Feathers as bioindicators of PCB exposure in clapper rails.

In this study we used feathers to biomonitor exposure to the polychlorinated biphenyl (PCB) Aroclor 1268 congener mixture in clapper rails (Rallus longirostris). This species has been used as an indicator species of environmental damage for the LCP superfund site located in Brunswick, GA, USA which is contaminated with Aroclor 1268, a congener mixture that has been used in limited amounts elsewhere and therefore can be used as a contaminant marker. The Aroclor 1268 congener mixture, including congener profiles, were quantified in feathers using gas chromatography (GC). Concurrently, each sample was quantified for the total Aroclor 1268 congener mixture using an enzyme-linked immunosorbant assay (ELISA) and compared to the GC results to determine if ELISA was an efficient method for quantifying or qualifying PCBs in feathers. ELISA consistently quantified PCB loads over an order of magnitude lower than the GC. Based on sample replication, extraction recovery, and sample spike, it appears that GC is the more reliable method of detection and that ELISA methods may be more suitable for qualitative exposure assessment for this particular Aroclor. Moreover, since all clapper rails from the LCP site had the Aroclor 1268 congener mixture in their feathers, this experiment showed that birds were returning to the site to breed despite the adverse effects experienced by this population from the contamination revealed in previous studies. This study also supports the utility of feathers as a non-lethal mechanism by which to biomonitor PCBs in the environment.

Isolation, characterization and comparative aspects of the major serum apolipoproteins, B-100 and AI, in the common marmoset, Callithrix jacchus.

The two major apolipoproteins of marmoset serum have been isolated and characterized, and on the basis of physicochemical and immunological criteria are homologous with the human AI and B-100 proteins. Marmoset apolipoprotein AI was the principal protein of high-density lipoproteins (HDL) and was purified by gel filtration chromatography and electrophoresis in alkaline-urea polyacrylamide gel followed by electrophoretic elution. Purified marmoset apolipoprotein AI displayed an Mr of approx. 27000, was polymorphic (five forms) on isoelectric focussing, with pI values in the range 4.8-5.0, and migrated similarly to human apolipoprotein AI in alkaline-urea gels. An overall resemblance was seen in the amino acid composition of marmoset apolipoprotein AI and that of its human counterpart with the notable exception that marmoset AI contained 1 isoleucine residue/mole. An immunological reaction of partial identity between the human and monkey proteins was seen upon immunodiffusion of their HDLs against antiserum to human apolipoprotein AI. Marmoset B-100 was the predominant apoprotein of VLDL and LDL, resembling the human protein in its elution profile on gel filtration chromatography in anionic detergent, and in its high apparent Mr (approx. 520000). The marmoset and human B-100 proteins were alike in amino acid composition and carbohydrate content. Moreover, their immunological behaviour with an antiserum to marmoset apolipoprotein B showed them to share certain antigenic determinant(s). We conclude that the physicochemical properties of the principle apolipoproteins of Callithrix jacchus, a New World primate, markedly resemble those of the human AI and B-100 proteins, suggesting therefore that they may function similarly in lipid transport and metabolism. Counterparts to human apolipoproteins AII, E, CII and CIII have also been tentatively identified.

Biochemical and immunological evidence for the presence of an apolipoprotein B-like component in the serum low-density lipoproteins of several animal species.

The major component of the protein moiety of human LDL, i.e. apolipoprotein B, has been compared biochemically and immunologically with its counterpart in the LDL of several groups of animals (mammals, birds, snakes and fish). A marked resemblance was found in the amino acid composition of the apo-B fractions from all the phylogenetic groups, although immunological cross-reactivity with human apolipoprotein B occurred only in the case of non-human primate (Old World monkey), non-primate mammalian (pig and guinea pig) and bird (chicken) apo-B components (63%, 24% and about 8% respectively). The cross-reactivity of each animal apo-B component with its human counterpart was 7-14% lower than that observed between the parent LDL's. The resemblance in amino acid composition between the various apo-B preparations suggests that certain structural characteristics are required in this protein in order for it to bind and stabilise the lipid complement of serum LDL.

Chimpanzee serum lipoproteins. Isolation, characterisation and comparative aspects of the low density lipoprotein and apolipoprotein-BH.

Evaluation of the serum lipoprotein profile in non-fasting, adult chimpanzees by analytical ultracentrifugation revealed a lower mean LDL level (269 mg/dl) than typical of man. The major molecular form(s) of low density lipoprotein (LDL) was then isolated in the density interval 1.024-1.050 g/ml by sequential ultracentrifugation. The physicochemical properties of chimpanzee LDL, including net surface charge as judged by electrophoresis, molecular size (220 A) by electron microscopy, and chemical composition closely resembled those of man. The antigenic structures of chimpanzee and human LDL were essentially indistinguishable, since immunodiffusion against antiserum to either the human or ape lipoprotein produced a precipitin reaction of complete identity between the two antigens. By micro-immunoprecipitation, the immunological cross-reactivity of LDL from the two species was in the range 85-97%, depending on the nature of the assay.

Lipid composition of metacestodes of Taenia taeniaeformis and lipid changes during growth.

