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At least 19 recordsLinked to original sources
PubMed2006

Depositing archived paraffin tissue core biopsy specimens in paraffin tissue microarrays using a paraffin tissue punch modified with a countersink.

Paraffin tissue microarrays (PTMAs) introduced by Kononen et al in 1998 have become a widely used technique in routine pathology and even more so in research. Kononen used a tissue puncher/arrayer (Beecher Instruments, Sun Prairie, WI, USA) to take paraffin tissue core biopsy specimens (PTCBs) of 0.6-2 mm in diameter from routine paraffin tissue blocks and transfer them to another paraffin block with up to 1000 holes. As pointed out by Mengel et al, however, it is not possible to use the Kononen/Beecher system to construct PTMAs out of archived PTCBs. To overcome this drawback in the extremely popular Beecher system, the paraffin tissue punch was modified by incorporating a conical 4 mm deep countersink. This countersink was milled with a conical precision cutter that can be bought in an ordinary hardware store (cost <5 US dollars). The countersink facilitates the insertion of an archived PTCB into the paraffin tissue punch and enables the construction of PTMAs with previously archived PTCBs using the widely distributed Beecher system. Moreover, this paraffin tissue punch can be used for other systems to create PTMAs, such as the low-budget systems designed by Vogel.

Biopsy↗
PubMed2006

Selective inhibition of paraffin deposition under high flow rate as a function of the crude oil paraffin type and content by fluorescence depolarization: polypropylene and high-density polyethylene.

High-density polyethylene (HDPE) and polypropylene (PP) were studied to identify tailor-made materials for walls of pipelines and ducts for crude paraffinic oil that inhibit paraffin depositions. The interfacial interaction was investigated from 50 to 70 degrees C and as a function of the n-C(36)H(74) paraffin concentration added to the paraffinic crude oil. The static and the dynamic interfacial tensions were observed, respectively, by traditional contact angle measurements and by fluorescence depolarization of the natural fluorescent probes of the crude oil, flowing at a high rate. The static interaction showed a low dependence on the n-paraffin content for both surfaces. For PP, it decreased slightly as the n-paraffin concentration increased, evidencing an increase in the liquid-liquid interaction. The dynamic interfacial tension with PP clearly decreased as temperature and n-paraffin concentration increased, the latter effect being attributed to the PP methyl groups hindering the interaction between the n-paraffin and the PP main chain. For the flow on HDPE, the interaction proved to be highly dependent on the n-paraffin concentration and temperature. It increased as n-paraffin was added and temperature decreased. The former effect is attributed to the alignment of the n-paraffin chains within the high rate flowing liquid and the similar molecular geometry of the n-paraffin and the linear polymer surface (almost without branches), which increases the number of sites available for interaction. PP proved to be more suitable for transportation of crude oil rich in paraffins with more than 36 carbon atoms, while HDPE was more suitable for those with smaller paraffinic chains.

Journal Article↗
PubMedDate not supplied

Determination of paraffins in food simulants and packaging materials by liquid chromatography with evaporative mass detection and identification of paraffin type by liquid chromatography/gas chromatography and fourier transform infrared spectroscopy.

A liquid chromatographic method with evaporative mass detection (EMD) is described for the determination of paraffins in food contact materials that do not contain polyolefin oligomers, or paraffins migrating from these materials into fatty food simulants or certain simple foods. A normal-phase column operating at maximum column efficiency separates nonparaffinic and paraffinic materials without resolving the latter into individual components, and EMD is used to quantitate the paraffins. An on-line qualitative method that uses liquid chromatography/gas chromatography with flame ionization detection discriminates between paraffin waxes and oils in food contact materials, food simulants, and certain simple foods; a Fourier transform infrared spectrophotometric qualitative method also discriminates between waxes and oils, but is usually restricted to food contact materials that do not contain polyolefins and to migration experiments with organic solvents as fatty food simulants (with some other fatty food simulants, paraffin type must then be identified in the food contact material).

