Ljerka Prester

Biogenic amines in fish, fish products and shellfish: a review

Fish, cephalopods and shellfish provide a healthy source of high-quality proteins, essential vitamins, minerals and polyunsaturated fatty acids. The beneficial effects of fish consumption on human health such as protection against coronary heart disease and certain cancer may be offset by fish decomposition and the formation of chemical contaminants such as biogenic amines. There are several toxicological effects of biogenic amines on humans, especially histamine. It is the causative agent of histamine or scombroid fish poisoning which is a significant public health problem. In individuals with diminished histamine detoxification, ingestion of even a low or moderate histamine- or tyramine-containing fish may lead to food intolerance. Biogenic amines such as putrescine, tyramine and cadaverine can potentiate histamine toxicity. Furthermore, dietary polyamine intake should be minimised in some cancer patients. Besides their potential toxicity, biogenic amines are used for the evaluation of hygienic quality of different marine and freshwater species. Spoilage pattern and biogenic amine formation are species specific. Histamine has been traditionally used as an indicator of the quality of histidine-rich fish (dark-muscle fish). On the other hand, putrescine and cadaverine are the most objective indicators of quality of histidine-poor fish (white-muscle fish), shellfish and fermented seafood products.

Dental amalgam mercury exposure in rats.

The aim of this study was to measure the distribution of mercury, in tissues of rats exposed to amalgam over a two months period. Possible interaction of mercury with copper and zinc in organs was also evaluated. Rats were either exposed to mercury from 4 dental amalgams, or fed the diet containing powdered amalgam during two months. Mercury was measured in the kidney, liver and brain, copper in kidney and brain and zinc in kidney. The results showed significantly higher concentrations of mercury in the kidneys and the brains of rats in both exposed groups compared to control. Even after two months of exposure to mercury brain mercury concentration in rats with amalgam fillings was 8 times higher than in the control and 2 times higher than in rats exposed to amalgam supplemented diet. The highest mercury concentration in the latter group was found in the kidneys and it was 5 times higher than in the control group. We found no significant differences between mercury levels in exposed and control rats liver. Exposure to mercury from dental amalgams did not alter the concentrations of copper and zinc in the tissues. Histopathological analyses of rats tissues did not show any pathological changes. These results support previously proposed nose-brain transport of mercury released from dental amalgam fillings.

Endotoxin and biogenic amine levels in Atlantic mackerel (Scomber scombrus), sardine (Sardina pilchardus) and Mediterranean hake (Merluccius merluccius) stored at 22 °C

Whole Atlantic mackerel (Scomber scombrus), sardine (Sardina pilchardus) and Mediterranean hake (Merluccius merluccius) from the Croatian Adriatic were stored at 22 °C and changes in histamine, putrescine, tyramine and cadaverine levels were monitored in relation to bacterial endotoxin. After 12 h, histamine levels in sardine were above the legal limit of 50 mg kg−1, set by the US Food and Drug Administration, and an increase in putrescine content preceded the increase in histamine. After 24 h, histamine contents in mackerel and sardine reached 1090 ± 101 and 577 ± 275 mg kg−1, respectively, which exceeded the toxic threshold of 500 mg kg−1. At the same time, the putrescine content was also high in both fish (353–420 mg kg−1). The time-course of endotoxin production was similar in all fish species stored at 22 °C. A high correlation was found between endotoxin and histamine, and between endotoxin and putrescine in mackerel and sardine. On the other hand, high endotoxin levels in hake, after 24 h, were associated with the low histamine and putrescine content (40–60 mg kg−1).

Chelation of aluminium by combining DFO and L1 in rats

The hypothesis that two known chelators 1, 2-dimethyl-3-hydroxypyrid-4-one (L1) and desferrioxamine (DFO) might be more efficient as combined treatment than as monotherapies in removing aluminium from the body was tested in a new acute rat model. Five-week old female rats received chelators: L1 (p.o.), DFO (i.p.) or L1+DFO as 100 or 200 mg/kg dose half an hour after a single i.p. administration of 6 mg Al/kg body weight in the form of chloride. Serum aluminium concentration and urinary aluminium and iron excretions were determined by electrothermal or flame atomic absorption spectrometry. Both chelators were effective only at the higher dose level. While DFO was more effective than L1 in enhancing urinary aluminium excretion, L1 was more effective than DFO in enhancing urinary iron excretion. In the combined treatment group L1 did not increase the DFO effect on aluminium and DFO did not increase the effect of L1 on iron elimination. However, in this group a simultaneous increase in both aluminium and iron elimination was observed. Our results support the usefulness of this animal model for preliminary in vivo testing of aluminium chelators. Urinary values were more useful because of the high variability of serum results. Result of combined chelators treatment should be confirmed in a different experimental model before extrapolation to other systems. This testing procedure of course does not provide all the relevant answers for evaluating the efficiency of chelating agents in aluminium toxicity.

