The gene coding for the major birch pollen allergen Betv1, is highly homologous to a pea disease resistance response gene.

Pollen of the white birch (Betula verrucosa) is one of the main causes of Type I allergic reactions (allergic rhinoconjunctivitis, allergic bronchial asthma) in Middle and Northern Europe, North America and the USSR. Type I allergies are a major threat to public health in these countries, since 10-15% of the population suffer from these diseases. BetvI, an allergenic protein with an Mr of 17 kd is a constituent of the pollen of white birch and is responsible for IgE binding in more than 95% of birch pollen allergic patients. Here, we report the complete nucleotide sequence and deduced amino acid sequence of a cDNA clone coding for the major pollen allergen (BetvI) of white birch. It is similar to the N-terminal peptide sequences of the allergens of hazel, alder and hornbeam (close relatives) but it has no significant sequence homology to any other known allergens. However, it shows 55% sequence identity with a pea disease resistance response gene, indicating that BetvI may be involved in pathogen resistance of pollen.     

Genetics of the quantitative Lp(a) lipoprotein trait

The Lp(a) lipoprotein is a complex particle composed of a low density lipoprotein (LDL)-like lipoprotein and the disulfide bonded Lp(a) glycoprotein. The complex represents a quantitative genetic trait. SDS gel electrophoresis under reducing conditions of sera followed by immunoblotting with affinity-purified polyclonal anti-Lp(a) demonstrated inter- and intra-individual size heterogeneity of the glycoprotein with apparent Mr in the range 400-700kDa. According to their relative mobilities compared to apo B-100 the Lp(a) patterns were categorized into phenotypes F, B, S1, S2, S3 und S4 and into the respective double-band phenotypes. This size heterogeneity seems to be controlled by multiple alleles designated LpF, LpB, LpS1, LpS2, LpS3, LpS4 and a null allele (LpO) at a single locus. Phenotype frequencies observed in 441 unrelated subjects were in good agreement with those expected from the genetic hypothesis. Comparison of Lp(a) lipoprotein concentrations in the different phenotypes revealed a highly significant association of phenotypes B, S1 and S2 with high, and phenotypes S3 und S4 with intermediate Lp(a) concentrations. A third mode is represented by the null phenotype were no Lp(a) band is detected upon immunoblotting and Lp(a) lipoprotein is low or absent. We conclude that the same gene locus is involved in determining Lp(a) glycoprotein phenotype and Lp(a) lipoprotein concentrations in plasma. This major gene seems to be the Lp(a) glycoprotein structural gene locus.     

Purification of the growth-related protein p25 of the Ehrlich ascites tumor and analysis of its isoforms

1. Two of the three isoforms of the growth-related protein p25 of the Ehrlich ascites tumor have been purified to homogeneity by giant two-dimensional polyacrylamide gel electrophoresis. 2. Antibodies raised against the isoform p25/1 react also with isoforms p25/2 and p25/3. 3. Limited tryptic digestion of p25/1 and p25/2 resulted in similar oligopeptide patterns. Corresponding oligopeptides of both isoforms have identical amino acid sequences. 4. The isoforms p25/2 and p25/3 are phosphorylated derivatives of unphosphorylated p25/1. The phosphorus is bound to serine and a further unknown phosphorylation site.     

Age-related involution and terminal disorganization of the human thymus

The terminal involution pattern of the human thymus was studied based on autopsy cases (both sexes, age range 63-91 years). Large sections through the entire thymic fat body were examined with the help of both conventional histological and immunohistochemical techniques. The findings demonstrate that thymic atrophy in old humans (a) goes far beyond the degree of involution observed in small rodents; (b) results in a system of thin, branching, in part interrupted, non-keratinizing epithelial plates containing no typical Hassall bodies; (c) concerns all components of the thymus except fat tissue which progressively replaces original thymic structures; and (d) involves various types of disorganization of individual lobules with T and B lymphocytes often located outside rather than within epithelial remnants. Effects of low-level radiation on this final regression of the human thymus are unknown.     

