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At least 145 records · Page 8Linked to original sources
PubMed1995

A comparison between the effects of paraffin and plastic embedding of the normal and obstructed minipig detrusor muscle using the optical dissector.

PURPOSE: The purpose of this study was to estimate the relative shrinkage of the normal, obstructed and recovery minipig urinary bladder by comparing tissues from the same bladders embedded in paraffin or plastic. MATERIALS AND METHODS: Optical dissectors were used to make nucleus numerical density estimates in thick paraffin and plastic sections from the same bladder. The ratio of the 2 numerical densities depends only on differences in tissue shrinkage. In 9 minipigs a partial bladder outlet obstruction was created by implanting a 6 to 7 mm. Teflon ring around the proximal urethra. After an obstruction period (median 63 days) the ring was removed and after a recovery period (median 60 days) the animals were sacrificed. Biopsies were taken prior to obstruction, at removal of obstruction, and after recovery and were processed for paraffin and plastic sections to evaluate relative shrinkage. Two control pigs were sham-operated and biopsies taken at the same 3 time points. RESULTS: The optical dissector method was found to be an easy way to estimate the relative shrinkage of paraffin-embedded bladder tissue in proportion to plastic-embedded tissue. Both in human and minipig bladders, paraffin embedding caused a relative shrinkage of about 30% in proportion to plastic embedding. Both the obstructed and recovery detrusor muscles responded to embedding by either method in a manner indistinguishable from the normal bladder. CONCLUSION: When dealing with stereological evaluation of the detrusor muscle, the relative shrinkage of the embedded normal, obstructed and recovery bladder tissue can be ignored.

Animals↗
PubMed1995

A microwave method that enhances detection of aberrant p53 expression in formalin-fixed, paraffin-embedded tissues.

OBJECTIVE: Detection of aberrantly accumulated p53 protein by immunohistochemistry may have prognostic significance in many human neoplasms. We wished to identify a technique applicable to formalin-fixed, paraffin-embedded sections that would reliably yield results equivalent to frozen-section immunohistochemistry. DESIGN: We compared the frequency of p53 immunostaining obtained by applying monoclonal antibodies PAb1801, DO7, or DO1, a 1:1 PAb1801-DO7 cocktail, and a 1:1 PAb1801-DO1 cocktail to fresh-frozen and formalin-fixed, paraffin-embedded tissues from 36 lung and upper aerodigestive-tract carcinomas. With the formalin-fixed tissues, we compared pepsin predigestion with microwave irradiation in citrate buffer as means of enhancing the sensitivity of p53 detection. SETTING AND PATIENTS: All tissues were obtained from surgical resections of tumors, from patients who underwent surgery at the Minneapolis Department of Veterans Affairs Medical Center between 1990 and 1992. MAIN OUTCOME MEASURES: The sensitivity of different paraffin section techniques for immunohistochemical detection of accumulated p53 protein was determined in reference to the optimal frozen section method (defined as the method that yielded the greatest number of p53-positive cases in frozen tissue). RESULTS: Microwave antigen retrieval markedly enhanced staining with PAb1801 and DO7 in paraffin sections, as compared with pepsin predigestion and no pretreatment. This technique was 100% sensitive relative to the optimal frozen tissue method. In contrast, staining with DO1 alone was not enhanced by microwaving. CONCLUSIONS: Microwave pretreatment in conjunction with the use of either PAb1801 or DO7 is highly efficacious in the immunohistochemical detection of aberrant p53 expression in formalin-fixed, paraffin-embedded tissues.

Antibodies, Monoclonal↗
PubMed1994

Comparison of polymerase chain reaction and immunohistochemistry for the detection of Mycoplasma pulmonis in paraffin-embedded tissue.

The polymerase chain reaction (PCR) is a reliable method of detecting specific DNA sequences. The purpose of this study was to develop a PCR method of detecting Mycoplasma pulmonis in paraffin-embedded tissue sections and to compare the sensitivity of this method with that of the avidin-biotin complex (ABC) immunohistochemistry technique. We infected mice intranasally with 10(7) M. pulmonis and sacrificed them 28 days later. Using a published oligonucleotide primer sequence for M. pulmonis, we examined 8-microns paraffin sections by PCR for a 710 base-pair segment of the genome. A sequential 8-microns paraffin section was stained for M. pulmonis, using standard ABC immunohistochemistry methods. By PCR and dot blot hybridization, 60 of 62 paraffin-embedded lungs were positive for M. pulmonis, whereas only 17 of 62 lungs were positive, using the ABC method. In this study, we demonstrated that PCR of paraffin-embedded tissues followed by dot blot hybridization of the PCR products was much more sensitive than the ABC method in identifying mouse lungs infected with M. pulmonis.