Determination of mite Allergens in House Dust Using the Enzyme Immunoassay

Determination of mite Allergens in House Dust Using the Enzyme Immunoassay The aim of this study was to determine the level of two major mite allergens Dermatophagoides pteronyssinus (Der p 1) and Dermatophagoides farinae (Der f 1) in 30 urban homes in Zagreb, Croatia, using the enzyme immunoassay with two monoclonal antibodies which has been established as the reference method for indoor allergen analysis. Dust samples were taken by vacuuming a carpeted area and collected on cellulose filters. The ranges of Der p 1 and Der f 1 were (0.1-12.5) μg g-1 (median 0.32 μg g-1) and (0.1-31.2) μg g-1 (median 0.35 μg g-1), respectively. Der p 1 and Der f 1 (>2 μg g-1) associated with increased risk of sensitization to mite allergens were found in approximately 16% homes for each allergen. The sum of allergen (Der p 1 + Der f 1) exceeded the lower threshold in 27% of homes. Analytical evaluation of the ELISA assay showed satisfactory results for precision (intra-assay CV <6.9%, inter-assay CV<13.3%), accuracy (91% to 93%), and sensitivity (2 ng mL-1). The ELISA assay for the measurement of dust mite allergens demonstrated very good analytical characteristics for routine laboratory use, and will provide the essential basis for our future studies of various indoor allergens. Određivanje Alergena Grinja U Kućnoj Prašini Enzim-Imunokemijskom Metodom Cilj ovoga rada bio je odrediti razine alergena grinja Dermatophagoides pteronyssinus (Der p 1) i Dermatophagoides farinae (Der f 1) u 30 uzoraka kućne prašine uzorkovane u gradskim stanovima u Zagrebu enzim-imunokemijskom metodom (ELISA, Indoor Biotechnologies Ltd, Carfiff, UK). Metoda se koristi tehnikom dvaju monoklonskih protutijela, a primjenjuje se kao standardna metoda za određivanje alergena grinja u prašini. Uzorci prašine skupljeni su usisavanjem prašine s tepiha u celulozne filtre. Maseni udjeli Der p 1 bili su u rasponu od 0.10 μg g-1 do 12.5 μg g-1 (medijan 0.32 μg g-1), a Der f 1 od 0.10 μg g-1 do 31.2 μg g-1 (medijan 0, 35 μg g-1). Prisutnost Der p 1 i Der f 1 (>2 μg g-1) u kućnoj prašini povezana je s povećanim rizikom od senzibilizacije alergenima grinja. U ovom radu je u oko 16% stanova ustanovljena ta razina, i to za oba alergena. Ako se zbroje maseni udjeli alergena (Der p 1 + Der f 1), tada je razina alergena u kućnoj prašini >2 μg g-1 nađena u oko 27% stanova. Analitičkom procjenom metode ELISA dobiveni su zadovoljavajući rezultati za preciznost u seriji (KV < 6, 9%), preciznost iz dana u dan (KV < 13, 3%), točnost (91% do 93%) te osjetljivost (2 ng mL-1). Metoda ELISA čini nužnu bazu za naša buduća ispitivanja alergena unutarnjih prostora.

Monoisoamyl ester of DMSA reduces 203Hg(NO3)2 retention in rats: 1. Chelation therapy during pregnancy

In this study, efficacy of monoisoamyl meso-2,3-dimercaptosuccinate (Mi-ADMS) was tested to mobilize mercury in the period of gestation in rats. Its action was compared to meso-2,3-dimercaptosuccinic acid (DMSA). Pregnant dams (in second third of gestation) received a single intravenous injection of 203Hg(NO3)2 and oral chelating therapy with DMSA or Mi-ADMS 0.5, 24, and 48 hours after that. Each chelator was administered in three single doses of 0.5 mmol/kg body weight on three consecutive days. The fifth day after 203Hg exposure, retentions were measured in whole body, organs, and fetuses. Results (expressed as the percentage of 203Hg dose) showed that all retention values among treated animals were lower than in the control group. Significantly higher reduction of whole body gut, liver, kidney, and brain retentions in Mi-ADMS (to 2–5% of control values) than in DMSA-treated groups (to 37–80% of control values) was found. 203Hg retention in uterus, fetuses, and placentae were reduced to 7–8% in Mi-ADMS and to 41–56% of control value in DMSA group. The major routes of 203Hg excretion after DMSA treatment was urine, whereas fecal excretion was the same as that of controls. After Mi-ADMS treatment, both urinary and fecal 203Hg excretions were ∼2–3 times higher than the control values resulting in the lowest body retention. J. Trace Elem. Exp. Med. 10:173–181, 1997.

