen at the periphery of globular structures which were not stained. Staining the sections with Alcian blue did not greatly improve the visualization of CPC-precipitated glycosaminoglycans. The specificity of staining was assessed on serial sections by selective dissociation of glycosaminoglycan aggregates with 2 M calcium chloride and their digestion by bovine testicular hyaluronidase. The glycosaminoglycans were probably combined with lipids, because treatment of the sections with a chloroform/methanol mixture removed the CPC-induced precipitates from both predentin and dentin.

An assay for heparin by decrease in color yield (DECOY) of a protein-dye-binding reaction

The interference by heparin and some related molecules with the well-known Bradford dye-binding assay for proteins is used as the basis of a rapid, sensitive method for the quantitation of these polysaccharides. Whereas the available methods for the assay of glycosaminoglycans have lacked specificity for sulfated polyanions in general and for heparin in particular, the procedure described here distinguishes among different uronic acid derivatives and, when performed in conjunction with heparinase digestion or cetylpyridinium chloride precipitation, can be used to determine heparin content of complex biological samples.

Cetylpyridinium chloride adsorption on the wettability and elemental surface composition of human enamel

To determine the influence of cetylpyridinium chloride (CPC) adsorption on the wettability and elemental surface composition of human enamel, with and without adsorbed salivary constituents, surface-free energies and elemental compositions were determined. The surface-free energies were estimated from contact angle measurements; whereas the elemental compositions were determined by X-ray photoelectron spectroscopy. Surface-free energies of ground and polished enamel (88 +/- 8 mJ.m-2 and saliva-coated enamel (103 +/- 4) became similar (109-112) upon adsorption of CPC. Also, the N/C concentration ratios of the ground and polished enamel surface (0.06) and saliva-coated enamel (0.21) become equal upon CPC adsorption. The N/C concentration ratio after CPC adsorption (N/C = 0.04) corresponds with the value expected on basis of the molecular structure of CPC. The strongest evidence for adsorption of CPC to both ground and polished enamel and saliva-coated enamel is presented by the double nitrogen N1s peak. This double nitrogen1s peak is not observed for ground and polished enamel nor for enamel with a salivary coating on top of adsorbed CPC, which indicates that adsorbed CPC can be completely screened by salivary proteins. This study demonstrates that CPC has a definite capacity to adsorb both on ground and polished enamel as well as on pellicle-coated enamel.

Sodium retention from mouthwashes

Sodium intake from food and other sources must be carefully monitored in patients with hypertension and other disorders. Retention of sodium was measured during routine use of three commercially available, nonprescription mouthwashes: Cepacol, Plax, and Viadent. A test group of 17 adults rinsed with 15 ml of the three mouthwashes, and with 5% saline and distilled water as experiment controls. Sodium not recovered in the expectorate was considered to be retained for absorption by oral or other tissues. The sodium in each product (in mg/l) varied widely: Viadent, 144; Cepacol, 410; and Plax 5320. The analyzed expectorate revealed approximately 33% of the sodium in the 15 ml used for rinsing was retained, amounting to 0.7 mg for Viadent, 1.9 mg for Cepacol, and 28.3 mg for Plax. The results indicate that persons on sodium-restricted diets should be aware that some brands of mouthwash may be a potentially significant source of sodium.

Techniques to preserve soluble surface components in birch pollen wall: a scanning and transmission electron microscopic study

The exine of birch pollen was examined by scanning and transmission electron microscopy in the native state and after fixation in different aqueous fixatives: glutaraldehyde + OsO4; glutaraldehyde + cetylpyridinium chloride (CPC) + OsO4; glutaraldehyde + cuprolinic blue (CB); and periodate + lysine + paraformaldehyde (PLP). The native pollen exine showed a thin (3-5-nm) border of electron-dense material lining the tectum and electron-dense material within microchannels and bacula cavities. Fixation with the addition of CPC resulted in a voluminous surface coat surrounding the pollen grain, but empty microchannels and bacula cavities. After fixation with the addition of CB, there was a thin surface coat, whereas microchannels and bacula cavities were partially filled with electron-dense material. The other fixatives led to empty microchannels and bacula cavities. There was no surface coat on the pollen grain. However, after all fixation procedures, a thin electron-dense border of the tectum remained visible. Concerning the electron-dense material filling microchannels and bacula cavities in the native pollen grain, the results obtained in the present study suggest that it is either completely lost (after conventional and PLP fixation) or, after fixation with a precipitating additive, partially (CB) or completely (CPC) solubilized and precipitated on the surface of the pollen grain as a surface coat.

