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PubMed2001

Comparison of ThinPrep and TriPath PREP liquid-based preparations in nongynecologic specimens: a pilot study.

ThinPrep (TP) and TriPath PREP (TriP) are two liquid-based cytologic preparations that produce a thin layer of cells. This study compares the diagnostic accuracy and different cytomorphologic alterations produced by these preparations in nongynecologic specimens. Samples from 10 urines (3 urothelial carcinomas and 7 negative), 4 positive serous fluids, and 7 fine-needle aspirates (FNAs) were prepared by both techniques. FNAs represented one each of: Hashimoto's thyroiditis (HT), hyperplastic colloid nodule (HCN), Hodgkin's lymphoma, liposarcoma, chondrosarcoma, squamous-cell carcinoma (SCC) metastatic to the lymph node, and carcinoid tumor. All 5 participants, none of whom had prior knowledge of the clinical history or histologic diagnosis, reviewed and interpreted the slides. Both techniques produced a clean background and were equally accurate in urines, serous fluids, and three FNAs. TriP was slightly more accurate in four FNAs: HCN and HT where colloid and lymphocytes were better represented, SCC where keratin and malignant cells were more readily identified among lymphocytes, and carcinoid which was easier to evaluate on TriP due to less cellular shrinkage and more dispersion of cells between aggregates. TP preparations had more cell shrinkage, and the chromatin was harder to evaluate. Both techniques produced artificial aggregations of lymphocytes, but TriP had a more evenly dispersed single-cell population between aggregates, rendering them easier to evaluate for atypia. TP produced fragmentation of large sheets that were flattened, while TriP contained larger branching sheets in a three-dimensional (3-D) configuration. TP produced a true monolayer of cells that were all spread at the same plane, while in TriP the cells were spread at slightly different planes, requiring frequent focusing of the viewed plane. While both techniques are acceptable for diagnostic purposes, they both introduce new cytomorphologic alterations that pathologists need to recognize. TriP seems superior to TP in FNAs specimens where preservation of architecture and cellular integrity are important considerations.

Artifacts↗
PubMed1998

Use of touch preps for intraoperative diagnosis of sentinel lymph node metastases in breast cancer.

BACKGROUND: Intraoperative touch prep (TP) is highly accurate for determining positive breast cancer margins and thereby reducing the need for second surgeries. It also may be useful in determining the status of the sentinel lymph node (SLN) during the initial surgical resection. The objective of this study was to test the ability of intraoperative TP to predict metastatic disease and, thus, the necessity for axillary lymph node dissection (ALND) at the time of SLN biopsy. METHODS: Fifty-five patients with invasive breast cancer were entered in the SLN biopsy protocol. The SLN was identified by gamma probe, dissected, and sent to pathology for TP and permanent sections. Level I and II ALND was then performed. Any radiolabeled LN in the lymphadenectomy specimen also was sent for TP and permanent sections. RESULTS: A total of 124 radiolabeled lymph nodes (LNs) were submitted for TP; of these, 93 (75%) were SLNs. Pathologic diagnosis by TP was correct compared with permanent sections for 99.2% of the nodes. There were no false positives. There was one (0.8%) false negative. The positive predictive value was 100% and the negative predictive value was 99%. Sensitivity was 95.7% and specificity was 100%. CONCLUSIONS: TP is a simple, quick, and accurate method for detecting metastatic disease in the SLN and, when used intraoperatively, enables the surgeon to determine whether or not an ALND is necessary at the time of the initial surgery.

Adult↗
PubMedDate not supplied

Use of touch preps for diagnosis and evaluation of surgical margins in breast cancer.

BACKGROUND: The best cosmetic results with conservative breast surgery are obtained at the time of initial excisional biopsy. The usefulness of the touch prep (TP) technique was evaluated for accuracy in diagnosis as well as in evaluation of margins at the time of original breast biopsy. METHODS: Four hundred twenty-eight consecutive patients with breast masses seen from January 1993 to December 1994 were evaluated prospectively using TP. RESULTS: Three hundred forty-five benign and 83 malignant tumors were evaluated. Tumors ranged in size from microscopic to 8 cm. Pathologic diagnosis was correct as compared to permanent section in 99.3%. The three carcinomas missed on TP were focal and in situ. Sensitivity was 96.39%, and specificity was 100%. Positive predictive value was 100%, and negative predictive value was 99.3%. For margin evaluation, the sensitivity and specificity were both estimated to be 100%. CONCLUSIONS: TP has the advantage of being a simple, quick (2 to 3 minutes), safe (no loss of diagnostic material), and accurate method for diagnosis and estimation of tumor margins at the time of the original surgery.

