Two Sri Lankan cases of identified sea snake bites, without envenoming.

Sea snakes are among the most venomous creatures encountered around coasts and reefs, in estuaries, rivers and at sea. Their venoms are more toxic than those of land snakes. However, they are rarely aggressive or menacing. Bites have become unusual with the advent of modern fishing methods but the two encounters we report, in the Indian Ocean off the shores of Sri Lanka, emphasise that sea snake bites may not result in envenoming.     

南海某岛礁作业人员睡眠状况与身心健康状况关系的研究

目的 研究南海某岛礁作业人员睡眠状况与身心健康状况的关系。方法 由经过统一培训的医务人员连续91d每日逐人逐项当面调查、记录。其中的“指数”指标，采用视觉模糊评分法。结果 随着在礁时阃的延长，作业人员睡眠状况明显变差，其主要影响因素依次为值勤（28．73％）、情绪（20．09％）、多梦（10．16％）、噪音（8．86％）和气候（7．73％）等。睡眠状况与身心健康状况明显相关，相关系数7=0．937～0．980，P＜0．01；睡眠指数对身心健康状况各指标均有明显影响（P＜0．01），睡眠时间主要影响体能指数、健康指数、工作质量指数、工作积极性指数、注意力指数及情绪指数等（P＜0．05～0．01），对食欲指数、记忆力指数影响则不明显。结论 在岛礁期间，影响作业人员睡眠的主要因素是值勤和情绪，睡眠状况明显影响身心健康状况。     

香烟烟雾对大鼠血清SOD、MDA和GSHPx水平的影响及硒强化沙棘油的保护作用

目的　探讨吸烟对大鼠血清自由基的影响 ,研究硒强化沙棘油对吸烟所致损伤的保护作用。方法　通过造成大鼠香烟烟雾损伤的模型 ,测定不吸烟对照组、吸烟组和硒强化沙棘油组大鼠血清脂质过氧化物丙二醛 (MDA)含量、全血超氧化物歧化酶 (SOD)和谷胱甘肽过氧化物酶 (GSHPX)活性。结果　大鼠体重减轻 ,大鼠血清MDA含量由对照组的 (6 .77± 0 .6 1)μmol/L升高到 (7.83± 1.0 0 ) μmol/L ,P <0 .0 1,全血SOD和GSHPX 活性也发生了改变。结论　大鼠吸入香烟烟雾 6 0d ,可使大鼠血清自由基含量升高 ,硒强化沙棘油可以保护吸烟造成的脂质过氧化损伤。     

渤海红海葵的生物医学研究——Ⅱ 渤海红海葵刺丝囊的生物医学特征

刺胞动物通过其触手及腔内类触手结构(胃丝、膈膜丝与抢丝)(internal tentaclelike:the gastric filaments,the septal filamentsand the acontia)上数以万千计的刺丝囊使人螫伤致毒。毒液从刺丝囊内通过细丝(刺丝)转输至受害者的组织内。理论上认为,任何具有刺丝囊的刺胞动物都存在潜在的螫器,所致伤害的程度可以从轻微皮炎直至即刻死亡。实际观察分析发现,螫伤的严重性质取决于刺胞动物的种类,刺丝囊的穿透能力,受害     

Radionuclide accumulation in near-shore sediments along the Bulgarian Black Sea coast

The accumulation of radionuclides in Black Sea marine ecosystems was investigated by low level gamma spectrometry. Artificial as well as natural radionuclides were determined in bottom sediments samples from 35 reference locations along the Bulgarian Black Sea coast, evenly distributed from the Rumanian to the Turkish border including the main Black Sea resorts and rivers. The measurement of radionuclides in sea bed sediments was carried out during six consecutive seasons using a HPGe detector. The data obtained show that the nuclide concentrations depend strongly on the sediment nature. Results for sandy sediments are within close range, while those for slime and silt vary to a much greater extent. The radionuclide content in the sandy sediments of the main Black Sea resorts is at the lowest limit of the determined values. Small seasonal changes of radionuclide concentration in sandy sediments were observed while greater variations in slime and silt occur. From the data obtained ¹³⁴Cs/¹³⁷Cs and ¹³⁷Cs_meas/¹³⁷Cs_Chern ratios are calculated to determine the Chernobyl part of the measured ¹³⁷Cs. The activities determined in the sediments for natural radionuclides correspond to those cited in the literature for natural levels, showing no additional anthropogenic contamination. A data base for the nuclide concentration values was created which will enable the modeling of radionuclide transfers by estimation of their concentration variations, accumulation and influence on the marine ecosystems.     