Diagnostic test for mucopolysaccharidosis. I. Direct method for quantifying excessive urinary glycosaminoglycan excretion

This direct method for quantifying excessive urinary glycosaminoglycan excretion exploits the specific binding of 1,9-dimethylmethylene blue (DMB). The procedure obviates cumbersome and labor-intensive procedures for separating glycosaminoglycans from other constituents of urine. Pediatric pharmaceutical formulations (except heparin), in concentrations expected in urine, do not interfere with spectrophotometry, nor does protein. Results can be expressed in terms of urinary creatinine; thus the test is applicable to very small urine specimens (0.1 mL), such as those obtainable from neonates. In a pilot study, results of the direct DMB test for 48 urine specimens agreed with the clinical diagnosis, and quantitative measurements correlated moderately (r = 0.76) with results of a commonly used procedure (carbazole-borate reactivity after precipitation with cetylpyridinium chloride). The present method was also used to assess metabolic correction in a patient with Hurler's syndrome after treatment by bone-marrow transplantation. This quantitative method surmounts the major technical problems of developing mass screening programs for infants, thus offering the potential for earlier diagnosis and treatment of mucopolysaccharidosis diseases.

Surface charge effects upon membrane transport processes: the effects of surface charge on the monensin-mediated transport of lithium ions through phospholipid bilayers studied by 7Li-NMR spectroscopy

Addition of monensin to preparations of large unilamellar vesicles prepared from egg-yolk phosphatidylcholine (egg PC) or egg PC containing 5% phosphatidylserine (PS-) or cetylpyridinium (CP+) ions in lithium chloride solution allows the transport of Li+ ions to be monitored by an NMR magnetisation transfer technique. The kinetics of the transport are followed as a function of the metal ion and monensin concentrations and are compatible with a model in which one monensin molecule transports one Li+ ion. The data allow the extraction of the rate constants for the association and dissociation of the monensin-Li+ complex in the water/membrane interfaces and the evaluation of the stability constants for complex formation in the interfaces. Placing positive charge (CP+) on the membrane surface reduces the formation rate by a factor of about three but hardly alters the dissociation rate. Placing negative charge (PS-) on the membrane surface hardly alters the formation rate but speeds the dissociation rate by about a factor of three. Data from relaxation times of 7Li+ inside the vesicles and from the total enclosed volumes as the vesicles are formed, point to appreciable Li+ surface interactions that increase as the charge on the surface is made more negative. The size of the vesicles formed by the dialytic detergent removal technique increases with the surface charge. The results support a view that enzyme-phospholipid or substrate-phospholipid interactions could play an important role in determining the efficacity of action of membrane bound enzymes. The relevance of the results in the role of Li+ in the control of manic depression is also discussed.

Influence of cetylpyridinium chloride on the ultrastructural appearance of sulphated glycosaminoglycans in human colonic mucosa

The effect of adding cetylpyridinium chloride to the fixative on the preservation of sulphated glycosaminoglycans (SGs) was studied in human normal colonic mucosa. SGs were visualized at the ultrastructural level through the application of Spicer's High Iron Diamine (HID) technique followed by a post-fixation with potassium ferrocyanide-reduced osmium tetroxide. SGs were mainly localized in basement membranes of epithelium and capillary wall and along collagen fibers. The morphology of the reactive sites depended on the presence of cetylpyridinium chloride, SGs being granular in absence of the salt and more or less elongated when cetylpyridinium chloride was added to the fixative. We suggest that the use of cetylpyridinium chloride during fixation may help to preserve SG molecule at the ultrastructural level.

Infrared spectroscopy of heparin-cation complexes

Hydrated and partially hydrated films and aqueous solutions of heparin, heparans and N-desulphated preparations of these polymers were studied by near- and fundamental-region-i.r. spectroscopy in the presence of a range of countercations. The results suggest that ion binding is not explicable solely in terms of simple electrostatic theory, and that specific cation effects, and the hydration pattern of the polymer-cation complex need to be taken into account.

