共查询到20条相似文献,搜索用时 4 毫秒
1.
Lorraine C. Backer 《Harmful algae》2009,8(4):618-622
Over the last few decades, scientific research has helped to describe the disease neurotoxic shellfish poisoning (NSP) by identifying the causative organism, Karenia brevis, and by characterizing the disease-causing toxins, a suite of polyether toxins called brevetoxins. In addition to causing disease in exposed human populations, K. brevis blooms and associated management responses have been linked to other effects on coastal communities. Some of these effects are negative, such as the loss of tourism dollars and the increased burden on local health care services caused by increases in human disease incidence. However, some of the effects are positive, such as the significant improvement in detecting brevetoxins in environmental samples and clinical specimens. This review discusses the health and economic effects from K. brevis blooms on Florida coastal communities and the current efforts to identify the data needed to assess social and cultural effects. 相似文献
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Environmental exposures to Florida red tides: Effects on emergency room respiratory diagnoses admissions 总被引:1,自引:0,他引:1
Barbara Kirkpatrick Lora E. Fleming Lorraine C. Backer Judy A. Bean Robert Tamer Gary Kirkpatrick Terrance Kane Adam Wanner Dana Dalpra Andrew Reich Daniel G. Baden 《Harmful algae》2006,5(5):526-533
Human exposure to Florida red tides formed by Karenia brevis, occurs from eating contaminated shellfish and inhaling aerosolized brevetoxins. Recent studies have documented acute symptom changes and pulmonary function responses after inhalation of the toxic aerosols, particularly among asthmatics. These findings suggest that there are increases in medical care facility visits for respiratory complaints and for exacerbations of underlying respiratory diseases associated with the occurrence of Florida red tides.This study examined whether the presence of a Florida red tide affected the rates of admission with a respiratory diagnosis to a hospital emergency room in Sarasota, FL. The rate of respiratory diagnoses admissions were compared for a 3-month time period when there was an onshore red tide in 2001 (red tide period) and during the same 3-month period in 2002 when no red tide bloom occurred (non-red tide period). There was no significant increase in the total number of respiratory admissions between the two time periods. However, there was a 19% increase in the rate of pneumonia cases diagnosed during the red tide period compared with the non-red tide period. We categorized home residence zip codes as coastal (within 1.6 km from the shore) or inland (>1.6 km from shore). Compared with the non-red tide period, the coastal residents had a significantly higher (54%) rate of respiratory diagnoses admissions than during the red tide period. We then divided the diagnoses into subcategories (i.e. pneumonia, bronchitis, asthma, and upper airway disease). When compared with the non-red tide period, the coastal zip codes had increases in the rates of admission of each of the subcategories during the red tide period (i.e. 31, 56, 44, and 64%, respectively). This increase was not observed seen in the inland zip codes.These results suggest that the healthcare community has a significant burden from patients, particularly those who live along the coast, needing emergency medical care for both acute and potentially chronic respiratory illnesses during red tide blooms. 相似文献
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赤潮过程浮游植物与营养物质时间变化率研究 总被引:2,自引:0,他引:2
利用2000年大亚湾澳头海域赤潮定点连续调查资料及其多年现场调查资料,采用灰色回归模型,综合分析赤潮发生过程水体中浮游植物细胞密度与营养物质(NO3-、NH4+、PO4^3-、SiO3^2-、Fe)的时间变化率关系,分析了叶绿素a含量与浮游植物细胞密度相互关系.结果表明,预测值与实测基值本一致,复相关系数范围在0.51~0.83.当水体叶绿素浓度为5.8μg·dm-3,预示可能发生赤潮,通过采样分析水体叶绿素a含量或利用水色卫星遥感资料反演水体叶绿素浓度,计算浮游植物细胞密度,为赤潮的预测预报提供简便有效的方法.此外.本水域初级生产力由磷控制. 相似文献
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Dubok Choi Sunjong Yu Seung Ho Baek Yoon-Ho Kang Young-Cheol Chang Hoon Cho 《Biotechnology and Bioprocess Engineering》2016,21(3):463-476
In the present study, we synthesized 65 dichlorobenzylamine derivatives and investigated their algicidal activity against harmful red tides. The 3,4-dichlorobenzylamine derivatives showed relatively high activity against Cochlodinium polykrikoides, Heterosigma akashiwo, Chattonella marina, and Heterocapsa circularisquama, and the synthesized compounds 27, 28, 33, 34, 35, and 36 showed the highest algicidal activity after 24 h at 0.1 ~ 1.0 μM LC50 against the four harmful algae species. To verify the safety of the compounds, acute ecotoxicology tests using the water flea (Daphnia magna) and zebrafish (Danio rerio) were conducted, and the tests confirmed that compounds 33 and 34 were not harmful because the target organisms showed high survival rates at 15 μM. The results indicate that compounds 33 and 34 are suitable substances for use in controlling harmful algae species. 相似文献
