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At least 973 records · Page 54Linked to original sources

PubMed1997

Toxin production of Alexandrium minutum (Dinophyceae) from the Bay of Plenty, New Zealand.

Paralytic shellfish toxins of two clonal cultures of Alexandrium minutum isolated during the 1993 toxic shellfish events in the Bay of Plenty, New Zealand, were analyzed using high-performance liquid chromatography. Toxin composition profiles of both cultures showed neosaxitoxin (> 65 mole%) as the principal toxin, with saxitoxin and gonyautoxins (GTX1-4) as minor components. Neither C-toxins (C1-4) nor GTX5-6 were detectable in the two isolates. Bay of Plenty isolates of A. minutum have a unique toxin profile not found in any other isolates of this species that have been characterized. This weakens the hypothesis that A. minutum was recently introduced to New Zealand waters by ballast water or other long-distance transport mechanisms, and argues instead that the species was endemic to the area, but not noticed in the past. The average toxicity of the cultures was 8.8 and 11.0 pg saxitoxin equiv. cell-1 with acetic acid or HCl extraction, respectively. These are at the high end of the range of toxicity reported for A. minutum strains from around the world, and on a cell volume basis are comparable to the most toxic strains of the Alexandrium tamarense group. The toxin profile of A. minutum most closely matches that of mussels and to a lesser degree tuatua harvested from the Bay during the 1993 outbreak, but is quite different from the profile measured in scallops and pipi. Plausible mechanisms for bioconversion of the ingested algal toxins within the latter two shellfish species can be proposed, but it seems more likely that either other strains of A. minutum or other saxitoxin-producing dinoflagellates were ingested by those shellfish. This study established that A. minutum from the Bay of Plenty contains saxitoxins, has a unique toxin composition compared to all other isolates of this species, and was responsible for at least part of the PSP toxicity measured in shellfish during the 1993 outbreak.

Animals↗

PubMed1998

An overview of the marine food poisoning in Mexico.

In the course of the last decade, huge events related to harmful algal blooms (HAB) have severely affected the environment in Mexico, even causing several human casualties. The tally of the toxins known up to date in Mexican waters includes: neurotoxin shellfish poisoning (NSP), paralytic shellfish poisoning (PSP), amnesic shellfish poisoning (ASP), tetrodotoxin (TTX) or puffer fish poisoning, ciguatera fish poisoning (CFP) and diarrhetic shellfish poisoning (DSP). Actual epidemiological figures profoundly modified the trends manifested on previous decades. Notwithstanding that the red tides are a long time known phenomena in Mexican coasts, no regular observation of the marine environment has been set up. Although there are monitoring activities for PSP toxins on the shellfish culturing facilities that are exploited for export to the U.S.A., these are only effectively applied on specific spots of the Mexican coasts, implying that the biggest part of the country coastal zones are not formerly surveyed. The misleads caused by the medical conception that food poisoning events are mainly due to microbial contamination, is among the factors why the marine food poisoning events are a neglected disease. In spite of the fact that no official statistics consider HAB related events as a subject of research or further monitoring by the health authorities, sporadic scientific documents related to poisoning events were produced in Mexico. An interesting picture is presented for most of the marine toxins mentioned. Trend and prognosis estimates made with such scarce information, provide a minimum measurement of the reality and urge the need for a permanent monitoring program on the Mexican coasts, a place with one of the greatest marine toxin diversity worldwide.

Animals↗

PubMed1999

Comparison between HPLC and a commercial immunoassay kit for detection of okadaic acid and esters in Portuguese bivalves.

