The spotted ratfish Hydrolagus colliei as a potential biomonitor of mercury and selenium from deep-waters of the northern Gulf of California.

The purpose of this work was to use the deep-water chimaera Hydrolagus colliei to examine the bioaccumulation and availability of Hg and Se in its deep-water habitat; the Se:Hg molar ratio was calculated to establish baseline information of the species and its associated ecosystem. The organisms were collected from northern Gulf of California. Hg levels in muscle were higher than liver and the opposite pattern happened with Se concentrations. Female had total lengths and weights higher than male but there were not found differences between elements concentrations by sex. Hg in muscle was correlated with weight. Molar Se:Hg ratio in muscle was the lowest compared to the liver. It was hypothesized that Hg and Se uptake to H. colliei were by its feeding habits because is a dominant species component of the demersal ecosystem and that play and important functional role in the control of oceanic ecosystem structure and function.

Aneurysmal subarachnoid hemorrhage: A pilot study for using longitudinal cognitive and neuropsychological testing for functional outcomes.

OBJECTIVES: Patients with aneurysmal subarachnoid hemorrhage (aSAH) often sustain substantial cognitive and functional impairment. Traditional outcome measures have emphasized radiographic and gross clinical outcomes, but cognitive and functional outcomes are less frequently documented. This pilot study assessed the feasibility of administering longitudinal cognitive and neuropsychological testing and tracked patterns of functional improvement in aSAH patients. PATIENTS AND METHODS: Standardized cognitive and neuropsychological testing were administered to a prospective cohort of aSAH patients admitted for treatment to our tertiary care center. Thirty consecutive aSAH patients (Hunt and Hess score 1-3) were enrolled over 23-months and baseline evaluations were completed within 24-h after admission. Patients were followed prospectively after treatment (coiling or clipping) at 1-, 3-, 6-, and 12-months. Functional outcome measures included the Montreal Cognitive Assessment, the Neuropsychiatric Inventory-Questionnaire, and the Functional Activities Questionnaire. RESULTS: Of the 30 patients, 23 (77%) followed-up at 3-months, 21 (70%) at 6-months, and 19 (63%) at 12-months. Improvement from baseline to follow-up at 12-months was noted for general cognitive function (p = .004), memory (p = .025), and executive function (p = .039), with the greatest improvement occurring within 6-months. Daily function also improved mostly within 6-months (p = .022) while changes in neuropsychological disturbances were insignificant from baseline to follow-up at 12-months (p = .216). CONCLUSION: Standardized cognitive and neuropsychological testing provides metrics for evaluating functional outcomes following treatment of aSAH. The addition of a brief battery of tests to routine clinical and radiographic evaluations is feasible. The main limitations are related to practice and referral patterns, and future studies are needed to evaluate the impact of treatment modalities on functional outcomes.

The influence of the size and condition of the reamers on bone temperature during intramedullary reaming.

BACKGROUND: The objectives of this study were to determine whether intramedullary reaming increases bone temperature in vivo to a level that is high enough to produce bone necrosis and to determine the influence of the size and the condition of the reamers on the temperature increase. METHODS: Bone temperature variations were recorded in vivo during intramedullary tibial reaming in fourteen minipigs. The left tibiae were progressively reamed from 6 to 9 mm. The right tibiae were reamed with only 8 and 9-mm reamers. The variables studied were the initial and final temperature and the increase in the temperature. Two weeks after reaming, the tibiae were removed and studied histologically. RESULTS: Intramedullary reaming produced an average increase (and standard deviation) in bone temperature of 6.9 degrees C +/- 4.1 degrees C. The peak temperatures ranged from 34.9 degrees C to 49.4 degrees C. The average maximum bone temperature was 38.1 degrees C +/- 2.8 degrees C when the reaming was done progressively from 6 to 9 mm and 41.1 degrees C +/- 4.4 degrees C when the reaming was done only with the 8 and 9-mm reamers. The mean increase in the temperature in the second group of animals (8.2 degrees C +/- 4.3 degrees C) was greater than that in the first group (5.4 degrees C +/- 3.5 degrees C). Reaming with sharper reamers in the first seven animals resulted in a smaller mean increase in temperature than did reaming with less sharp reamers in the last seven animals (4.6 degrees C compared with 9.2 degrees C; p = 0.001). Histological examination of the tibiae showed periosteal proliferation and an altered disposition of the osteons at the inner cortex with occasional necrotic bone fragments in the medullary canal. CONCLUSIONS: Intramedullary reaming in the minipig increased bone temperature. When the reamer initially used was larger than the diameter of the medullary canal and when the reamers were blunted by repeated use, the maximum temperature reached by the bone was higher. This increase in temperature with use of typical medullary reaming techniques did not exceed the limits that would produce bone necrosis.