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Organochlorines (DDT, toxaphene, PCBs, chlordane, HCHs, dieldrin) were quantified in the blubber of eleven fur seals of the species Arctocephalus pusillus pusillus. The sample clean-up included microwave-assisted extraction (MAE), gel-permeation chromatography (GPC), adsorption chromatography on silica gel and quantitation with GC/ECD. Compounds of technical toxaphene (CTTs) were determined after separation from the PCBs. Highest levels arose for p , p ′-DDE (7–1000 μg/kg). A so far unknown compound labelled Q1 caused the second most abundant peak in the samples. Q1 was identified as a heptachloro compound by GC/MS in the electron capture negative ionisation and electron impact ionisation mode. Levels of Q1 were estimated relative to the ECD response factor of trans -nonachlor. These estimated Q1 levels ranged from 27 to 351 μg/kg being in the range or higher than the levels of PCBs (6–697 μg/kg), toxaphene (10–97 μg/kg), chlordane (3–159 μg/kg), and dieldrin (4–36 μg/kg). One sample which showed significantly higher DDT and PCB levels (but not toxaphene, dieldrin, Q1, and chlordane) than the others is most likely migrated from an area higher polluted with DDT and PCBs. Another one showed very low levels which were not explained. Except these samples, the levels determined in the blubber were among the lower levels reported for this kind of tissue. The data also confirmed that the organochlorine levels in Africa are varying from region to region, and that there is still a need for further research.

Levels of organochlorines (PCBs, DDT, toxaphene, chlordane, hexachlorobenzene (HCB), hexachlo-rocyclohexanes (HCHs), dieldrin, Q1) were determined in eggs of both penguins (Adelie Pygoscelis adeliae, Chinstrap Pygoscelis antarctica, Gentoo Pygoscelis papua) and skuas (South Polar Skua Catharacta maccormicki, Brown Skua Catharacta antarctica lonnbergi, Mixed Pair Skua Catharacta maccormicki x lonnbergi) from the Antarctic. Focused open-vessel microwave-assisted extraction (FOV-MAE) was performed for the extraction of entire, partly lyophilised eggs (approx. 50 g). After gel-permeation chromatography (GPC) and adsorption chromatography on deactivated silica gel, the quantitation was performed by GC/ECD on two capillary columns of different polarity. Compounds of technical toxaphene (CTTs) were determined after separation of the PCBs. The sample clean-up method was validated with certified reference material SRM 1588. In general, skua eggs revealed higher organochlorine levels than penguin eggs. Mai...

Objective To determine whether supplementation with the long-chain omega-3 polyunsaturated fatty acids eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) affects behavioral symptoms and cognitive impairments in children 6–12 years of age diagnosed with attention-deficit/hyperactivity disorder (ADHD). Study design The randomized, double-blind placebo-controlled 16 weeks trial was conducted with 95 children diagnosed with ADHD according to DSM-IV criteria. Behavior was assessed by parents, teachers and investigators using standardized rating scales and questionnaires. Further outcome variables were working memory, speed of information processing and various measures of attention. For a subgroup of 81 participants, erythrocyte membrane fatty acid composition was analyzed before and after the intervention. Results Supplementation with the omega-3 fatty acid mix increased EPA and DHA concentrations in erythrocyte membranes and improved working memory function, but had no effect on other cognitive measures and parent- and teacher-rated behavior in the study population. Improved working memory correlated significantly with increased EPA, DHA and decreased AA (arachidonic acid).

Avian infectious laryngotracheitis virus (ILTV), a herpesvirus, is a highly contagious pathogen that causes an upper respiratory tract infection in chickens. It is one of the major problems in the poultry industry worldwide. Current vaccines are not satisfactory due to the induction of latent infection. Here we describe a system for the construction of recombinant ILTV. A 4-kbp ILTV EcoRI DNA fragment was cloned into plasmid pUC13 and sequenced. Computer prediction revealed two potential open reading frames with 216 and 259 amino acid residues, respectively. The 259-residue polypeptide was serine-rich. The β-galactosidase (β-gal) gene of E. coli was cloned into the XhoI/BglII site of this DNA fragment, integrated into the ILTV genome via homologous recombination, expressed under the control of the immediate-early cytomegalovirus promoter, and caused the formation of blue plaques in the presence of X-gal. The insertion of a foreign gene into the ILTV genome and the successful expression of the incorporated gene demonstrated the potential for the construction of attenuated recombinant ILTV vaccines and the development of ILTV as vectors for polyvalent vaccines against avian upper respiratory tract infections.

