Purification and partial characterization of thyroid hormone binding proteins in canine serum

Thyroxine-binding prealbumin (TBPA) and thyroxine-binding globulin (TBG) were isolated from canine serum and partially characterized. TBPA was isolated by retinol-binding protein (RBP) affinity chromatography and further purified by preparative agarose gel electrophoresis or FPLC ion exchange chromatography. TBG was purified by thyroxine (T₄)-Sepharose chromatography followed by gel filtration on Sephacryl S-300 and preparative electrofocusing in a granulated dextran gel. Molecular weights were estimated by SDS-polyacrylamide gradient gel electrophoresis. Canine TBPA had a tetramer molecular weight of 56,000, an extinction coefficient of 12.8 cm²cg⁻¹, an isoelectric point of 5.26–5.70 and a microheterogeneity pattern similar to that of human TBPA. Partial immunochemical identity with human TBPA was also found. Plasma concentrations of TBPA were measured by rocket immunoelectrophoresis in 43 normal and 35 hypothyroid dogs. Reference levels for TBPA ranged between 205 and 474 mg/l. Hypothyroid dogs had a mean TBPA level of 315.0 mg/l (SD: 91.1 mg/l). TBG had a molecular weight of 75,000 and an isoelectric point of 5.0. No immunochemical identity with human TBG was found. Gel filtration of serum on Sephacryl S-200, identification of T₄-binding proteins with ¹²⁵I-T₄, and protein- and lipoprotein staining of fractions was performed. Thyroxine-binding was found to TBG in the β-globulin region, TBPA in the ₂-region, albumin, and to the high density lipoprotein (HDL₂) in the ₁-region and the very low density lipoprotein (VLDL) in the pre-β region. A corresponding band to the latter protein in serum was masked by TBG and TBPA, and T₄-binding in the ₁-region was not always seen in serum. Many similarities were found between man and dog regarding TBPA, but not TBG. The differences in structure of TBG may in part be responsible for the low serum T₄ levels and rapid T₄ metabolism seen in dogs.     

Effect of diets based on foods from conventional versus organic production on intake and excretion of flavonoids and markers of antioxidative defense in humans

Different food production methods may result in differences in the content of secondary metabolites such as polyphenolic compounds. The present study compared conventionally (CPD) and organically produced (OPD) diets in a human crossover intervention study (n = 16) with respect to the intake and excretion of five selected flavonoids and effect on markers of oxidative defense. The urinary excretion of quercetin and kaempferol was higher after 22 days of intake of the OPD when compared to the CPD (P < 0.05). The excretions of flavonoids in urine as a percentage of intake (0.6-4%) were similar after both interventions. Most markers of antioxidative defense did not differ between the diets, but intake of OPD resulted in an increased protein oxidation and a decreased total plasma antioxidant capacity compared to baseline (P < 0.05). Some varietal difference was seen in the study, and because selection of more resistant varieties is of central importance to organic farming, it cannot be excluded that the observed effects originate from these differences. The food production method affected the content of the major flavonoid, quercetin, in foods and also affected urinary flavonoids and markers of oxidation in humans.     

Pathway of dephosphorylation of myo-inositol hexakisphosphate by phytases of legume seeds

Using a combination of high-performance ion chromatography analysis and kinetic studies, the pathway of dephosphorylation of myo-inositol hexakisphosphate by the phytases purified from faba bean and lupine seeds, respectively, was established. The data demonstrate that the legume seed phytases under investigation dephosphorylate myo-inositol hexakisphosphate in a stereospecific way. The phytase from faba bean seeds and the phytase LP2 from lupine seeds degrade phytate by sequential removal of phosphate groups via D-Ins(1,2,3,5,6)P(5), D-Ins(1,2,5,6)P(4), D-Ins(1,2,6)P(3), and D-Ins(1,2)P(2) to finally Ins(2)P, whereas the phytases LP11 and LP12 from lupine seeds generate the final degradation product Ins(2)P via D-Ins(1,2,4,5,6)P(5), D-Ins(1,2,5,6)P(4), D-Ins(1,2,6)P(3), and D-Ins(1,2)P(2).     

