The nonobese diabetic (NOD) mouse is an excellent model of insulin-dependent (type I) human diabetes mellitus. We report that a single injection of complete Freund's adjuvant (CFA) given at an early age (5 wk) prevented the appearance of diabetes and greatly increased the life span of NOD mice without additional therapy. No treated mouse developed hyperglycemia by the age of 12 mo (n = 13), whereas all untreated mice died of diabetes before 8 mo of age (n = 38). All CFA-treated mice were alive and healthy at 12 mo of age. Some CFA-treated NOD mice that were monitored for long-term survival are still alive with no sign of disease at 18 mo of age (n = 5). Administration of CFA resulted in decreased in vitro splenic lymphocyte proliferative responses to alloantigen and mitogen. Cell-mixing experiments indicated that antigen-nonspecific inhibitory cells were elicited in the spleen and increased in the bone marrow. These regulatory cells were Thy-1- and nonadherent to nylon wool, as has been described for natural suppressor (NS) cells. These data lend support to a relationship between the boosting of endogenous NS activity and the establishment of tolerance to self in the context of autoimmunity. Our results suggest that early nonspecific immunotherapy of genetically predisposed individuals could prevent the development of autoimmune diabetes.

We present an inexpensive, portable and integrated microfluidic instrument that is optimized to perform genetic amplification and analysis on a single sample. Biochemical reactions and analytical separations for genetic analysis are performed within tri-layered glass-PDMS microchips. The microchip itself consists of integrated pneumatically-actuated valves and pumps for fluid handling, a thin-film resistive element that acts simultaneously as a heater and a temperature sensor, and channels for capillary electrophoresis (CE). The platform is comprised of high voltage circuitry, an optical assembly consisting of a laser diode and a charged coupled device (CCD) camera, circuitry for thermal control, and mini-pumps to generate vacuum/pressure to operate the on-chip diaphragm-based pumps and valves. Using this microchip and instrument, we demonstrate an integration of reverse transcription (RT), polymerase chain reaction (PCR), and capillary electrophoresis (CE). The novelty of this system lies in the cost-effective integration of microfluidics, optics, and electronics to realize a fully portable and inexpensive system (on the order of $1000 in component costs) for performing both genetic amplification and analysis - the basis of many medical diagnostics. We believe that this combination of portability, cost-effectiveness and performance will enable more accessible healthcare.

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This work describes a self-contained, simple, disposable, and inexpensive gel capillary cassette for DNA amplification in near point of care settings. The cassette avoids the need for pumps or valves during raw sample delivery or polymerase chain reaction (PCR) amplification steps. The cassette contains capillary reaction units that can be stored at room temperature for up to 3 months. The current cassette configuration format simultaneously tests up to 16 patients for two or more targets, accommodates different sample types on the same cassette, has integrated positive and negative controls and allows flexibility for multiple geometries. PCR reagents in the cassette are desiccated to allow storage at room temperature with rehydration by raw sample at the time of testing. The sample is introduced to the cassette via a transfer pipette simply by capillary force. DNA amplification was carried out in a portable prototype instrument for PCR thermal cycling with fluorescence detection of amplified products by melt curve analysis (MCA). To demonstrate performance, raw genital swabs and urine were introduced to the same cassette to simultaneously detect four sexually transmitted infections. Herpes Simplex Viruses (HSV-1 and HSV-2) were detected from raw genital swabs. Ureaplasma urealyticum (UU) and Mycoplasma homonis (MH) were detected from raw urine. Results for multiple patients were obtained in as little as 50 min. This platform allows multiparameter clinical testing with a pre-assembled cassette that requires only the introduction of raw sample. Modification of the prototype device to accommodate larger cassettes will ultimately provide high throughput simultaneous testing of even larger numbers of samples for many different targets, as is required for some clinical applications. Combinations of wax and/or polymer cassettes holding capillary reaction units are feasible. The components of the cassette are suited to mass production and robotic assembly to produce a readily manufactured disposable reaction cassette that can be configured for disease-specific testing panels. Rapid testing with a disposable reaction cassette on an inexpensive instrument will enable on the spot evaluation of patients in the clinic for faster medical decision-making and more informed therapeutic choices.

Diagnosis platforms incorporating low-cost microfluidic chips enable sensitive, rapid, and accurate genetic analysis that could facilitate customized therapies tailored to match the vulnerabilities of any types of cancer. Using ex vivo cancer cells, we have detected the unique molecular signature and a chromosomal translocation in multiple myeloma. Multiple myeloma is characterized by IgH rearrangements and translocations that enable unequivocal identification of malignant cells, detected here with integrated microfluidic chips incorporating genetic amplification via reverse transcriptase-polymerase chain reaction and capillary electrophoresis. On microfluidic chips, we demonstrated accurate and versatile detection of molecular signatures in individual cancer cells, with value for monitoring response to therapy, detecting residual cancer cells that mediate relapse, and evaluating prognosis. Thus, testing for two clinically important molecular biomarkers, the IgH VDJ signature and hybrid transcripts signaling the t(4;14) chro-mosomal translocation, with predictive value in diagnosis, treatment decisions, and monitoring has been efficiently implemented on a miniaturized microfluidic system.