The benefit patients derive from aortocoronary reoperation.

There is an increasing incidence of aorto coronary reoperation necessitated by intractable angina which averages 2% of 4676 initial bypass procedures. Graft obliteration, graft stenosis or progression of disease led to recurrence of symptoms in 96 patients (84 male, 12 female) who underwent a second operation. Not all occluded or stenotic bypasses were feasible for reoperation. Hospital mortality (30 days) was higher than after initial CABG, but could be reduced from 12.1% to 4.8%. Subjective and objective follow-up investigations were obtained in 77 of 84 survivors and demonstrate that successful reoperation is about 10% lower in patients with a malignant form of atherosclerosis (60%) than in patients who only suffer from occluded grafts or new proximal significant stenoses in previously unbypassed vessels (70%).

A program package applicable to the detection of overlaps between restriction maps.

A computer program package for the storage, change, and comparison of restriction maps is described. The programs are intended to detect overlaps between relatively short (about 10-40 kb; abbreviations ref.2) maps and to merge the overlapping fragments into large restriction maps. They run on a 16-bit-microcomputer with limited memory and addressing capability. Due to the restricted reliability of restriction maps compared with DNA sequence data a particular storage method was used. The source code of the programs is freely available (+).

The muntjak satellite IA sequence is composed of 31-base-pair internal repeats that are highly homologous to the 31-base-pair subrepeats of the bovine satellite 1.715.

The nucleotide sequence of a cloned Muntjak satellite IA repeat unit (Muntiacus muntjak vaginalis) was determined. The repeat is 807 base pairs (bp) long. By introducing minor deletions and insertions, the whole sequence of the satellite can be arranged in 27 subrepeats of 31 bp length. Although diverged relative to each other, all subrepeats show a homology of more than 53% with the common consensus sequence. In 29 out of the 31 bp the consensus sequence of the Muntjak satellite subrepeat is identical to the 31-bp subrepeat of the bovine satellite 1.715. This suggests that both satellites are derived from a common ancestral sequence. The results have interesting implications for the evolution of the two satellites.

Recognition sequences of restriction endonucleases and methylases--a review.

The properties and sources of all known endonucleases and methylases acting site-specifically on DNA are listed. The enzymes are crossindexed (Table I), classified according to homologies within their recognition sequences (Table II), and characterized within Table II by the cleavage and methylation positions, the number of recognition sites on the DNA of the bacteriophages lambda, phi X174 and M13mp7, the viruses Ad2 and SV40, the plasmids pBR322 and pBR328 and the microorganisms from which they originate. Other tabulated properties of the restriction endonucleases include relaxed specificities (Table III), the structure of the restriction fragment ends (Table IV), and the sensitivity to different kinds of DNA methylation (Table V). Table VI classifies the methylases according to the nature of the methylated base(s) within their recognition sequences. This table also comprises those restriction endonucleases, which are known to be inhibited by the modified nucleotides. Furthermore, this review includes a restriction map of bacteriophage lambda DNA based on sequence data. Table VII lists the exact nucleotide positions of the cleavage sites, the length of the generated fragments ordered according to size, and the effects of the Escherichia coli dam- and dcmI-coded methylases M X Eco dam and M X Eco dcmI on the particular recognition sites.

Organization and evolution of a gene cluster for human immunoglobulin variable regions of the kappa type.

An 80,000 base-pair region from the gene locus encoding the variable regions of the human immunoglobulins of the kappa type (V kappa genes) was cloned and analysed. The region comprises five V kappa sequences of subgroup I and one interspersed V kappa pseudogene of subgroup II. The six genes and pseudogenes are arranged at different distances but in the same orientation. The organization of the cluster can be explained by a series of amplification steps; the existence of a V kappa II pseudogene in a V kappa I gene cluster may have been the result of a transposition event; a final duplication step led to a second closely related copy of the cluster. From sequence data for altogether 16,000 base-pairs it appears that gene conversion-like events and subsequent selection contribute to both homogeneity and diversity of the V kappa repertoire.

Nucleotide sequence of a region downstream of the mouse CK immunoglobulin gene.

2318 bp downstream of the CK (1) gene segment were sequenced in a clone (L1-D) derived from mouse liver DNA. The 966 bp at the 5' side of this stretch were found to be identical to a sequence which had been determined previously in a myeloma T derived clone, i.e. no somatic mutations had occurred in the transition from the germline to the rearranged configuration. The remaining 1352 bp had not been known and extend the sequenced part of the mouse JK-CK region to about 7.5 kb. Within the newly sequenced area three BspRI sites have been located which were used in chromatin studies (Weischet et al., accompanying publications). In L1-D sequences have been found which are possible targets of aberrant recombination events.

DNA sequence of the constant gene region of the mouse immunoglobulin kappa chain.

The constant (C; ref. 3) gene segment of the immunoglobulin kappa light chain and about 1 kb upstream as well as downstream of the segment have been sequenced. The sequences of the C gene segment itself and parts of the upstream region were determined both in liver and in myeloma T DNA clones derived from the same mouse inbred strain. The sequences were identical, i.e. no somatic mutations were detected. Two sites in the region not coding for protein are discussed as possible targets of aberrant variable (V) gene translocations. Doublet frequencies were calculated in the approx. 2500 bp of the C region sequence reported in this paper and in the approx. 3400 bp of two rearranged V gene regions.