Simple and convenient preconcentration procedure for the isotopic analysis of uranium in seawater.

The demand for monitoring anthropogenic U isotopes, 236U and 233U, in seawater will continue to increase due to radioecological issues and the need for tools for environmental dynamics research. In response to this growing demand, herein, a novel and simple method was developed for the collection of U isotopes in seawater, both in the laboratory and field, using a fabric-like amidoxime adsorbent. The results from the adsorption studies showed that the optimum conditions for processing seawater in a glass beaker were as follows: seawater pH 4, amidoxime adsorbent 0.20 mmol per 500 g seawater and an adsorption time of 9 hours. Alternatively, when using a closed polyethylene container in experiments on-board a ship and using the same ratio of adsorbent to seawater as in the beaker experiment in the laboratory, the optimum conditions were as follows: seawater pH 8 and an adsorption time of 24 hours. Under the above-mentioned conditions, more than 95% of the U underwent adsorption in both the beaker and the polyethylene container experiments. In the case of analyte desorption, more than 80% of U in seawater was recovered using 2-3 mol dm-3 HCl or HNO3 as the eluent. Thus, it was concluded that the amidoxime adsorbent can serve as a simple and effective pre-concentration method for the ultra-trace monitoring of U isotopes in seawater.

Light-Addressable Potentiometric Sensor as a Sensing Element in Plug-Based Microfluidic Devices.

A plug-based microfluidic system based on the principle of the light-addressable potentiometric sensor (LAPS) is proposed. The LAPS is a semiconductor-based chemical sensor, which has a free addressability of the measurement point on the sensing surface. By combining a microfluidic device and LAPS, ion sensing can be performed anywhere inside the microfluidic channel. In this study, the sample solution to be measured was introduced into the channel in a form of a plug with a volume in the range of microliters. Taking advantage of the light-addressability, the position of the plug could be monitored and pneumatically controlled. With the developed system, the pH value of a plug with a volume down to 400 nL could be measured. As an example of plug-based operation, two plugs were merged in the channel, and the pH change was detected by differential measurement.

Multifocal Cellulitis due to Disseminated Neisseria Gonorrhoeae in a Male Patient.

We report a rare case of disseminated gonococcal infection in a 37-year-old man presenting with multifocal cellulitis. The patient presented with fever and painful swelling of the right foot and left hand, and was admitted to our hospital. CT scanning of the extremities revealed multifocal cellulitis. Transthoracic echocardiography findings were normal, and piperacilin/tazoactam therapy was initiated. On antibiotic day 4, Neisseria gonorrhoeae was cultured from a purulent effusion collected from a focal site. Chlamydia trachomatis was detected in urine samples by PCR. We made the diagnosis of multifocal cellulitis due to N. gonorrhoeae in a patient with chlamydia urethritis. The antibiotic agent was changed from piperacilin/tazobactam to ceftriaxone. Levofloxacin was also administered for chlamydia urethritis. By admission day 14, all lesions had resolved and administration of antibiotic agents was terminated. Disseminated gonococcal infection, although rare, should be included in the differential diagnosis of all sexually active patients who present with multifocal cellulitis - also a rare condition, particularly in light of the fact that in recent times, patterns of sexual activity have changed, which was a pertinent factor in this case.

Effects of adrenomedullin on acute ischaemia-induced collateral development and mobilization of bone-marrow-derived cells.

Adrenomedullin exerts not only vasodilatory effects, but also angiogenic effects. In the present study, we investigated the effects of adrenomedullin on collateral formation and circulating bone-marrow-derived cells after acute tissue ischaemia. Bone marrow of 8-10-week-old female C57BL/6J mice was replaced with that from GFP (green fluorescent protein) transgenic mice (GFP mice). At 8 weeks after transplantation, hindlimb ischaemia was induced by resecting the right femoral artery and a plasmid expressing human adrenomedullin (50 mug) was injected into the ischaemic muscle, followed by in vivo electroporation on a weekly basis. Overexpression of adrenomedullin significantly enhanced the blood flow recovery compared with controls (blood flow ratio, 1.0+/-0.2 compared with 0.6+/-0.3 respectively, at week 4; P<0.05) and increased capillary density in the ischaemic leg as determined by anti-CD31 immunostaining of the ischaemic muscle (567+/-40 compared with 338+/-65 capillaries/mm(2) respectively, at week 5; P<0.05). There were more GFP-positive cells in the thigh muscle of the mice injected with adrenomedullin than in that of the control mice (29.6+/-4.5 compared with 16.5+/-3.3 capillaries/mm(2) respectively, at week 5; P<0.05). We repeated the same experiments using LacZ-knock-in mice instead of GFP mice, and obtained similar results. These findings suggest that adrenomedullin may augment ischaemia-induced collateral formation with some effects on circulating bone-marrow-derived cells.

Adrenomedullin augments collateral development in response to acute ischemia.

Expression of adrenomedullin, discovered as a vasodilatory peptide, is markedly up-regulated under pathological conditions such as tissue ischemia and inflammation, which are associated with neovascularization. Here, we tested the hypothesis that overly expressed adrenomedullin may augment collateral flow to ischemic tissues. We induced hindlimb ischemia in wild-type mice and injected a naked plasmid expressing human adrenomedullin or an empty vector into the ischemic muscle, followed by in vivo electroporation. Adrenomedullin markedly enhanced blood flow recovery as determined by Laser Doppler imaging. The mice treated with an empty vector suffered frequent autoamputation of the ischemic toe, which was completely prevented by adrenomedullin. Anti-CD31 immunostaining revealed that adrenomedullin significantly increased capillary density. The angiogenic effect of adrenomedullin was abrogated in endothelial nitric oxide synthase (eNOS)-deficient mice. These results indicate that adrenomedullin may promote collateral growth in response to ischemia through activation of eNOS.