Haptoglobin groups and rheumatoid arthritis

Haptoglobin types were determined in 200 patients with rheumatoid arthritis (RA) subdivided according to sex and familial occurrence of polyarthritis. A highly significant excess of the Hp2 gene was found among patients with a family history of polyarthritis, more pronounced among males. The possible association between Hp2 and predisposition for increased immune reactivity is discussed.     

A structural locus for coagulation factor XIIIA (F13A) is located distal to the HLA region on chromosome 6p in man

Linkage between the locus for coagulation factor XIIIA (F13A) and HLA-region genes has been revealed during a linkage study between F13A and approximately 40 other polymorphic marker genes. In males, the maximum lod score between F13A and HLA-region genes (HLA-A, -C, -B, -DR; C4A, -B; Bf; and/or C2) is 7.60 at theta 1 = .18. To GLO, the maximum lod score is 2.37 at theta 1 = .19; to PGM3, .22 at theta 1 = .35. Female data indicate a clear sex difference in recombination frequency between F13A and HLA. The present findings, in combination with earlier knowledge of PGM3/GLO/HLA localization and gene distances, show that F13A is distal to HLA on the short arm of chromosome 6 in man. It is thus likely that by including FXIIIA typing in linkage studies, the whole male 6p is within mapping distance of highly polymorphic, classical marker genes. Earlier findings that the Hageman factor gene (F12) is located in the same chromosomal region may indicate the presence of a coagulation factor gene cluster in this region.     

Extremely high frequencies of alpha-globin gene deletion in Madang and on Kar Kar Island, Papua New Guinea.

Extremely high frequencies of the deletion form of alpha(+)-thalassemia (-alpha/), as studied by the DNA mapping technique, were found in the population of Madang, a coastal province in the north of Papua New Guinea (PNG) and in the population of Kar Kar, an island situated near Madang. Ninety-seven percent of the population tested from Madang and 89% of that from Kar Kar Island were either alpha(+)-thalassemia heterozygotes or homozygotes. By contrast, no examples of the deletion form were detected in the Eastern Highlands of PNG. The haplotype frequencies of alpha(+)-thalassemia (-alpha/) in Madang and Kar Kar Island were found to be 81.33% and 66.67%, respectively. A more detailed analysis of the gene deletion revealed that in both populations 96% were of the 4.2 kilobase (kb) type and 4% were of the 3.7-kb type. Thus, this group is the only example in which the 4.2-kb deletion is predominant over 3.7-kb defect. The presence in high frequencies of alpha(+)-thalassemia in the coastal area of Madang and on the neighboring island, where malaria has long been holoendemic or hyperendemic, and its virtual absence from the nonmalarious highlands of PNG suggest the role of malaria as the selective factor in maintaining alpha(+)-thalassemia. If this selective pressure is still operating, and since alpha(+)-thalassemia has no apparent homozygous disadvantage, the abnormal haplotype (-alpha/) will be in the process of fixation in this population.     

Enhancement of the horseradish peroxidase-catalyzed chemiluminescent oxidation of cyclic diacyl hydrazides by 6-hydroxybenzothiazoles

6-Hydroxybenzothiazole, 2-cyano-6-hydroxybenzothiazole, and 2-(6-hydroxy-2-benzothiazolyl)thiazole-4-carboxylic acid (dehydroluciferin) dramatically enhance light emission from the horseradish peroxidase conjugate catalyzed oxidation of luminol, isoluminol, N-(6-aminobutyl)-N-ethyl isoluminol, and 7-dimethylaminonaphthalene-1,2-dicarboxylic acid hydrazide by either peroxide or perborate. Light emission is enhanced by up to 1000-fold, which is an improvement over the enhancement previously observed using firefly luciferin (4,5-dihydro-2-(6-hydroxy-2-benzothiazolyl)thiazole-4-carboxylic acid). Enhancement is influenced by enhancer concentration and pH. Spectral scans of light emitted in enhanced and unenhanced reactions are similar, suggesting that aminophthalate products, and not the enhancers, are the emitters.     

Age changes of skull dimensions

At cranial level, external apposition during ageing has been postulated by some authors. In longitudinal studies, a gradual increase of cranial diameters has been shown by cephalometry (Kendrick et al. 1967) or by lateral radiography (Israel 1968, 1970). However, these results are contested at methodological level by other longitudinal studies (Tallgren 1974). It is the aim of this study to analyse, in a cross-sectional sample, the effects of senescence on several cephalic dimensions. A series of skulls of known age and sex has been selected for this purpose.     

Partial trisomy 11p with interatrial septal aneurysm. Case report and literature review

A newborn female infant presented with hypotonia, joint hyperextensibility, cardiac murmur, macroglossia, and hepatosplenomegaly. Karyotype of the child revealed partial trisomy of chromosome 11p derived from a paternal balanced translocation. Echocardiogram obtained in the newborn period suggested interatrial aneurysm, which was confirmed on post-mortem examination. Interatrial septal aneurysm is a rare abnormality not previously described in partial trisomy 11p.     

A type-1 casein kinase from yeast phosphorylates both serine and threonine residues of casein. Identification of the phosphorylation sites

A protein kinase (casein kinase 1A) active on casein and phosvitin but not on histones has been purified to near homogeneity from yeast cytosol and meets most criteria for being considered a type-1 casein kinase: it is a monomeric enzyme exhibiting an Mr of about 27 kDa by sucrose gradient centrifugation: it is not affected by inhibitors of type-2 casein kinases, such as heparin and polyglutamate, and shows negligible affinity for GTP. It also readily phosphorylates the residue Ser-22 of beta-casein located within the sequence -Ser(P)-Ser(P)-Ser(P)-Glu-Glu-Ser22-Ile-Thr-Arg- which is typically affected by casein kinases of the first class. On the other hand, casein kinase 1A displays the unusual property of phosphorylating threonine residue(s) in both whole casein and alpha s1-casein. The threonine residue phosphorylated in alpha s1-casein and accounting for most of the 32P incorporated into this protein by casein kinase 1A has been identified as Thr-49, which occurs in the sequence -Ser(P)-Glu-Ser(P)-Thr(P*)49-Glu-Asp-Gln-, whose two Ser(P) residues are already phosphorylated in the native protein. It is concluded that some type-1 casein kinases can also phosphorylate threonine residues provided they fulfil definite structural requirements, probably an acidic cluster near their N-terminal side.     

The effect of concentration on the antioxidant effectiveness of alpha-tocopherol in lipid peroxidation induced by superoxide free radicals

Egg yolk phosphatidylcholine liposomes were rapidly oxidized in the presence of chelated iron and a superoxide-generating system. alpha-Tocopherol incorporated in the bilayer was oxidized at the same time. No lipid or alpha-tocopherol oxidation occurred in liposomes composed of dimyristoyl phosphatidylcholine. The antioxidant did not inhibit lipid peroxidation until its concentration reached a critical level, which depended on the effectiveness of the oxidative stress. Beyond this level, peroxidation was inhibited completely and, simultaneously, the rate of oxidation of tocopherol was lowered. The results suggest that the antioxidant efficiency of alpha-tocopherol depends on its ability to react mainly with the chain-initiating or chain-propagating lipid radicals. This, in turn, is closely tied to the tocopherol content of the membrane. Ascorbate inhibited the consumption of alpha-tocopherol, possibly by regenerating its reduced form.