Liquid chromatography (HPLC), used to identify diarrhoeic shellfish poisoning (DSP) toxins in Portuguese shellfish, has detected okadaic acid (OA), dinophysistoxin-2 (DTX2) and esters of both of these. In Donax clams, a surprisingly high level of esters has been recently associated with some outbreaks of diarrhoea in shellfish consumers. In view of these events, we have proposed that screening for esters must be included in monitoring programmes for DSP toxins. HPLC is laborious, time-consuming and suffers from some interferences at low detection levels in total meat extracts. An enzyme-linked immunosorbent assay (ELISA) based on the procedure of Usagawa et al. ('DSP-Check' kit) was tested against HPLC. The 'DSP-Check' kit was capable of quantitatively detecting DSP toxins in all the tested contaminated samples containing only okadaic acid, provided that the parent toxins were within the range of detection and were not in the ester form. A high correlation was observed between the two methods when appropriate dilutions were performed. The immunoassay kit tested appeared to be more sensitive, specific and faster than HPLC for determination of DSP in total shellfish meat extracts. No problems were found when using hydrolysed semi-purified extracts in order to detect esters of okadaic acid. In view of the results obtained so far, Donax clams appeared to be an excellent indicator of shellfish contamination with diarrhoeic toxins. On sandy beaches of the Portuguese southern coast, were rock mussels are not so abundant, they should be screened more often than other species in order to prevent diarrhoea in humans.

Calibration↗

PubMed2002

Detection of hepatitis A virus in mussels from different sources marketed in Puglia region (South Italy).

Hepatitis A virus (HAV) infection is endemic in Puglia (South Italy). Epidemiological studies indicate that shellfish consumption, particularly mussels, is a major risk factor for HAV infection, since these products are eaten raw or slightly cooked. Nested reverse transcriptase-polymerase chain reaction (RT-PCR) has been shown to be a sensitive technique for the detection of HAV in mussels. The aim of the present study was to detect the presence of HAV in a large sample of mussels by nested RT-PCR and to confirm the presence of infectious viral particles in positive samples by cell culture infection and RT-PCR confirmation. Two hundred and ninety samples of mussels from different sources were collected between December 1999 and January 2000. One hundred samples were collected before being subjected to depuration, 90 after depuration, and 100 were sampled in different seafood markets. HAV-RNA was detected in 20 (20.0%) of non-depurated mussels, in 10 (11.1%) of depurated samples, and in 23 (23.0%) of samples collected in the shellfish markets, without any significant difference in the prevalence of positive samples by collection sources (chi2 = 4.79, p = 0.09). Of the 53 samples found positive by nested RT-PCR, 18 (34.0%) resulted positive by cell culture assay. No relationship between viral contamination and bacterial contamination was found (p = 0.41). This study confirms the usefulness of molecular techniques in detecting HAV in shellfish and, thus, for the screening of a large sample of naturally contaminated mussels. Improved shellfish depuration methods are needed to obtain virus-safe shellfish and reduce the risk for public human health.

Animals↗

PubMed2002

Balancing risks in the management of contaminated first nations fisheries.

In the 1980s and 1990s, the Government of Canada closed and/or issued advisories for a number of shellfish fisheries in coastal areas of British Columbia because of dioxin contamination. Only the direct health risks (i.e., cancer) of consuming contaminated shellfish for the general population were considered by the Government in the formulation of risk management options. A focus on the direct risks does not provide an adequate basis for risk decisions as the countervailing risks which may be created from management measures may easily be overlooked. This study describes the potential health impacts of risk management options for aboriginal coastal peoples in the management of dioxin contamination. Gold River and Powell River in British Columbia, Canada, are the areas of focus. The cancer risks of consuming dioxin contaminated shellfish for these sites are estimated. To assess the countervailing risks of management decisions for comparison, a scenario was developed in which First Nations peoples substitute shellfish with store-bought foods in their diets in the event of a fishery closure or advisory. Increases in mortality due to coronary heart disease are estimated. The results suggest that the health risks of dietary changes among aboriginal peoples may be as significant as those related to eating dioxin contaminated shellfish.

Animals↗

PubMed2004

Investigation of hygienic quality and freshness of marketed fresh seafood in Northern Taiwan.

To survey the hygienic quality and freshness of fresh fish and shellfish, 533 specimens of fish and shellfish were collected from fishing piers, traditional markets and supermarkets (including warehouses) in northern Taiwan during the winter (January-February) and summer (July-August) seasons for hygienic quality and freshness examinations. The indicators included total bacterial count, fecal coliform, Escherichia coli, volatile basic nitrogen (VBN) and K value judged from ATP-related compounds. It was found that the hygienic quality and freshness of fish and shellfish decreased in summer, especially for clam and mussel. The ratio of unacceptable hygienic quality or freshness of fish and shellfish was the highest in fecal coliform, followed by E. coli and others. The fecal coliform count in products from the traditional markets was the highest, followed by those from supermarkets and fishing piers. Secondary contamination seems to be the most important problem for hygienic quality and freshness of fish and shellfish.