Use of cationic detergents for polyacrylamide gel electrophoresis in multiphasic buffer systems

An improved system for polyacrylamide gel electrophoresis in the presence of cationic detergents, cetyltrimethylammonium bromide and cetylpyridinium chloride, respectively, is described. An acidic discontinuous buffer system generated according to the theory of multiphasic zone electrophoresis developed by T. M. Jovin (1973, Biochemistry 12, 871-904) was used. It was optimized with respect to the operational conditions and to the desirable range of relative mobility values for the proteins that have molecular weights from 16,500 to 90,300. Also presented is a procedure for the elimination of interference from cationic detergents frequently encountered during staining of gels. The electrophoretic system was suitable for fractionating a wide variety of proteins. The technique can also be used to provide an alternative estimate of molecular weight. To fully account for accurate estimations, the Ferguson relationship between mobility and gel concentration and the relation of molecular weight to mobility at a single gel concentration were both considered. Examples reported in this paper include the separation and/or molecular weight determination of several common proteins, histones, and microfibrillar and myofibrillar proteins. The results suggest that electrophoresis in the presence of cationic detergents offers the same degree of reliability in analysis of most proteins as is provided by the anionic detergent sodium dodecyl sulfate electrophoresis.

Degradation of glycosaminoglycans by extracts of calf vitreous hyalocytes

The ability of extracts of calf vitreous hyalocytes to catalyze the degradation of glycosaminoglycans was studied by incubation with radioactively labeled substrates. The degradation of the polymeric substrates to lower molecular weight products was assayed by three methods: (1) paper chromatographic separation of low molecular weight, mobile digestion products from undigested, high molecular weight material which remains at or near the origin; (2) loss of the ability of the glycosaminoglycan to be precipitated by cetylpyridinium chloride; (3) gel chromatography to separate low molecular weight digestion products, which appear in the retarded volume, from undegraded, high molecular weight material, which is eluted in the void volume. The acidic pH optimum of the reaction suggests a lysosomal origin of the enzyme activity.

Electron microscopic localization of concanavalin A receptor sites in pollen surface material after fixation with glutaraldehyde-cetylpyridinium chloride

Pollen from birch trees (Betula pendula) was fixed in glutaraldehyde containing 0.5% cetylpyridinium chloride (CPC), incubated with concanavalin A (Con A)-ferritin, postfixed in osmium, dehydrated, and embedded in Epon. On ultrathin sections, ferritin particles were observed closely associated with the electron-dense material precipitated by CPC on the surface of the pollen grains. Controls for CPC, which were fixed in glutaraldehyde alone, showed no electron-dense material on the surface. In controls for Con A, which were incubated in Con A-ferritin in the presence of the inhibitory sugar (alpha-methyl-D-mannopyranoside), no ferritin particles were observed. The above-described procedure thus allows the localization of sugar residues in highly soluble pollen wall glycoproteins.

[Molecular organization of pheophytin a in aqueous solutions of detergents]

Absorption, fluorescence and excitation fluorescence spectra of pheophytin a have been measured in aqueous solutions of nonionic (Triton X-100), anionic (sodium lauryl sulphate) and cationic (Cetyl pyridinium chloride) detergents at different concentrations and pH after system relaxation. By measuring the second derivative and differential spectra, it has been shown, that if detergent concentrations are lower than critical micelles concentration, or if the detergent is completely absent, the pigment forms conglomerates containing both dimeric and monomeric forms with an efficient energy transfer between them. If detergent concentrations are higher than critical micelles concentration, pheophytin a localizes in detergent micelle in monomeric form at neutral and acidic pH, and allomerizes at alkaline pH. The spectral characteristics of pheophytin a dimers in the conglomerate and its monomers in micelles poorly (if at all) depend on the sign of the detergent molecule charge.

Ultrastructural demonstration of a glycoproteinic surface coat in allergenic pollen grains by combined cetylpyridinium chloride precipitation and silver proteinate staining

In allergenic birch pollen grains, highly watersoluble surface substances were precipitated by the cationic detergent cetylpyridinium chloride (CPC) during aqueous fixation. After processing the pollen for electron microscopy, ultrathin sections of pollen grains were subjected to the periodic acid - thiocarbohydrazide - silver proteinate (PA-TCH-SP) procedure according to Thiery (1967) for the detection of vicinal glycol groups. It was found that the material precipitated by CPC on the surface and within the exine cavities of the pollen wall strongly reacted with the PA-TCH-SP reagent thus indicating the presence of polysaccharides on the surface of birch pollen grains. In samples which had not been treated with the cationic detergent, PA-TCH-SP reactivity was reduced to thin linings on the surface and within the exine cavities. In both cases the exine proper did not stain whereas the intine showed moderate staining. Within the aperture region of the intine, PA-TCH-SP reactivity is preferably associated with fibrillar or reticular structures. The results are discussed with special reference to biochemical findings on allergenic birch pollen proteins.

