A membrane-associated form of C-reactive protein is the galactose-specific particle receptor on rat liver macrophages

Rat liver macrophages express a galactose-specific receptor which mediates endocytosis of particles or neuraminidase-treated blood cells. From rat serum we now have isolated and purified a galactose-specific lectin by affinity chromatography. Comparative analysis of this serum galactose-binding protein with the galactose-particle receptor protein purified from rat liver macrophages and with C-reactive protein (CRP) reveals close relation or identity of these proteins. An apparent m.w. of 30,000 was determined for all three proteins by SDS-PAGE under reducing conditions and m.w. of about 130,000 by native PAGE. All three proteins exhibit the same pentameric, ring-shaped structure in electron microscopy after negative staining. Antibodies raised against the serum galactose-binding protein or against the macrophage receptor cross-react. A mAb specific for rat neo-CRP labels liver macrophages but not hepatocytes and reacts with the isolated protein in a Western blot assay. Furthermore, the galactose-particle receptor can be functionally replaced by purified CRP: the binding capacity for neuraminidase-treated E of receptor-depleted liver macrophages can be restored by preincubation with purified rat CRP. We therefore conclude that CRP occurs as a membrane-associated protein constitutively expressed on liver macrophages functioning as a receptor mediating galactose-specific binding of particulate ligands.     

Mapping of the silver fox genes: assignments of the genes for ME1, ADK, PP, PEPA, GSR, MPI, and GOT1

Evidence is presented for the assignment of seven fox genes on the basis of the segregation data for chromosomes and enzymes of fox x Chinese hamster somatic cell hybrids. The chromosomal loci of the following enzyme genes were determined: ME1, VFU1; ADK and PP, VFU4; PEPA, VFU5; GSR, VFU7; and MPI and GOT1, VFU15. The localization of these genes now extends the fox genetic map to 22 mapped genes. Based on comparative analysis of mammalian genetic maps, karyotype evolution in Carnivora is discussed.     

An experimental model of apneusis and periodic respiration]

In experiments on sodium pentobarbital (40 mg/kg, i. p.) anesthetized mongrel cats of either sex weighting from 2.0 to 4.0 kg, it was stated, that sodium or lithium hydroxybutyrate (HOB) (200 mg/kg, i. v.) effectively slowed down breathing with inspiratory holdings. Thus 3-5 minutes after HOB administration, eupneic pattern of respiration was changed firstly to inspiratory apneustic one (100% of cats), and then to periodic one (80% of cats). This pattern persisted for 60-90 minutes, and after that the respiratory pattern usually changed its direction to the opposite one. In these conditions alterations of arterial blood composition (pH, pO2, pCO2, SO2) and hemodynamic variables (heart rate, arterial pressure) can not be considered as the cause of apneustic pattern of respiration. It is suggested, that HOB can be used for simulating such terminal respiratory patterns as apneustic and periodic ones.     

Effects of Rodiola extract on the cytotoxic activity of natural killer cells of the liver, spleen, lungs and small intestine in rats after partial hepatectomy

In experiments on Wistar rats the cytotoxic activity of NK on the 1, 2, 10 days after partial hepatectomy (PH) and the application of Rodiola extract (RE) was studied. After 5 injections of RE the NK activity in gut increased by 112%, and after 12 ones (towards the end of experiment) by 222% in the spleen. The decreasing of this index in a first day after PH in lung, liver and gut was shown to restore in these tissues to the end of experiment. The absence of NK cytotoxicity diminishing just after PH in all the tissues was shown in operated animals, receiving RE and the decreasing of this index was found only in the lungs (by 335%).     

Alpha 1 chain of chick type VI collagen. The complete cDNA sequence reveals a hybrid molecule made of one short collagen and three von Willebrand factor type A-like domains

A cDNA library constructed from chick aorta poly(A+) RNA in the expression vector pEX1 was screened with rabbit polyclonal antisera. Additional clones were obtained by DNA-DNA hybridization with subclones from the most 5'- and 3'-ends. The overlapping clones span 4.6 kilobases and code for the entire alpha 1 (VI) chain. The nucleotide sequence reveals a 3057-base pair open reading frame that codes for 1019 amino acids. Analysis of the deduced amino acid sequence predicts that alpha 1 (VI) has one collagenous domain (COL) of 336 residues flanked by three repeated domains of about 200 residues each, one at the amino (A'3) and two at the carboxyl ends (A'2 and A'1), respectively, that are similar to the type A repeats of von Willebrand Factor. The COL domain presents two short interruptions near the carboxyl end of the triple helix and three of the six potential N-asparaginyl-linked carbohydrate attachment sites (Asn-Xaa-Ser/Thr). Furthermore, it contains 1 cysteine at position 89 that could participate in the formation of dimers and 3 Arg-Gly-Asp sequences that might be potential sites for cell adhesion. The COL domain shows an extended region, starting from position 40, within the triple helix, made of 14 Gly-Xaa-Yaa triplets that lack proline in the Y position, suggesting that it might be more flexible than the rest of the domain. At the junction of the COL with the N- and C-terminal domains, there are several cysteines that could confer the well known resistance of type VI collagen to pepsin and collagenase digestion under nonreducing conditions. The present sequence data allow a structural model for type VI collagen assembly to be proposed that is consistent with the structure implied from previous electron microscopic observation by Furthmayr et al. (Furthmayr, H., Wiedemann, H., Timpl, R., Odermatt, R., and Engel, J. (1983) Biochem. J. 221, 303-311).     

Cartographic analysis of the population of amphibians,reptiles, and birds of the West Siberian plain and Altai

For the entire territory of West Siberia, including its plain and mountainous parts, two maps were constructed for populations of amphibians together with reptiles, and of birds. Communities of these classes of vertebrates differ from one another in their spatial differentiation. The differences are demonstrated for the plain and mountainous territories considered jointly and separately.