Chromatography, Gas↗
PubMed1999

[Utility of the paraffin-embedded section method on the detection of estrogen receptor from breast cancer tissues--comparison of the paraffin-embedded section method (6F11 and 1D5) with frozen section (H222) and dextran-coated charcoal (DCC) ones].

From March 1988 to December 1990, we detected estrogen receptor (ER) from breast cancer tissues with the dextran-coated charcoal (DCC) method. From September 1990 to March 1998, we repeated the above with the frozen section method (cloneH222; DAINABOT). With the paraffin-embedded section method using two antibodies of anti-ER (clone6F11; NOVOCASTRA and clone 1D5; MBL), we examined the ER of the same 185 primary breast cancer tissues. We had already detected these tissues with the frozen section method, and we also applied the same procedure for the 43 primary breast cancer tissues which had already been detected with the DCC method. We compared these data. The positive rates of ER with DCC, H222, 6F11 and 1D5 were 49%, 53%, 53% and 52% respectively, which were within the reported range. The accuracy between H222 and 6F11 which was calculated as the percentage that were in positive and negative concordance by the two methods, was 88%. The accuracies between H222 and 1D5, between 6F11 and 1D5, between DCC and 6F11, between DCC and 1D5 were respectively 89%, 96%, 79%, and 77%. Although the accuracy between DCC and the paraffin-embedded section was not necessarily high, we obtained a higher concordance between the frozen and paraffin-embedded sections. The highest concordance existed between 6F11 and 1D5. The 30% of negative cases with DCC were positive with paraffin-embedded section. Among these methods of ER detection from breast cancer tissues, the paraffin-embedded section method seemed to be the most useful.

Breast Neoplasms↗
PubMed1975

[Metabolism of paraffinic and naphthalenic hydrocarbons in higher animals. I. Retention of paraffins (normal, cyclo and branched) in rats].

Apparent retention of aliphatic hydrocarbons in the Rat is studied. Animals weighing 150 g are put into metabolism cages and given a 15 mg dose of one of the paraffins studied in solution in the peanut oil of the ration. There is no urinary excretion, and fecal elimination is low (5-10%), as long as the carbon chain stays below 24 atoms. Real retention is measured on animals recieving a single dose of 15 mg in the same conditions. Branched paraffins give only very low residual amounts 15 days after ingestion, while n-paraffins and cyclo-paraffins remain unchanged in the carcass, as long as the number of carbon atoms is not greater than 20; the proportion of the latter paraffins is about 8% of the dose ingested (5 days as 21 days after intake). Beyond C 20, real retention decreases rapidly to zero.

Alkanes↗
PubMedDate not supplied

Immunoelectron microscopy on material retrieved from paraffin: accurate sampling on the basis of stained paraffin sections.

As a rule, immunoelectron microscopy (immuno-EM) is performed on fresh material processed according to specialized methods (e.g., freezing or embedding in hydrophilic resins). Paraffin-embedded tissue has only occasionally been used as a source of material for immuno-EM; this was usually as a last resort, when no fresh material was available. The authors used archival formalin-fixed, paraffin-embedded basal cell carcinomas for studying the fine-structural distribution of the cell surface molecule CD44 and its variants, as well as some other antigens. The results demonstrate, firstly, that paraffin-embedded material is far more suitable for immuno-EM than frequently assumed and, secondly, that the use of paraffin-embedded material enables highly accurate sampling on the basis of immunohistochemically or conventionally stained light microscopic sections.

Basal Cell Carcinoma↗
PubMed2003

Use of isopropyl alcohol in histological assays: dehydration of tissue, enbessing into paraffin, and processing of paraffin sections.

Isopropyl alcohol (isopropanol) can be used as a substitute for ethyl alcohol in tissue dehydration during embedding into paraffin and dehydration of stained sections. The use of isopropyl alcohol during paraffinization allows us to exclude treatment with intermediate solvents of paraffin (chloroform, xylene, and benzene), which reduces the degree of tissue compaction and simplifies and accelerates histological assay.