Animals↗
PubMed1994

Analysis of changes in DNA sequence copy number by comparative genomic hybridization in archival paraffin-embedded tumor samples.

Analysis of previously unknown genetic aberrations in solid tumors has become possible through the use of comparative genomic hybridization (CGH), which is based on competitive binding of tumor and control DNA to normal metaphase chromosomes. CGH allows detection of DNA sequence copy number changes (deletions, gains, and amplifications) on a genome-wide scale in a single hybridization. We describe here an improved CGH technique, which enables reliable detection of copy number changes in archival formalin-fixed paraffin-embedded tumor samples. The technique includes a modified DNA extraction protocol, which produces high molecular weight DNA which is necessary for high quality CGH. The DNA extraction includes a 3-day digestion with proteinase K, which remarkably improves the yield of high molecular weight DNA. Labeling of the test DNA with a directly fluorescein-conjugated nucleotide (instead of biotin labeling) improved significantly the quality of hybridization. Using the paraffin-block technique, we could analyze 70 to 90% of paraffin blocks, including very old samples as well as samples taken at autopsy. CGH from paraffin blocks was highly concordant (95%) with analyses done from matched freshly frozen tumor samples (n = 5 sample pairs; kappa coefficient = 0.83). The method described here has wide applicability in tumor pathology, allowing large retrospective prognostic studies of genetic aberrations as well as studies on genetic pathogenesis of solid tumors, inasmuch as premalignant lesions and primary and metastatic tumors can be analyzed by using archival paraffin-embedded samples.

Chromosome Mapping↗
PubMed1997

Usefulness of a new CD5 antibody for the diagnosis of T-cell and B-cell lymphoproliferative disorders in paraffin sections.

We used a new antibody (NCL-CD5-4C7) immunoreactive for CD5-positive cells in paraffin-embedded tissue, with the microwave antigen retrieval method, to analyze a number of well-characterized cases of B-cell and T-cell non-Hodgkin's lymphomas whose CD5 immunoreactivity was documented by immunohistochemical analysis performed on frozen sections and/or flow cytometric immunophenotypic analysis of neoplastic cell suspensions. In all of the cases included in the study, small, reactive T lymphocytes within histologic sections were strongly positive for CD5 and served as an internal positive control. All CD5-positive T-cell non-Hodgkin's lymphomas (13 [100%] of 13) from several histologic subgroups, were immunoreactive for CD5 in paraffin sections, although 4 of 13 exhibited weak or limited staining of neoplastic cells. The majority of cases of B-cell small lymphocytic lymphoma/chronic lymphocytic leukemia (SLL/CLL) (13 [81%] of 16) and mantle cell lymphoma (14 [93%] of 15), both B-cell lymphoproliferative disorders that are immunoreactive for CD5, were immunoreactive for CD5 in paraffin sections, although 5 of 13 cases of SLL/CLL and 6 of 14 cases of mantle cell lymphoma exhibited weak and/or limited staining of neoplastic cells. Other B-cell non-Hodgkin's lymphomas of various subtypes, including marginal zone, follicular, diffuse large cell, and lymphoblastic types, were nonreactive for CD5 in paraffin sections, as expected. CD5 antibody NCL-CD5-4C7 should be useful for the routine characterization of suspected T-cell and B-cell lymphoproliferative disorders when only paraffin-embedded tissue is available for immunophenotypic analysis.

CD5 Antigens↗
PubMed1991

Immunohistochemical demonstration of keratin 7 in routinely fixed paraffin-embedded human tissues.