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沿岸海域富营养化与赤潮发生的关系 总被引:10,自引:0,他引:10
综述了赤潮的发生与沿岸海域富营养化的关系。近几十年来,人类活动使得天然水体的富营养化进程大大加速。营养负荷的增加与高生物量水华的增多相联系。控制营养输入后,浮游植物生物量或有害藻类水华事件也相应减少。营养的组成与浮游植物的种类组成及水华的形成有密切联系。有机营养对有害藻类水华的促进作用受到关注。营养输入时机影响浮游植物种间竞争的结果,因而对浮游植物的群落演替具有深远影响。由于浮游植物存在生理差异,因而对营养加富的反应因种而异。营养在调控某些有毒藻类的毒素产量方面也发挥着重要作用。此外,营养输入与藻类水华之间存在复杂的间接联系。当然,营养状况并非浮游植物群落演替的唯一决定因素。研究结果提示,控制营养输入、减缓水域富营养化是减少有害藻类水华发生的有效途径,而深入研究典型有害藻类的营养生理对策则为防治并最终消除有害藻类水华提供了理论基础。 相似文献
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Effects of winds, tides and river water runoff on the formation and disappearance of Alexandrium tamarense blooms in Hiroshima Bay, Japan were investigated using data from March to June of 1992–1998. The north wind at the initial growth phase of A. tamarense appeared to have prevented bloom formation by dispersing the organism offshore and/or through turbulent mixing. The decrease in the cell density at the end of the blooms was significantly affected by tidal mixing, indicating that the turbulent mixing induced by tidal excursions may be one of the factors terminating the bloom. Box model analyses applied to the data collected from the observations in 1996 and 1997 showed that river water runoff apparently dispersed the bloom, implying that stratification of the water column due to river water runoff is not necessary for the bloom formation. In conclusion, calm conditions with less wind and tidal mixing along with less river water runoff are considered to be important for the formation of the A. tamarense bloom in Hiroshima Bay, Japan. 相似文献
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William H. Thomas Marcia Pollock Don L.R. Seibert 《Journal of experimental marine biology and ecology》1980,45(1):25-36
Natural phytoplankton assemblages from the Scripps Pier were grown in two chemostats under conditions that simulated two rates of upwelling followed by oligotrophic conditions. At a moderate upwelling rate (D = 0.3·day?1) centric diatoms were selected, while at a low rate (D = 0.1·day?1) a mixture of species dominated. Pumping of low-nutrient water (oligotrophy) resulted in a mixture of species at both rates. Upwelling at a high rate decreased diversity of the crop as compared with the low rate or oligotrophy. These results are compared with those of others who have subjected natural assemblages to continuous culture. 相似文献
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Influence of red cell membrane on diffusion of oxygen 总被引:2,自引:0,他引:2
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R. J. Roselli 《Bulletin of mathematical biology》1980,42(6):765-795
Estimates of capillary tracer permeability calculated using multiple indicator data depend upon the particular model adopted
to describe blood tissue exchange. The model proposed by Crone (1963) is appropriate when some of the injected tracer diffuses
into the tissue but does not return appreciably to the bloodstream before data collection is terminated. Under these conditions
extraction of tracer by the tissue depends on a single dimensionless parameter, αcap, defined as the ratio of capillary permeability surface area to water flow. The effects of finite red cell tracer permeability
on the Crone model estimate of capillary permeability are examined in the present study. The results indicate that even when
back diffusion from the extravascular space is negligible, significant errors in the Crone model estimate can be expected
when capillary permeability is relatively high and the ratio of red cell to capillary permeability is less than unity. However,
when an aliquot of blood is equilibrated with tracer prior to injection and the dimensionless capillary permeability is relatively
low (i.e. αcap ≦ 0.25 for a haematocrit≦50%), the whole blood Crone model estimate of αcap will be within 10% of the actual value, irrespective of red cell permeability. Red cell-plasma exchange for commonly used
tracer-organ combinations should not significantly affect Crone estimates of capillary permeability under normal physiological
conditions, but may be important in low flow situations.
