Regional distribution of nitric oxide synthase and NADPH-diaphorase activities in the central nervous system of teleosts

Neuronal nitric oxide synthase (nNOS) and NADPH-diaphorase activities were investigated in discrete areas of the central nervous system of goldfish and brown trout. Both species showed a similar distribution pattern of nNOS activity with regional differences in all examined areas. Telencephalon and hypothalamus showed the highest nNOS values, while in the goldfish cerebellum and its valvula nNOS was not detectable. In both species, NADPH-diaphorase activity showed a lower regional variability, compared to nNOS. The highest activity was measured in the olfactory bulbs where, conversely, low levels of nNOS activity were present. The non close correspondence between NOS and NADPH-diaphorase activities confirms the discrepancies indicated by morphological data. Western blot analysis revealed the presence of a nNOS isoform of about 150 kDa mol. wt. corresponding to that of mammals. The pattern of nNOS expression in the considered brain regions of the goldfish and trout was comparable to the levels of the nNOS activity.     

ω-3鱼油脂肪乳对危重症患者肠黏膜防护作用的研究

目的 研究ω-3鱼油脂肪乳对危重症患者肠黏膜的防护作用.方法 选取感染性休克及严重创伤危重症患者40例(试验组)及健康体检者30例(对照组),试验组患者随机分为A组及B组,每组各20例,均给予低热量肠外营养治疗,A组加用ω-3鱼油脂肪乳.采用分光光度法检测试验组治疗前、治疗1周后及对照组的外周血中二胺氧化酶(DAO)和内毒素的活性,ELISA法检测TNF-α水平.结果治疗1周后A组血浆DAO[(1.95±0.22)U/ml]、内毒素[(0.50±0.21)EU/ml]、TNF-α[(151.22±0.12)g/L]水平及B组血浆内毒素[(0.52±0.24)EU/ml]水平显著低于治疗前[分别为(3.31±1.15)U/ml、(0.76±0.25)EU/ml、(185.61±1.19)g/L、(0.78±0.30)EU/ml],P<0.05,治疗1周后A组DAO、TNF-α水平显著低于B组[分别为(3,17±0.65)U/ml、(173.56±1.21)g/L],P<0.05,内毒素水平两组比较差异无统计学意义(P>0.05).治疗1周后B组血浆DAO、TNF-α水平与对照组比较差异有统计学意义(P<0.05).结论 ω-3鱼油脂肪乳对危重症患者的肠黏膜有防护作用.     

从绿鳍马面鲀鱼油中分离制备高纯度二十二碳六烯酸甲酯

现代医学证明,二十碳五烯酸和二十二碳六烯酸具有多种生物活性。本文报道:通过综合运用金属盐沉淀法、尿素包合法、真空蒸馏法以及反相液相层析法从绿鳍马面纯鱼油中分离得到95%纯度的DHA甲酯。     

The effects of chlordiazepoxide (Librium) on the intensity and habituation of agonistic behavior in male Siamese fighting fish

The effects of chlordiazepoxide (Librium) on the intensity and habituation of the threat display in male Siamese fighting fish (Betta splendens) was evaluated by exposing each subject to a male conspecific eliciting stimulus. In an independent groups design, the subjects were tested in either plain tap water, or a drug solution of 15 g/ml or 30 g/ml. Chlordiazepoxide attenuated threat behavior and facilitated habituation of the display without inducing noticeable sedation. The results were evaluated in term of a sdual-process theory of habituation involving independent hypothetical processes of sensitization and habituation which produce the net observed habituation.This research was supported by a National Science Foundation Institutional Development Grant to Earlham College and Grant AYE-8525 from the National Science Foundation awarded to the author. Portions of this research were presented at the Eastern Psychological Association meetings, Boston, 1972. The chlordiazepoxide (Librium) was supplied by Hoffmann-La Roche, Inc., Nutley, New Jersey, U.S.A.     

Effects of the herbicides clomazone, quinclorac, and metsulfuron methyl on acetylcholinesterase activity in the silver catfish (Rhamdia quelen) (Heptapteridae)

Fingerlings of the silver catfish (Rhamdia quelen) were exposed to three herbicides widely used in rice culture in south Brazil: clomazone, quinclorac, and metsulfuron methyl. LC50 was determined and acetylcholinesterase (AChE) activity was evaluated in brain and muscle tissue of fish exposed to different herbicide concentrations after 96h (short term). The LC50 value (nominal concentration) was 7.32 mg/L for clomazone and 395 mg/L for quinclorac, but was not obtained for metsulfuron-methyl since all fingerlings survived the highest concentration of 1200 mg/L. Brain and muscle AChE activity in unexposed fish were 17.9 and 9.08 micromol/min/g protein, respectively. Clomazone significantly inhibited AChE activity in both tissues, achieving maximal inhibition of about 83% in brain and 89% in muscle tissue. In contrast, quinclorac and metsulfuron methyl caused increases in enzyme activity in the brain (98 and 179%, respectively) and inhibitions in muscle tissue (88 and 56%, respectively). This study demonstrated short-term effects of exposure to environmentally relevant concentrations of rice field herbicides on AChE activity in brain and muscle tissue of silver catfish.     