Determination of Alt a 1 (Alternaria alternata) in poultry farms and a sawmill using ELISA.

Farm and sawmill workers are exposed to high levels of allergenic fungi, such as Alternaria alternata, which are associated with respiratory diseases and asthma. The aim of this study was to measure the concentration of Alt a 1, a major allergen of A. alternata, in indoor dust samples collected in poultry farms and a sawmill using a monoclonal antibody-based enzyme immunoassay. A total of 45 dust samples were collected in poultry farms (30) and the sawmill (15) in Zagreb County (Croatia). The Alt a 1 allergen was detected in all dust samples (100%) collected in three poultry farms. The levels of Alt a 1 were in the range of 0.1–14 μg/g, and the median value was 0.37 μg/g. About 86% of dust samples contained Alt a 1 in the range of 0.1–1.0 μg/g. In the sawmill, no detectable level of Alt a 1 was found (limit of detection =0.12 μg/g). This study has shown that occupational exposure to Alt a 1 allergen in poultry farms deserves monitoring.

Determination of biogenic amines and endotoxin in squid, musky octopus, Norway lobster, and mussel stored at room temperature.

Determination of Biogenic Amines and Endotoxin in Squid, Musky Octopus, Norway Lobster, and Mussel Stored at Room Temperature Little research has been published on the indicators of spoilage in Mediterranean molluscan shellfish and crustaceans. Thus is why we studied changes in the concentrations of endotoxin and four biogenic amines (histamine, putrescine, tyramine and cadaverine) in European common squid (Loligo subulata, Lamarck, 1798), musky octopus (Eledone moschata, Lamarck, 1798), Norway lobster (Nephrops norvegicus, Linnaeus, 1758), and mussel (Mytilus galloprovincialis, Lamarck, 1819) from the Adriatic Sea stored at room temperature for 24 h. Endotoxin load in fresh squid, Norway lobster, and mussel (<1 EU mg-1) indicated good microbiological quality of raw samples. Biogenic amine index (as the sum of histamine, putrescine, tyramine, and cadaverine) correlated well with endotoxin load in squid (r=0.978, p<0.001) and musky octopus (r=0.874, p<0.01). A good correlation was also found between endotoxin and putrescine in Norway lobster (r=0.777, p<0.05). The highest endotoxin load was found in decomposed mussels and was associated with histamine alone. In conclusion, increase in biogenic amine levels is species-specific. Endotoxin analysis could be used for rapid assessment of microbiological quality of cephalopods and shellfish. Određivanje biogenih amina i endotoksina u lignji, muzgavcu, škampima i dagnji pohranjenima na sobnoj temperaturi Istraživanja o pokazateljima kontaminacije mekušaca i člankonožaca iz mediteranskih zemalja su rijetka. Cilj ovoga rada bio je ispitivanje koncentracije endotoksina i četiriju biogenih amina (histamin, putrescin, tiramin i kadaverin) u lignji (Loligo subulata, Lamarck, 1798), muzgavcu (Eledone moschata, Lamarck, 1798), škampima (Nephrops norvegicus, Linnaeus, 1758) i dagnji (Mytilus galloprovincialis, Lamarck, 1819) iz Jadranskog mora koji su bili pohranjeni na sobnoj temperaturi tijekom 24 h. Količina endotoksina u svježoj lignji, škampima i dagnji (<1 EU mg-1) upućuje na njihovu dobru mikrobiološku kvalitetu. Visoka korelacija ustanovljena je između indeksa biogenih amina (suma histamina, putrescina, tiramina i kadaverina) i endotoksina u lignji (r=0,978, p<0,001) i muzgavcu (r=0,874, p<0,01). Također je ustanovljena visoka korelacija između endotoksina i putrescina u škampima (r = 0,777, p<0,05). Najveća razina endotoksina (povezana s porastom histamina) ustanovljena je kod dagnje. U zaključku, porast biogenih amina je species-specifičan. Analiza endotoksina mogla bi se primijeniti kao brza metoda za određivanje mikrobiološke ispravnosti mekušaca i člankonožaca.

Indoor exposure to mould allergens.