The immunoreactivity of OV-TL 12/30, a monoclonal anti-keratin 7 antibody (Mab), was investigated on frozen as well as paraffin-embedded human tissues. Its reactivity patterns were compared with another well-characterized monoclonal antibody to keratin 7 (RCK 105), and with broadly cross-reacting monoclonal (OV-TL 12/5) as well as polyclonal (pKer) keratin antisera. In frozen sections of normal and malignant human tissues both keratin 7 Mabs gave similar staining patterns. The immunoreactivity for OV-TL 12/30 and the polyclonal antibody (pKer) in tissue sections fixed in 4 per cent formalin or Bouin solution, was completely restored when pretreated with 0.1 per cent pronase, 0.1 per cent trypsin in phosphate-buffered saline (PBS) or with 0.5 per cent pepsin in 0.01 N HCl. Except for loss of immunoreactivity on human normal stomach surface epithelium and glandular mucous cells, Mab OV-TL 12/30 reacted strongly positive with essentially all those formalin- or Bouin-fixed paraffin-embedded tissues that had been shown to stain in non-fixed, frozen sections. In addition to the good correlation in human tissues, a complete correlation between the reactivity on frozen and paraffin-embedded human carcinomas (n = 86) was found as well. While both RCK 105 (anti-keratin 7) and OV-TL 12/5 (anti-keratin 5, 7, 14, 19) did not stain on paraffin-embedded sections, the polyclonal control antiserum (pKer) lost immunoreactivity in some cell types (e.g. mucous cells in compound glands, hepatocytes, pancreatic acinar cells, and proximal and distal convoluted tubules of the kidney). Our study shows that the keratin 7 Mab OV-TL 12/30 is an excellent marker for tumour histopathology since it is reactive in paraffin-embedded formalin-fixed human tissues.

Antibodies, Monoclonal↗
PubMed1981

Effects of chlorinated paraffins on rat liver microsomal activities and morphology. Importance of the length and the degree of chlorination of the carbon chain.

Short term effects of chlorinated paraffins with different length of the carbon chain and different degree of chlorination were investigated with respect to rat liver cytochrome P-450 mediated metabolism and liver cell morphology. When paraffins were administered by i.p. injection liver weights increased inversely with the length of the carbon chain. The short carbon chain paraffins with a high degree of chlorination increased the concentration of liver microsomal cytochrome P-450, inhibited the metabolism of 7-ethoxyresorufin but increased the metabolism of benzo(a)pyrene, especially the formation of the 4,5-diol metabolite. Short carbon chain paraffins gave rise to a proliferation of the smooth ER, increased the number of cytoplasmic fat droplets as well as the number and size of mitochondria and peroxisomes and finally induced the occurrence of autophagosomes and lysosomes. The fat droplets were preferentially degraded in lysosomes. In all respects the long carbon chain paraffins were less biologically active.

Animals↗
PubMed1990

Colocalization of estrogen and progesterone receptors with an estrogen-regulated heat shock protein in paraffin sections of human breast and endometrial cancer tissue.

We have studied by immunocytochemistry and monoclonal antibodies the presence and localization of estrogen receptors, progesterone receptors, and a 24-kD estrogen-regulated heat shock protein in biopsies from breast and endometrial cancer patients. Three different tissue processing protocols were used to colocalize the antigens in the same tissue sections: a) frozen sections, b) formalin fixation with routine paraffin embedding, and c) picric acid-formaldehyde (PAF) fixation with a rapid embedding in paraffin. Frozen sections showed good receptor staining but poor 24-kD protein immunoreactivity, while routine paraffin sections (with or without DNase pretreatment) were inadequate to reveal the nuclear receptor proteins at the same level seen in frozen sections. On the other hand, all three proteins could be detected satisfactorily in PAF-fixed paraffin-embedded tissue. Using this procedure we were able to visualize 24-kD protein and estrogen receptor or progesterone receptor in individual cells in paraffin sections. The study revealed that in all of the estrogen receptor positive breast and endometrial tumor samples, almost 90% of the cells expressing the cytoplasmic 24-kD protein contained estrogen receptor in the cell nucleus. In contrast, 24-kD immunoreactive cells did not express progesterone receptors in almost 40% of the progesterone receptor positive tumor samples.

Adenocarcinoma↗
PubMed1998

The effects of cadexomer iodine paste in the treatment of venous leg ulcers compared with hydrocolloid dressing and paraffin gauze dressing. Cadexomer Iodine Study Group.

