Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 420643

The pneumatonograph. A laboratory study.

R A Moses·W J Grodzki
View original source ↗Export metadata ↓

Abstract

The scale reading of the pneumatonograph (PTG) is dependent on the force of application to the cornea. Since this force is relatively greater at low intraocular pressure, the scale is compressed, yielding an overestimate of intraocular pressure in physiologic range. When the PTG is held vertically, the weight of the plunger is added to the gas propulsion force and the compression of the scale is accentuated. When a 10-g plunger load is added, as is advocated for tonography, the scale compression is further accentuated. We conclude that the PTG scale is compressed, the PTG is position-sensitive, and that the PTG is totally unsuited to tonography. The PTG is not an applanation tonometer and should not be confused with applanation tonometers.

Explore related subjects

False Positive ReactionsHumansIn Vitro TechniquesIntraocular PressureTonometry, OcularJournal ArticleResearch Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

R A Moses, W J Grodzki. 1979. The pneumatonograph. A laboratory study.. https://doi.org/10.1001/archopht.1979.01020010291023

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2006

Novel homogenous time-resolved fluorometric RT-PCR assays for quantification of PSA and hK2 mRNAs in blood.

OBJECTIVES: The purpose of this study was to design, validate, and optimize internally standardized real-time quantitative RT-PCR assays and to identify and avoid problems with assay reliability and examine the impact of an exogenous internal standard. DESIGN AND METHODS: The model system consisted of internally standardized quantitative real-time RT-PCR assays specific for PSA and hK2 mRNA based on time-resolved fluorometric detection of lanthanide chelates. RESULTS: Reproducibility was best when large copy numbers (>5000 per milliliter blood) were analyzed. Addition of an exogenous target-mimicking internal standard had no significant effect on the reproducibility of the method, but increased the calculated copy numbers by an average of 2-fold. CONCLUSIONS: We developed an internally standardized, specific and reproducible real-time RT-PCR analysis method for PSA and hK2 mRNA in circulating cells in the bloodstream. Both PSA and hK2 assays are sufficiently sensitive to detect two LNCaP cells per milliliter whole blood.

False Positive Reactions↗