Adult↗
PubMed2005

The HOXC13-controlled expression of early hair keratin genes in the human hair follicle does not involve TALE proteins MEIS and PREP as cofactors.

We previously showed that the homeodomain protein HOXC13 is involved in the expression control of the early human hair keratin genes hHa5 and hHa2, which contain specific HOXC13 binding sites in their proximal promoters. Hox specificity is generally thought to be enhanced by the interaction with members of the TALE superclass of homeodomain proteins Pbx, Meis, and Prep. Using reverse transcription PCR with total human hair follicle RNA, we demonstrated transcripts of the major TALE proteins PBX1-4, MEIS1, 2 and PREP1, 2 in the human hair follicle. In view of the presence of MEIS/PREP responsive elements in close vicinity to the HOXC13 binding sites of the hHa5 and hHa2 promoters, we determined the expression sites of these TALE proteins in the human hair follicle. We found that MEIS1, MEIS2, PREP1 and PREP2 were differentially expressed in the three layers of the inner root sheath. In addition, MEIS2 and PREP1 exhibited expression in the mid-to upper hair cortex, with PREP1 being also expressed in the dermal papilla and the connective tissue sheath of the hair follicle. In virtually all cases, the expression of these TALE proteins was exclusively cytoplasmic. Considering that in contrast, HOXC13 is expressed in the nuclei of matrix, precortex and lower cuticle cells of the hair follicle, our data suggest that despite the presence of MEIS/PREP binding sites in the hHa5 and hHa2 promoters, the HOXC13-controlled activation of these genes in the hair follicle does not seem to involve these TALE proteins as cofactors.

Cell Nucleus↗
PubMed1987

Tritiated-thymidine labeling of rectal epithelial cells in 'non-prep' biopsies of individuals at increased risk for colonic neoplasia.

Recent measurements have shown increased proliferation of colonic epithelial cells in individuals at heightened risk for cancer of the large intestine. This biomarker has facilitated measurements of the effects of nutritional intervention in studies that are attempting to inhibit tumor development in high-risk individuals. In this study, further measurements were made of the proliferation of rectal epithelial cells, when biopsies were removed from mucosa that had not previously been disturbed by any tapwater or other enema preparations. Progressive increases were found in the numbers of [3H]dThd-labeled epithelial cells in rectal crypts, and in labeling index profiles, in patients having previous sporadic adenomas or colon cancer, compared to individuals who had not developed colonic neoplasms. The most quiescent proliferative equilibrium was found in individuals without previous colonic disease. Findings indicated that 'non-prep' rectal biopsies obtained from the most accessible region of the large intestine, show modifications in the biomarker of cell proliferation paralleling colon cancer risk.

Aged↗
PubMed1993

Thiamine-repressible expression vectors pREP and pRIP for fission yeast.

The promoter and polyadenylation signal of the thiamine-repressible gene nmt1 of Schizosaccharomyces pombe have been used to construct the pREP extrachromosomally replicating plasmids and the pRIP integrative expression plasmids. These plasmids permit thiamine-mediated control of transcription to be applied to cloned genes.

Base Sequence↗
PubMed2006

A comparative photoelastic stress analysis of internal root stresses between RC Prep and saline when applied to the Profile/GT rotary instrumentation system.

The purpose of this study was to measure and compare the amount of stress produced by GT ProFile (GT) and ProFile (PF) rotary files lubricated with either RC Prep (RCP) or saline (S) on the walls of prepared simulated canals. Twenty-four 10-mm long canals with a 10 mm radius of curvature were prepared in PL-2 photoelastic acrylic blocks which were lubricated with either RCP or S. The files were inserted into a Nouvag handpiece mounted to an Instron 4502 universal testing machine and lowered into the canal at a rate of 60 mm/min and a rotational speed of 300 RPM. The following four GTs and four PFs were sequentially introduced into predetermined depths of each canal: 20/.10, 20/.08, 20/.06, 20/.04, 40/.04, 35/.04, 30/.04, and 25/.04. Total areas of stress created by each file were captured by digital video images and measured using Image J software. Statistical analysis of the data was performed using a two-way ANOVA (p < 0.05, n = 24). The GT/RCP group demonstrated a significant average of 64.22% less stress than GT/S group. The PF (25, 30, and 35)/RCP groups demonstrated a significant average of 27.02% less stress than the same S groups. PF (40) produced a negligible amount of stress regardless of the lubricant type. The results reveal that using RCP as a lubricant when instrumenting curved canals with GT and PF results in less stress when compared to saline.

Acrylic Resins↗
PubMed2005

Measurement of in vivo multi-component T2 relaxation times for brain tissue using multi-slice T2 prep at 1.5 and 3 T.