Penetration of selected Dead Sea minerals through a healthy rabbit skin, from a sustained-release transparent varnish, as a prospective treatment for psoriasis

Bathing in the Dead Sea is an established treatment for psoriasis. Penetration of Dead Sea minerals into psoriatic skin is an effective factor in this treatment, but applying it clinically requires frequent bathing in the Dead Sea or in its bath-salt solution. We tested an ethyl-cellulose-based transparent varnish with a sustained-release property, for its penetrability of such minerals. Minerals tested were MgBr₂, and KBr, known for their relevance in psoriatic proliferation. They were applied for up to three weeks. We could demonstrate that two weekly applications of the salt-containing varnish on healthy rabbit skin are enough to obtain elevated levels of magnesium and potassium in their plasma. We propose the application of Dead Sea minerals containing varnish as a clinical treatment for psoriasis.     

Modification of the Na-dependent action potential in myelinated fibers of rat sciatic nerve exposed to phorbol ester

Exposure of rat sciatic nerve to the active phorbol 1,2-beta-myristate-13-acetate (b-PMA), but not to the active analogue 4-alpha-phorbol-12,13-didecanoate (a-PDD), is followed by a decrease of the compound action potential amplitude, rate of rise, and conduction velocity, and an increase of the threshold, and of the duration of the refractory period. The effect is concentration-dependent, the Kd being 250 nM. The attenuated Na-dependent action potential is tetrodotoxin (TTX)-sensitive, but after exposure to b-PMA the sensitivity to TTX is decreased from Kd = 45 nM to 400 nM. Action potential depression is larger when Ca is replaced by Mg (but not by Ba), or when Na is replaced by Li. The replacement of K by Cs, or exposure to potassium channel blockers such as 4-aminopyridine (4AP) and tetra-ethyl ammonium (TEA) has no effect. The results indicate that in the myelinated axons of rat sciatic nerve, exposure to b-PMA induces modification of Na channels.     

Dissolved silver in the Baltic Sea

The increased use of silver as a biocide in nanoparticle formulations has heightened concern on possible environmental implications owing to its toxicity. There is however very little data on the concentration levels of silver in marine and freshwaters. Here, I report data on dissolved (<0.4 μm filter) silver concentration in the surface waters of the Baltic Sea, the first such data reported for a European coastal water body. Levels of dissolved silver in the Baltic are comparable to those reported for other American estuarine waters and range from non-detectable in the open Baltic Sea Proper (<1 pM) to 9.4 pM (1 ng/L) in the Stockholm Archipelago, with a mean of 2.8 pM (0.2 ng/L). Inputs from wastewater treatment are clearly discernable and might constitute the main source of silver to the Stockholm Archipelago and possibly the Baltic Sea Proper.     

Metallothionein cDNA cloning, metallothionein expression and heavy metals in Scapharca inaequivalvis along the Northern Adriatic coast of Italy

The aims of this work were: (1) identification of the metallothionein (MT) gene coding sequence in order to prepare an MT probe in Scapharca inaequivalvis and (2) quantification of Cd, Zn, Cu, MT and MTmRNA expression in tissues of molluscs from three areas along the Northern Adriatic coast of Italy. By RT-PCR we cloned the MTcDNA of S. inaequivalvis using the RNA extracted from hepatopancreas of specimens exposed to Cd. The 61 amino acids sequence of MT was deduced and was 70% identical to S. brughtonii MT. Cd concentration in molluscs from the wild was significantly higher in gills from specimens sampled near Ravenna. Zn concentration in the same tissue was significantly higher in Ravenna with respect to Porto Garibaldi while no difference with respect to Cesenatico was detected. Cu levels showed significant differences among sites in gills and mantle whereas values in the hepatopancreas were similar in all sites. The low MT levels were indicative of a low metal exposure; few differences were found in MTmRNA concentrations, which resulted significantly higher in hepatopancreas of molluscs from Porto Garibaldi.     

Classical conditioning in the sea anemone, Cribrina xanthogrammica

Earlier attempts to classically condition sea anemones have yielded inconclusive results. Using light as CS and shock as US, conditioning as distinguished from sensitization and pseudoconditioning was demonstrated in anemones. Procedural controls included substitution of light alone, shock alone, and random light and shock in place of paired light-shock trials. Responses measured were electrical output and folding of the oral disc. The conditioned response was distinguished from the unconditioned response to light and the unconditioned response to shock in terms of response latency of both electrical and behavioral measures.