Concentrated, digestible DNA after hydroxylapatite chromatography with cetylpyridinium bromide precipitation

A method for the direct extraction of the DNA from the unfavorable phosphate eluant of hydroxylapatite chromatography is described. The DNA--reversibly precipitated with the cationic detergent cetylpyridinium bromide--can be subjected to further enzymatic manipulations within minutes. This method is applied to the rapid separation of pBR322 plasmid from the chromosomal DNA.

Polysaccharide localization, coccolith formation, and Golgi dynamics in the coccolithophorid Hymenomonas carterae

The periodic acid-thiocarbohydrazide-silver proteinate staining technique according to Thiéry (1967) was employed for visualization of the ultrastructural localization of polysaccharides in the coccolithophorid alga Hymenomonas carterae . Preferential staining was observed in the Golgi apparatus, including constituents and precursors of "scales" and " coccoliths " (scales with a rim of elaborate CaCO3 crystals), which are extruded and become part of the cell wall. Cells fixed in the presence of the polyanion-precipitating agent cetylpyridiniumchloride showed a voluminous coat over the crystalline matter of the coccolith giving the extracellular coccoliths the appearance of being glued together. Soluble acid polysaccharides are thought to occur in the coat. Evidence is presented that the coat and the crystalline matter are produced simultaneously. The excellent stainability of the Golgi apparatus allowed study of its morphology in considerable detail, and permitted a tentative reconstruction of the formation of coccoliths and scales and of the Golgi dynamics in general. The question of whether Golgi cisternae are mobile or static entities is dealt with.

Nuclear localization of lactoferrin in the human granulocyte: Artifact incurred during slide preparation

Within the blood cells, lactoferrin is found only in the late stage neutrophilic granulocytes. Lactoferrin first appears in these cells during the myelocyte stage of development coincidentally with the specific or secondary granules. Most investigators report a cytoplasmic immunocytochemical localization reaction within the granulocyte. However, others have observed a prominent nuclear localization reaction. Treating the cells with certain fixatives was shown to prevent the relocation of lactoferrin from the cytoplasm to the nucleus when the localization was done on granulocytes prepared by smearing. The present study demonstrated that the relocation of lactoferrin is only a problem when cells were smeared or cytocentrifuged onto slides or fractionated for the purpose of isolating cellular organelles. Under these conditions the selection of fixative is an important consideration. Exposing isolated lactoferrin to a fixative effective in retaining lactoferrin in the cytoplasm of granulocytes smeared on slides did not alter a number of its physical properties. The results suggest that maintenance of the normal cytoarchitecture or effect of fixative on other cellular components prevents the relocation of lactoferrin within the cell during tissue processing and the direct action of fixation on lactoferrin is probably not responsible for this effect.

Laser nephelometric determination of glycosaminoglycans--method and application

Light scattering due to the formation of insoluble complexes between the long-chain quaternary ammonium salt N-cetylpyridinium chloride and glycosaminoglycans was utilized for a relative simple, sensitive and precise determination of total and specific types of glycosaminoglycans by laser nephelometry. The addition of the ammonium salt to solutions of various glycosaminoglycans in 0.03 mol/l NaCl produces a time-dependent increase in light scattering, which reaches a maximum between 14 and 18 h of complex formation, irrespective of the type of glycosaminoglycan studied. Only keratan sulphate does not generate light scattering, and is therefore not detectable by the procedure. The scattering of laser light by certain types of sulphated glycosaminoglycans (e.g. heparan sulphate, heparin) depends more on the degree of sulphation (charge density) than on chain length within a certain range. Optimum light scattering was found at 28 mmol/l N-cetylpyridinium chloride and at a ionic strength around 0.03 mol/l NaCl. The detection limits and linear ranges of the individual glycosaminoglycans were evaluated. For the determination of chondroitin sulphate, laser nephelometry is at least 8 times more sensitive and much more simple than the modified carbazole method (glucuronic acid). The intra-assay and inter-assay coefficients of variation are about 4% and 7%, respectively. Laser nephelometry is much more sensitive than turbidimetry. Complex synthetic mixtures of glycosaminoglycans and biological fluids were accurately differentiated by successive chemical and enzymatic degradation of the respective glycosaminoglycans followed by the measurement of the resulting reduction of laser light scattering. In synovial fluids from non-inflammatory joint diseases, light scattering (units/ml) was about 4.5 times higher than in synovial fluids from inflammatory articular lesions. In both pathologic conditions nearly all of the light scattering can be attributed to hyaluronic acid.