A lipid analysis was performed on developing metacestodes of Taenia taeniaeformis removed from the livers of rats at times varying from 3 to 35 weeks post infection. Lipid accounted for 7-21% of the dry weight of the parasites. The highest proportions were found at the earlier stages. The distribution was as follows; neutral lipid 27-45%; glycolipid 5-11%; and phospholipid 50-61%. The major neutral lipid was cholesterol, and minor neutral lipids were sterol esters, triglycerides, diglycerides and monoglycerides. Hydrocarbons were present throughout development, but in the highest amounts at the earlier stages. Five different glycolipids were found, all of which were identified as glycosphingolipids. An increase in the proportion of more complex glycolipids was noted as parasites grew older. Ten different phospholipids were identified, with the major components being phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine. Other phospholipids were: lysophosphatides, phosphatidylinositol, phosphatidic acid, diphosphatidylglycerol, sphingomyelin, and an unknown phospholipid component. Changes in the relative amounts of the two major phospholipids were found when the early and late stages were compared. Two lipids found throughout development were identified as glycosylated dolichol phosphates, and they comprised between 1 and 3% of the total phospholipid fraction. Nineteen fatty acids were detected, and the fatty acid distribution for each lipid class at each stage was determined. Seven major fatty acids were common to each. These were: hexadecanoic, octadecanoic, oleic, linoleic, arachidonic, docosanoic, and docosahexaenoic.

Waldenström's macroglobulinaemia treated with cylophosphamide and chlorambucil.

A case of primary macroglobulinaemia of Waldenström is described in which prolonged treatment with the alkylating agents of cyclophosphamide and chlorambucil led to a sustained reduction in the concentration of circulating macroglobulin together with a concurrent improvement in the patient's symptoms.

Assay of an activator for lipoprotein lipase.

A method is described which enables the ability of human serum to activate guinea pig lipoprotein lipase to be measured in terms of an arbitrary standard. Evidence is offered which strongly suggests that the substance measured is also the activator of human lipoprotein lipase and observations on the relative levels of activator in human sera are given.

Quantitative analysis of serum lipoproteins by micro-scale thin-layer chromatography.

A method has been devised for the complete chemical analysis of serum lipoproteins, in which the constituents are separated by thin-layer chromatography and then measured by means of a flame ionisation detector. Since the response of the detector differs for each constituent, it is necessary to use a previously prepared calibration curve for each one. A complete analysis can be obtained from a single run on about 20 microgram of lipoprotein. However, from 5--10 chromatograms are needed for an adequate degree of precision. The method, which could be adapted to the measurement of tissue lipids, takes less than 2 h to complete. This speed and simplicity seem to give the method considerable potential for the investigation of patients with disorders of lipid transport.

Plasma lipids, lipoproteins and apoproteins in a case of apo C-II deficiency.

A new case of apo C-II deficiency is described. The patient had plasma triglyceride levels ranging from 10.2-30.5 mmol/l. Apo C-II deficiency was confirmed by gel electrophoresis, isoelectric focusing and immunochemistry. In this patient plasma lipoproteins were mainly chylomicrons and very low density lipoproteins, LDL and HDL levels being very low. Infusion of normal plasma effectively reduced plasma triglycerides and enhanced low density and high density lipoproteins cholesterol levels. These data suggest that in vivo a precursor-product relationship exists between triglyceride rich lipoproteins and LDL and HDL, and further stress the role of the lipoprotein lipase-apo C-II system in modulating these metabolic interconversions.

The anomalous behaviour of the permittivity of human serum low density lipoprotein around 37 degrees C.

The structure of human serum low density lipoprotein has been investigated, as a function of temperature, by measurement of permittivity. Statistical analysis of the dielectric data reveals a transition at around the temperature of the human body. This may be associated with a structural change in the interior of the molecule.

Chemical composition of lipid droplets isolated from larvae of Taenia taeniaeformis.

Young developing larvae of Taenia taeniaeformis contain large deposits of osmiophilic droplets. These droplets are spherical, approximately 1.5 micron in diameter and are primarily localized in the tegument. After cellular disruption of the parasite, followed by centrifugation, the lipid droplets were found in a floating layer of lipid. The lipid droplets in the lipid layer resembled the droplets as seen in situ. The isolated lipid droplets mainly consisted of neutral lipids with triglycerides, sterol esters, sterols and free fatty acids being the major components. Smaller amounts of other neutral lipids were also present, as were glycolipids, phospholipids and protein. The lipid droplets were not membrane bound. The relationship between lipid droplets, lipid utilization and membrane synthesis during parasite growth is discussed.

Lipid and protein composition of the surface tegument from larvae of Taenia taeniaeformis.

A tegumental fraction from fully developed larvae of Taenia taeniaeformis was recovered by low speed centrifugation following incubation of the parasites in a 0.1% solution of digitonin. Scanning electron microscopy of the parasite carcass revealed no surface microtrichs, and transmission electron microscopy indicated that the subtegumental layer was undamaged. The tegumental fraction, judging from the distribution of 3H-Concanavalin A, was enriched for surface components, exhibited low succinic dehydrogenase activity, and an electron microscopic examination of the pellet showed a slightly expanded but intact distal tegumental layer. The fraction, which made up 3.0% of the dry weight of the parasite, consisted of 52% protein and 32% lipid. Thirty-three proteins, ranging in Mr from 9,000 to 276,000 daltons, were detected after sodium dodecyl sulfate solubilization and polyacrylamide gel electrophoresis. Seven of these proteins were glycoproteins. Cholesterol, phosphatidylethanolamine, phosphatidylserine, and glycosphingolipids were the major lipids.