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At least 199 records · Page 11Linked to original sources
PubMed1979

Acyl-CoA reductase specificity and synthesis of wax esters in mouse preputial gland tumors.

Long-chain alcohols are synthesized in the mouse preputial gland tumor (ESR-586) by NADPH:acyl-CoA oxidoreductase. In this study, a series of labeled acids was tested as substrates for the oxidoreductase in a cell-free system from the tumor, and the distribution of label into alcohols, waxes, and other products was determined. The system contained the labeled acid, an acyl-CoA-generating system, an NADPH-generating system, and tumor homogenate. The highest rates of alcohol synthesis were obtained with palmitic (16:0), heptadecanoic (17:0), stearic (18:0), myristic (14:0), elaidic (18:1 trans), and linoleic (18:2) acids, which yielded, respectively, 151, 124, 102, 76, 65, and 35 pmol alcohol/min per mg protein. Decanoic (10:0), lauric (12:0), oleic (18:1 cis), linolenic (18:3), arachidonic (20:4), and behenic (22:0) acids all gave lower activities. Acyl-CoA formation did not appear to be rate limiting with any of the substrates tested except behenic acid. In addition to the fatty alcohol product, a small amount of fatty aldehyde was formed in the system. Incorporation of the labeled fatty acids into wax esters was examined and the distribution of label between the alcohol and acid components of the waxes was determined. Incubation of [1-(14)C]palmitic acid yielded 3.4% free alcohol, 8.3% alcohol esterified in waxes, and 7.7% palmitoyl groups esterified into waxes, whereas, at the other extreme, [1-(14)C]linolenic acid yielded 0.8%, 0.6%, and 38%, respectively, into the homologous components.-Wykle, R. L., B. Malone, and F. Snyder. Acyl-CoA reductase specificity and synthesis of wax esters in mouse preputial gland tumors.

Animals↗
PubMed1996

Oleyl Oleate and Homologous Wax Esters Synthesized Coordinately from Oleic Acid by Acinetobacter and Coryneform Strains

Newly isolated Acinetobacter (NRRL B-14920, B-14921, B-14923) and coryneform (NRRL B-14922) strains accumulated oleyl oleate and homologous liquid wax esters (C30:2-C36:2) in culture broths. Diunsaturated oleyl oleate preponderated in 75 mg liquid wax esters (280 mg lipid extract) recovered from 100-ml cultures of Acinetobacter B-14920 supplemented with 810 mg oleic acid-oleyl alcohol. With soybean oil instead of oleic acid, wax esters (260 mg) were increased to approximately 50% of the lipid extract. Production of wax esters by cultures supplemented with combined fatty (C8-C18) alcohols and acids suggests a coordinated synthesis whereby the exogenous alcohol remains unaltered, and the fatty acid is partially oxidized with removal of C2 units before esterification. Consequently, C8-C18 primary alcohols control chain lengths of the wax esters. Exogenous fatty acids are presumed to enter an intracellular oxidation pool from which is produced a homologous series of liquid wax esters.

Journal Article↗
PubMed2001

Host finding and oviposition behavior in a chrysomelid specialist--the importance of host plant surface waxes.

Although several studies have elucidated the role of plant epicuticular waxes in host recognition and oviposition by herbivorous insects, there is little known about this subject in Chrysomelidae. In the present study, chemical cues for host recognition behavior and oviposition by the monophagous chrysomelid species Cassida stigmatica were investigated with special regard to surface waxes of the host plant. Tanacetum vulgare (Asteraceae). After hibernation in the soil, adults of this species must climb the plant's petioles, which emerge from the ground in spring. The response of adult C. stigmatica to contact and volatile cues from petioles and leaves of T. vulgare was investigated in a "stem arena," in which differently treated petioles and petiole dummies were offered. Volatile and contact cues of T. vulgare petioles served as well for host recognition. The contact cues were isolated from the petioles and leaves by hexane extraction and by cellulose acetate treatment, which removed cuticular waxes. The attractive volatiles were not extracted sufficiently by hexane. To examine the role of cuticular waxes of the host leaf surface in oviposition, female C. stigmatica were offered intact leaflets and leaflets from which cuticular waxes had been stripped by cellulose acetate treatment. Females did not discriminate between intact and stripped leaflets when only the upper leaf surfaces were offered. However. when the lower leaf surfaces that are generally used as oviposition sites were offered, C. stigmatica preferred to lay eggs on intact leaflets. We conclude that waxes of the lower leaf surface contain crucial information for oviposition in C. stigmatica.