Nondestructive detection of decay in living trees

We used a four-point resistivity method to detect wood decay in living trees. A low-frequency alternating current was applied to the stem and the induced voltage measured between two points along the stem. The effective resistivity of the stem was estimated based on stem cross-sectional area. A comparison within a group of trees showed that trees with butt rot had an effective resistivity that was at least a factor of two lower than that of healthy trees. In tests on several groups of Norway spruce (Picea abies (L.) Karst.) comprising more than 300 trees in total, the method detected butt rot with high accuracy. We validated the method both by measurements and by finite element modeling and simulations.     

AIDS-Kaposi's sarcoma-derived cells express cytokines with autocrine and paracrine growth effects

When grown in vitro, cells from Kaposi's sarcoma lesions of AIDS patients (AIDS-KS cells) constitutively release several growth promoting activities. When inoculated into nude mice, the AIDS-KS cells induce a KS-like lesion of mouse origin. Here it is shown that the AIDS-KS cells express messenger RNA for a complex mixture of cytokines that correlate with several of the biological activities of these cells. Basic fibroblast growth factor, which is a potent angiogenic factor, and interleukin-1 messenger RNAs are expressed at very high levels and seem to account for a large proportion of the activities, since their corresponding proteins are released in biologically active form into the culture media where they induce autocrine and paracrine growth effects.     

Migration performance of wild and hatchery sea trout (Salmo trutta L.) smolts—Implications for compensatory hatchery programs

Migration success of hatchery-reared and wild sea trout smolts through the lower stretches and the estuary of a Baltic Sea river were studied. During 3 years, wild and hatchery trout smolts were implanted with acoustic transmitters and released 14 km upstream from the river mouth. In order to monitor their out-migration pattern, acoustic receivers were deployed along the migratory route. Data on number of fish detected and date and time of detections were analysed and the migratory performance of wild and hatchery-reared fish was compared. A significantly higher proportion of wild fish (80%) successfully migrated to the coast compared to fish of hatchery origin (27.5%) and migration was faster in wild smolts. Hatchery fish were larger and had a higher condition factor and lipid concentrations, which are proposed as possible reasons for the poorer migratory performance of the hatchery-reared fish.     

Prevalence of interfering antibodies in dogs and cats evaluated using a species‐independent assay

Background

Interfering antibodies in human serum and plasma are known to react with mammalian antibodies in immunoassays and cause false‐positive test results. Although this phenomenon was recently shown in companion animals, knowledge regarding immunoassay interference in veterinary medicine is very limited.

Objectives

The aims of this study were to set up a species‐independent immunoassay procedure to detect interference in serum samples, to screen for interference in a cross‐section of canine and feline patient samples from an animal hospital, and to determine if the detected interference could be neutralized using an immunoassay based on nonmammalian reagents.

Methods

A 2‐site sandwich‐type interference assay was set up using commercially available mouse reagents. A total of 369 serum samples from 320 dogs and 263 samples from 218 cats were analyzed using the interference assay. Multiple samples were submitted from 36 dogs and 39 cats. Nineteen samples identified as interference‐positive were analyzed in an assay using chicken antibodies.

Results

Interference was detected in samples from 28 dogs (9%) and 10 cats (5%) screened with the interference assay. Except for 1 cat, consistent results were obtained for all 75 dogs and cats that submitted more than 1 sample. The interference was eliminated when analyzed in the chicken‐based assay (P < .001).

Conclusions

Substances with reactivity toward mouse IgG can be detected in serum samples from dog and cat patients using a 2‐site interference assay. The detected substances are most likely interfering antibodies, possibly originating from immunization with other mammalian species.     

Effect of Physical State of Nonpolar Lipids on Rheology and Microstructure of Gluten‐Starch and Wheat Flour Doughs

To clarify the effects of solid fat and liquid oil on dough in more detail in a simpler system, gluten‐starch doughs with different gluten contents were investigated. The results from rheological measurements indicate that dough with a higher starch content has less resistance to strain and dough with a lower starch content has a rubber‐like structure. The effects of the physical state of nonpolar lipids such as fat and oil on gluten‐starch doughs and wheat flour doughs were investigated using rheological measurements and scanning electron microscopy. Fat‐containing dough had more gas cells and a very smooth gluten gel surface with few holes, which may provide higher tolerance to strain. Moreover, the fat seemed to uniformly distribute the gluten gel between the starch granules in the dough, which reduced the friction between starch granules and led to a lower storage modulus. A mechanism governing the effect of fats on loaf volume is proposed based on the phenomena observed in the fat‐containing dough.