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At least 577 records · Page 32Linked to original sources
PubMed1997

Preoperative assessment of tumor angiogenesis by vascular endothelial growth factor mRNA expression in homogenate samples of breast carcinoma: fine-needle aspirates vs. resection samples.

BACKGROUND AND OBJECTIVES: Tumor angiogenesis is receiving increased attention as a prognostic factor and also as a possible target for new anticancer agents. We investigated whether extent of vascular endothelial growth factor (VEGF) mRNA expression correlated with degree of neovascularization, and whether this expression in fine-needle aspirates could be a marker for assessing angiogenic potential of breast tumors. METHODS: VEGF mRNA expression was semiquantitated by reverse transcriptase-polymerase chain reaction (RT-PCR) followed by Southern blotting. Tumor neovascularization was assessed by immunohistochemical staining with anti-CD31 (PECAM) antibody. RESULTS: There was a positive correlation between degree of neovascularization and semiquantitated VEGF mRNA expression in invasive ductal carcinomas (r2 = 0.346, n = 48, P < 0.05). Extent of VEGF mRNA expression in fine-needle aspirates was closely correlated with that in resected invasive ductal carcinomas equal to or less than 3 cm in size (r2 = 0.874, n = 14, P < 0.05). CONCLUSION: These data suggest that semiquantitation of VEGF mRNA expression in fine-needle aspirates is useful for assessing angiogenic potential of invasive ductal carcinomas.

Biopsy, Needle↗
PubMed2000

A Versatile Periodate-Coupled Fluorogenic Assay for Hydrolytic Enzymes We would like to thank Prof. R. Furstoss and Dr. A. Archelas at the Faculté des Sciences de Luminy, Marseille (France) for providing a sample of Aspergillus niger EH and Dr. C. Weijers at the Department of Food Technology and Nutrition Sciences, Wageningen University (the Netherlands) for providing a sample of Rhodotorula glutinis EH. This work was supported by the University of Bern, the European COST program (Action D12), the Swiss Office Fédéral de l'Education et de la Science, the Wander Stiftung, the Ministero della Università e della Ricerca Scientifica e Tecnologica (MURST), and Consiglio Nazionale delle Ricerche (CNR) (Roma). P.C. gratefully acknowledges Merck for generous financial support from the 1999 ADP Chemistry Award.

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Journal Article↗
PubMed2001

Enzyme Fingerprints by Fluorogenic and Chromogenic Substrate Arrays We would like to thank Prof. R. Furstoss and Dr. A. Archelas at the Faculté des Sciences de Luminy, Marseille, France, for providing a sample of Aspergillus niger EH, and Dr. C. Weijers at the Department of Food Technology and Nutrition Sciences, Wageningen University, the Netherlands, for providing a sample of Rhodotorula glutinis EH. This work was supported by the University of Bern, the European COST program (Action D12), the Swiss Office Fédéral de l'Education et de la Science, Protéus SA (Nîmes, France), the Ministero della Università e della Ricerca Scientifica e Tecnologica (MURST), and Consiglio Nazionale delle Ricerche (CNR) (Roma). P.C. gratefully acknowledges Merck for generous financial support from a 2000 ADP Chemistry Award.

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Journal Article↗
PubMed1984

Mutagenicity testing of high performance liquid chromatography fractions from wood stove emission samples using a modified Salmonella assay requiring smaller sample volumes.

Organic extracts of emissions from wood combustion have been fractionated by high performance liquid chromatography (HPLC) into 25-28 fractions. Each fraction was tested for mutagenic activity in a modified Ames Salmonella/microsome bioassay requiring one-third of the test volumes needed for the ususal test. Direct mutagenic activity was noted predominantly in the most polar fractions, whereas indirect mutagenic activity was associated with the fractions containing polycyclic aromatic hydrocarbons (PAH) and with polar fractions probably consisting of aza-arenes and aromatic amines.

Air Pollutants↗
PubMed1993

Power of testing proportions in small two-sample studies when sample sizes are equal.

In planning experiments having two groups of equal but small size, investigators face the uncertainty of power calculations that rely on asymptotic methods. This paper presents a method for determining power for two-sided tests. I compare two randomization tests, Fisher's exact test (FET), and the mid-P (MID), with the uncorrected chi-square test (CHI). Results show power as a function of relative risk for these methods, and assesses their relative power and type I error rates. MID is shown to have intermediate power between CHI, which is the most powerful, and FET, the least powerful. Situations are shown in which CHI and MID occasionally exceed the nominal level of alpha.

Data Interpretation, Statistical↗
PubMed1981

[Marked life events prior to an acute schizophrenic episode. Comparison of a sample of first admissions with a normal sample (author's transl)].

Brown and Birley demonstrated a triggering effect in schizophrenic disorders for life events. In our study no similar result was found. As many events were discovered in controls as in first admission schizophrenic patients for the two 3-month periods assessed: 1-3 months and 4-6 months prior to onset of an acute episode or prior to interview. But methodology used in this study differs with respect to the periods assessed: Brown and Birley used 3-week periods, we used 3-month periods. Patients as well as controls reported significantly more events for the period immediately prior to the onset or interview. We suppose that neither patients nor controls actually experienced fewer events in the second period but that they remembered more of them for the period nearer to the interview.

Acute Disease↗
PubMed2003

Low-temperature electrothermal vaporization of thenoyltrifluoroacetone complex of Sc(III) and Y(III) for sample introduction in an inductively coupled plasma atomic emission spectrometry, and their determination in biological samples.

A new method for inductively coupled plasma atomic emission spectrometry (ICP-AES) determination of trace Sc and Y, based on gaseous compound introduction into the plasma as their thenoyltrifluoroacetone (TTA) complexes by electrothermal vaporization was developed. Using the reagent TTA as chemical modifier can not only enhance the analytical signals, but also reduce the vaporization temperature. At a temperature of 1,000 degrees C the trace Sc and Y can be vaporized completely into ICP. The factors affecting the formation of the chelate and its vaporization behavior, such as drying time, vaporization temperature/time, reaction medium and the amount of TTA, were investigated in detail. Under the optimized conditions (drying temperature/time 100 degrees C/10 s, vaporization temperature/time 1,000 degrees C/4 s), the limits of detection for Sc and Y were 19 pg and 34 pg (3sigma), respectively, and the relative standard deviations for Sc and Y were 4.2% (cSc=0.2 microg mL(-1); n=7) and 2.6% (cY=0.5 microg mL(-1); n=7). The linear ranges of the calibration graphs cover three orders of magnitude. The method was applied to the analysis of the biological reference materials (GBW 07602, bush branches and leaves; GBW 07604, poplar leaves), and the results obtained were in good agreement with the certified values.

Electrochemistry↗