2-Propanol↗
PubMed1997

Staining paraffin embedded sections of scald of barley before paraffin removal.

Staining of paraffin embedded sections with periodic acid-Schiff reagent and fast green before paraffin removal resulted in differentiation of barley seed and leaf tissue from fungal structures of Rhynchosporium secalis. Crystal violet, toluidine blue O and antiline blue also successfully stained fungal structures of R. secalis in barley leaf tissues. Staining of embedded sections before paraffin removal allows simple processing of a series of sections, saves time and reduces solvent consumption.

Aniline Compounds↗
PubMed1968

Paraffin oxidation in Pseudomonas aeruginosa. I. Induction of paraffin oxidation.

The induction of paraffin oxidation in intact cells of Pseudomonas aeruginosa was investigated. Oxidation of (14)C-heptane by cell-free extracts of adapted cells showed that the activity of whole cells is a reliable reflection of the synthesis of the first enzyme in the degradation of n-alkanes. Induction was significantly affected by glucose and could be completely repressed by malate. The amino acids l-proline, l-alanine, l-arginine, and l-tyrosine exhibited a rather low repressor action. Malonate, a nonrepressive carbon source, allowed gratuitous enzyme synthesis. A number of compounds which did not sustain growth were found to be suitable substitutes for paraffins as an inducer. Among these were cyclopropane and diethoxymethane. The induction studied under conditions of gratuity with the latter compound as an inducer showed immediate linear kinetics only at saturating inducer concentrations. With n-hexane as the inducer, a lag time was always observed, even when high concentrations were used.

Alkanes↗
PubMed1982

Ampliative medicament allergy: concomitant sensitivity to multiple medicaments including yellow soft paraffin, white soft paraffin, gentian violet and Span 20.

A patient developed multiple rare medicament contact allergies including sensitivities to gentian violet, yellow and white soft paraffin, and Span 20 (sorbitan monolaurate). Nickel sensitivity antedated these medicament allergies. The possibility that nickel sensitivity is a marker of predilection to develop multiple medicament allergies was tested. We were unable to demonstrate an increased incidence of nickel sensitivity in a group of patients with 2 or more medicament allergies.

Adult↗
PubMed1999

Use of the paraffin wax baiting system for identification of Pseudomonas aeruginosa clinical isolates.

Pseudomonas aeruginosa is the primary pathogen among the Pseudomonads and is known for its minimal nutritional requirements, capacity to use paraffin as a sole carbon source, and biofilm formation. Because the ability of Pseudomonads to grow on paraffin is not commonly found among human pathogens and the primary Pseudomonas human pathogen is P. aeruginosa, we studied the adaptation of the paraffin baiting system for the growth and identification of clinical isolates of P. aeruginosa. We also studied the effectiveness of combining a fluorescence assay measuring fluorescein (pyoverdin) production and oxidase test with the paraffin baiting assay for P. aeruginosa speciation. Strains were tested for the capacity to use paraffin as a sole carbon source using the paraffin baiting system with Czapek's minimal salt medium. Of 111 P. aeruginosa clinical isolates tested for using paraffin as a sole carbon source, 45% exhibited growth on paraffin at 24 h and 76.6% exhibited growth on paraffin at 48 h. The ability of the reference strains and clinical isolates were then tested for their ability to associate with the paraffin slide in the presence of an additional carbon source. Of 111 P. aeruginosa clinical isolates tested, 85 strains (76.6%), and 102 (93%) were associated with the paraffin surface at 24 and 48 h. We successfully combined fluorescence and oxidase assays with the paraffin baiting system for identification of P. aeruginosa. The simple and inexpensive paraffin baiting system is a useful method for the identification and study of P. aeruginosa suitable for both the clinical and research laboratory.

Biofilms↗