Use of saliva-based nano-biochip tests for acute myocardial infarction at the point of care: a feasibility study.

BACKGROUND: For adults with chest pain, the electrocardiogram (ECG) and measures of serum biomarkers are used to screen and diagnose myocardial necrosis. These measurements require time that can delay therapy and affect prognosis. Our objective was to investigate the feasibility and utility of saliva as an alternative diagnostic fluid for identifying biomarkers of acute myocardial infarction (AMI). METHODS: We used Luminex and lab-on-a-chip methods to assay 21 proteins in serum and unstimulated whole saliva procured from 41 AMI patients within 48 h of chest pain onset and from 43 apparently healthy controls. Data were analyzed by use of logistic regression and area under curve (AUC) for ROC analysis to evaluate the diagnostic utility of each biomarker, or combinations of biomarkers, in screening for AMI. RESULTS: Both established and novel cardiac biomarkers demonstrated significant differences in concentrations between patients with AMI and controls without AMI. The saliva-based biomarker panel of C-reactive protein, myoglobin, and myeloperoxidase exhibited significant diagnostic capability (AUC = 0.85, P < 0.0001) and in conjunction with ECG yielded strong screening capacity for AMI (AUC = 0.96) comparable to that of the panel (brain natriuretic peptide, troponin-I, creatine kinase-MB, myoglobin; AUC = 0.98) and far exceeded the screening capacity of ECG alone (AUC approximately 0.6). En route to translating these findings to clinical practice, we adapted these unstimulated whole saliva tests to a novel lab-on-a-chip platform for proof-of-principle screens for AMI. CONCLUSIONS: Complementary to ECG, saliva-based tests within lab-on-a-chip systems may provide a convenient and rapid screening method for cardiac events in prehospital stages for AMI patients.

Microchip-based enumeration of human white blood cells.

The advent of flow cytometry has considerably changed the ways in which medical testing is conducted. However, the cost of flow cytometers, their large size, and their maintenance needs make them scarce in resource-poor settings and available almost only in clinical pathology laboratories in developed countries. Because cell enumeration is a basic and crucial support of diagnosis, prognosis, and treatment, an alternative cell-counting method that would potentially be cost-effective, portable, and suitable for use in resource-poor settings is warranted. We describe here a protocol for conducting cell-counting experiments in a simple microfluidic structure. This protocol describes how to build a simple microfluidic cell and perform a total white blood cell (WBC) count through capture and immunolabeling of the WBCs with an anti-CD45 antibody.

The functions of Klarsicht and nuclear lamin in developmentally regulated nuclear migrations of photoreceptor cells in the Drosophila eye.

Photoreceptor nuclei in the Drosophila eye undergo developmentally regulated migrations. Nuclear migration is known to require the perinuclear protein Klarsicht, but the function of Klarsicht has been obscure. Here, we show that Klarsicht is required for connecting the microtubule organizing center (MTOC) to the nucleus. In addition, in a genetic screen for klarsicht-interacting genes, we identified Lam Dm(0), which encodes nuclear lamin. We find that, like Klarsicht, lamin is required for photoreceptor nuclear migration and for nuclear attachment to the MTOC. Moreover, perinuclear localization of Klarsicht requires lamin. We propose that nuclear migration requires linkage of the MTOC to the nucleus through an interaction between microtubules, Klarsicht, and lamin. The Klarsicht/lamin interaction provides a framework for understanding the mechanistic basis of human laminopathies.

Drosophila klarsicht has distinct subcellular localization domains for nuclear envelope and microtubule localization in the eye.

The Drosophila klarsicht (klar) gene is required for developmentally regulated migrations of photoreceptor cell nuclei in the eye. klar encodes a large ( approximately 250 kD) protein with only one recognizable amino acid sequence motif, a KASH (Klar, Anc-1, Syne-1 homology) domain, at its C terminus. It has been proposed that Klar facilitates nuclear migration by linking the nucleus to the microtubule organizing center (MTOC). Here we perform genetic and immunohistochemical experiments that provide a critical test of this model. We analyze mutants in the endogenous klar gene and also flies that express deleted forms of Klar protein from transgenes. We find that the KASH domain of Klar is critical for perinuclear localization and for function. In addition, we find that the N-terminal portion of Klar is also important for function and contains a domain that localizes the protein to microtubules apical to the nucleus. These results provide strong support for a model in which Klar links the nucleus to the MTOC.