Sequential activity of gamma-delta T-cell receptor bearing lymphocytes, specific T-cell factors, and alpha-beta T-cell receptor bearing T-cells: a hypothesis

The cell-mediated immune response against cell-bound antigens are biphasic responses. The 'classical' components of cell-mediated immunity such as delayed type hypersensitivity (DTH) and cytotoxic T-cells, are preceded by antigen-specific T-cell factor production. These antigen-specific T-cell factors can be detected in the serum 1-2 days after immunization, which suggests that these antigen-specific T-cell factors play an important role in the initiation of cell-mediated immune responses. Factor-producing lymphocytes can be detected already 1 day after immunization at the site of the antigen challenge, and at first 4-5 days after immunization in the peripheral lymphoid organs. The phenotype of these factor-producing lymphocytes is Thy-1+, CD3+, L3T4 (CD4)-, Lyt2 (CD8)-, whereas the T-lymphocytes inducing the DTH response are Thy 1+, CD3+, L3T4 (CD4)+, Lyt2 (CD8)-. This suggests that these factor-producing lymphocytes are gamma-delta bearing T-lymphocytes. gamma-delta TCR bearing T-cells can develop independently of the thymus, and are present in athymic nude mice. Immunization of athymic (nude) mice induces antigen-specific T-cell factor production as well. This suggests that the gamma-delta bearing T lymphocytes present in nude mice can react to cell-bound antigens and produce these factors.     

Chromosomal aberrations in follicular thyroid carcinoma. Case report of a primary tumor and its metastasis

We present the result of a cytogenetic study of a case of follicular carcinoma of the thyroid and its metastasis. Both tumors have a low number of chromosomes. The primary tumor is characterized by a idic(22;22)(p11;p11). The skeletal metastasis has also structural abnormalities of chromosome 22.     

Standardization of allergenic extracts of Aspergillus fumigatus. Liberation of IgE-binding components during cultivation

During cultivation of Aspergillus fumigatus a rapid liberation of IgE-binding components was found reaching maximum values during the logarithmic phase of growth (phase I). After a fall in IgE-binding titers during phase II, appearance of additional IgE-binding components was noted during the period of lysis of the microorganism (phase III). These latter allergenic components are different from the phase I IgE-binding components, as was shown by crossed-inhibition studies. The number of precipitating antigenic components was not related with the corresponding IgE-binding titers and showed an increase during all phases of growth. The rapid changes in both IgE- and IgG-binding properties and the discrepancies between precipitating properties and IgE binding are discussed in relation to standardization and quality control of aspergillus extracts.     

Individual differences in the effects of serotonergic anxiolytic drugs on the motivation to self-administer cocaine

Numerous clinical studies have indicated that lifetime anxiety is highly prevalent in drug addicts. In the treatment of drug abuse, dually diagnosed drug addicts may benefit from pharmacological intervention strategies that alleviate the psychiatric symptomatology. We have previously shown that rats with different coping strategies in a stressful environment show strong differences in the motivation to self-administer cocaine. That is, cocaine self-administration under a progressive ratio (PR) schedule of reinforcement was enhanced in high grooming (HG) rats as compared with low grooming (LG) rats. To identify the pharmacological basis of these differences, we tested the acute effects of several anxiolytic drugs on cocaine self-administration in HG and LG rats under a PR schedule of reinforcement. Chlordiazepoxide increased PR responding in both the HG and LG rats, while the selective corticotrophin releasing hormone 1 receptor antagonist R121919 had no effect on cocaine self-administration under the PR schedule. Interestingly, buspirone and fluoxetine decreased PR responding in HG rats only and thereby abolished the individual differences in PR responding between HG and LG rats. In support of the differential effects of the serotonergic drugs on PR responding in HG and LG rats, we found that the in vitro electrically evoked release of [3H]serotonin from mesocorticolimbic brain slices was reduced in the medial prefrontal cortex, substantia nigra and nucleus accumbens core, and increased in the nucleus accumbens shell of HG rats relative to LG rats. These findings show that serotonergic anxiolytics abolish the pre-existing individual differences in cocaine self-administration between HG and LG rats, which show differences in the reactivity of serotonergic neurons. This suggests that the effectiveness of pharmacological interference may depend on the neurochemical and motivational state of the individual.     

Localization of the HST/FGFK gene with regard to 11q13 chromosomal breakpoint and fragile site

The HST/FGFK gene, a member of the fibroblast growth factor gene family and a protooncogene, is localized on chromosomal band 11q13. Genes in this region are frequently involved in hematopoietic and solid tumors. Here we show that the HST gene lies telomeric to the BCL1 gene, the t(11;14)(q13;q32) breakpoint, and the FRA11A rare fragile site.     