BACKGROUND: The aim was to examine cadexomer iodine paste in a comparative clinical trial. METHODS: A 12-week, randomized, open, controlled, multicenter, multinational trial in patients with exudating, venous leg ulcers of cadexomer iodine paste (Iodosorb/Iodoflex), hydrocolloid dressing (Duoderm E, Granuflex E), or paraffin gauze dressing (Jelonet) was carried out. All patients used short-stretch compression bandages (Comprilan) throughout the study. The primary efficacy variable was a reduction in ulcer size (%), and the secondary end-point was the time taken to stop exudation, when the patient had completed the study according to the protocol. A total of 153 patients entered the study and were treated for 12 weeks or until cessation of exudation. RESULTS: The mean reduction in ulcer size in all patients was 62% with cadexomer iodine vs. 41% and 24% for hydrocolloid and paraffin gauze (ns). Of those treated for 12 weeks (n = 51), ulcer area reduction was 66% for cadexomer iodine and 18% for hydrocolloid (p = 0.0127). For the whole material, the rate of healing (ulcer area reduction per week) was significantly higher for cadexomer iodine than for paraffin gauze (0.64 cm2/week vs. 0.19 cm2/week, p = 0.0353). The treatment costs were similar in all groups; however, when the costs were correlated with healing over a 12-week period, cadexomer iodine paste was found to be more cost effective than hydrocolloid dressing or paraffin gauze dressing. CONCLUSIONS: This study shows that cadexomer iodine paste is an efficient, cost-effective and safe alternative to hydrocolloid dressing and paraffin gauze dressing for the treatment of venous leg ulcers.

Adult↗
PubMed2000

Scaled structures in late stages of microphase separation of binary paraffin mixtures

Since the dynamic properties in paraffin mixtures are different from those in alloys and polymer blends, paraffin mixtures are believed to be another class of substances establishing the "universality" of the dynamical scaling behavior of phase separation. In this paper, the scaled structures of microphase separation in paraffin mixtures are described using a scaling function based on a two-phase model with kinetics based on the Cahn-Hilliard equation. It has been demonstrated that at the late stages of the microphase separation the scaling behavior in the paraffin mixtures agrees well with the universal features predicted by the scaling function. The scaled structures of microphase separation in paraffin mixtures can be directly calculated from the volume fraction of the minority phase without any adjustable parameter.

Journal Article↗
PubMed2001

Biodegradation of long-chain n-paraffins from waste oil of car engine by Acinetobacter sp.

Microorganisms that degrade long-chain n-paraffins from used car engine oil were isolated from soil. For the screening, a fraction of n-paraffin prepared from car engine oil was applied as the sole carbon source. The strain was identified as Acinetobacter sp. The ability of the strain to assimilate long-chain n-paraffins was assessed and characterized. The strain mineralized long-chain n-paraffins (0.1% w/v) in the minimal medium after cultivation for 96 h and also reduced the weight of the waste oil added (1% w/v) by 20% after 72 h without an extracellular biosurfactant. When n-hexadecane was fed as substrate, 1-hexadecanol and 1-hexadecanoic acid were detected as the intermediates by gas chromatography/mass spectrometry. This indicates that the long-chain n-paraffins were metabolized via the terminal oxidation pathway of n-alkane.

Journal Article↗
PubMed2006

Honey dressing versus paraffin tulle gras following toenail surgery.

OBJECTIVE: Anecdotal reports suggest that certain honey dressings have a positive effect on wound healing. However, there is limited empirical evidence supporting its use. This double-blind randomised controlled trial investigated the effect of a honey dressing on wound healing following toenail surgery with matrix phenolisation. METHOD: Participants (n=100) were randomly assigned to receive either an active manuka honey dressing (n=52) or paraffin-impregnated tulle gras (n=48). The primary outcome was time (days) taken for complete re-epithelialisation of the nail bed. RESULTS: Mean healing times were 40.30 days (SD 18.21) for the honey group and 39.98 days (SD 25.42) for the paraffin tulle gras group. Partial avulsion wounds healed statistically significantly faster (p=0.01) with paraffin tulle gras (19.62 days, SD 9.31) than with the honey dressing (31.76 days, SD 18.8), but no significant difference (p=0.21) was found following total avulsion when comparing honey (45.28 days, SD 18.03.) with paraffin tulle gras dressings (52.03 days, SD 21.3). CONCLUSION: The results suggest that patients may benefit more from paraffin tulle gras dressings than honey dressings following partial toenail avulsion. No statistically significant difference was found for healing times after total toenail avulsion, although the marginal benefit of the honey dressing on these healing times warrants further investigation.