Animals↗
PubMed2002

Oviposition responses by hessian fly, Mayetiola destructor, to wheats varying in surfaces waxes.

Leaf waxes are known to contain oviposition stimulants for Hessian fly. In dual-choice tests comparing seedlings of each of three nonglaucous lines of wheat with its corresponding glaucous line, Hessian flies laid similar numbers of eggs on each genotype. However, when plants from these genotypes were tested at the flag-leaf stage. Hessian flies deposited 25-100% more eggs on the nonglaucous genotype compared to normal wax genotype in each pair. Leaf waxes extracted from the genotypes in one of these pairs (Avalon and nonglaucous Avalon) at the seedling and the flag-leaf stage and tested on paper leaf models elicited oviposition responses similar to those observed on the intact plants. Scanning electron microscopy showed differences in crystal density on nonglaucous and glaucous genotypes only at the flag-leaf stage. Gas chromatography-mass spectrometry of the leaf wax extracts showed that fly oviposition responses were associated with differences in the chemical composition of the waxes. This is the first report of Hessian fly oviposition responses varying among genotypes of wheat with different surface wax composition.

Animals↗
PubMed2003

Effect of wax epilation before hair removal with a long-pulsed alexandrite laser: a pilot study.

BACKGROUND: Recent reports indicate that laser hair removal is most effective on anagen hairs. However, no published trials have examined laser epilation after hair cycle synchronization. OBJECTIVE: To evaluate the potential for enhanced laser hair removal after the induction of telogen hairs into anagen by wax epilation. METHODS: We identified four 2.5-cm square areas with equivalent hair length and density on the backs of 13 dark-haired white men. To induce typically telogen hairs into anagen, two areas on each patient were wax epilated. Two weeks later, one waxed area and one unwaxed area were treated with a long-pulsed alexandrite laser. One month after laser treatment, a subjective comparison was made based on hair density, length, and thickness. RESULTS: In 12 of 13 patients, lasered areas that had been pretreated with wax epilation were clearer of hair as compared with areas that had been pretreated by shaving (P=0.0034). No significant difference was noted between waxed and unwaxed control areas that had not been laser treated (P=1.0). CONCLUSION: Wax epilation 2 weeks before laser hair removal improves cosmetic outcomes at 1 month. This effect may be secondary to the recruitment and heightened sensitivity of early anagen hairs.

Adult↗
PubMed1988

Comb wax mediates the acquisition of nest-mate recognition cues in honey bees.

Honey bees, Apis mellifera, acquire nest-mate recognition cues from wax, the predominant material used in nest construction. Exposure of a newly emerged worker bee to wax-comb substrate significantly reduced the acceptability of that worker to sister bees. Cues acquired from the comb provided colony-specific information about the identity of worker bees; moreover, the effect of comb exposure has been previously shown to override individually produced cues. Food odors (anise oil), when dissolved in paraffin wax, affected worker-recognition characteristics but food odors did not affect these characteristics when fed to bees in sugar candy. Paraffin wax alone did not affect the recognition cues of bees, showing that the wax can be a neutral medium for the transmission of cues. The wax comb in the colony and the hydrocarbon outer layer of the bee cuticle may be a continuous medium for any hydrocarbon-soluble substances used by honey bees in nest-mate recognition; if so, a mechanism by which environmental cues are acquired by honey bees is provided.

Journal Article↗
PubMed1955

Studies on antibody production. IV. The role of a wax fraction of Mycobacterium tuberculosis in adjuvant emulsions on the production of antibody to egg albumin.

After injection of ovalbumin as a water-in-oil emulsion a pronounced adjuvant effect is demonstrable following the incorporation of tubercle bacillary wax into the oily phase of the mixture. With single doses of antigen (10 mg. ovalbumin) there is a 4- to 5-fold increase in the amount of antibody at the median of 3 week serum levels in animals receiving a small dose of wax (40 microg.). With a 5 mg. dose of wax there is an 8-fold increase in serum antibody levels at the median. A striking feature of the action of wax is the stimulation of a macrophage proliferation locally at the site of injection, and the production of morphological abnormalities in these cells. As judged by staining techniques for antibody content, these locally assembled cells are not active in the formation of antibody. Wax injected in mineral oil results in a remarkable systematized stimulation of the reticulo-endothelial system. The greatly increased serum antibody levels demonstrated after the use of tubercle bacillary wax in antigen mixtures is attributed to a widespread proliferation of plasma cell elements in the lymphatic glands, spleen and liver.