Animals↗

PubMed2000

[Magnitude of rainfall on viral contamination of the marine environment during gastroenteritis epidemics in human coastal population].

BACKGROUND: Sewage treatments are not efficient to eliminate enteric microorganisms. Viruses are able to persist and are discharged into the marine environment with treated effluents. Few data are now available on the magnitude and the contributive processes of marine viral contamination. This work evaluates the relationship between the magnitude of rainfall and the viral contamination of the marine environment during winter epidemics of gastroenteritis in human coastal populations. METHODS: A RT-PCR method was used to detect enterovirus, hepatitis A virus, Norwalk-like virus, astrovirus and rotavirus in shellfish, harvested monthly between August 1995 and July 1998. The frequency of virus detection in shellfish was expressed as an Index of Viral Contamination. Acute gastroenteritis in the population was estimated using the French Sentinel System for Monitoring of Communicable Diseases. Rainfall effects on the efficiency of sewage treatment were assessed using an estimated staying time of sewage effluents in the plant. RESULTS: The results indicate that the highest viral contamination occurs in winter. Maximal indexes of viral contamination were respectively 70% in January 1996, 100% in January 1997, but only 31% in January 1998. Viral contamination variations seemed to follow the pattern of the winter epidemic of acute gastroenteritis in the local population in 1996 and 1997. These observations should be linked to the winter rainfalls. Heavy rains on short periods of time could create an hydraulic overload in the sewage treatment plant, reducing the staying time of the sewage effluents and thus the efficiency of the disinfection process. CONCLUSION: The magnitude of the viral contamination of shellfish seems to result from the simultaneity between the winter epidemics of acute gastroenteritis in the coastal population and heavy rainfall. To prevent public health hazards associated with shellfish consumption, the monitoring of microbiological quality in shellfish harvesting areas should include accompagning survey of viral epidemic in the coastal population, and of sewage outputs in the coastal environment.

Disease Outbreaks↗

PubMed2006

Bivalve molluscs as vectors of marine biotoxins involved in seafood poisoning.

Molluscs of many sorts, which are high in protein and trace minerals, have always been a substantial portion of the human diet. A great variety of mollusc species are therefore of commercial importance throughout the world. Episodes of poisoning occasionally happen to the consumers of molluscs, the main hazard being represented by bivalve molluscs. These organisms are filter-feeders, feeding mainly on a wide range of phytoplankton species. Among the thousands of species of microscopic algae at the base of the marine food chain, there are a few dozen which produce potent toxins. One major category of impact occurs when toxic phytoplankton are filtered from the water as food by shellfish, which then accumulate the algal toxins to levels which can be lethal to humans. Incidences of poisoning related to marine algal toxins come under the main categories of paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), diarrhetic shellfish poisoning (DSP), and amnesic shellfish poisoning (ASP), depending upon the toxins and the symptoms that they cause. Since the beginning of the 1990s, a research program has been initiated to examine the toxin profiles in mussels from the Adriatic Sea. Since then, a number of polyether toxins have been isolated and characterized, some of which represent new additions to the DSP class of biotoxins. During this investigation, new types of toxins have also been isolated. The recent application of LC-MS methods for the detection of Adriatic marine biotoxins made it possible to speed up the analysis of toxic samples.

Animals↗

PubMed2004

Solid phase adsorption toxin tracking (SPATT): a new monitoring tool that simulates the biotoxin contamination of filter feeding bivalves.

