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Elevated blood ammonia (hyperammonemia) may cause delirium, brain damage, and even death. Effective treatments exist, but preventing permanent neurological sequelae requires rapid, accurate, and serial measurements of blood ammonia. Standard methods require volumes of 1 to 3 mL, centrifugation to isolate plasma, and a turn-around time of 2 h. Collection, handling, and processing requirements mean that community clinics, particularly those in low resource settings, cannot provide reliable measurements. We describe a method to measure ammonia from small-volume whole blood samples in 2 min. The method alkalizes blood to release gas-phase ammonia for detection by a fuel cell. When an inexpensive first-generation instrument designed for 100 µL of blood was tested on adults and children in a clinical study, the method showed a strong correlation (R2 = 0.97) with an academic clinical laboratory for plasma ammonia concentrations up to 500 µM (16 times higher than the upper limit of normal). A second-generation hand-held instrument designed for 10-20 µL of blood showed a near-perfect correlation (R2 = 0.99) with healthy donor blood samples containing known amounts of added ammonium chloride up to 1000 µM. Our method can enable rapid and inexpensive measurement of blood ammonia, transforming diagnosis and management of hyperammonemia.

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INTRODUCTION: Pancreatic cancer has a dismal prognosis because it is often diagnosed at an advanced stage. Therefore, serological biomarkers are eagerly sought for early detection. The digestive enzyme pro-carboxypeptidase A (PCPA) may be able to fill this role. The purpose of this study was to validate and extend previous research done at New York University (NYU), demonstrating that measurement of serum PCPA is a sensitive biomarker for early stage pancreatic cancer. MATERIALS AND METHODS: Samples were collected from 10 early and 16 late stage patients at Jersey Shore University Medical Center (JSUMC) and Robert Wood Johnson Hospital (RWJ) with adenocarcinoma of the head of the pancreas. RESULTS: The percentages of early and late stage cancer patients with PCPA values above the upper limit (2.35 u/L) were 90.0% and 56.0%, respectively. Mean PCPA values for early and late stage cancer were determined to be 22.95 u/L and 3.55 u/L, respectively. In one case, the prospective patient was detected by our assay one month before diagnosis. Additionally, data from an ampullary cancer patient supports the proposed mechanism behind this test. CONCLUSIONS: Combining the JSUMC and NYU results show 94% sensitivity, demonstrating that determining serum PCPA has the requisite sensitivity to detect early stage pancreatic cancer.

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A systematic investigation of the factors governing the reaction product composition, hydrogen bonding, and symmetry was conducted in the MoO3/3-aminoquinuclidine/H2O system. Composition space analysis was performed through 36 individual reactions under mild hydrothermal conditions using racemic 3-aminoquinuclidine. Single crystals of three new compounds, [C7H16N2][Mo3O10] x H2O, [C7H16N2]2[Mo8O26] x H2O, and [C7H16N2]2[Mo8O26] x 4 H2O, were grown. The relative phase stabilities for these products are dependent upon the reactant mole fractions in the initial reaction gel. This phase stability information was used to direct the synthesis of two new noncentrosymmetric compounds, using either (S)-(-)-3-aminoquinuclidine dihydrochloride or (R)-(+)-3-aminoquinuclidine dihydrochloride. [(R)-C7H16N2]2[Mo8O26] and [(S)-C7H16N2]2[Mo8O26] both crystallize in the noncentrosymmetric space group P2(1) (No. 4), which has the polar crystal class 2 (C2). The second-harmonic generation activities were measured on sieved powders. The structure-directing properties of the molybdate components in each compound were determined using bond valence sums. The structures of all five compounds were determined using single-crystal X-ray diffraction.