Recombination within the class III region by a double cross over event

Analysis of class I, class II, and class III gene products of the human MHC in a Caucasoid family with four children gave evidence for a double crossing over event in monozygotic twins between the C2, Bf/C4A, C4B gene loci. In view of the small genetic distance between C2 and C4, a point mutation within the Bf locus must be considered alternatively.

The position of the gene locus for monocyte alloantigens (HMA system) on chromosome 6

In ten families with 65 children (with 64 informative meioses), a close linkage between the monocyte antigen locus (HMA) and HLA was found with a recombination frequency of 1.56%.

Recognition of a polymorphic monocyte antigen

138 sera from renal transplant recipients were screened for the presence of monocyte-specific antibodies. Most of the sera contained antibodies against monocytes, T- and/or B-lymphocytes. One serum was identified which defined a monocyte-specific antigen, MOLI. This serum was investigated in intensive population and family studies for the estimation of the formal genetic criteria of this 'new' monocyte antigen. A gene frequency of 0.0614 was obtained by population analysis. Family investigations conveyed the information that the gene coding for MOLI was transmitted in linkage with HLA genes. A positive linkage disequilibrium of MOLI and HLA-B17 was found.

High incidence of relapses in thrombotic thrombocytopenic purpura. Clinical study of 38 patients

Described in this study are 38 patients who received treatment for thrombotic thrombocytopenic purpura in 15 hospitals in Israel and the New York City area since 1977, when plasma therapy was introduced. Thirty-seven patients received plasma therapy and 30 survived. In 12 patients (37 percent of survivors), relapsing thrombotic thrombocytopenic purpura developed, manifested by thrombocytopenia and microangiopathic hemolytic anemia, and less frequently by neurological or renal abnormalities. Six patients had a second relapse, and two had five relapses. To assess the severity of the disease, a scoring system was designed based on the four major manifestations of thrombotic thrombocytopenic purpura listed above. The patients who died had a significantly higher score than those who survived. The initial episodes and the relapses of patients with relapsing thrombotic thrombocytopenic purpura were milder than those in patients who only had a single episode and survived. Two relapses, however, were fatal, demonstrating that relapsing thrombotic thrombocytopenic purpura is not a benign disorder. Infections, pregnancy and surgery were frequently associated with the initial episodes and the relapses. Hence, patients who recover from thrombotic thrombocytopenic purpura should be alerted to the possibility of relapse in association with these conditions.

MHC antigen expression in sequential biopsies from cardiac transplant patients--correlation with rejection

Class I induction on the myocardium of transplanted heart was investigated with regard to its temporal relationship to rejection episodes, how it is affected by anti-rejection therapy and whether it is dependent upon the presence of a T cell infiltrate in the biopsy. Sequential cardiac biopsies (total 114) from 11 patients from the time of transplant to 1 year after transplant were studied using immunocytochemical techniques. The effect of different immunosuppressive regimens on MHC antigen expression was also studied. All the biopsies diagnosed as showing rejection for the first time showed induction of Class 1 on the myocardium with 79% during subsequent rejection episodes. Class I induction was associated with a leucocyte infiltrate, not always containing T cells, and disappeared in 47% of biopsies taken 3-4 weeks after treatment with steroids and/or ATG. Increased expression of Class II, in particular DQ antigens on interstitial structures, paralleled Class 1 induction. MHC antigen expression returned to normal in 8/9 patients, at 1 year after transplant. Different immunosuppressive regimens affected the number of biopsies showing Class 1 induction on the myocardium. Our results suggest that in clinical heart transplantation class I induction is related to the rejection process.

Model of TPN-associated hepatobiliary dysfunction in the young pig

Gallbladder 'sludge' and cholestasis are two common complications associated with total parenteral nutrition (TPN), but the aetiology of each is uncertain. An animal model has been developed in the young pig which demonstrates these two complications. Five female piglets, of Landrace Large White Cross variety weighing 4.5-5.9 kg, received nutritional support for 2 weeks with a continuous infusion of TPN solution at a dose of 150 kcal kg-1 day-1. The solution was 35 per cent dextrose, 5 per cent L-amino acids with conventional electrolyte, mineral and vitamin additives. No lipid was used in the solution. Five weight-matched animals were used as controls. All animals in the TPN group developed 'sludge' in their gallbladders, decreased basal bile flow, decreased bile salt excretion and a diminished response to bile salt stimulated bile flow, as compared with controls. There was no abnormality in routine liver function tests or liver histology. It is concluded that TPN therapy in this animal model is associated with the appearance of gallbladder 'sludge', and cholestasis as demonstrated by direct bile flow studies. It is suggested that this bile flow abnormality is due to a decrease in bile salt dependent and bile salt independent fractions of canalicular bile flow. The model provides the opportunity to investigate TPN related hepatobiliary dysfunction in an animal that has similar liver function to man and comparable nutritional requirements.

The function of food in residential treatment

This paper describes the behaviour and backgrounds of adolescents in a therapeutic community and proposes that all experiences in the residential context need to form a single integrated psychotherapeutic process. Although reference is made to group and organizational issues, the central consideration is of the significance of food and its treatment potential in this total process.