Adult↗
PubMed1990

Bronchoalveolar lavage in liquid paraffin pneumonitis.

We evaluated cells and lipids recovered in the bronchoalveolar lavage fluid from seven patients with liquid paraffin pneumonitis. For each patient, the BALF was whitish with oil droplets on the surface. Alveolar macrophages contained numerous, large vacuoles that did not react with May-Grunwald-Giemsa, Papanicolaou, or periodic acid-Schiff but were stained in black with Sudan B, orange with Sudan III and red with oil Red O. Liquid paraffin was identified on thin layer chromatography of BALF-extracted lipids as a very hydrophobic compound migrating on the solvent front as control liquid paraffin. This abnormal spot was definitely identified as liquid paraffin by infrared spectroscopy and gas liquid chromatography for the first patient. The number and percentage of AMs were largely decreased in the BALF of each patient, whereas the number of neutrophils, eosinophils and lymphocytes was increased. These findings suggest that this cell-mediated inflammatory response plays a role in the development of interstitial fibrosis at late stages of liquid paraffin pneumonitis.

Aged↗
PubMed1991

Detection of hepatitis B virus DNA in paraffin-embedded liver tissues in chronic hepatitis B or non-A, non-B, hepatitis using the polymerase chain reaction.

We developed a polymerase chain reaction assay for the direct detection of hepatitis B virus in paraffin-embedded liver tissue and applied this assay to determine whether hepatitis B virus DNA exists in livers with chronic hepatitis non-A, non-B. Fifty five liver biopsy samples were studied: 11 from patients with HBeAg-positive chronic hepatitis (paraffin-embedded) and 44 from patients with chronic hepatitis non-A, non-B (21 paraffin-embedded; 25 fresh frozen). Thirty three (75%) of the non-A, non-B cases were positive for hepatitis C virus antibodies. Approximately 1 to 10 ng of DNA was extracted from the paraffin-embedded tissue and amplified using oligonucleotide (23-mer) primers specific for the S gene (positions 261 to 692). The beta-globin gene was used as an internal control for sensitivity because this is a single copy gene and allows for relative quantification. In each of the chronic hepatitis B livers, the expected 432-base-pair amplification product for hepatitis B virus DNA and beta-globin gene product were both detected. On the other hand, in the 21 paraffin-embedded chronic hepatitis non-A, non-B livers, no hepatitis B virus DNA was detected, although beta-globin gene was observed in all. Furthermore, in all 25 frozen non-A, non-B livers, beta-globin gene was observed, but no hepatitis B virus band was seen. The limit of detection of hepatitis B virus DNA by this method was estimated to be one genomic copy of hepatitis B virus DNA per cell.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1978

Paraffin oil pneumonia. Analysis of saturated hydrocarbons in different human tissue.

Temperature-programmed gas chromatographic analysis on columns packed with Apiezon L as stationary phase is shown to be the best method for the qualitative and quantitative analysis of simple and complex hydrocarbon mixtures when compared with all the other applicable techniques (thin-layer chromatography, column chromatography, ultraviolet spectroscopy, infrared spectroscopy, nuclear magnetic resonance spectroscopy, mass spectrometry) described in this paper. Using the method in a patient with mineral oil pneumonia it could be demonstrated that he expectorated a maximum of 79.5 mg liquid paraffin daily and also transported equally complex saturated hydrocarbons in a concentration of 1.3 mg% in plasma and of 1.6 mg% in the cellular blood components. In an additional experiment the direct determination of liquid paraffin resorbed from the gastrointestinal tract was possible in a patient with a left chyle fistula in the neck. After a dose of 50 g liquid paraffin administered as a laxative, 246 ml chyle was collected within the following 14 h which yielded a total of 4.5 mg liquid paraffin. Its composition was identical with the administered laxative. Assuming a daily lymph volume of 1.51, the resorbed amount would correspond to a resorption rate of 0.5 (see article) liquid paraffin. The importance of these results as well as the diagnostic consequences arising from the described analytical technique are discussed in detail.