Adjuvants, Immunologic↗
PubMed1990

Ear wax removal: a survey of current practice.

OBJECTIVE: To determine the methods of removing ear wax used by local general practitioners and the incidence of associated complications. DESIGN: Postal survey of 312 general practitioners serving a population of about 650,000; supplementary study of ear, nose, and throat outpatients to quantify the improvement in aural acuity after wax removal. SETTING: Catchment area of the Edinburgh otolaryngological unit. PARTICIPANTS: 289 General practitioners who responded to the survey; 21 outpatients in the ear, nose, and throat department with occlusive wax. RESULTS: 274 General practitioners removed wax by syringing, but only 53 (19%) always performed the procedure themselves; the remainder routinely delegated the task to practice nurses, some of whom had received no instruction. Ears were rarely examined again after the procedure. Complications had been experienced by 105 practitioners (38%) and included perforation, canal lacerations, and failure of wax removal. The removal of occlusive wax improved hearing by a mean of 5 dB over the frequencies analysed. CONCLUSIONS: About 44,000 ears are syringed each year in the area and complications requiring specialist referral are estimated to occur in 1/1000 ears syringed. The incidence of complications could be reduced by a greater awareness of the potential hazards, increased instruction of personnel, and more careful selection of patients.

Cerumen↗
PubMed1994

Immunohistochemical demonstration of c-erbB-2 oncoprotein in gastric adenocarcinoma: comparison of cryostat and paraffin wax sections and effect of fixation.

AIMS: To investigate the effects of fixation on the immunohistochemical demonstration of c-erbB-2 oncoprotein using paraffin wax and cryostat sections; to compare c-erbB-2 expression in non-neoplastic and neoplastic gastric tissues. METHODS: Adjacent blocks of tumour and non-neoplastic tissue from four gastrectomy specimens were put into a panel of 10 fixatives including acetone, B5, Bouin's fluid, Carnoy's fluid, buffered formalin, formol dichromate, zinc formalin, 4% paraformaldehyde, periodate-lysine-paraformaldehyde (PLP) and periodate-lysine-paraformaldehyde-dichromate (PLPD) before embedding in paraffin wax for sectioning. Similar tissue blocks were snap frozen and cryostat sections were postfixed in these fixatives, either alone or in combination, before immunostaining. RESULTS: In paraffin wax embedded sections the best fixative was PLP, and in frozen tissues the best results were obtained after fixation of cryostat sections in buffered formalin followed by cold methanol and acetone. Applying these fixatives to samples from a further 16 gastrectomy specimens, strong membrane staining of c-erbB-2 protein was found in the tumour in eight of 16 cases (50%) using paraffin wax sections, and staining was stronger in the better differentiated carcinomas. For frozen tissues, positive membrane staining was found in all gastric adenocarcinomas, but differential staining intensity associated with tumour differentiation could not be detected. CONCLUSIONS: These results indicate that fixation and paraffin wax embedding affect the results of immunohistochemical demonstration of c-erbB-2 in gastric cancer. The choice of fixative is critical in the demonstration and evaluation of c-erbB-2 protein expression by immunohistochemistry in gastric carcinomas. Staining results also vary depending on whether frozen or paraffin wax embedded tissues are studied.

Adenocarcinoma↗
PubMed1998

The effect of wax on compaction of microcrystalline cellulose beads made by extrusion and spheronization.

The effect of wax on the deformation behavior and compression characteristics of microcrystalline cellulose (Avicel PH-101) and acetaminophen (APAP) beads is described. Beads of Avicel PH-101 and APAP formulations were prepared using extrusion and spheronization technology. A waxy material, glyceryl behenate, N.F. (Compritol), was added to the formulations in amounts ranging from 10% to 70% of total solid weight. Beads with a selected particle size range of 16-30 mesh were compressed with an instrumented single punch Manesty F press utilizing a 7/16-in. flat-faced tooling set. Compaction profiles were generated for the tablets to evaluate the effect of wax on the densification of beads containing wax. Beads made without wax (the control formulation) required greater compression forces to form cohesive tablets. As the amount of wax in the bead formulation was increased, the beads become more plastic and compressible. The Heckel equation which relates densification to compression pressure was used to evaluate the deformation mechanisms of the bead formulations. The analysis shows that as the level of wax in the bead formulation is increased, the yield pressure decreases, indicating that the beads densify by a plastic deformation mechanism.