Supported by Grant No. HL 19153 (SCOR in Pulmonary Vascular Diseases).
This work was done during Dr. Roselli’s tenure as an NHLBI Training Grant Fellow (NHLBI Training Grant No. 07123). 相似文献
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We previously showed that resistance training significantly increased the red blood cell count (RBC) and hematocrit (Hct)
and decreased the mean cell hemoglobin concentration (MCHC) in physically inactive men. Since the enhanced hematopoiesis may
result, at least partly, from bone metabolism, the purpose of this study was to further investigate the effect of resistance
training on serum bone-specific alkaline phosphatase activity (B-ALP), a biomarker of bone formation, and focus on the relationship
between the change in B-ALP from baseline to 20-week follow-up and the corresponding changes in RBC, Hct and MCHC. Seventy-four
men aged 20–45 years were randomly assigned to training and control groups. The training group underwent a 20-week progressive
resistance training. Fasting blood samples were analyzed for serum B-ALP at baseline, and at 10-week and 20-week follow-up.
B-ALP in the control group exhibited no significant change. In contrast, the training group increased its B-ALP from baseline
at 10-week and 20-week follow-up (both P < 0.01 compared to control group). Within the training group, B-ALP was elevated at 10-week and 20-week follow-up when compared
to baseline (both P < 0.001). A significant correlation was found between change in B-ALP from baseline to 20-week follow-up and the corresponding
changes in RBC, Hct and MCHC in the training group (r = 0.49, P < 0.01; r = 0.56, P < 0.01, and r = −0.38, P < 0.05, respectively). We concluded that resistance training increased biomarkers of bone formation, which had association
with RBC turnover. Adaptive changes of bone metabolism induced by resistance training might facilitate erythropoiesis. 相似文献
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Chia-Ping H. Yang 《Biologia Plantarum》1981,23(3):214-219
The action of light on ribosome formation was examined in the cabbage seedlings, a system extensively used in the studies
of anthocyanin synthesis. Ribosomes were extracted 18 h after the beginning of the irradiation and separated by sucrose gradient
centrifugation. In the cotyledons of dark-grown cabbage seedlings, a brief red light induces an increase both in total ribosomes
and in the fraction present as polysomes; the effect of red light is reversed by far red light, indicating the involvement
of phytochrome in polysome formation in cabbage seedlings. Continuous red and continuous far red light are about equally effective
in bringing about an increase of total ribosomes and of the polysome fraction. Streptomycin, which inhibits chlorophyll synthesis
and chloroplast development, and enhances anthocyanin synthesis in cabbage seedlings, causes a decrease of total ribosomes
and of the fraction present as polysomes. In hypocotyls, the red-far red reversibility is evident only for the polysome content
and streptomycin does not decrease the polysome/monosomo ratio as it does in cotyledons. 相似文献
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The water permeability of human red blood cells has been monitored by nuclear magnetic resonance (NMR) following exposure to inhibitors of various transport processes across their membranes. No significant inhibition of water diffusion could be detected after the treatment of red blood cells with the anion exchange transport inhibitor dihydro-4,4'-diisothiocyano-stilbene-2,2'-disulfonate (H2DIDS) or the glucose transport inhibitors diallyl-diethyl-stilbestrol (DADES), cytochalasin B, or 30 mM iodoacetamide. It is for the first time that the effects of glucose transport inhibitors has been studied in detail by the NMR approach. A special case proved to be phloretin, an inhibitor of anion, nonelectrolyte and glucose permeability. A small but statistically significant inhibition of water permeability (around 12% at 20 degrees C) was induced by exposure to 2 mM phloretin (for 60 min at 37 degrees C); after a pretreatment of cells with 12 mM N-ethylmaleimide (NEM), for 60 min at 37 degrees C, the degree of inhibition induced by phloretin increased (becoming 17% at 20 degrees C). None of the inhibitors prevented or potentiated the strong inhibitory effect on water diffusion of a mercurial, p-chloromercuribenzene sulfonate (PCMBS). No increase in the activation energy of water diffusion occurred by treatment with the reagents used (exception the effect of PCMBS). The present results clarify some conflicting reports concerning the effects on water permeability of inhibitors of various transport processes in red blood cells and indicate that in addition to the drastic inhibition induced by mercurials other reagents may also have inhibitory effects. 相似文献