Oxygen limited thermal tolerance in fish?--Answers obtained by nuclear magnetic resonance techniques

In various phyla of marine invertebrates limited capacities of both ventilatory and circulatory performance were found to set the borders of the thermal tolerance window with limitations in aerobic scope and onset of hypoxia as a first line of sensitivity to both cold and warm temperature extremes. The hypothesis of oxygen limited thermal tolerance has recently been investigated in fish using a combination of non-invasive nuclear magnetic resonance (NMR) methodology with invasive techniques. In contrast to observations in marine invertebrates arterial oxygen tensions in fish were independent of temperature, while venous oxygen tensions displayed a thermal optimum. As the fish heart relies on venous oxygen supply, limited cardio-circulatory capacity is concluded to set the first level of thermal intolerance in fish. Nonetheless, maximized ventilatory capacity is seen to support circulation in maintaining the width of thermal tolerance windows. The interdependent setting of low and high tolerance limits is interpreted to result from trade-offs between optimized tissue functional capacity and baseline oxygen demand and energy turnover co-determined by the adjustment of mitochondrial densities and functional properties to a species-specific temperature range. At temperature extremes, systemic hypoxia will elicit metabolic depression, thereby widening the thermal window transiently sustained especially in those species preadapted to hypoxic environments.     

The management of possible fishbone ingestion

OBJECTIVE: We assessed the usefulness of computed tomography (CT) in cases of suspected impaction of fish bones in the esophagus. The findings of this study were also compared with those of studies in which surgery was used to remove or confirm the presence of fish bones. We accordingly propose a management protocol to ensure optimum outcome for patients with a history of fish bone ingestion. METHODS: X-ray and CT imaging were performed in 76 patients in whom esophageal impaction of fish bones was suspected. RESULTS: Plain X-ray revealed impacted fish bones in 17 patients (22%), soft-tissue swelling but no evidence of foreign body in 5 (7%), and no abnormal findings in 54 (71%). These findings were apparent on CT scans in 31 (41%), 8 (10%), and 37 (49%), respectively. Of the 31 patients in whom CT revealed a fishbone, 17 (55%) also exhibited X-ray evidence of foreign body. Of the remainder, X-ray revealed only soft-tissue swelling in 3 (10%), and was unremarkable in 11 (35%). Among the 5 patients in whom X-ray demonstrated only soft-tissue swelling, CT was positive for foreign body in 3 (60%). Of the 54 patients in whom X-ray appearances were normal, CT revealed foreign bodies in 11 (20%) and other abnormalities in 6 (11%). CONCLUSION: In the present study, sensitivity and specificity of plain X-ray was 54.8% (17 of 31) and 100% (45 of 45), respectively. However, for CT, both sensitivity and specificity were 100%. CT was determined to be very useful in the diagnosis of impacted fish bones in the esophagus.     

The role of sport-fish consumption advisories in mercury risk communication: a 1998-1999 12-state survey of women age 18-45

