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K Nichols

Publications and source records attributed to K Nichols.

59 records · Page 4Linked to original sources

[Correlation of hematologic parameters with bone marrow and spleen uptake in FDG PET].

OBJECTIVE: To assess the relationship between various hematologic parameters and bone marrow (BM) and splenic uptake of FDG in PET imaging. MATERIAL AND METHODS: 29 patients with Hodgkin's disease (HD) referred for baseline FDG PET imaging before treatment and without evidence of bone marrow (BM) involvement were included in the study. Splenic uptake also was analyzed in 18 patients without splenic involvement. BM and splenic activity were visually graded on a 3 point scale. Activity pattern was classified as homogeneous or heterogeneous. Semi-quantitative analysis was also performed by drawing regions of interest (ROI) over the spine and spleen. ROIs also were drawn over right lung and liver. FDG uptake ratios for the spine and spleen in comparison with the lung and liver were generated. Visual scoring of marrow and splenic uptake, and the various ratios were correlated with hemoglobin (Hb), white blood cell (WBC), and platelet counts, and correlation coefficients were calculated. RESULTS: In 27/29 patients (93 %) BM and in 18/18 patients (100 %) spleen uptake was diffuse. There was a direct correlation between BM and spleen uptake of FDG with increasing WBC, which was stronger than the inverse correlation seen with Hb (the lower the Hb the greater the uptake). Correlation with platelet counts was weaker. CONCLUSION: There is a correlation between hematologic parameters such as Hb, WBC and platelet counts and the uptake of FDG in BM and spleen in PET imaging. Knowledge of this correlation should help to better interpret and understand PET imaging.

Adolescent↗

The solubility of calcium and phosphorus in neonatal total parenteral nutrition solutions.

Precipitation of calcium phosphate in neonatal total parenteral nutrition (TPN) solutions remains a significant problem. Whereas numerous studies have attempted to establish guidelines for maximum concentrations of various combinations that can be mixed, differences in study design and reliance upon subjective visual assessment severely limit their applicability. The purpose of this study was to quantitatively determine calcium and phosphate compatibility in commonly used neonatal TPN solutions containing a final concentration of either 1 or 2% amino acids. The final dextrose concentration was 10%. Electrolytes, heparin, and pediatric vitamins and trace minerals were also added. Calcium gluconate (10%) and potassium phosphate (mono and dibasic) were added by calibrated micropipetors. Calcium concentrations ranged from 5 to 60 mEq/L and phosphate from 5 to 40 mM/L with a minimum of 84 combinations tested for each amino acid concentration. Calcium concentrations were measured in duplicate for each tested combination. Control solutions containing calcium but no phosphate were included to validate the assay methodology. All samples were stored at room temperature for 23.5 hours and then placed in a water bath at 37 degrees C for 30 minutes to simulate incubator conditions encountered during TPN infusion. Calcium determinations were then repeated and precipitation was judged to have occurred whenever calcium concentrations fell below 90% of the initial measured values. These data allowed plotting a calcium and phosphorus reference curve for TPN solutions containing 1 and 2% amino acids based on quantitative assessment. These reference curves should allow pharmacists to avoid compounding TPN solutions that will precipitate, thus saving considerable cost to the pharmacy and preventing complications.

Calcium↗