Distribution of polyanionic sites in the developing gonads and the dorsal mesentery of the chick embryo

The distribution of glycoconjugates was investigated in the embryonic trunk mesoderm used as a substrate by migrating primordial germ cells (PGCs) by means of ultrastructural cytochemistry. In both mesentery and developing gonads polyanionic sites were abundant in epithelial and mesenchymal cell coats, basal laminae, and extracellular matrices (ECM). In the latter, polyanions distributed on microfibrils and granules were associated with collagen fibers, forming an entangled network. No preferential association of this fibrillo-granular material with PGCs was observed, suggesting that polyanions present in ECM likely act by promoting inflation of the extracellular spaces rather than by providing mechanical guides for the moving cells.

An ultrastructural study of histochemical staining of complex carbohydrates in the mouse posterior vitreous body

The vitreous body contains complex carbohydrates that can be demonstrated morphologically. Vitreous hyaluronic acid is very soluble but it can be precipitated by cetylpyridinium chloride (CPC) while being cross-linked by glutaraldehyde. Oligosaccharide chains of vitreous glycoproteins are fixed with glutaraldehyde alone. Mouse eyes were fixed with glutaraldehyde or glutaraldehyde and CPC and the complex carbohydrates of the posterior vitreous cortex were studied by electron microscopy. Cationic dyes were used in the fixative or for block-staining on most fixed tissue blocks to allow detailed observations of complex carbohydrates. Most blocks were postfixed with OsO4. The hyaluronic-acid domain on vitreous collagen fibrils sequentially contracted and expanded in size with various histochemical manipulations. Contraction of the domain of hyaluronic acid generally indicates an increased charge density. OsO4 contributes considerable charge density upon forming osmate esters, but tissue postfixed with OsO4 contained large globular forms of hyaluronic acid rather than the small globules observed in non-osmicated preparations. A model is proposed to explain the seemingly paradoxical findings by reference to suggested mechanisms of polysaccharide-ligand-OsO4 interactions.

A study of glycosaminoglycan excretion in normal and stone-forming subjects using a modified cetylpyridinium chloride technique

Precipitation with cetylpyridinium chloride followed by hexuronic acid assay has been used to study glycosaminoglycan excretion in normal subjects and calcium stone formers. It was found necessary to concentrate dilute urines prior to assay to achieve satisfactory precipitation of the glycosaminoglycans. No significant differences in daily glycosaminoglycan excretion were detected between normal and stone-forming subjects.

Measurement of serum glycosaminoglycans by laser nephelometry

A simple, sensitive micromethod for the assay of serum hyaluronic acid and chondroitin sulphates is presented. The method is based on the binding of the quaternary ammonium salt, cetylpyridinium chloride (CPC) to serum polyanions, and quantitation of the complexes by laser nephelometry. Measurement of the CPC complexes in serum before and after digestion with specific enzymes enables quantitation of hyaluronic acid and chondroitin sulphates in less than 100 microliters serum. Using this technique, hyaluronic acid is detectable in a small number of normal human sera at concentrations up to 4 mg/l, and chondroitin sulphates are consistently present at concentrations ranging from 2 to 25 mg/l.

Surface coat material associated with the cells of the developing lens vesicle in the chick embryo

Ruthenium red (RR) and cetylpyridinium chloride (CPC) were used to demonstrate the distribution of cell surface coat material (SCM) on the free epithelial surface of the developing lens vesicle in stages 14-17 (50-64 hours) chick embryos. Observations were made by light microscopy and transmission. (TEM) and scanning (SEM) electron microscopy. A progressive increase in SCM is observed on cellular apices within the epithelium of the lens vesicle by means of RR staining, particularly at the margins of the aperture which are the sites of presumptive fusion. In contrast, a relatively thin layer of SCM persist on the adjacent surface ectoderm. Ruthenium red-positive SCM extends across the aperture of the lens vesicle prior to initial contact between the advancing epithelial surfaces. The presence of abundant SCM is interpreted as a possible significant prerequisite to invagination and to epithelial adhesion and fusion prior to detachment of the lens from surface ectoderm. When CPC is added to the fixative, a flocculent precipitate over the aperture of the lens vesicle and an associated band of modified surface ectoderm which extends ventrally from its lower margin are observed. The modified ectoderm and associated SCM likely represent a presumptive region of active coordinated cellular migration.