The objective of this study was to implement a clinically relevant multi-slice multi-echo imaging sequence in order to quantify multi-component T2 relaxation times for normal volunteers at both 1.5 and 3 T. Multi-echo data were fitted using a nonnegative least square algorithm. Twelve echo data with nonlinear echo sampling were acquired using a receive-only eight-channel phased array coil and volume head coil for phantoms and normal volunteers, and compared to 32-echo data with linear echo sampling. It was observed that the performance of the 180 degrees refocusing trains was more spatially uniform for the receive-only eight-channel phased array coil than for the head coil, particularly at 3 T. The phantom study showed that the estimated T2 relaxation times were accurate and reproducible for both single- and multi-slice acquisition from a commercial phantom with known T2 relaxation times. Short T2 components (T2 <50 ms) were mainly observed within the white matter for normal volunteers, and the fraction of short T2 water components (i.e., myelin water) was 7-12% of total water. It was observed that the calculated myelin water fraction map from the nonlinearly sampled 12-echo data was comparable with that from the linearly sampled 32-echo data. Quantification of T2 relaxation times from multi-slice images was accomplished with a clinically acceptable scan times (16 min) for normal volunteers by using a nonselective T2 prep imaging sequence. The use of the eight-channel head coil involved more accurate quantification of T2 relaxation times particularly when the number of echoes was limited.

Adult↗
PubMed1981

Isolation of drugs from blood serum by the Du Pont Prep I Automated Sample Processor and a C18 bonded phase adsorption column.

We describe a fast and efficient method for the isolation of drugs from blood serum by use of the DU PONT PREP I Automated Sample Processor and octadecyl bonded phase columns. Drugs are selectively adsorbed onto C18 bonded phase and eluted with methanol. The recovered residue is essentially free of sample matrix chromogens and shows very low background on thin layer chromatography. It is also suitable for analysis by gas liquid chromatography and high pressure liquid chromatography. Recovery of drugs added to serum is greater than 90 per cent for most drugs studied which include weakly acidic, neutral and alkaline drugs. The method offers tremendous savings to the user in time and dollars, since it is fully automated from the extraction step to the drying of the extract, and the columns are reusable at least 10 times. Up to 12 samples can be processed simultaneously in less than 60 minutes.

Autoanalysis↗
PubMed1988

Purification of specific heterologous F(ab)2 fragments with DEAE-Zeta-Prep cartridges for ion-exchange chromatography.

A simple two-step procedure for purifying F(ab)2 fragments of horse immunoglobulins is described. In the first step, the horse plasma is diluted, made up to 12% (w/v) with ammonium sulphate and digested with pepsin. In the second step, the previously dialyzed solution is chromatographed. Instead of a normal ion-exchange resin, a DEAE-cellulose, covalently linked to a synthetic vinyl polymer, was used (DEAE-Zeta-Prep). With this assembly it is possible to perform chromatography at a high flow-rate without the problems related to the use of large columns. The yield and purity of the final product are satisfactory. This method has been scaled up for industrial application.

Animals↗
PubMed1999

In vitro antimicrobial effect of RC-Prep within dentinal tubules.

The antimicrobial effect of RC-Prep and its components--10% urea peroxide, 15% EDTA, and glycol--were evaluated individually, in vitro, within dentinal tubules. Standardized bovine incisor root specimens that had been infected with either Staphylococcus aureus or Streptococcus peltzer were incubated with each agent for 10 and 45 min. After exposure to the agent, dentin samples were collected from within the lumina using ISO 23 to 31 burs. Dentin powder samples were incubated with bacterial broth, and the amount of bacteria present was assessed by spectrophotometry. All agents tested were more effective in killing bacteria after incubation for 45 min than after 10 min.

Analysis of Variance↗
PubMed2002

The thin prep rat aortic ring assay: a modified method for the characterization of angiogenesis in whole mounts.

The rat aortic ring model has gained broad acceptance as an angiogenic assay. This system can be used to study the activity of angiogenic and anti-angiogenic factors, and investigate the molecular mechanisms of the angiogenic process. We describe here a thin prep modification of the aortic ring model, which significantly simplifies the procedure and allows staining of aortic outgrowths as whole mounts. Using this procedure, intact preparations of angiogenic outgrowths are successfully and reproducibly stained with endothelial cell (anti-CD-31 and -Tie2 antibodies, Griffonia Simplicifolia isolectin-B4) and smooth muscle cell (anti-alpha-smooth muscle actin antibody) markers. Combined use of double immunostaining and confocal microscopy allows concurrent visualization of endothelial and mural cells in the same cultures. Whole mount immunostains of rat aorta cultures are an effective way to rapidly characterize the cellular composition of the angiogenic outgrowths, and localize proteins implicated in the regulation of angiogenesis. This method should facilitate the work of the many vascular biologists that have adopted the rat aorta model as a tool to study angiogenesis and its mechanisms.