Indoor Exposure to Mould Allergens Humid indoor environments may be colonised by allergenic filamentous microfungi (moulds), Aspergillus spp., Penicillium spp., Cladosporium spp., and Alternaria spp. in particular. Mould-induced respiratory diseases are a worldwide problem. In the last two decades, mould allergens and glucans have been used as markers of indoor exposure to moulds. Recently, mould allergens Alt a 1 (Alternaria alternata) and Asp f 1 (Aspergillus fumigatus) have been analysed in various environments (residential and occupational) with enzyme-linked immunosorbent assays, which use monoclonal or polyclonal antibodies. Household Alt a 1 and Asp f 1 levels were usually under the limit of the method detection. By contrast, higher levels of mould allergens were found in environments with high levels of bioaerosols such as poultry farms and sawmills. Data on allergen Alt a 1 and Asp f 1 levels in agricultural settings may provide information on possible colonisation of respective moulds and point out to mould-related diseases in occupants. Izloženost alergenima plijesni u unutarnjem okolišu Vlažni, unutarnji prostori mogu biti kolonizirani alergogenim, filamentoznim mikrogljivicama (plijesni) uglavnom rodova Aspergillus, Penicillium, Cladosporium i Alternaria. Respiratorne bolesti uzrokovane plijesnima zdrastveni su problem diljem svijeta. U posljednja dva desetljeća, neki sastavni dijelovi plijesni kao alergeni i glukan rabe se kao pokazatelji izloženosti plijesni u unutarnjem okolišu. Nedavno su alergeni plijesni Alt a 1 (Alternaria alternata) i Asp f 1 (Aspergillus fumigatus) određivani u različitom okolišu (kućnom i profesionalnom) enzim-imunokemijskom metodom koja rabi monoklonska ili poliklonska antitijela. Razina Alt a 1 i Asp f 1 u kućnoj prašini ispod je granice detekcije. Nasuprot tomu, alergeni plijesni su određeni u okolišu s visokom razinom bioaerosola kao peradarnici i pilane. Razine alergena Alt a 1 i Asp f 1 u nekim poljoprivrednim objektima pružaju informaciju o mogućoj kolonizaciji plijesnima, što upućuje na moguće zdravstvene učinke kod zaposlenika.

Determination of Aspergillus Fumigatus Allergen 1 in Poultry Farms Using the Enzyme Immunoassay

Determination of Aspergillus Fumigatus Allergen 1 in Poultry Farms Using the Enzyme Immunoassay Poultry farms contain high levels of allergenic fungi, and Aspergillus spp. is the most common genus of moulds. Aspergillus fumigatus antigens are responsible for the development of several respiratory diseases including asthma. The aim of this study was to measure the mass fraction of Asp f 1, a major allergen of Asperillus fumigatus in 37 indoor dust samples collected from four poultry farms in a rural area of the Zagreb County (Croatia) using the enzyme-linked immunosorbent assay. More than 62 % of dust samples had detectable Asp f 1 levels (limit of detection 3.6 ng g-1). The overall mean Asp f 1 level was 17.9 ng g-1 [range (3.8 to 72.4) ng g-1]. Satisfactory results were obtained for analytical within-run imprecision (6.7 %), between-run imprecision (10.5 %), and accuracy (91 % to 115 %). Microclimate parameters (air temperature, relative humidity, and velocity) were within the recommended ranges in all poultry farms. This study has shown that Asp f 1 settles on dust at poultry farms and that occupational exposure to this allergen deserves monitoring in livestock buildings. Određivanje alergena Asp f 1 (Aspergillus fumigatus) u peradarniku enzimimunokemijskom metodom Peradarnici sadržavaju veliku koncentraciju alergenih plijesni, a rod Aspergillus najčešće je zastupljen. Antigeni soja Aspergillus fumigatus odgovorni su za nastanak nekoliko respiratornih bolesti uključujući astmu. Cilj ovoga rada bio je odrediti masenu frakciju Asp f 1, glavnog alergena soja Asperillus fumigatus u 37 uzoraka prašine uzorkovanih u četiri peradarnika sa šireg područja Zagrebačke županije rabeći enzimimunokemijsku metodu. Više od 62 % uzoraka prašine u tri peradarnika imalo je mjerljivu koncentraciju Asp f 1 (granica detekcije = 3.6 ng g-1). Ukupni srednji maseni udio Asp f 1 iznosio je 17.9 ng g-1 (raspon od 3.8 ng g-1 do 72.4 ng g-1). Dobiveni su zadovoljavajući rezultati za analitičku nepreciznost u seriji (6.7 %), nepreciznost iz dana u dan (10.5 %) i točnost (91 % do 115 %). Mikroklimatski parametri (temperatura zraka, relativna vlaga i protok zraka) u svim peradarnicima bili su u okviru preporučenih vrijednosti. Rezultati ovoga rada pokazuju da Asp f 1 sedimentira na prašinu u peradarnicima te da profesionalnu izloženost tom alergenu treba pratiti u jedinicama za uzgoj stoke.