Use of cardiac CT and calcium scoring for detecting coronary plaque: implications on prognosis and patient management.

Clinicians often use risk factor-based calculators to estimate an individual's risk of developing cardiovascular disease. Non-invasive cardiovascular imaging, particularly coronary artery calcium (CAC) scoring and coronary CT angiography (CTA), allows for direct visualization of coronary atherosclerosis. Among patients without prior coronary artery disease, studies examining CAC and coronary CTA have consistently shown that the presence, extent and severity of coronary atherosclerosis provide additional prognostic information for patients beyond risk factor-based scores alone. This review will highlight the basics of CAC scoring and coronary CTA and discuss their role in impacting patient prognosis and management.

Note on the methods for determination of chromic oxide in shrimp feeds.

Chromic oxide is used as an inert marker to measure apparent digestibility of feeds in insects, terrestrial, and aquatic animals. Quantitative determination of chromic oxide content in the sample requires the oxidation of water insoluble trivalent chromic oxide to its water-soluble hexavalent form. The two commonly used oxidizing agents are 70% perchloric acid or a mixture of sodium molybdate, sulfuric, and perchloric acid. Chromic oxide content of the oxidized solution is then measured against known standards either directly by spectrophotometry in the visible range at 350, 370, or 440 nm or after forming a colored complex with diphenylcarbazide (DPC) by colorimetry at 540 nm. This study compared the two methods of oxidation followed by spectrophotometry at the three wavelengths and by DPC colorimetry. DPC colorimetry gave precise results than the direct measurement of dichromate ion, irrespective of the method of oxidation used. Ash from samples oxidized by perchloric acid and quantified by DPC colorimetry gave a better measure of actual chromic oxide content as compared to the other methods tested.

Characteristics of human mononuclear cell fractions separated on the basis of theophylline sensitivity of E rosette forming ability.

T lymphocytes may be separated into theophylline-sensitive (Tsens) and theophylline-resistant (Tres) fractions based on their loss or retention of ERFC-forming ability after incubation with 3 mM theophylline. It has been claimed that Tsens cells have a predominant suppressor function, whilst Tres cells have mainly helper activity. We have studied the sensitive and resistant fractions to ascertain their degree of homogeneity with regard to putative markers for helper and suppressor function. Incubation with theophylline caused no significant change in the expression of OKT3, OKT4, OKT8, and OKM1 antigens. Compared to Tsens, Tres contained significantly more cells expressing OKT4 or Leu 3A antigens and cells bearing Fc mu receptors or containing Gall bodies. The Tsens fraction was enriched for cells with Fc gamma receptors but not for cells expressing OKT8 or LEU 2A. The results suggest that the Tres fraction is enriched for cells with putative helper markers and that the Tsens fraction is enriched for cells with some suppressor markers but also contains a large number of cells of monocytic lineage. However, the two fractions are not homogeneous with respect to Fc receptor status, presence of Gall bodies or antigens defined by OKT or Leu antisera, hence the use of theophylline sensitivity as a means of estimating the sizes of the helper and suppressor populations does not seem advisable.