The use of polymethylmethacrylate to compare the adsorption and staining reactions of some cationic antiseptics

This study assessed the value of acrylic, in powder and optically clear forms, to measure the adsorption and staining properties of some cationic antiseptics. The uptake of chlorhexidine gluconate, chlorhexidine acetate, alexidine and cetyl pyridinium chloride onto acrylic powder was measured spectrophotometrically. Similarly, tea staining of perspex blocks exposed twice daily to the antiseptics and hexetidine, was measured over a 5 day period. The adsorption of chlorhexidine gluconate and acetate was similar and greater than alexidine but less than cetyl pyridinium chloride. Desorption of the adsorbed antiseptics was minimal after 48 hours soaking in water. Acid produced a variable desorption of antiseptics. Tea staining of blocks was significantly greater with antiseptic treated specimens compared to control specimens. However, staining resulting from alexidine was greater than cetyl pyridinium chloride which was greater than chlorhexidine. Hexetidine produced the least staining. Saliva treatment of specimens only increased the tea staining of control blocks. The results indicated that adsorption levels alone would not explain the differences in antiplaque and staining activity reported for the cationic antiseptics.

Selective inactivation of lactate dehydrogenase isoenzymes with ionic surfactants

Ionic surfactants selectively inactivate porcine lactate dehydrogenase (LDH) isoenzymes in 30 mM phosphate buffer, pH 7.4. The cationic surfactants hexadecylpyridinium bromide and hexadecyltrimethylammonium bromide rapidly inactivate LDH isoenzymes containing the B subunit; inactivation of LDH-A4 is slower and also retarded by the cofactor reduced nicotinamide adenine dinucleotide. The anionic surfactants sodium decyl sulfate and sodium dodecyl sulfate rapidly inactivate LDH isoenzymes containing the A subunit; inactivation of LDH-B4 is much slower and retarded by the cofactor. The selectivity of the inactivation process correlates with electrostatic interactions: positively charged surfactants preferentially inactivate isoenzymes containing a subunit of net negative charge, and negatively charged surfactants preferentially inactivate isoenzymes containing a subunit of net positive charge. Inactivation takes place near the critical micelle concentration for the cationic surfactants. Inactivation with anionic surfactants occurs above the critical micelle concentration. The cationic surfactants show little discrimination among LDH-B4 and the hybrid isoenzymes, AB3, A2B2, and A3B, inactivating all at approximately the same surfactant concentration. The anionic surfactants, however, show a more graded inactivation-concentration profile with discrete differences in threshold surfactant concentrations required for complete inactivation of the four A subunit containing isoenzymes. At a particular surfactant concentration, loss in activity can be correlated with the percent A- or B-subunit composition of the isoenzyme.

[New progress in detection of antigens from human ejaculate in relationship with human sterility (extraction with N-cetylpyridinium chloride) (author's transl)]

In an attempt to obtain certain sub-surface spermatozoa antigens, human spermatozoa were treated with N-cetylpyridinium chloride in basic buffer, The extract was further ultrasonated and separated with gel chromatography over a Sephadex--G--100 column. The obtained fractions were lyophilized and tested against human sperm agglutinating and sperm immobilizing sera, in order to detect their antigenicity. Positive and negative controls revealed intensive precipitations and no precipitations respectively. Fraction A4 reacted intensively with sperm immobilizing sera. The final objectives of these sperm antigens solubilization studies are twofold. On the one hand we are looking for a method to lower sperm antibodies titres in sterile females, and on the other hand we are seeking an immunological contraceptive method.

