A prospective study comparing rapid assessment of smears and ThinPrep for endoscopic ultrasound-guided fine-needle aspirates.

BACKGROUND AND STUDY AIMS: ThinPrep is often used for endoscopic ultrasound fine-needle aspiration (EUS-FNA) samples but the sensitivity of this method is unknown. The objective of the study was to compare sensitivity and accuracy of ThinPrep versus the smear method in pancreas and lymph node samples obtained by EUS-FNA. PATIENTS AND METHODS: Patients with suspected malignancy in the pancreas or lymph node underwent EUS-FNA. On-site rapid assessment of all aspirates using the smear method was performed. After rapid assessment, three additional passes from each site were submitted into ThinPrep liquid medium. Cytopathologists interpreting the smear method and ThinPrep slides were blinded to each other. The gold standard was final cytology or pathology results. RESULTS: A total of 130 patients (36 % women, mean age 63 years) underwent EUS-FNA of 139 sites (50 pancreas, 89 lymph node). Malignancy was confirmed in 47 pancreas samples (94 %) and 48 lymph node samples (54 %). Mean +/- SD number of passes made for the smear method was 2.6 +/- 1.3. For pancreatic cancer, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the ThinPrep versus the smear method were: 62 % versus 98 %, 100 % versus 100 %, 100 % versus 100 %, 14 % versus 75 %, and 64 % versus 98 %, respectively. For lymph nodes the values were 67 % versus 92 %, 100 % versus 98 %, 100 % versus 98 %, 72 % versus 72 %, and 82 % versus 94 %, respectively. CONCLUSIONS: The smear method is more sensitive and accurate than ThinPrep in detecting malignancy from EUS-FNA samples of the pancreas and lymph nodes. Smear method with on-site rapid assessment should be favored over ThinPrep in suspected malignancy.

Medicinal chemistry of difluoropurines.

A series of over 70 difluoropurine analogs was synthesized by varying the C-2, 6 and 8 substituents about the purine ring system. After initial in vitro and in vivo screening, testing concentrated on the 2,6-diaminopurine analog (dFdAP) and the guanosine analog (dFdG). dFDAP appears to be a prodrug for dFdG. Both compounds significantly inhibited mammary tumor growth in mice, caused a moderate inhibition in ovarian and lymphosarcoma models, and demonstrated no activity in lung and melanoma models. This is a narrower spectrum of activity than that of gemcitabine (dFdC). The antitumor activity of dFdAP in human xenografts that are refractory to standard clinical agents was comparable or superior to that of gemcitabine. However, during the preliminary toxicology testing, dFdG was associated with several deaths caused by cardiac toxicity. Therefore, although dFdG is a potentially useful oncolytic, further investigation is required.

The case against mandatory continuing education.

Requiring continuing education (CE) for RN relicensure began in the 1970s and has remained a controversial issue over the past 25 years. This article is a description of the process used by nurses in one state to investigate the complex issues surrounding mandatory continuing education for relicensure and the factors that led state nursing leaders to support the continuation of a voluntary CE system. Included are the findings of a survey of all states currently requiring continuing education for relicensure. The primary reason given for mandating CE was to protect the public, however, no data are available to support this premise.

p120 Ras GTPase-activating protein interacts with Ras-GTP through specific conserved residues.

Previous structural studies of RasGAP have failed to clearly localize sites of Ras interaction to individual amino acids. Hypothesizing that sites of interaction with Ras-GTP would be conserved, 11 of the most highly conserved amino acid residues of RasGAP were changed by mutation. Each mutant protein was purified as a glutathione S-transferase catalytic domain fusion and analyzed for protein stability, Ras GTPase stimulating activity, affinity for Ras-GTP, and when possible, secondary structure. The majority of conserved positions were found to be important structurally but with no direct role in Ras interactions. However, Arg786, Lys831, and Arg925 were observed to be essential for binding to Ras-GTP but not for protein structure. RasGAP residues 890-902 (block 3A) were observed to be homologous to residues 1540-1552 of the yeast adenylyl cyclase with amino acid substitutions in both regions resulting in increased affinity for Ras. This is the first example of a conserved Ras interaction motif in distinct Ras effector proteins. Our data are supportive of a model for GAP/Ras-GTP association in which the conserved, positively charged Arg786, Lys831, and Arg925 residues form salt bridges with the conserved, negatively charged residues in the Ras effector loop.