A simple and sensitive in situ method for monitoring the occurrence of toxic algal blooms and shellfish contamination events has been developed. The technique involves the passive adsorption of biotoxins onto porous synthetic resin filled sachets (SPATT bags) and their subsequent extraction and analysis. The success of the method is founded on the observation that during algal blooms significant amounts of toxin, including the low polarity lipophilic compounds such as the pectenotoxins and the okadaic acid complex toxins, are dissolved in the seawater. The results of field trials during Dinophysis acuminata and Protoceratium reticulatum blooms are presented. These data prove the concept and demonstrate that the technique provides a means of forecasting shellfish contamination events and predicting the net accumulation of polyether toxins by mussels. As an early warning method it has many advantages over current monitoring techniques such as shellfish-flesh testing and phytoplankton monitoring. In contrast to the circumstantial evidence provided by genetic probe technologies and conventional phytoplankton monitoring methods, it directly targets the toxic compounds of interest. The extracts that are obtained for analysis lack many of the extraneous lipophilic materials in crude shellfish extracts so that many of the matrix problems associated with chemical and biological analysis of these extracts are eliminated. Analyses can confidently target parent compounds only, because analytical and toxicological uncertainties associated with the multiplicity of toxin analogues produced by in vivo biotransformation in shellfish tissues are reduced. Time integrated sampling provides a good simulation of biotoxin accumulation in filter feeders and the high sensitivity provides lengthy early warning and conservative estimates of contamination potential. The technique may reduce monitoring costs and provide improved spatial and temporal sampling opportunities. When coupled with appropriate analytical techniques (e.g. LC-MS/MS multi-toxin screens, ELISA assays, receptor binding assays), the technique has the potential to offer a universal early warning method for marine and freshwater micro-algae toxins.

Adsorption↗

PubMed1986

Widespread outbreaks of clam- and oyster-associated gastroenteritis. Role of Norwalk virus.

Consumption of raw shellfish has long been known to be associated with individual cases and sporadic outbreaks of enteric illness. However, during 1982, outbreaks of gastroenteritis associated with eating raw shellfish reached epidemic proportions in New York State. Between May 1 and December 31, there were 103 well-documented outbreaks in which 1017 persons became ill: 813 cases were related to eating clams, and 204 to eating oysters. The most common symptoms were diarrhea, nausea, abdominal cramps, and vomiting. Incubation periods were generally 24 to 48 hours long, and the duration of illness was 24 to 48 hours. Bacteriologic analyses of stool and shellfish specimens did not reveal a causative agent. Norwalk virus was implicated as the predominant etiologic agent by clinical features of the illness and by seroconversion and the formation of IgM antibody to Norwalk virus in paired serum samples from persons in five (71 percent) of seven outbreaks in which testing was done. In addition, Norwalk virus was identified by radioimmunoassay in clam and oyster specimens from two of the outbreaks. Determining the source of the shellfish was not always possible, but northeastern coastal waters were implicated. The magnitude, persistence, and widespread nature of these outbreaks raise further questions about the safety of consuming raw shellfish.

Antibodies, Viral↗

PubMed1979

Human enteroviruses in oysters and their overlying waters.

The presence of enteroviruses in oysters and oyster-harvesting waters of the Texas Gulf coast was monitored over a period of 10 months. Viruses were detected in water and oyster samples obtained from areas both open and closed to shellfish harvesting. Viruses were detected periodically in waters that met current bacteriological standards for shellfish harvesting. No significant statistical relationship was demonstrated between virus concentration in oysters and the bacteriological and physiochemical quality of water and shellfish. Viruses in water were, however, moderately correlated with total coliforms in water and oysters and with fecal coliforms in oysters. Total coliforms in water were realted to total coliforms in sediment were related only to total coliforms in sediment. Among the physiochemical characteristics of water, turbidity was related statistically to the organic matter content of water and to fecal coliforms in water. There was a marked effect of rainfall on the bacteriological quality of water. Of a total of 44 water samples, 26 yielded virus in concentrations from 4 to 167 plaque-forming units per 100-gallon (ca. 378.5-liter) sample. Of a total of 40 pools of 10 to 12 oysters each, virus was found in 14 pools at a concentration of 6 to 224 plaque-forming units per 100 g of oyster meat. On five occasions, virus was found in water samples when no virus could be detected in oysters harvested from the same sites. This study indicates that current bacteriological standards for determining the safety of shellfish and shellfish-growing waters do no reflect the occurrence of enteroviruses.