BACKGROUND: In 2002, in the United States, 48 states issued advisories for sport-fish consumers that included 39 chemical contaminants. The most commonly identified chemical was methyl mercury, which is linked to reproductive and developmental effects. Advisories to reduce consumption of contaminated fish have been issued by states since the early 1970s. Advisories are being integrated to include both sport and commercial fish. METHODS: As part of a comprehensive risk-communication project, from December 1998 through August 1999 the Wisconsin Division of Public Health and the State of Maine Bureau of Health conducted a 12-state random-digit-dial telephone survey of 3015 women of childbearing age (ages 18-45). The goal was to assess the prevalence of fish consumption, understanding of mercury toxicity, and awareness of state sport-fish consumption advisories for mercury. We gathered information concerning respondents' demographic characteristics, understanding of mercury toxicity, fish consumption during the preceding 12 months, and sport-fish consumption advisory awareness. RESULTS: The overall survey completion rate was 57% with a Council of American Survey Research Organizations (CASRO)-calculated response rate of 50%. Completion rates varied from 37% in New Jersey to 73% in Minnesota. Fish consumption during the previous 12 months was reported by 87% of respondents (range by state of 82-90%). Nearly 10% of women reported consuming two or more fish-meals per week over the prior 12 months. Twenty-nine percent reported sport-fish consumption during the same time period, with a greater state-to-state variability (14-43%). Most women (71%) were aware of mercury's toxicity to a developing child (87% among those aware of an advisory and 67% among those unaware of an advisory). However, awareness of state advisories was only 20%, ranging by state from 8% to 32%. Women who were older, had more than a high school education, and had a household member with a fishing license were the most informed about mercury and fish-consumption advisories. CONCLUSIONS: Most women of childbearing age consume commercial fish and a substantial number also consume sport-caught fish. Despite this potential exposure to dietary mercury, most are unfamiliar with their state's mercury fish-consumption advisory. Most women were aware of the most toxic effects of mercury but less informed about mercury and its relationship to types of fish and fish characteristics. Minorities, women over age 30, family incomes above 25,000 US dollars, and those with some collage education were more likely to be consuming two or more fish-meals per week. Until source control and environmental remediation efforts can reduce the environmental burden of mercury below levels of concern, combined sport and commercial fish consumption advisories will remain the primary means of reducing human exposure to methylmercury. Assuring and assessing the effectiveness of such advisories is paramount. Our survey documents that current efforts to inform vulnerable populations are far from optimal.     

Exposure assessment and initial intervention regarding fish consumption of tribal members of the Upper Great Lakes Region in the United States

The Ojibwe Health Study (OHS) has concluded 10 years of data collection and exposure assessment. Eight hundred and twenty-two participants from tribes in the states of Wisconsin, Michigan, and Minnesota (USA) completed fish consumption and environmental risk perception questionnaires. Many participants provided hair and blood samples for mercury and polychlorinated biphenyl (PCB) residue analyses as body burden indicators of these persistent environmental pollutants. Fish were collected by the tribal organizations and contaminants were analyzed for numerous tribal reports and professional environmental journal articles, these data were used by the Great Lakes Indian Fish and Wildlife Commission to produce tribal-specific geographic information systems maps as part of a public health intervention strategy. These maps are currently available at for six Wisconsin tribes that regularly harvest walleye. To determine the health impacts (if any) of pollutants on cancer, diabetes, and reproduction, it was necessary to know the recent trends in key indicators such as cancer mortality ratios and birth gender ratios. The Great Lakes Inter-Tribal Council provided the OHS and each participating tribe in Wisconsin and Michigan with a health profile. Total fish consumption (estimated by recall) for 720 tribal participants was self-reported as 60 g/day, but the highest actual consumption was measured as 11.2 g/day in one of the tribal groups. The highest blood concentrations in tribal participants were 18.6 ppb total serum PCBs and 11.8 ppb total blood mercury. Ninety percent of the participants had less than 3.8 ppb total serum PCBs and 2.6 ppb total blood mercury. Compared to other studies of subsistence fishing populations, these exposures were only moderately elevated and not high enough to warrant widespread restrictions on diets. Furthermore, the benefits of eating a fish diet must be continually emphasized. However, sport fishermen and their families who consume larger and more contaminated fish should abide by their state fish consumption advisories to minimize their health risks.     

Species differences in contaminants in fish on and adjacent to the Oak Ridge Reservation, Tennessee

Risks to humans and other organisms from consuming fish have become a national concern in the USA. In this paper, we examine the concentrations of 137Cs, arsenic, beryllium, cadmium, lead, mercury, and selenium in three species of fish from two river reaches adjacent to the US Department of Energy's Oak Ridge Reservation in Tennessee. We were interested in whether there were species and locational differences in radiocesium and metal concentrations and whether concentrations were sufficiently high to pose a potential health risk to humans or other receptors. Striped bass (Morone saxatilis) were significantly larger than white bass (M. chrysops), and crappie (Pomoxis spp.) were the smallest fish. Lead was significantly lower in striped bass, mercury was significantly higher in striped bass, and selenium was significantly higher in white bass compared to the other species. There were no other species differences in contaminants. White bass, the only species that was sufficiently abundant for a comparison, had significantly higher concentrations of cadmium, lead, and selenium in fillets from the Clinch River and significantly higher concentrations of mercury in fillets from Poplar Creek. The low concentrations of most contaminants in fish from the Clinch River do not appear to present a risk to humans or other consumers, although mercury concentrations in striped bass ranged as high as 0.79 ppm, well above the 0.5-ppm action level for human consumption of some US states.