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Complexation of iron by microbial siderophores and effects of iron chelates on the growth of marine microalgae causing red tides 总被引:2,自引:0,他引:2
The growth rates of 13 species of abundant red tide algae in media with different iron species complexed with microbial siderophores (Ferrichrome and Ferrioxamine) and Fe‐Catechol were investigated. Our study demonstrated that the Fe‐chelates (at molar ratios = 1:1) were bioavailable to some red tide species. In Fe‐Catechol medium, growth was observed for the raphidophyte Heterosigma akashiwo, the dinoflagellates Heterocapsa circularisquama and Heterocapsa triquetra, the diatom Ditylum brightwellii, the cryptophyte Rhodomonas ovalis, the chlorophyte Oltmannsiellopsis viridis, and the haptophyte Cricosphaera roscoffensis. In Ferrioxamine medium, we found the growth of the dinoflagellate Karenia mikimotoi, the diatom Ditylum brightwellii, and the cryptophyte Rhodomonas ovalis. But, the existence of higher ligand concentrations (molar ratios ≥ 1:10) decreased the growth rates of most red tide species that were examined. Furthermore, all red tide species examined were not able to grow in Ferrichrome medium. In particular, the Chattonella species examined did not grow in the presence of Fe‐chelates. These results suggest that bioavailability of iron depends not only on ligand species, but also on the concentration of the ligands; moreover, microbial siderophores may play an important role in controlling the uptake of iron complexed with organic materials that exist in coastal water and the formation of red tides in coastal areas. 相似文献
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As recently as a decade ago, Karenia brevis red tides and their effects on animal resources in the Gulf of Mexico were principally perceived as acute blooms that caused massive fish kills. Although occasional mortalities of higher vertebrates were documented, it has only been in the past decade that conclusive evidence has unequivocally demonstrated that red tides and their brevetoxins are lethal to these organisms. Brevetoxins can be transferred through the food chain and are accumulated in or transferred by biota at many trophic levels. The trophic transfer of brevetoxins in the food web is a complex phenomenon, one that is far more complicated than originally conceived. Unexplained fish kills and other animal mortalities in areas where red tide is endemic are being increasingly linked with post-bloom exposures of biota to brevetoxins. Mass mortality events of endangered Florida manatees (Trichechus manatus latirostris) follow a consistent spatial and temporal pattern, occurring primarily in the spring in southwestern Florida. Persistent blooms can also cause a cascade of environmental changes, affecting the ecosystem and causing widespread die-offs of benthic communities. Ongoing fish kills from sustained blooms can lead to short-term declines in local populations. Although animal populations in areas where red tide is endemic are unquestionably at risk, it remains to be determined to what extent populations can continue to recover from these sustained effects. 相似文献
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A double-beam quadruple-cell spectrophotometric technique is described that can be used to evaluate the interaction between sterols and HPLC fractions from Nannochloris sp. which are cytolytic (aponin) toward the red tide organism. The interaction with ergosterol but not beta-sitosterol is consistent with complex formation and also with the reduction of cytolytic activity of aponin in the presence of ergosterol, as previously noted. Implications for the mechanism of aponin cytolytic activity are considered. 相似文献
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