Animals↗

PubMed1997

Seafood-associated diseases and control in Canada.

Paralytic shellfish poisoning (PSP) has been documented for two centuries and control programmes have been operated for fifty years. Although some illnesses are reported almost every year, the last known death from PSP occurred in 1981. In more recent years, amnesic shellfish poisoning, ciguatera poisoning, diarrhoetic shellfish poisoning, scombroid (histamine) poisoning and tetramine poisoning have been documented. The most frequently observed of these diseases is scombroid poisoning from improperly stored fish, but PSP and ciguatera poisoning have the most serious consequences. Vibrio infections arising from naturally-contaminated shellfish are virtually unknown, and viral illnesses from polluted harvested waters are rare. Control is achieved through monitoring of waters for indicators of human pathogens. Inspection systems based on the hazard analysis and critical control point principles are being introduced into all areas of fish and shellfish harvesting. The Inspection Directorate of the Department of Fisheries and Oceans joined the new Canadian Food Inspection Agency in 1997, which co-ordinates all Federal control measures for food in Canada.

Amnesia↗

PubMed2006

High amount of dinophysistoxin-3 in Mytilus chilensis collected in Seno de Reloncaví, chile, during massive human intoxication associated with outbreak of Vibrio parahaemolyticus.

This study describes the detection of high amount of 7-O-acyl-derivative dinophysistoxin-1 (Dinophysistoxin-3) in filter bivalves collected on February 2005 in the Seno de Reloncaví, Puerto Montt City, Southern Chile, in the same period of time where an intoxication episode was associated with the presence of Vibrio parahaemolyticus in shellfish. The Diarrhetic Shellfish Poisoning (DSP) mouse bioassay of mussel extract samples, performed as described for regulatory testing, were negative to DSP toxins. Therefore, the same mussel samples collected from 8 places of Seno de Reloncaví were then analyzed by the HPLC-FLD method with pre-column derivatization procedure for DSP toxins. The samples showed mainly 7-O-acyl-derivative dinophysistoxin-1 (Dinophysistoxin-3) in concentrations ranging from 190.3 +/- 6.8 to 311.1 +/- 4.8 ng of DSP toxin/g hepatopancreas and less amounts of Dinophysistoxin-1 ranging from 1.9 +/- 1.5 to 11.7 +/- 4.6 ng of DSP toxin/g hepatopancreas. After alkaline hydrolysis of the mussel extracts, 279.4 +/- 7.2 ng of Dinophysistoxin-1 /g hepatopancreas (mean +/- SEM, N=6) were found in mussel extracts (Zone 8). These data showed that these shellfish samples are contaminated with the ester form 7-O-acyl-derivatives of Dinophysisyoxin-1, far beyond the safe regulatory limit. This paper also shows a direct relation between lipid content in the mussel tissue extracts and the levels of Dinophysistoxin-3. The 7-O-acyl-derivative dinophysistoxin-1 ester was the only compound associated with DSP toxins detected in the shellfish samples, and in view of the fact that metabolic transformation of Dinophysistoxin-3 into Dinophysistoxin-1 in humans has recently been described in the literature, the consumption of shellfish contaminated with 7-O-acyl-derivatives dinophysistoxin-1 could be a major reason that explains the diarrhetic symptoms shown by the intoxicated patients.

Adult↗

PubMed2005

[Vibrio parahaemolyticus infections and algal intoxications as emergent public health problems in Chile].