Acetaminophen↗
PubMed1990

Immunohistochemical detection of DNA replication in mouse uterine cells by bromodeoxyuridine labeling of wax- and resin-embedded tissue sections.

To apply the bromodeoxyuridine (BrdU) labeling method using a monoclonal antibody to the study of cell proliferation in the mouse uterus, methods of fixation and embedding of tissues and of immunofluorescent staining were compared in terms of the rate of detection of labeled cells and specificity and stability of fluorescence obtained. BrdU was administered intravenously 2 hr before death and uterine blocks were embedded in polyester wax and Technovit resin after fixation in formalin and periodate-lysine-paraformaldehyde, respectively. The indirect method with anti-BrdU and fluorescein isothiocyanate (FITC) conjugated antimouse IgG antisera and the direct method with FITC conjugated anti-BrdU antibody were applied to both wax- and resin-embedded sections. Labeled and total cells were counted in luminal and glandular epithelia and stomata adjoining them. Counterstaining with hematoxylin for counting total cells produced intense fluorescence over the whole of resin sections and made counting of labeled cells impossible. On wax sections, on the other hand, the results were satisfactory, although the number of labeled cells detected was decreased slightly. In wax sections fluorescence due to nuclear incorporation of BrdU in the indirect method could be easily distinguished from the cytoplasmic or extracellular emission seen in some cells by its location and characteristic color. In resin sections, however, more careful observation was needed since the second antibody used in the indirect method cross-reacted with IgG in eosinophils and produced cytoplasmic fluorescence of the same color. By the indirect method greater numbers of labeled cells were detected in wax sections than in resin sections. The difference was distinct in tissues with extensive cell proliferation. By the direct method the fluorescence obtained was weaker and apt to fade more quickly than that obtained by the indirect method; use of the direct method reduced the number of labeled cells detected in both wax- and resin-embedded sections.

Animals↗
PubMedDate not supplied

Determination of benzene in polypropylene food-packaging materials and food-contact paraffin waxes.

An analytical procedure was developed for determination of benzene in polypropylene food packaging and was adapted for determination of benzene in commercial paraffin waxes intended for food-contact use. The polymer was dissolved in hexadecane at 150 degrees C. The wax was melted in an 80 degrees C oven. A simple helium-sparging apparatus was used to remove the volatile chemical from the polymer or wax. The contaminant was collected in methanol, distilled water was added, and the resulting solution was analyzed by headspace gas chromatography. The instrument was equipped with a 30 m fused silica open tubular capillary column and a photoionization detector. Average recoveries of benzene from polymer and paraffin wax at low parts-per-billion concentrations were 63 and 70%, respectively. Limits of detection and quantitation for analysis of polypropylene were 8 and 17 ppb, respectively; the limit of quantitation for analysis of paraffin wax was 2 ppb. In several commercial polypropylene products examined, benzene levels ranged from none detected to 426 ppb. In 3 commercial waxes examined, concentrations of 16-73 ppb benzene were determined. The presence of benzene was confirmed by gas chromatography/mass spectrometry.

Benzene↗
PubMed1977

Comparison of the mode of immunopotentiating action of BCG and wax D. II. Effect on the methylcholanthrene carcinogenesis.

The effects of BCG and wax D on methylcholanthrene (MCA) carcinogenesis in mice were studied. BCG given 8 weeks after MCA administration conferred a significant protection against carcinogenesis. When given either on the same day as MCA injection or 4 weeks after MCA, BCG slightly increased tumor incidence. Wax D provided a marked protection against tumor development when given 4 weeks after MCA. An enhanced tumor development was obtained, when wax D was administered either on the day of MCA injection or 8 weeks after MCA. These results indicated that the effects of BCG and wax D on MCA carcinogenesis varied with the timing of administration. When BCG and wax D increased the level of delayed type hypersensitivity (DTH) at the initiating time of tumor development, a protection against carcinogenesis was obtained. On the other hand, BCG and wax D enhanced tumor development, when it increased antibody formation at the time of initiation of tumor development.

