Assessment of HIV prevalence among MSM in Tokyo using self-collected dried blood spots delivered through the postal service.

BACKGROUND: Men who have sex with men (MSM) are at high risk of HIV infection. However, there are only few data on HIV prevalence in MSM in Japan. The objective of this study was to explore the HIV prevalence in MSM at Shinjuku 2-chome, a well known gay quarter in Tokyo. METHODS: MSM directly collected the dried blood spot (DBS) self-collection HIV test kit from a drop-in center in Shinjuku 2-chome between August 2015 and December 2016. The participants collected their own blood by finger-prick and anonymously posted the kit to the laboratory. The participants accessed the study website and checked the results of their tests using unique ID and password. DBS was soaked in phosphate buffered saline overnight and the eluted sample was examined by the fourth generation HIV Ag/Ab test of LUMIPULSE (FUJIREBIO INC.), and followed by HISCL (Sysmex Corp.) when the first assay was positive. The result was defined provisionally positive if both were positive. RESULTS: A total of 1702 HIV test kits were distributed and 1403 DBS were returned (return rate: 82.4%). Since 20.2% of participants collected the test kit more than once, the estimated number of actual test kit users was 1120. Based on the results of the test kit, 34 cases were provisionally diagnosed with HIV. The estimated prevalence was 3.04% (95% confidence interval: 2.03-4.04). Of these 34, 24 (70.6%) were later confirmed to be HIV-positive in the hospital, while the remaining 10 were lost to follow-up. Among the participants, 34.5% received HIV test for the first time. Especially in those aged 20-29, 46.0% were first time HIV testers. CONCLUSIONS: The prevalence of HIV infection in the study population was 3.04%. The high collection suggested a demand for this type of testing in MSM. The test should be expanded further to difficult-to-reach or hidden populations. TRIAL REGISTRATION: This study was registered with the University Hospital Medical Information Network Clinical Trial Registry in August 20th, 2015 (Registry number: UMIN000018699 ).

Novel determination system for urea in alcoholic beverages by using an FIA system with an acid urease column.

A novel determination method for urea using an acid urease column-FIA system was developed, and the system was applied to the determination of urea in rice wine. This novel FIA system was characterized by CO2 detection due to the property of acid urease and by a microfluidic gas-diffusion device with the use of an ultra-thin hollow fiber membrane. A biosensing system fabricated in this study was assembled with a double-plunger pump, a sample-injection valve, an immobilized acid urease column as a recognition element for the assay of urea, a gas-diffusion unit, and a flow-type spectrophotometer. The gas-diffusion unit consisted of a double-tubing structure in which the outer tubing was made of PTFE (i.d. 1.0 mm; o.d. 1.5 mm) and the inner tubing was of porous PTFE (i.d. 0.19 mm; o.d. 0.25 mm). Standard urea solutions (20 microl) were measured through monitoring variations in the absorbance of a coloring agent solution resulting from a pH shift due to carbon dioxide molecules being enzymatically generated. A wide and linear relationship was obtained between the concentration of urea (16 microM - 1.0 mM) and the change in absorbance. This FIA system has great advantages that the system did not suffer from ammonia and ethanol in samples. This system, armed with a microfluidic gas-diffusion device, was applicable to the determination of various substrates of many kinds of decarboxylase, amino-acid oxidase, and amino-acid oxygenase, producing CO2 and NH3 molecules.

A disappearing left atrial thrombus.

The authors report a case of a migrating left atrial thrombus identified under direct visualization using transthoracic echocardiography in an elderly patient with atrial fibrillation. The left atrial-ventricular-aortic course of the thrombus was observed in real time, and prompt diagnosis and treatment of an acute cardioembolic cerebral infarction were performed. This case provides an example of the importance of transthoracic echocardiography in the diagnosis of stroke.