Similarity of vegetative map and prophage map of bacteriophage Mu-1

The vegetative map of bacteriophage Mu was extended by the localization of three more amber mutations belonging to different complementation groups, and the position of the c gene on the vegetative map was approximately determined. The data confirm the previous finding that the vegetative map is linear (Wijffelman et al., 1972).Defective Mu lysogens were isolated from an Escherichia coli K12 strain, which has an insertion of Mu in the trp operon, by selecting for TonB colonies. All these defective lysogens were no longer immune to Mu infection, suggesting that the gene controlling immunity is located near to the end of the prophage proximal to tonB. By analyzing the remaining prophage genes in the defective lysogens, it was possible to determine the order of 16 amber mutations belonging to different complementation groups. The results show that the position of the genes on both the vegetative map and the prophage map is the same.The prophage map of Mu was determined by using the same method in another 9 independently isolated insertion mutants. In 7 of these mutants the gene order in the prophage is the same as found for the above-mentioned strain. The other two contain the prophage genes in the reversed order. All defective lysogens derived from these two insertion mutants by selection for TonB colonies were immune. The results show that Mu is integrated in a unique way and that both orientations may occur. The similarity between prophage map and vegetative map and the consequence for the mechanism of the integration process are discussed.     

Risk factors for asthma among children in Maputo (Mozambique)

BACKGROUND: Few studies have looked at risk factors for asthma in African children. We aimed to identify the risk factors associated with childhood asthma in Maputo (Mozambique). METHODS: This case-control study included 199 age-matched children (100 asthmatic and 99 nonasthmatic) who attended Maputo Central Hospital between January 1999 and July 2000. We collected information concerning their familial history of atopy, birth weight, environment and breast-feeding. Detailed information about morbidity and treatment was obtained for each asthmatic child. RESULTS: The children were aged between 18 months and 8 years; 60% were male. The asthmatic children were hospitalized more frequently than the nonasthmatic children (P < 0.0001). Most of the asthmatic children lived in the urban area of Maputo [odd ratio (OR) = 6.73, CI = 3.1-14.0, P < 0.0001], had a parental history of asthma (OR = 26.8, CI = 10.8-68.2, P < 0.0001) or rhinitis (OR = 4, CI = 1.2-13.3, P = 0.005), had at least parent who smoked and were weaned earlier than the nonasthmatic children (OR = 2.4, CI = 1.3-4.4, P < 0.001). CONCLUSION: Childhood asthma was strongly associated with a family history of asthma and rhinitis, the place of residence, having smokers as parents and early weaning from maternal breast milk. These results highlight the need to reassess the management of asthmatic children in Maputo.     

Effect of epitope density on the induction of the IgE immune response in mice

The effect of hapten density on benzylpenicilloyl (BPO)-protein conjugates upon the induction of BPO-specific IgE immune response was investigated in BALB/c and C3H mice. Bovine gamma-globulin (BGG) and ovalbumin (OA) were employed as carrier proteins. In both strains of mice, moderately substituted conjugates (BPO19-BGG, and BPO-OA with an epitope density from 2 to 7.5) elicited a persistent BPO-specific IgE, while heavily substituted conjugates (BPO38-BGG) induced only a transient response. In contrast, lightly substituted conjugates (BPO3.2-, BPO9.5-BGG, and BPO1-OA) failed to produce BPO-specific IgE antibodies. There was no significant difference in carrier-specific IgE immune response among these various conjugates. These results suggest that moderately substituted hapten-protein conjugates are one of the favorable conditions for eliciting hapten-specific IgE immune response in mice.     

Ultrastructural and biochemical aspects of liver mitochondria during recovery from ethanol-induced alterations. Experimental evidence of mitochondrial division.

To study the morphologic and biochemical changes occuring in liver mitochondria during recovery from ethanol-induced injury, rats fed a 6-month high-alcohol regimen plus a nutritionally adequate diet which did not induce fatty liver were compared with isocalorically fed controls. After this period the alcohol-fed animals displayed striking ultrastructural changes of liver mitochondria and a decreased respiratory activity with succinate or malate-glutamate as substrate. On the contrary, the respiratory rate with I-glycerophosphate was 50% increased. Regression changes were studied after alcohol was withdrawn from the diet. Enlarged mitochondria rapidly disappeared (in 24 hours), although a few megamitochondria were still present after 8 days of abstinence. A similar recovery was observed for the functional alterations. At the end of the experimental period, only a slight decrease of the maximal respiratory rate using malate-glutamate as a substrate was noted. The ultrastructural findings and the morphometric data suggest that the way in which mitochondrial normalization takes place is based on partition of these organelles.