There is interest in the paradigm that relates environmental sea changes to the emergence of diseases that affect both aquatic organisms in the sea and human beings. The emergence of Vibrio parahaemolyticus as an important cause of epidemic summer diarrhea in 2004 and 2005, confined mainly to the tenth region in Chile, could be a manifestation of this trend. This and other areas of the country have also experienced several outbreaks of paralytic shellfish poisoning (PSP), diarrheal shellfish poisoning (DSP) and amnesic shellfish poisoning (ASP) caused by harmful algal blooms (HAB) of Alexandrium catenella, Dinophysis acuta and Pseudonitzchia species, respectively. The short historical record of these pathological phenomena in Chile suggests that they are increasing in frequency and expanding their geographical range. The V parahaemolyticus isolates responsible for the Chilean outbreaks correspond mainly to the pandemic strain O3:K6. HAB found in Chile and the intoxications caused by them have similar biological characteristics to those described in other areas of the world. The tenth region, the area where these problems are emerging, produces approximately 80-90% of the shellfish consumed in Chile and a large proportion of the shellfish that is exported. Prevention of these public health problems can be attained by developing policies that increase environmental surveillance for Vibrios and toxic algae, improve the epidemiological surveillance of acute diarrhea and algal intoxications after the ingestion of raw bivalves, and educate the population on the mode of transmission of these diseases. Scientific capacity and laboratories need to be developed to widen the limited knowledge of the biology of Vibrio and toxic algae and the environmental factors that favor their emergence as public health and economic problems in Chile.

Bacterial Toxins↗

PubMedDate not supplied

Phycotoxins.

The 1997-1998 period brought many new developments to the phycotoxin field. There were several reviews on phycotoxins in general, on their toxicological evaluation, and on their analysis. The ecophysiology, biosynthesis, and metabolism of polyether toxins and paralytic shellfish poisoning (PSP) toxins were also reviewed. The proceedings of the Eighth International Conference on Harmful Algae (Vigo, Spain, June 25-29, 1997) have been published and provide an excellent source of information on phycotoxins and toxic plankton bloom research. In addition, the much anticipated proceedings of the IX International IUPAC Symposium on Mycotoxins and Phycotoxins (Rome, Italy, May 27-31, 1996) have been published. Further evidence was provided to support the theory that Prorocentrum lima is the source organism for diarrhetic shellfish poisoning (DSP) toxins in Nova Scotian shellfish. In another study, different Prorocentrum species and isolates were analyzed for DSP toxins. In addition to detecting some new compounds, such as a DTX1 isomer, it was found that toxins were produced by both axenic and nonaxenic batch cultures, indicating that bacteria are probably not involved in the biosynthesis. The source organism for the spirolides, a family of fast-acting toxins reported from Nova Scotia, Canada, was determined to be Alexandrium ostenfeldii, a species that is found worldwide. The biogenetic origin of yessotoxin was reported to be Protoceratium reticulatum, another widely occurring organism. A great deal of attention and research funding has been directed at the serious problems associated with Pfiesteria piscicida. Analysts are eagerly awaiting publication of toxin structures, which will then allow the development of analytical methods. An incident of the mass mortality of California sea lions was reported in the Monterey area in May 1998. Analyses of tissue and urine samples revealed the presence of domoic acid. High levels of domoic acid were also found in anchovies and sardines, a common food source of sea lions. This is reminiscent of an incident of mass bird mortality in 1992 in the same region. Toxicological studies of domoic acid continue with one investigation on the effect of pH on toxicity in the mouse assay and others examining toxic effects in rats and cynomolgus monkeys. A study on the uptake and depuration of domoic acid in the Dungeness crab was reported. On October 20, 1997, EU (European Union) directive CE97/61 established a regulatory limit of 20 ppm for domoic acid in European shellfish, the same level as in North America. A detailed study on the oral toxicity of DSP toxins in mice was reported. Recent work by several researchers has revealed the genotoxic potential of okadaic acid and other DSP toxins. Previous work had clearly demonstrated the tumor-promoting potential of DSP toxins, but this recent evidence, which shows mutations in the progeny of okadaic acid-treated cells and the formation of DNA-adducts, increases concerns over the hazards associated with DSP-contaminated shellfish. The toxicology of yessotoxin was evaluated by Ogino et al. The toxin showed weak cytotoxicity, but was not orally lethal to mice at 10 mg/kg, and did not cause intestinal fluid accumulation, inhibition of protein phosphatase 2A (PP2A), or hemolytic effects. Similarly, Tubaro et al. saw no evidence for diarrheogenicity of homoyessotoxin isolated from mussels and from the proposed planktonic producer, Lingulodinium polyedrum. All this provides further evidence that yessotoxin should not be classed as a DSP toxin. A number of new toxins have been detected and identified. Two analogues of yessotoxin, homoyessotoxin, and 45-hydroxyhomoyessotoxin were isolated from mussels of the Adriatic Sea and identified by Satake et al. A recent DSP event in Ireland associated with cultured mussels led to the identification of azaspiracid, a unique marine toxin with spiro ring assemblies. (ABSTRACT TRUNCATED)

Animals↗

PubMed2001

Survey of the distribution of red tide toxins (okadaic acid and dinophytoxin-1) in the Dalian Bay sea area of China by micellar electrokinetic capillary chromatography.

