Behavioral and Histopathological Impairments Caused by Topical Exposure of the Rat Brain to Mild-Impulse Laser-Induced Shock Waves: Impulse Dependency.

Although an enormous number of animal studies on blast-induced traumatic brain injury (bTBI) have been conducted, there still remain many uncertain issues in its neuropathology and mechanisms. This is partially due to the complex and hence difficult experimental environment settings, e.g., to minimize the effects of blast winds (tertiary mechanism) and to separate the effects of brain exposure and torso exposure. Since a laser-induced shock wave (LISW) is free from dynamic pressure and its energy is spatially well confined, the effects of pure shock wave exposure (primary mechanism) solely on the brain can be examined by using an LISW. In this study, we applied a set of four LISWs in the impulse range of 15-71 Pa·s to the rat brain through the intact scalp and skull; the interval between each exposure was ~5 s. For the rats, we conducted locomotor activity, elevated plus maze and forced swimming tests. Axonal injury in the brain was also examined by histological analysis using Bodian silver staining. Only the rats with exposure at higher impulses of 54 and 71 Pa·s showed significantly lower spontaneous movements at 1 and 2 days post-exposure by the locomotor activity test, but after 3 days post-exposure, they had recovered. At 7 days post-exposure, however, these rats (54 and 71 Pa·s) showed significantly higher levels of anxiety-related and depression-like behaviors by the elevated plus maze test and forced swimming test, respectively. To the best of the authors' knowledge, there have been few studies in which a rat model showed both anxiety-related and depression-like behaviors caused by blast or shock wave exposure. At that time point (7 days post-exposure), histological analysis showed significant decreases in axonal density in the cingulum bundle and corpus callosum in impulse-dependent manners; axons in the cingulum bundle were found to be more affected by a shock wave. Correlation analysis showed a statistically significant correlation between the depression like-behavior and axonal density reduction in the cingulum bundle. The results demonstrated the dependence of behavior deficits and axonal injury on the shock wave impulse loaded on the brain.

Mobile and accurate detection system for infection by the 2009 pandemic influenza A (H1N1) virus with a pocket-warmer reverse-transcriptase loop-mediated isothermal amplification.

The 2009 pandemic H1N1 influenza A virus spread quickly worldwide in 2009. Since most of the fatal cases were reported in developing countries, rapid and accurate diagnosis methods that are usable in poorly equipped laboratories are necessary. In this study, a mobile detection system for the 2009 H1N1 influenza A virus was developed using a reverse-transcriptase loop-mediated isothermal amplification (RT-LAMP) kit with a disposable pocket-warmer as a heating device (designated as pwRT-LAMP). The pwRT-LAMP can detect as few as 100 copies of the virus--which is nearly as sensitive as real-time reverse-transcription polymerase chain reaction (RT-PCR)--and does not cross-react with RNA of seasonal influenza viruses. To evaluate the usefulness of the pwRT-LAMP system, nasal swab samples were collected from 56 patients with flu-like symptoms and were tested. Real-time RT-PCR confirmed that the 2009 H1N1 influenza A virus was present in 27 of the 56 samples. Of these 27 positive samples, QuickVue Influenza A+B immunochromatography detected the virus in only 11 samples (11/27; 40.7%), whereas the pwRT-LAMP system detected the virus in 26 of the 56 samples (26/27 of the positive samples; 96.3%). These findings indicate that the mobile pwRT-LAMP system is an accurate diagnostic system for the 2009 H1N1 influenza A virus, and has great potential utility in diagnosing future influenza pandemics.

[The characteristics of blast traumatic brain injury].

With the increase in terrorist activity in recent times, the number of blast injuries has also increased in civilian and military settings. In a recent war, the number of patients who suffered blast traumatic brain injury (bTBI) increased, so treatment of bTBI is currently a very important issue. Blast injury is complicated and can be divided into 4 categories: primary, secondary, tertiary, and quaternary. Primary blast injury results from exposure to blast waves; secondary blast injury is trauma caused by fragments of explosive devices; tertiary blast injury is the result of collision with objects; and quaternary blast injury is the result of exposure to toxic and other substances. Blast waves mainly injure air-containing organs such as the lung, bowel, and ear. The brain may also be affected by blast waves. From the clinical perspective, hyperemia and severe cerebral edema occur frequently in patients who sustain significant bTBI. Penetrating or closed head injury caused by the explosion may be associated with vasospasm and pseudoaneurysm formation. Mild traumatic brain injury during war can be associated with posttraumatic stress disorder. To elucidate the mechanism of bTBI, many research works using animal models and computer analysis are underway. Such studies have so far shown that blast waves can cause damage to the brain tissue and cognitive deficits; however, detailed investigations on this topic are still required. Treatment of bTBI patients may require clinical knowledge and skills related to intensive care, neurology, and neurosurgery. Moreover, further research is required in this field.

LAMP using a disposable pocket warmer for anthrax detection, a highly mobile and reliable method for anti-bioterrorism.

