'Microsmatic' primates revisited: olfactory sensitivity in the squirrel monkey.

Using a conditioning paradigm, the olfactory sensitivity of three squirrel monkeys to nine odorants representing different chemical classes as well as members of a homologous series of substances was investigated. The animals significantly discriminated dilutions as low as 1:10,000 n-propionic acid, 1:30,000 n-butanoic acid and n-pentanoic acid, 1:100,000 n-hexanoic acid, 1:1Mio n-heptanoic acid, 1:30, 000 1-pentanol, 1:300,000 1,8-cineole, 1:1Mio n-heptanal and 1:30Mio amyl acetate from the near-odorless solvent, with single individuals scoring even slightly better. The results showed (i) the squirrel monkey to have an unexpectedly high olfactory sensitivity, which for some substances matches or even is better than that of species such as the rat or the dog, and (ii) a significant negative correlation between perceptibility in terms of olfactory detection thresholds and carbon chain length of carboxylic acids. These findings support the assumptions that olfaction may play a significant and hitherto underestimated role in the regulation of primate behavior, and that the concept of primates as primarily visual and 'microsmatic' animals needs to be revised.

Genetic linkage of HLA-class II locus to mite-specific IgE immune responsiveness.

BACKGROUND: IgE response to common inhalant allergens seems to be the major determinant of the development of atopic rhinitis and asthma but it has been difficult to demonstrate genetic control of the IgE response. OBJECTIVE: To investigate genetic linkage between specific IgE reactions to purified aero-allergens (grass, birch, cat, mite) and the HLA-class II locus. METHODS: DNA-based HLA-class II typing was performed for determination of DRB1, DQB1 and DPB1 alleles. Linkage was studied by the affected sibpair method and the extended transmission disequilibrium test in 100 children from 40 nuclear families selected from a homogeneous population in south-western Germany. RESULTS: Significant linkage of mite-specific IgE response to HLA-DPB (P = 0.00001), HLA-DRB (0.02) and HLA-DQB (P = 0.001) was revealed by sibpair analysis of MHC class II alleles and confirmed by the extended transmission disequilibrium test for HLA-DRB (P = 0.01) and HLA-DPB (P = 0.04). No consistent significant linkage between the HLA-class II locus and IgE response to grass pollen, birch pollen, and cat dander could be demonstrated. CONCLUSION: The findings are consistent with the existence of one or more genes in the HLA-class II region modifying the IgE immune response to common environmental allergens.

Anti-ganglioside monoclonal antibody AA4 selectively inhibits IgE-induced signal transduction pathways in rat basophilic leukemia cells.

In rat basophilic leukemia 2H3 (RBL-2H3) cells, mAb AA4 binds to two derivatives of ganglioside GD1b that associate with the Src family kinase p53/56lyn and a serine kinase. Pre-incubation of cells with mAb AA4 blocks immunoglobulin E (IgE) mediated histamine release. In the present study we investigated the effect of incubation with mAb AA4 on signal transduction events. In addition to stimulation of the high affinity IgE receptor (Fc epsilonRI), cells were also activated by the calcium ionophore A23187 and the acetylcholine agonist carbachol in RBL-2H3 cells transfected with the G protein-coupled m3 muscarinic receptor. Incubation of cells with mAb AA4 in a dose-dependent manner inhibited the following Fc epsilonRI-induced signal transduction events: the increase of intracellular free calcium, phosphoinositol breakdown, tyrosine phosphorylation of proteins including the beta- of Fc epsilonRI and secretion. However, there was no inhibition of degranulation or of these biochemical events when cells were stimulated with calcium ionophore or activated via a G protein-coupled pathway. Our results demonstrate that mAb AA4 selectively blocks Fc epsilonRI-induced cell activation at a very early step upstream of receptor tyrosine phosphorylation. As mAb AA4 has previously been found to bind to gangliosides associated with Fc epsilonRI, inhibition of very early biochemical events may be due to interaction of mAb AA4 with the Fc epsilonRI induced signal transduction cascade at the receptor level.

Expression of mRNA for the proto-oncogene c-fos in rat basophilic leukaemia cells.