Two kinds of diarrhoetic shellfish toxins, okadaic acid (OA) and dinophytoxin-1 (DTX-1) were determined by micellar electrokinetic capillary chromatography (MEKC) with ultraviolet detection. A detection limit of 3.25 microg/mL for both of them was achieved. The UV absorbance of these toxins measured at 200 nm showed good linearity in the range of 6.25-200 microg/mL with R = 0.992 for OA and 0.997 for DTX-1. Three kinds of shellfish (Chlamys farreri, Mytilus edulis and Ruditaps philippinarum) collected from eight locations (sampling in the intertidal zone) along the Dalian Bay sea area of China were surveyed in February and May of 2000. Results indicated that three kinds of shellfish were contaminated by OA and DTX-1. Based on per gram of hepatopancreas in February, the contamination contents ranged from 0 to 1.26 microg for OA and from 0 to 1.82 microg for DTX-1, and in May, the contents ranged from 0 to 1.45 microg for OA and 0 to 2.56 microg for DTX-1. Among the eight locations, Hei Shi Jiao and Long Wang Tang were the most contaminated areas. Of the three kinds of shellfish, Mytilus edulis was the most significant species in accumulating OA and DTX-1.

Animals↗

PubMed1995

Associations between diet and health behavior: results from the 1992 Rhode Island Behavioral Risk Factor Survey.

The 1992 Rhode Island Behavioral Risk Factor Surveillance System was used to assess self-reported health behaviors of consumers of finfish and raw shellfish. We hypothesized that consumers of finfish, foods considered to be healthy, were more likely than nonconsumers of finfish to partake in health-promoting behaviors. Similarly, we postulated that consumers of raw molluscan shellfish, foods linked to an elevated risk of acquiring various illnesses, were more likely than nonconsumers of raw-shellfish to partake in risk-taking behaviors. Finfish eaters were significantly more likely than abstainers to report recent exercise, efforts to lose weight, periodic monitoring of serum cholesterol, and not currently being smokers. Raw shellfish eaters were significantly more likely than abstainers to report recent acute and chronic alcohol consumption. The results suggest that inquiry into dietary patterns may be an avenue for exploring other health behaviors.

Adolescent↗

PubMed1996

Detection of okadaic acid esters in the hexane extracts of Spanish mussels.

Two types of low polar derivatives of OA and dinophysitoxins have been reported in shellfish or in phytoplankton: 7-0-acyl esters containing a fatty acyl group attached through the 7-OH group and diol esters in which the carboxylic group of the toxins has been esterified. These compounds cannot be directly detected by liquid chromatography and fluorimetric detection as 9-anthryldiazomethane derivatives, owing in the first case to their low polarity and high molecular weight, and in the second case because they have the carboxylic group esterified. All of them must be hydrolysed before derivatization to be detected as Adam derivatives of the corresponding non-acylated toxins. In the Lee procedure, after extraction of the shellfish digestive glands with 80% methanol, a liquid-liquid partition with a non-polar solvent such as hexane is carried out in order to remove non-polar lipids. The presence of non-polar toxins was investigated in Spanish mussels and confirmed in the hexane layer, usually discarded in conventional extraction procedures, by analysis of the alkaline hydrolysis products. A preferred solubilization of these toxins in a non-polar solvent like hexane is reported. The inclusion of a hydrolytic step of the hexane extract in the general procedure is suggested in order to monitor the contribution of non-polar diarrhoetic shellfish poisons (DSPs) to the total DSP shellfish toxicity. This is the first report of DSPs other than OA and DTX2 in Spanish mussels.

Animals↗