Animals↗
PubMed1997

Microleakage of Diaket and amalgam in root-end cavities prepared using MicroMega sonic retro-prep tips.

The in vitro sealing ability of the root-canal sealer Diaket when used as a root-end filling material was compared with that of amalgam using linear micro-leakage of Indian ink. Eight groups of 20 extracted teeth each were formed, plus 12 control teeth as follows: 1) root-end resection of 45 degrees bevel, root-end cavity preparation with an 008 round bur, amalgam root-end filling; 2) 45 degrees bevel, bur, Diaket; 3) 45 degrees bevel, using a sonic retro-prep tip, amalgam; 4) 45 degrees bevel, sonic, Diaket; 5) no bevel, bur, amalgam; 6) no bevel, bur, Diaket; 7) no bevel, sonic, amalgam; 8) no bevel, sonic, Diaket. Root-end cavity depths of 3 mm were prepared. Specimens were immersed in Indian ink for 2 weeks. The teeth were demineralized, rendered transparent and linear dye penetration recorded. Results showed that Diaket provided a superior seal to amalgam irrespective of the root-end preparation. The degree of bevel of the resected root-end did not influence leakage. Sonic instrumentation resulted in a larger root-end cavity than with burs.

Apicoectomy↗
PubMed2000

Cooperative interactions between PBX, PREP, and HOX proteins modulate the activity of the alpha 2(V) collagen (COL5A2) promoter.

Cell type-specific expression of the human alpha2(V) collagen (COL5A2) gene depends on a cis-acting element that consists of two contiguous protein binding sites (FPA and FPB) located between nucleotides -149 and -95, relative to the transcription start site. The present study focused on the characterization of the FPB-bound complex. DNA binding assays and cell transfection experiments revealed that the bipartite core sequence of FPB (5'-ATCAATCA-3') binds the PBX1/2, PREP1, and HOXB1 proteins, and this in turn leads to promoter transactivation. In the presence of all three nuclear factors, cooperative interactions between recombinant PBX1 and PREP1 or PBX1 and HOXB1 result in binding of the heterodimers to FPB in vitro. Similarly, overexpression of different combinations of PBX1, PREP1, and HOXB1 transactivates FPB-driven transcription. In contrast to the composition of the FPB complex purified from COL5A2-positive cells, the FPB complex from COL5A2-negative cells contains PBX2 and PREP1 but lacks PBX1. However, PBX1 exogenously introduced into COL5A2-negative cells cannot stimulate FPB-driven transcription unless co-expressed with PREP1. Within the intrinsic limitations of the experimental model, our results indicate that combinatorial interactions among PBX and PREP or HOX proteins are involved in regulating tissue-specific production of collagen V.

Base Sequence↗
PubMed1984

The use of the PREP system for handling of body fluids.

The Du Pont PREP automated sample processor is a centrifugally based, microprocessor controlled instrument that was designed for extraction of samples from biological fluids. Extraction takes place in cartridges containing either organic resins or bonded silica packings as extraction sorbants. This paper will discuss the application of several lipophilic and ion exchange sorbants to the extraction of biological samples from body fluids. The advantages of these different types of sorbants will be compared and their performance with automated sample preparation will be shown. A variety of applications including the extraction of benzodiazepine, barbiturate, aminoglycoside and anticonvulsant drugs and their metabolites from serum, urine, and tissue homogenates will be discussed.

Acyclovir↗
PubMed2003

PreP: gene expression data pre-processing.

UNLABELLED: PreP is a versatile, powerful, standalone application that aims at pre-processing gene expression data. AVAILABILITY: Documentation and executable file for MS-Windows are available at http://chirimoyo.ac.uma.es/bitlab/services/index.htm

Algorithms↗
PubMed2000

Comparison of iodophor and alcohol pledgets with the Medi-Flex blood culture prep kit II for preventing contamination of blood cultures.

Iodophor and alcohol pledgets were compared with the Medi-Flex Prep Kit II for skin disinfection before venipuncture. Of 12,367 blood cultures collected, 6,362 were done with conventional pledgets and 6, 005 were done with Medi-Flex kits. Contamination occurred in 351 of 6,362 blood cultures (5.5%; range, 3.7 to 8.1%) with conventional pledgets versus 328 of 6,005 (5.5%; range, 3.5 to 7.5%) with Medi-Flex kits.

Bacteremia↗