Salmonellae Associated with Further-processed Turkey Products

"Further-processed" turkey products, prepared from chilled, eviscerated, and thawed carcasses at two commercial turkey-processing plants, were evaluated, for the presence of salmonellae. These organisms were isolated from swab samples from 12% of chilled, eviscerated turkey carcasses, 27% of finished products, and 24% of processing equipment. The same serotypes as those found throughout a plant on any one visit were recovered from 31% of rinse-samples taken from hands and gloves of processing personnel. Salmonellae were found in samples taken on 37 of 48 visits; a greater number of recoveries were made on days when freshly killed turkeys were processed (87%) than when frozen-defrosted carcasses were processed (59%). The predominant serotype isolated from meat and environment usually changed from visit to visit. Salmonella sandiego and Salmonella anatum were the most frequent among 23 serotypes recovered. Most of the isolated serotypes are commonly associated with turkeys and have been incriminated as causative agents of human salmonellosis. The implication is that further-processed turkey products, if inadequately cooked by the consumer and if improperly refrigerated between the time of manufacture and consumption, could directly transmit salmonellae. These same products might also contaminate other foods by introducing salmonellae into food-preparation areas.     

Inhibitory action of selenite on Escherichia coli, Proteus vulgaris, and Salmonella thompson

Weiss, K. F. (Iowa State University, Ames), J. C. Ayres, and A. A. Kraft. Inhibitory action of selenite on Escherichia coli, Proteus vulgaris, and Salmonella thompson. J. Bacteriol. 90:857-862. 1965.-The resistance of three microorganisms, Escherichia coli (ISU-41), Proteus vulgaris (ISU-37c), and Salmonella thompson (ISU-86-2), to increasing concentrations of selenite was determined. E. coli was completely inhibited by 1.25% sodium hydrogen selenite, and 0.25% sodium hydrogen selenite caused a pronounced lag. P. vulgaris survived selenite concentrations of over 3%. S. thompson was inhibited completely by 3% selenite but not by 2.5%, although there was a considerable lag and a decrease in total growth. The relationship of growth, uptake, and reduction of selenite was determined. The susceptible E. coli incorporated up to twice as much selenium as did the other two organisms during the early stages of incubation. Radioautographs of seleno analogues of sulfur-containing amino acids revealed the presence of seleno-cystine in all three organisms, and seleno-methionine in E. coli. Compounds having R(F) values corresponding to possible oxidation products of seleno-methionine were present in the hydrolysates of P. vulgaris and S. thompson. Kinetic aspects of selenite uptake, rather than the ultimate localization of selenite in the cell protein, appear to be the factors that determine the degree of resistance or of susceptibility to selenite.     

Full-length rat alpha and beta cardiac myosin heavy chain sequences. Comparisons suggest a molecular basis for functional differences

The two cardiac myosin heavy chain isoforms, alpha and beta, differ functionally, alpha Myosin exhibits higher actin-activated ATPase than does beta myosin, and hearts expressing alpha myosin exhibit increased contractility relative to hearts expressing beta myosin. To understand the molecular basis for this functional difference, we determined the complete nucleotide sequence of full-length rat alpha and beta myosin heavy chain cDNAs. This study represents the first opportunity to compare full-length fast ATPase and slow ATPase muscle myosin sequences. The alpha and beta myosin heavy chain amino acid sequences are more related to each other than to other sarcomeric myosin heavy chain sequences. Of the 1938 amino acid residues in alpha and beta myosin heavy chain, 131 are non-identical with 37 non-conservative changes. Two-thirds of these non-identical residues are clustered, and several of these clusters map to regions that have been implicated as functionally important. Some of the regions identified by the clusters of non-identical amino acid residues may affect actin binding, ATP hydrolysis and force production.     

Heavy ion effects on yeast: inhibition of ribosomal RNA synthesis

Diploid wild-type yeast cells were exposed to beams of heavy ions covering a wide range of linear energy transfer (LET) (43-13,700 keV/microns). Synthesis of ribosomal RNA (rRNA) was assessed as a functional measure of damage produced by particle radiation. An exponential decrease of relative rRNA synthesis with particle fluence was demonstrated in all cases. The inactivation cross sections derived were found to increase with LET over the entire range of LET studied. The corresponding values for relative biological effectiveness were slightly less than unity. Maximum cross sections measured were close to 1 micron 2, implying that some larger structure within the yeast nucleus (e.g., the nucleolus) might represent the target for an impairment of synthetic activity by very heavy ions rather than the genes coding for rRNA. Where tested, an oxygen effect for rRNA synthesis could not be demonstrated.