Human-specific GAPDH qRT-PCR is an accurate and sensitive method of xenograft metastasis quantification.

Metastasis is the primary cause of cancer-related mortality. Experimental models that accurately reflect changes in metastatic burden are essential tools for developing treatments and to gain a better understanding of disease. Murine xenograft tumor models mimic the human scenario and provide a platform for metastasis analyses. An ex vivo quantitative method, gaining favor for its ease and accuracy, is quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR); however, it is currently unclear how well this method correlates with gold-standard histological analysis, and its use has required detection of overexpressed exogenous genes. We have introduced a variation of the qRT-PCR method: human-specific glyceraldehyde 3-phosphate dehydrogenase (GAPDH) qRT-PCR, which allows quantification of metastasis in xenograft models without the requirement of overexpressed exogenous genes. This makes the method easily amenable to many xenograft models without alteration of the cancer cells. We determined that the method is able to detect a few human cells within abundant mouse lung tissue. Further, the human-specific GAPDH qRT-PCR is more sensitive and correlates with histological analysis in terms of determining relative metastatic burden, suggesting that human-specific GAPDH qRT-PCR could be used as a primary method for quantification of disseminated human cells in murine xenograft models.

Macronutrient analysis of donor human milk labelled as 24 kcal/oz.

OBJECTIVE: To measure the macronutrient content (MNC) of donor human milk labelled as 24 kcal/oz ("high-calorie DHM," hcDHM), compare to bank-labelled MNC, and examine variability of hcDHM MNC among milk banks. STUDY DESIGN: MNC was measured with near-infrared spectroscopy for 75 convenience samples from five milk banks collected during September 2016-July 2017. Concordance of measured MNC with labelled values was evaluated using three different thresholds: within ±20%, similar to FDA labelling standards for class II nutrients in foods; ±10%; and ±5%. RESULTS: Protein and caloric content differed significantly between measured and labelled values and varied significantly among milk banks. Measured caloric content ranged from 16.50 to 30.27 kcal/oz, with 89.3% of hcDHM samples within ±20%, 58.7% within ±10%, and 18.7% within ±5% of labelled content. CONCLUSIONS: MNC of hcDHM used in clinical practice shows variation that may result in differences from desired diet. The clinical implications of such differences are unexplored.