Recently, the expression of the mRNA for the proto-oncogene c-fos following activation of the high-affinity receptor for immunoglobulin E in rodent mast cells has been reported. In the present study we investigated different biochemical events that may play a role in signal transduction pathways culminating in the expression of c-fos mRNA in rat basophilic leukaemia cells. Similar to IgE-mediated cell degranulation we demonstrated inhibition of the c-fos signal in the absence of calcium and after preincubation of cells with the protein tyrosine kinase inhibitor genistein. Activation of RBL-2H3 cells by short term PMA treatment failed to induce cell degranulation or expression of mRNA for c-fos. Depletion of protein kinase C by PMA pre-treatment resulted in substantial inhibition of the c-fos signal. In contrast to IgE-mediated cell degranulation, expression of mRNA for c-fos was not dependent on continued receptor aggregation. In addition, we demonstrate that c-fos mRNA expression is not restricted to Fc epsilon RI activation but can be induced by a variety of IgE independent mechanisms including calcium influx by ionophore A 23187 and stimulation of G proteins.

Relationship between safe sex and acculturation into the gay subculture.

There is some evidence, although conflicting, to suggest that socialization or acculturation into the gay community is associated with lower levels of unsafe sex. We attempted to determine the relationship between acculturation and sexual safety. We examined data from 282 men (from the Dallas AIDS Community Demonstration Project) who had sex with men and were not in a monogamous relationship to determine the associations between safer sex and indices of acculturation. The indices of acculturation included regular reading of local and national gay newspapers and magazines, and belonging to an organization for gay men. The data indicated that there were significant relationships between acculturation, talking to sexual partners about HIV risk reduction and sexual identity, and the dependent variable of frequency of condom use for anal sex. A regression equation indicated that 21% of the variance of anal condom use was predicted by these variables. These data suggest that acculturation into the gay community is associated with safer sexual behaviour, and we discuss the implications of these data for using role models and normative beliefs in HIV prevention programmes.

[Studies on the combined effects of shift work and noise on permanent hearing loss]. / Untersuchungen zur Wirkung der Belastungskombination von Schichtarbeit und Lärm auf den permanenten Hörverlust.

Combined exposure to shiftwork and noise was investigated with respect to its aural damaging effect. The investigations were carried out on 347 male and female noise-exposed textile workers working in single-shift and three-shift systems. The average hearing loss for the PTS at 3 kHz, 4 kHz, the total hearing loss at 0.5, 1, 2, 4, 6, 8 kHz and percentage of hearing loss according to Fowler/Sabine served as indicators. To fulfil this task an epidemiological cross-sectional study was performed. The results of the present study show lower average hearing loss values in the case of three-shift workers as compared with single-shift workers.

[Functional changes of the cervical spine and shoulder-neck region in workers employed in textile sewing]. / Funktionelle Veränderungen der Halswirbelsäule und Schulter-Nacken-Region bei Textilnäherinnen.

Functional disturbances of cervical spine, shoulder-nape-muscles and cervicothoracic ligamentous apparatus were examined in 100 needle-women. 105 nurses from outpatients departments served as group of comparison. In consideration of signs of occupational load clues to occupationally caused overstrain were found.

[Occupational medicine and occupational science evaluation of shift work systems with integrated 12-hour shifts]. / Arbeitsmedizinische und arbeitswissenschaftliche Bewertung von Schichtsystemen mit eingelagerten 12-Stunden-Schichten.

A field study was performed on 32 male deep drilling workers engaged in hard physical work and 10 male operators with mainly supervisory tasks; both groups working in a shiftwork system including 12 hr shifts. Both the analysis and evaluation of stresses and strains were carried out by means of physiological, psychological and sociological methods. The obtained results show that under the conditions of the given working requirements, existing reproduction conditions, and observed social structure of the populations operating and supervisory activities in a 8 hr shiftwork system including 12 hr shifts are acceptable. In case of hard physical work this shiftwork arrangement can't be agreed to for industrial-medical reasons.

[Occupational medicine outpatient management of shift workers]. / Arbeitsmedizinische Dispensairebetreuung der Schichtarbeiter.

Proceeding from the reasons why the amount of multi-shift work has to be increased further, the tasks of works doctors and research work in the field of industrial medicine are pointed out in this paper. The evaluation of 200,000 medical fitness and follow-up examinations annually and the present results of research work give reasons for revising the examination category "shift workers" in the legal regulations of the medical fitness and follow-up examinations which are being revised as well as orienting and concentrating on certain main fields of research.