Animals↗
PubMed1992

Effect of active hand exercise and wax bath treatment in rheumatoid arthritis patients.

The effect of active hand exercise and warm wax treatment was evaluated in 52 rheumatoid arthritis patients randomized into four groups: (1) both exercise and wax bath, (2) exercise only, (3) wax bath only, and (4) controls. Treatment was given three times a week for 4 weeks. Deficits in flexion and extension in digits II-V bilaterally, grip function, grip strength, pain, and stiffness were measured before and after the treatment period. The control group was measured at corresponding times. Wax bath treatment followed by active hand exercise resulted in significant improvements of range of motion (ROM) and grip function. Active hand exercise alone reduced stiffness and pain with nonresisted motion and increased ROM. Wax bath alone had no significant effect.

Adult↗
PubMed1978

Influence of wax coatings on release rate of anions from ion-exchange resin beads.

Ion-exchange resin beads were coated with various waxes to improve and control their release. The in vitro release rates of benzoate ions from the coated-resin beads were then investigated using a rotating sieve basket technique. The dramatic differences in release rates observed with the different waxes can be discussed in terms of the wax to resin ration and the solubility characteristics of the waxes. The initial release rates can be expressed in terms of a mathematical expression previously reported for the diffusion of ions in ion-exchange resins, thereby aiding in the elucidation of the effect of the waxes on release.

Anion Exchange Resins↗
PubMed1994

Mechanism of drug release from an acrylic polymer-wax matrix tablet.

An acrylic polymer-wax matrix system was evaluated for oral sustained-release tablets of diphenhydramine HCl. A desirable release profile of diphenhydramine was achieved by incorporating Eudragit L in a carnauba wax matrix. In this polymer-wax system, carnauba wax maintained the integrity of the matrix, whereas Eudragit L slowly eroded in the matrix as the drug was released. Thus, the area-to-volume ratio of the tablet remained constant over the duration of the drug release. In vitro drug release studies were conducted at physiological pHs that exist in the gastrointestinal tract. Drug release rates decreased as the polymer:drug ratio increased from 1:2 to 2:1. The drug release rate was faster in pH 7.5 phosphate buffer than in 0.1 N HCl solution. The drug release from these polymer-wax matrices is described by a combination diffusion/erosion mechanism. Based on the typical pH encountered in intestinal fluids, complete dissolution of the drug and polymer at pH 7.5 in 8-10 h would ensure good bioavailability of the drug following oral administration.

Diphenhydramine↗
PubMed1995

Programmable drug release of highly water-soluble pentoxifylline from dry-coated wax matrix tablets.

The programmable release of pentoxifylline from a dry-coated wax matrix tablet containing behenic acid as wax matrix was investigated at 37 degrees C in Japanese Pharmacopeia XII 1st (pH 1.2) and 2nd (pH 6.8) fluids. The dry-coated tablet consisted of a low drug concentration (33% w/w) in the outer layer tablet and a high concentration (50-67% w/w) in the core. The drug release from the wax matrix significantly increased after penetrating the core; therefore, the drug release profiles showed specific biphasic curves. Because the contact angle of the wax matrix tablet increased with a decrease in the drug concentration, the fluid penetration in wax matrix tablet increased with an increase of the drug concentration. The time required for 75% drug release (T75) decreased with an increasing drug concentration in the core, and the T75 at pH 6.8 was slightly longer than that in pH 1.2. The larger core tablet had a shorter T75, indicating that the drug release rate was controlled by regulating the drug concentration and/or the weight of the core tablet.

Chemical Phenomena↗
PubMed1978

Glossy mutants of maize. VIII. Accumulation of fatty aldehydes in surface waxes of gl5 maize seedlings.

In corn seedlings (Zea mays L.) homozygous for the mutation gl5, the surface waxes are characteristically altered. In this mutant the main wax constituents (83.5%) are aldehydes while in the normal waxes alcohols predominate (62.7%). Moreover, in the normal waxes aldehydes and alcohols are made up mainly of the C32 term (99%), whereas in gl5 waxes the principal aldehyde is still C32 (90.7%) but the free alcohol composition pattern is noticeably modified. Here the predominant terms are C24, C26, and C28, with C32 representing only 16.6% of the total. The results indicate that the mutant induces a block in the synthesis of fatty alcohols while accumulating fatty aldehydes, the substrates from which the alcohols originate.

Aldehydes↗