Behavioural, physiological and immunological consequences of social status and aggression in chronically coexisting resident-intruder dyads of male rats

The behavioural and physiological consequences of social status and reciprocal fighting in resident-intruder dyads of Long Evans male rats were evaluated. Before a chronic cohabitation of 10 days, residents and intruders were individually housed for one month to increase their aggressiveness. Control animals included isolates, i.e., animals kept individually housed throughout the experiment and pair-housed rats, i.e., pairs of rats housed together from their rats in the laboratory. In 19 out of 20 dyads, a clear dominance relationship developed with an advantage to the resident in 68% of the cases. Dominants showed more exploratory activity than subordinates in a open-field test at the end of the cohabitation period; subordinates groomed longer than animals from other experimental groups. Dominants had lower pain thresholds than individually and pair-housed animals. Both dominants and subordinates had higher tyrosine hydroxylase enzymatic activities in the left adrenal than isolated and pair-housed rats. Subordinates lost body weight and had higher plasma corticosteroid concentrations than animals from the other experimental groups. In addition, they had smaller thymus glands and reduced spleen lymphocyte responses to mitogenic stimulation in vitro, in comparison to dominant animals. These results show that subordination in the dyadic resident-intruder paradigm leads to a complex syndrome of behavioural and physiological changes, some of which may be modulated by the intensity of aggressive interactions.     

Benign intracranial hypertension and recombinant growth hormone therapy in Australia and New Zealand

Benign intracranial hypertension (BIH) is reported in three children from Australia and one from New Zealand, who were being treated with recombinant human growth hormone (rhGH). Three males and one female, aged between 10.5 and 14.2 y, developed intracranial hypertension within 2 weeks to 3 months of starting treatment. A national database, OZGROW, has been prospectively collecting data on all 3332 children treated with rhGH in Australia and New Zealand from January 1986 to 1996. The incidence of BIH in children treated with growth hormone (GH) is small, 1.2 per 1000 cases overall, but appears to be greater with biochemical GHD (<10IUml ^-1), i.e. 6.5/1000 (3 in 465 cases), relative risk 18.4, 95% confidence interval 1.9-176.1, than in all other children on the database. The incidence in patients with Turner's syndrome was 2.3/1000 (1 in 428 cases). No cases in patients with partial GHD (10–20 IUml ^-1) or chronic renal failure were identified. Possible causative mechanisms are discussed. The authors'practice is now to start GH replacement at less than the usual recommended dose of 14IUm-² week^-1 in those children considered to be at high risk of developing BIH. Ophthalmological evaluation is recommended for children before and during the first few months following commencement of rhGH therapy and is mandatory in the event of peripheral or facial oedema, persistent headaches, vomiting or visual symptoms. The absence of papilledema does not exclude the diagnosis.     

Protein components specifically associated with prespliceosome and spliceosome complexes.

We have carried out a systematic analysis of the protein composition of highly purified mammalian spliceosomes. We show that > 30 distinct proteins, including 20 previously unidentified components [designated spliceosome-associated proteins (SAPs)], are specifically associated with the spliceosome in a salt-resistant complex. In contrast to these spliceosome-specific proteins, we show that hnRNP proteins are not tightly associated with purified prespliceosome and spliceosome complexes. The splicing factor U2AF65, U1 snRNP-specific proteins, and several SAPs are present in the earliest prespliceosome complex (E). A set of 10 proteins is then added to the first ATP-dependent prespliceosome complex (A), and concomitantly, a significant decrease in the level of U2AF65 is observed. The fully assembled spliceosome is formed by the addition of 12 proteins in a reaction that requires ATP and both the 5' and 3' splice sites.     

AIDS education in Switzerland: implementing strategies to reach groups with high risk behaviours, particularly youth

In Switzerland the Federal Office of Public Health has developeda comprehensive set of AIDS care and prevention policies andactivities in recent years. For their actual implementation,the main responsibility lies with the health departments ofthe 26 Cantons. This paper originates from one of the largeCantons, Vaud. Major efforts have been made from the Federallevel to transmit relevant AIDS-related information to the generalpublic. Much remains to be done to assist people, especiallyhigh risk groups, to translate the vital prevention messagesinto behaviour changes. For youth in general, new attitudestowards sexual relations are called for, different from thoseof young people 10 or 15 years ago. In Vaud, a number of entrypoints are used to pass on this education: physicians and nursesinvolved in school health, teachers and, among the latter, twogroups with specific in-service training and part-time functions—mediators(who make themselves available to children in various risk situations)and health animators (promoting the inclusion of health educationtopics in the teaching). There is a special health programmefor 16–19 year olds. Also a substantial tradition of sexualeducation sessions in the school system offers valuable opportunitiesfor AIDS education. Further, innovative strategies are developedto reach and work with the male homosexuals and, to the extentpossible, intravenous drug addicts. In conclusion it is emphasizedthat, in many ways, AIDS education issues demand courage fromhealth and public leaders.     

Interventional digestive endoscopy in pediatrics]

Interventional endoscopy concerns the therapeutic acts carried out by endoscopic way at the level of the digestive tract. It is realized under general anaesthesia and it has profited from recent progress of the material (endoscopes and accessories). Some acts are realized in a current way in paediatrics: extraction of foreign body, dilation of oesophageal stenosis, gastrostomy. Other indications are rarer. In these cases, interventional endoscopy is usually done with the collaboration of the adult endoscopists, whose field of activity in interventional endoscopy is far much broader.     

Decreased serum levels of nutritional biochemical indices in healthy children with marginally delayed physical growth

Biochemical markers of nutritional status (albumin, transthyretin, insulin-like growth factor-I and zinc) were measured in slowly growing two- to five-year-old, low-income Parisian children whose weight-for-height or height-for-age z scores (WHZ or HAZ) were between — 1 and — 2 SD of the NCHS median. The results were compared to controls who were matched for age, sex, and ethnic origin with WHZ and HAZ between — 1 and + 2 SD. Mean serum levels of transthyretin, albumin and insulin-like growth factor-I and mean plasma zinc concentrations were significantly lower in the growth-impaired children than in the controls ( p = 0.002, p = 0.006, p = 0.015, and p = 0.035, respectively). While the height-retarded children had low mean serum insulin-like growth factor-I values, the weight-retarded subjects had decreased levels of albumin, transthyretin and zinc when compared to controls. Lower mean levels of nutritional markers in healthy, slowly growing children suggest that inadequate dietary intakes of zinc, protein and/or energy may result in marginal delays in weight and height gains.     

Evidence for superantigenic activity during murine malaria infection

TCR V beta usage was examined in C57BL/6 mice infected with Plasmodium yoelii. In addition to a polyclonal T cell activation, already described, a superantigenic-like activity was observed during the acute infection. This superantigenic activity induces a preferential deletion without prior expansion of CD4+ and CD8+ T cells bearing the TCR V beta 9 segment. The superantigen could be released by the parasite at different stages of its development since the deletion of V beta 9+ T cells was observed in blood and lymph nodes of mice infected either with sporozoites or with erythrocytic stages. Injection of sporozoite or parasitized erythrocytes to newborn mice led to a deletion and anergy of peripheral V beta 9+ T cells, without affecting thymic T cell populations. These observations suggest that the superantigen is released at very low concentrations during parasite development. The role of such parasite superantigenic activity in infectivity can be underlined by the observation that congenic BALB.D2 Mis1a mice lacking V beta 9 T cells are more susceptible to infection by P. yoelii.