Mercury content in the Siberian tiger (Panthera tigris altaica Temminck, 1844) from the coastal and inland areas of the Russia.

Being a global pollutant, mercury can originate from both natural as well as anthropogenic sources. Coastal marine atmospheric fog is considered a potential source of ocean-derived monomethylmercury (MMHg) to coastal terrestrial ecosystems. However, the ratio between mercury appearing through natural processes and that from the results of human activity is unclear. We assumed that the total mercury content in the fur of tigers would differ depending on the distance from the sea. Here we show that the average mercury content in tigers from the coast (0.435 ± 0.062 mg kg-1) is significantly different from tigers from the inland area (0.239 ± 0.075 mg kg-1), (p = 0.02). We found that the content of mercury in the fur of tigers is largely dependent of natural processes rather than human activity. We assume that the levels of mercury in coastal ecosystems in the south of the Russian Far East reflect the position of the region relative to the deep faults of the East Pacific Platform. Obtained data indicate that environmental risks associated with mercury pollution currently exist, but do not pose a serious threat to Siberian tigers.

[Severe carotid stenosis: cerebral autoregulation in the ipsilateral region]. / Kriticheskie stenozy vnutrennikh sonnykh arterii: tserebral'naia autoreguliatsiia v ipsilateral'nom basseine.

AIM: To study cerebral autoregulation (CA) in region of the stenotic carotid artery. MATERIAL AND METHODS: The study involved 35 patients with critical stenosis of the carotid arteries, including 24 patients were asymptomatic and 11 patients with symptomatic course. Blood flow velocity in middle cerebral arteries was monitored using Multi Dop X (DWL, Germany) with simultaneous noninvasive systemic blood pressure registration (CNAP, Austria). CA was assessed by calculating the phase shift (PS) between spontaneous oscillations of blood flow velocity and blood pressure within the range of systemic Mayer waves (80-120 mHz). RESULTS: In 18 patients, the CA indicators were in the normal range (PS 1.2±0.3 rad). Seventeen patients, including asymptomatic as well as symptomatic types, had impaired CA (PS 0.2±0.2 rad and 0.3±0.2 rad, respectively). Reconstructive surgery, irrespective of clinical manifestations, led to the significant increase in PS (p<0.001) in the early postoperative period (0.9±0.5 and 0.9±0.3 rad, respectively). CONCLUSION: A significant variability in the cerebrovascular reserve capacity in symptomatic and asymptomatic types of carotid artery stenosis was found. CA can be used in determining the indications for surgical treatment and evaluation of its effectiveness in patients with stenosis of carotid arteries.

Effect of ambient temperature increase on intestinal mucosa amylolytic activity in freshwater fish.

The relationship between the level of the intestinal mucosa amylolytic activity (AA) of juvenile goldfish Carassius auratus, carp Cyprinus carpio, roach Rutilus rutilus and perch Perca fluviatilis and the rate of water temperature increase was studied. Increase in water heating rate significantly influences AA and the level of upper lethal temperatures defined by critical thermal maximum (CTM) during different seasons. At a low rate of water temperature increase, 0.04 °C/h, AA and the level of CTM are maximal during all seasons. More rapid rates of heating, 4-50 °C/h, increase the AA during the summer and usually decrease it by 2- to 7.5-fold during other seasons. Rapid increase in ambient temperature in the autumn-winter period, unnatural for seasonal dynamics, produces a negative impact upon the fish's carbohydrate hydrolysis rate and thermal resistance.

Feeding behavior and brain acetylcholinesterase activity in bream (Abramis brama L.) as affected by DDVP, an organophosphorus insecticide.

1. Bream (Abramis brama) were exposed to sublethal concentration of organophosphorus insecticide DDVP and the amount of food consumed and brain acetylcholinesterase (AChE) examined in exposed fish. 2. Exposure to DDVP resulted in decreased amount of food consumed and inhibited brain AChE activity. 3. Intraperitoneal injection of the fish with cholinergic drugs, atropine and TMB-4 recovered the feeding efficiency in exposed fish. TMB-4 recovered brain AChE activity as well. 4. The results revealed that cholinergic system in fish brain constitutes biochemical mechanism controlling feeding behavior in fish.