A quick, reliable detection system is necessary to deal with bioterrorism. Loop-mediated isothermal amplification (LAMP) is a DNA amplification method that can amplify specific DNA fragments in isothermal conditions. We developed a new highly mobile and practical LAMP anthrax detection system that uses a disposable pocket warmer without the need for electricity (pocket-warmer LAMP). In our tests, the detection limit of the pocket-warmer LAMP was 1,000 copies of Bacillus anthracis pag and capB gene fragments per tube. The pocket-warmer LAMP also detected B. anthracis genes from DNA extracted from 0.1 volume of a B. anthracis colony. The lower detection limit of the pocket-warmer LAMP was not significantly different from that of a conventional LAMP using a heat block, and was not changed under cold (4 degrees C) or warm (37 degrees C) conditions in a Styrofoam box. The pocket-warmer LAMP could be useful against bioterrorism, and as a sensitive, reliable detection tool in areas with undependable electricity infrastructures.

Pretreatment with ascorbic acid prevents lethal gastrointestinal syndrome in mice receiving a massive amount of radiation.

While bone marrow or stem cell transplantation can rescue bone marrow aplasia in patients accidentally exposed to a lethal radiation dose, radiation-induced irreversible gastrointestinal damage (GI syndrome) is fatal. We investigated the effects of ascorbic acid on radiation-induced GI syndrome in mice. Ascorbic acid (150 mg/kg/day) was orally administered to mice for 3 days, and then the mice underwent whole body irradiation (WBI). Bone marrow transplantation (BMT) 24 h after irradiation rescued mice receiving a WBI dose of less than 12 Gy. No mice receiving 14 Gy-WBI survived, because of radiation-induced GI syndrome, even if they received BMT. However, pretreatment with ascorbic acid significantly suppressed radiation-induced DNA damage in the crypt cells and prevented denudation of intestinal mucosa; therefore, ascorbic acid in combination with BMT rescued mice after 14 Gy-WBI. DNA microarray analysis demonstrated that irradiation up-regulated expressions of apoptosis-related genes in the small intestine, including those related to the caspase-9-mediated intrinsic pathway as well as the caspase-8-mediated extrinsic pathway, and down-regulated expressions of these genes in ascorbic acid-pretreated mice. Thus, pretreatment with ascorbic acid may effectively prevent radiation-induced GI syndrome.

[Tooth loss and the incidence of ischemic stroke].

Chronic infectious diseases may increase the risk of stroke. We investigated whether periodontal disease was a risk factor for cerebral ischemia. A case-control study with 444 stroke patients, 194 hemorrhagic patients and 250 ischemic patients, and 164 hospital controls with nonvascular and noninflammatory neurological diseases, was performed. All subjects were evaluated by either a CT scan or MRI and their number of teeth was determined. The number of teeth in the patients with cerebral ischemia was found to be significantly fewer than for the cerebral hemorrhage group and a control group between 40 and 65 years of age. The degree of tooth loss was particularly remarkable in patients with atherothrombotic and cardioembolic brain infarction. As a result, tooth loss following severe periodontal disease may therefore be a risk factor for the onset of cerebral infarction in some patients.

[Intra-arterial administration of fasudil hydrochloride: duration of action].

Intra-arterial infusion (IA) of fasudil hydrochloride for cerebral vasospasm is performed in many institutions and is associated with few side effects. Nonetheless, as optimum dose and duration of action remain unknown, the present study aimed to clarify these variables. We performed intra-arterial injection of fasudil hydrochloride for eight patients with cerebral vasospasm 7-13 days after subarachnoid hemorrhage. Fasudil hydrochloride was administered via the internal carotid artery without selective microcatheterization, at a concentration and speed of 30 mg/20 ml/10-15 min, using a total dose of 30-60 mg. Cerebral angiography was used to measure change in blood vessel diameter at 19 points, and perfusion CT was used to detect changes in cerebral blood perfusion (CBP), cerebral blood volume (CBV), and mean transit time (MTT) at 12 hemispheres. Investigations were performed before IA, immediately after IA (post IA), and 4.5 to 6 hours later. For central vessels, (A1, M1) mean change in diameter (cm) measured pre IA, post IA, and 4.5-6 hours later was 1.2 +/- 0.68, 1.5 +/- 0.72, and 1.2 +/- 0.7, respectively. For peripheral vessels (peripheral to A1, M1, and the ophthalmic artery) change in diameter (cm) was 0.65 +/- 0.16, 0.97 +/- 0.24, and 0.71 +/- 0.24, respectively. Average CBP (m/100g/min) in the infused hemisphere at pre IA, post IA, and 4.5-6 hours later was 41.6 +/- 3.56, 46.4 +/- 5.82, 41.6 +/- 7.42, respectively. Average CBV (ml/100g) was 2.72 +/- 0.21, 2.73 +/- 0.21, 2.91 +/- 0.42, respectively and average MTT (sec) was 5.16 +/- 0.38, 4.57 +/- 0.70, 5.55 +/- 1.0, respectively. Changes in peripheral vessel diameter and in MTT were statistically significant. Therefore, when performing intra-arterial administration of fasudil hydrochloride, clinicians should be aware that vasodilator effect is less than 6 hours.