Adult↗
PubMed1994

Paraffin (kerosene) poisoning in childhood--is prevention affordable in South Africa?

Paraffin (known in some Western countries as kerosene) ingestion is the most common form of acute childhood poisoning in most developing countries. South African black communities reflect a similar pattern, yet the true size and cost of the problem are not known. Without such baseline data the effect of interventions cannot be evaluated. The aim of the study was to determine the incidence and treatment cost of paraffin poisoning in the Cape Peninsula, to identify high-risk areas and to discuss which measures offered the most economical and best preventive potential for this paediatric hazard. A 12-month retrospective study was undertaken in 1990. Relevant patient data were extracted from the files of 6 major Cape Peninsula hospitals. Treatment costs were calculated based on differential hospital costs per inpatient per day, with outpatient costs at one-third of the costs per day. Age-specific rates for affected residential areas were calculated to identify high-risk areas. A total of 436 children (62,5% male), mostly between the ages of 12 and 36 months, were treated at an estimated cost of R111 673. This amount would have been sufficient to provide 95% of households in the 8 identified high-risk areas with child-resistant paraffin containers. In these areas age-specific paraffin poisoning rates ranged from 1,8/1,000 to 7,7/1,000. Strategically planned interventions can be cost-effective when weighed against the treatment cost of cases of paraffin poisoning.

Accidents, Home↗
PubMed1995

Asbestos contamination in paraffin tissue blocks.

Electron microscopic analyses of tissue samples embedded in paraffin are routinely performed as a means of validating (establishing) the asbestos exposure of persons diagnosed with mesothelioma, a rare form of cancer often identified as being caused by exposure to asbestos. During analysis of tissue samples claimed to contain asbestos, we observed asbestos contamination in the paraffin of the tissue block. To investigate the extent to which such contamination is prevalent in tissue block samples, we obtained and analyzed samples of paraffin blocks from hospitals in six major cities and found them to contain measurable concentrations of asbestos. Whether this asbestos contamination originated in the virgin wax or was a result of processing has not been established. This result, which has not been previously reported, raises significant concerns about the validity of analyses for asbestos in tissue embedded in paraffin. In particular, diagnoses in which the presence of asbestos in tissue samples is taken as being indicative of past asbestos exposure, especially for those cases in which no known exposure has occurred, and studies purporting to show migration of asbestos to other organs in the body following inhalation or ingestion of asbestos require critical reevaluation. The need for reevaluation is particularly acute if appropriate control blanks were not evaluated as part of the studies.

Asbestos↗
PubMed1997

Terminal deoxynucleotidyl transferase staining of malignant lymphomas in paraffin sections: a useful method for the diagnosis of lymphoblastic lymphoma.

Terminal deoxynucleotidyl transferase (TdT) is a DNA polymerase located in the cell nucleus which catalyses the polymerization of deoxynucleotides at the 3'hydroxyl ends of oligo- or polydeoxynucleotide initiators without a template. TdT is known as a useful marker for the diagnosis of acute lymphoblastic leukaemia/lymphoma, but its detection usually requires fresh tissue specimens or cell suspensions, using either an enzyme analysis or immuno-fluorescence or -peroxidase staining. Until the recent development of the use of microwave-treated paraffin sections for immunoperoxidase staining, detection of TdT in paraffin sections required rather complicated processes. This new simple technique was applied to paraffin sections from the tumour tissue specimens of 16 patients with lymphoblastic lymphoma and of seven patients with non-endemic Burkitt's lymphoma, which is sometimes difficult to differentiate from lymphoblastic lymphoma because of their similar clinicopathological characteristics. In addition, as a control, ten cases each were examined of adult T-cell leukaemia/lymphoma (ATLL) and angioimmunoblastic lymphoma (AILD), which are both peripheral T-cell lymphomas. The tumour cells from 15 of the 16 (94 per cent) patients with lymphoblastic lymphoma were found to be TdT-positive. The specificity of the anti-TdT antibody used was confirmed by immunoblot and the specific 60 kD band was detected only in a specimen of lymphoblastic lymphoma. These results show that the immunostaining of TdT on paraffin-embedded sections is a useful method for differentiating lymphoblastic lymphoma from other lymphomas. This method is applicable to a routine diagnostic service.

Adolescent↗