An avian hepatoma cell line has been reported to be suitable for the cultivation of avian laryngotracheitis virus (ILTV) (Scholz et al. (1993) J. Virol. Methods, 273-286; Guo et al. (1993) Am. J. Vet. Res., in press). To provide information for the establishment of avian expression systems and for the construction of avian recombinant viruses, five expression plasmids were constructed to test two avian viral and two mammalian viral promotors for their suitability and strength for gene expression in this cell line. Chicken hepatoma cells were transfected with plasmids carrying the bacterial beta-galactosidase (beta-gal) gene as a reporter gene. The beta-gal gene of three plasmid constructs expressed in both E. coli and avian hepatoma cells, while the beta-gal gene of two other constructs expressed only in avian hepatoma cells. The beta-gal gene expressed independently of any viral infection when under the control of the early Rous sarcoma virus (RSV) promoter or the immediate-early cytomegalovirus (CMV) promoter. However, expression of beta-gal gene under the control of the SV40 early promoter/enhancer and the ILTV TK promoter was greatly potentiated when the transfected cells were co-infected with ILTV. This finding provides a system for the enhancement of gene expression in avian cells, especially when ILTV is used as vector.

A Cl(7) component of technical toxaphene (CTT), previously detected in marine mammals and fish and referred to as "7-1", was isolated from contaminated estuarine sediment using preparative solid-liquid chromatography followed by reversed-phase HPLC. The structure of this compound, elucidated by GC/MS and (1)H NMR, was 2-endo,3-exo,5-endo,6-exo,8,8,10-heptachlorobornane (hereafter referred to as B7-1000). This newly identified CTT eluted in the nonpolar fraction from silica and shares the alternating endo-exo chlorine substitution pattern with other relatively nonpolar, persistent congeners (e.g., B8-1413 and B9-1679). Based on ECNI-MS response, levels of B7-1000 in tissue samples of various higher organisms including humans were as high as 16% of B8-1413. Enantioselective determination of B7-1000 using a modified cyclodextrin chiral stationary phase (beta-BSCD) resulted in enantiomer ratios that were depleted in adipose tissue of a marine bird (skua) and Weddell seal blubber (0.3 and 0.5, respectively), but not in elephant seal blubber (1.1). Elucidation of the structure of B7-1000 thus validates previous predictions of persistence based on structure-activity relationships, chromatographic properties, and molecular modeling.

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A simple polymerase chain reaction (PCR)-based procedure was developed for the detection of avian infectious laryngotracheitis virus (ILTV) in chicken trachea, chorio-allantoic membrane (CAM), infected hepatoma cells and infectious cell culture supernatant. Samples were prepared by dilution in distilled water. After boiling and low speed centrifugation, samples were used for PCR analysis with two primers without special labeling. The PCR analysis for ILT virus could be completed in less than 8 h. Standard agarose gel electrophoretic analysis of the PCR products revealed a prominent band of 300 base-pairs in samples from ILTV-infected specimens, but not from specimens containing Newcastle disease virus, infectious bronchitis virus, avian adenovirus, fowlpox virus, Pachecoz or Marek's disease virus. One single ILTV infected cell or 10 plaque forming units of ILTV could be detected with this procedure. The procedure can be used for the identification of ILTV and the differentiation of ILTV from other avian respiratory tract infectants.

SUMMARY The acid stability of unpurified and highly purified hepatitis A virus (HAV) was tested and compared with that of poliovirus type l, coxsackievirus types A9 and B 1 and echovirus type 9. Only HAV had a high residual infectivity after 2 h of exposure to pH 1 at room temperature, remaining infectious for up to 5 h. At 38 °C, pH 1, HAV remained infectious for 90 min. Highly purified HAV was found to be infectious for 8 h at pH 1 and room temperature. This indicates that the increased stability is not due to protection by cellular material attached to the virus, but is a virus-specific marker. Under the same conditions, at pH 1 and room temperature, unpurified and highly purified HAV antigens were traceable for 5 and 4 h respectively.

The localization and movements of four nuclear proteins, originally contained in the germinal vesicle ofXenopus oocytes, were followed through early development from cleavage to late neurula. The study made use of monoclonal antibodies directed against germinal vesicle proteins. Biochemical methods showed that all proteins persist in the embryo without a change in molecular size or gross concentration. At early stages the proteins are localized preferentially in the cytoplasm of the animal hemisphere. They shift from the cytoplasm to the nucleus at stages specific for the individual proteins. During mitosis the proteins are released from the nucleus into the cytoplasm.

Dependent on the species, feedstuffs and plants differ considerably in their iodine content. Among the I-poorest feedstuffs there are grain concentrates, extracted soybean and rapeseed oil meals, mixed feed (without I-containing mineral mixture) and grasses. The I content of the plants decreases with proceeding growth. The I intake of ruminants via vegetable feed and drinking water is affected by the distance of the site from the seaside and the geological origin of the soil material. Ruminants get considerably less iodine via feedstuffs and water in the southern territory of the GDR than in the central and northern areas. Therefore, mineral mixtures for cattle and sheep are supplemented with 18 mg KIO3 per kg mixture in the southern districts. The I analysis of 205 charges of mineral mixtures revealed only a mean I content of 7 (3.8-11.3) mg per kg mixture.