Simple determination of carboxyhemoglobin by double wavelength spectrophotometry of absorbance difference and the comparison with gas chromatographic method

This paper describes the spectrophotometric determination of carboxyhemoglobin (CO-Hb) in blood on the basis of double wavelength spectrophotometry of absorbance difference. Absorbance measurements are made in the 500–600 nm region at a blood dilution of 100–200-fold. Blood is diluted with a solution containing Na₂S₂O₄ to provide two components of CO-Hb and deoxyhemoglobin (deoxy-Hb). Absorbance difference at the two wavelengths at which deoxy-Hb has the same absorbance reflects only the CO-Hb component because the opposite component is nulled out of the mixture. After measurement of the absorbance difference, the measuring solution is saturated with CO gas to make all Hb derivative CO-Hb and remeasured at the same wavelengths. The percent of CO-Hb is considered the absorbance difference ratio. Results obtained by the present method was in satisfactory agreement with gas chromatographic data in blood not containing methemoglobin (Met-Hb). Comparative experiments using the gas chromatographic method and the present method were performed with samples containing Met-Hb. However, while there is a deficiency in the gas chromatographic method when the samples contain Met-Hb, the results of the present method were in close agreement with theoretical values when samples are mixed with CO-Hb, O₂-Hb and Met-Hb. Advantages of this method are that it is simple and accurate, standard curve or equation for calculation and accurate dilution are not necessary.     

Psychosocial and Symbolic Dimensions of the Breast Explored through a Visual Matrix

This article explores knowledge about the breast in lived experience, addressing a gap in empirical research on a highly gendered cultural trope and embodied organ. We present findings from a study that used a free-associative psychosocial method—the Visual Matrix—in order to stimulate expressions of tacit aspects of the breast, aiming to generate an understanding of relations between embodied and enculturated experiences. Our data revealed how an aesthetic of the grotesque in one matrix allowed the mainly female group to use humour as a “creative psychic defence” against culturally normative and idealized aspects of the breast. This was expressed through symbolizations, affectively delivered in an exuberant mode, emphasizing the breast‘s potency and its potential for nurturance and “weaponization”. Through this feminine poetic, life and death became inseparable yet ambiguous dimensions of breasts. The breast’s life-affirming qualities included the sensual, the visceral, and the joyful—a material-semiotic knowing. This was incontrast to a second matrix, which expressed a more ambivalent and troubled response, and in which associations were weighted towards the spectacular breast of an ocular-centric culture that privileges hetero-masculine looking. We discuss differences between the two matrices in terms of psychosocial tensions between embodied and enculturated experiences.