The metabolism of 3-chloro-4-fluoro-aniline in dog and rat

1. 3-Chloro-4-fluorol[14C]aniline, orally administered to a female dog (0.135 mg/kg), was eliminated in the urine as 2-amino-4-chloro-5-fluorophenyl sulphate (83% in 48 h). 2. When 3-chloro-4-fluoro[14C]aniline was administered orally to male rats (ca 2.3 mg/kg), the 0-24 h urine contained 2-amino-4-chloro-5-fluorophenyl sulphate (52% of the aniline dosed), N-(5-chloro-4-fluoro-2-hydroxyphenyl)acetamide (13%) and an unidentified metabolite (16%). 3. 2-Amino-4-chloro-5-fluorophenyl sulphate was identified after extraction as salts by proton and fluorine-19 magnetic resonance spectroscopy. N-(5-Chloro-4-fluoro-2-hydroxyphenyl)acetamide was identified by mass spectrometry and proton magnetic resonance spectroscopy.

A modified phenylfluorone method for determining organotin compounds in the ppb and sub-ppb range

The phenylfluorone method for tin analysis has been modified to be specific for organotin samples in the ppb and sub-ppb range (4-.1 micrograms of tin). Two extractions of an aqueous solution containing bis (tri-n-butyltin) oxide (TBTO) and tin sulfate yield results which are quantitative for TBTO without interference from the tin sulfate. The extracts are wet oxidized with hydrogen peroxide and sulfuric acid. The tin is determined from its lambda max near 530 nm through its complex with 2,6,7-trihydroxy-9-phenylisoxanthane-3-one (phenylfluorone) in the presence of cetyltrimethylammonium bromide. A Beer Lambert plot is obtained in the range of 0.1 to 7.0 micrograms of tin/sample with slope of 0.0344 with a correlation coefficient of greater than 0.990. The method has been successfully used to analyze over 400 environmental samples.

Metabolic activity of articular cartilage in osteoarthritis. An in vitro study

Biochemical changes and in vitro rates of glycosaminoglycan synthesis were studied in thirty-seven samples of human articular cartilage from nineteen osteoarthritic and four normal control patients who were fifty to seventy-five years old. The samples were compared on the basis of histological grade of the arthritis, and subgroups based on the duration of disease, synovial pathological changes, joint studied, and sex were also compared. The osteoarthritic samples showed a progressive loss of glycosaminoglycans in the cartilage as the histological grade increased. In the early stages of the disease there was an increase in the chondroitin sulphate content as well as in the rate of glycosaminoglycan synthesis in several cases when the values for the osteoarthritic articular-cartilage samples were compared with those for the age-matched controls. In the late stages there was a progressive decrease in the rate of glycosaminoglycan synthesis and a relative decrease in chrondroitin sulphate synthesis compared with keratan sulphate synthesis, and these decreases were highly correlated with the histological grade.

Evaluation of the chloride and bromide salts of cetylpyridium for the transportation of sputum in tuberculosis bacteriology

The usefulness of cetylpyridium chloride and cetylpyridium bromide, at a final concentration of 1% in 1% solution of sodium chloride, for the transportation of sputum in tuberculosis bacteriology, was evaluated. It was found that these compounds did not alter the staining properties nor the viability of the tubercle bacilli for at least 14 days.

Use of athrombogenic tubing for perfusion rewarming following surface-induced deep hypothermia

A method of heparinless, oxygenatorless, left heart bypass perfusion rewarming following surface hypothermia, with the use of a closed circuit with 130 ml. prime volume including heat exchanger, has been devised. The use of polyurethane-polyvinyl-graphite (PPG)-coated tubing has previously been reported. In this text, the use of an athrombogenic coating with cetyl-pyridinium chloride (CPC) as a regional heparin carrier was studied in dogs, comparing groups with PPG tubing and total systemic heparinization or plain polyvinyl tubing without systemic heparinization. Heparin compounded in the CPC coating eluted into the blood and caused mild transient whole-body heparinization during rewarming from 20 degrees to 25 degrees C., as evidenced by prolongation of the thrombin time. Alterations of hematologic parameters in all three groups were similar to those during surface rewarming except for those affected by heparinization. The left heart bypass method was found useful for hypothermic open-heart surgery when utilized with an athrombogenic surface coating or total body heparinization. It was concluded that the CPC coating is superior to the PPG coating since no cracking surface develops, it is translucent, and it provides a more effective athrombogenic surface.

CPC-PTA section staining of acid glycans

A cetylpyridinium chloride-phosphotungstic acid procedure suggested by Kelényi and Kiss (1976) for the staining of mast cell granules in ultrathin sections was slightly modified with regard to pretreatment, pH of incubation, and rinsing of sections. The method also proved suitable for the demonstration of various mucosubstances and of cartilage proteoglycan aggrebates.