Long-term results with renal autotransplantation for ureteral replacement

From 1970 to 1984 renal autotransplantation was performed on 23 patients to replace all or a major portion of the ureter. The conditions necessitating ureteral replacement were postoperative ureteral injury in 16 cases, recurrent renal colic in 4, urinary undiversion in 2 and an atonic ureter in 1. Six patients presented with a solitary kidney and 1 underwent staged bilateral autotransplantation. After autotransplantation urinary continuity was restored by ureteroneocystostomy in 11 patients, pyelovesicostomy in 7, ureteroureterostomy in 2, pyeloureterostomy in 2 and ureterosigmoidostomy in 1. Postoperatively, there was no mortality and all but 1 of the autotransplanted kidneys functioned immediately. Two kidneys required removal postoperatively owing to bleeding. Currently, 20 patients are alive with functioning renal autotransplants at intervals of 1.5 to 14 years. The current serum creatinine level in these patients ranges from 1.1 to 2.2 mg. per dl., which in each case is improved or stable compared to the preoperative determination. Only 1 patient has experienced chronic bacteriuria. We conclude that renal autotransplantation provides excellent long-term treatment for patients who require ureteral replacement.

Tissue-type plasminogen activator in breast cancer: relationship with estradiol and progesterone receptors

Plasminogen activator (PA) is an estradiol-inducible enzyme and therefore a potential marker for a functional estradiol receptor (ER) in human breast carcinomas. In this investigation tissue-type PA (t-PA) correlated significantly with both ER and progesterone receptors (PR) in human breast carcinomas. In contrast, neither total PA activity nor urokinase-like PA showed any significant correlation with either ER or PR. Other proteases such as a trypsin-like protease, a chymotrypsin-like protease, and cathepsin B also showed no correlation with ER and PR. It was concluded that the t-PA form of PA may be a marker for a functional ER in breast carcinoma and thus be of value in predicting hormone-dependent breast cancers.

The design of atmosphere: ego-nurture and psychic change in residential treatment

This paper concerns the very special nature of Peper Harow, a residential establishment for disturbed young people. The paper explores the means by which adolescents become absorbed in, and are helped to identify with, the goals of a therapeutic community, and draws on symbols and metaphors from literature to illustrate the treatment process. Examples are given from the life of the community, and attempts are made to capture the atmosphere of a unique establishment.

Effect of bacterial products on prostaglandin E production by amnion cells

An in-vitro model was set up to study a possible causal relation between bacterial colonisation of extraplacental membranes and spontaneous preterm labour. When amnion cells in tissue culture were exposed to bacterial products, their prostaglandin E output rose considerably. The degree of response varied with the organism. These findings support the theory that bacterial products may be responsible for the premature onset of labour.

Transfer of information and its impact on medical practice: the U. S. experience

Since 1977, the Consensus Development Program of the Office of Medical Applications of Research (OMAR), part of the National Institutes of Health (NIH), has sponsored more than 50 consensus development conferences (CDCs) on the safety and efficacy of important biomedical technologies. The aim of these conferences, described fully elsewhere (4), is to inform the health care community, and to some extent the public, of the status of emerging biomedical technologies and the need for change in the use of existing health-related technologies. OMAR has therefore, worked diligently to publicize conference findings among these audiences. Further, OMAR has sought to improve the effectiveness of these transfer activities by conducting assessments of the impact of CDCs on their primary audience, U.S. physicians.

Structure and function of the yeast URA3 gene: expression in Escherichia coli

The expression of the cloned Saccharomyces cerevisiae URA3 gene in Escherichia coli on both plasmid and phage vectors was studied. Isolates of the gene from two different laboratory strains of yeast differ in their ability to be expressed in E. coli in the absence of external adjacent promoters of transcription. The DNA sequence of the two genes was determined and revealed several differences in the DNA flanking the structural gene. One base change alters the "Pribnow-box" of an E. coli promoter present in the yeast sequences. Three amber alleles of the yeast gene were also cloned from yeast. Two of the alleles could be suppressed in E. coli by a tRNA suppressor mutation. One of the amber alleles was determined to be a mutation in the seventh codon of the structural gene, thereby establishing the reading frame and extent of the coding sequence. The initiator codon of the reading frame encoding the URA3 structural gene is preceded by two other ATG codons in a different reading frame 61 and 79 bp away. The nearer ATG begins an open reading frame that overlaps the structural gene sequences by 17 bp. With the DNA sequence of the URA3 gene many of the common yeast vector plasmids are now completely known at the level of DNA sequence.

Identification of a Ty insertion within the coding sequence of the S. cerevisiae URA3 gene

Insertion mutations in yeast caused by the transposable element Ty have been identified at several genetic loci. In all cases so far, the site of Ty insertion has been in the 5' non-coding region of the affected gene. Experiments presented here demonstrate that the ura3-52 mutation, a non-reverting ura3 mutation, is caused by a Ty insertion mutation within the coding region of the URA3 gene. This Ty insertion within a gene has a similar structure to those in non-coding regions.

HOMOLOGOUS RECOMBINATION BETWEEN EPISOMAL PLASMIDS AND CHROMOSOMES IN YEAST

We have observed genetic recombination between ura3  - mutations (among them extensive deletions) carried on "episomal" (i.e., 2μ DNA-containing) plasmids and other ura3  - alleles present at the normal chromosomal URA3 locus. The recombination frequency found was comparable to the level observed for classical mitotic recombination but was relatively insensitive to sunlamp radiation, which strongly stimulates mitotic recombination. Three equally frequent classes could be distinguished among the recombinants. Two of these are the apparent result of gene conversions (or double crossovers) which leave the URA3  + allele on the chromosome (class I) or on the plasmid (class II). The third class is apparently due to a single crossover that results in the integration of the plasmid into a chromosome. Plasmid-chromosome recombination can be useful in fine structure genetic mapping, since recombination between a chromosomal point mutation and a plasmid-borne deletion mutation only 25 base pairs distant was easily detected.