Flow Cytometric Analysis of Cellular Changes in Mice after Intradermal Inoculation with a Liposome–Iscom Adjuvanted Vaccine

As it is not known what changes to leucocyte homeostasis are mandatory for effective adjuvant action, the biological relevance of systemic changes elicited by different vaccine formulations can only be interpreted in the context of the immunological outcomes. We used flow cytometry to quantify the changes in leucocyte subsets induced in mice intradermally immunized with SAMA4 (adjuvant group), outer membrane proteins (OMP) purified from Actinobacillus pleuropneumoniae (OMP antigen group), SAMA4 adjuvanted OMP (OMP vaccine group), or phosphate-buffered saline (PBS: control group). This approach allowed direct comparisons to be made between the effects of antigen, adjuvant or antigen–adjuvant complexes on immune effector cell populations. Antigens complexed with the liposome–iscom hybrid adjuvant, SAMA4, generated strong antibody responses and cytotoxic T-cell activity in animals immunized intradermally, reflecting remobilization and recruitment of specific cell populations. Splenomegaly, due to granulocytosis, monocytosis and megakaryocytosis, was most prominent in the OMP vaccine group. Histological examination of spleen sections confirmed that these changes were due primarily to splenic haematopoiesis. Circulating numbers of granulocytes and monocytes increased significantly (P < 0.05) in the blood of the OMP vaccine group, as did granulocyte numbers in the lungs (P < 0.05). No changes in T- and B-cell numbers were detected by flow cytometry in the spleens, lungs or blood over the 28-day period in any treatment group. Thymocyte numbers (predominantly CD4⁺CD8⁺ cells) in the OMP vaccine group fell by 95% within 3 days of immunization. Identical cellular responses were obtained when an innocuous antigen, ovalbumin, was complexed with SAMA4 instead of OMP, thus demonstrating that the adjuvant effects of SAMA4 were due to synergistic interaction between antigen and adjuvant and not due to the presence of toxic components. The association of strong adaptive immune responses with such complex changes in leucocyte homeostasis induced by complexing adjuvant and antigen suggested that the changes were important for effective vaccination and were not purely circumstantial.     

Pituitary macroadenomas associated with hyperprolactinaemia: immunocytochemical and in-situ hybridization studies

OBJECTIVE: We have assessed whether in-situ hybridization for prolactin messenger RNA (mRNA) provides additional information for the classification of pituitary macroadenomas associated with hyperprolactinaemia. DESIGN: In-situ hybridization for PRL mRNA was performed on surgical biopsies of pituitary adenomas and the results correlated with serum PRL levels and PRL immunoreactivity. PATIENTS: Twenty-one patients (11 men, 10 women) were included; five had normal serum PRL levels, 11 mild hyperprolactinaemia (less than 3000 mU/l) and five marked hyperprolactinaemia (greater than 3000 mU/l). MEASUREMENTS: Immunocytochemistry for PRL and in-situ hybridization for PRL mRNA were performed on surgical biopsies. RESULTS: Immunoreactivity for PRL was detected in tumours from all patients with serum PRL greater than 3000 mU/l and in one of 11 patients with mild hyperprolactinaemia. Positive signal for PRL mRNA was detected in four of five immunopositive cases studied, in a further two cases with mild hyperprolactinaemia, and in one tumour associated with normal serum PRL level. CONCLUSIONS: In-situ hybridization provides evidence of PRL gene activation in the absence of immunoreactivity for prolactin. This may reflect low levels of hormone storage or defective translation of the mRNA.     

The assessment of in vitro modulation of milk fat globule membrane expression by human breast carcinomas

Although knowledge of functional differentiation and tumour-associated changes of breast carcinomas can be gained by the application of antibodies directed against the milk fat globule membrane, more significant information may be obtained by assessment of the potential of breast carcinomas to modulate their antigenic phenotype. In this study, the extend to which primary tumours can undergo modulation in vitro has been investigated, with consideration of the suitability of organ culture in combination with the immunohistochemical detection of two milk fat globule membrane epitopes, HMFG1 and HMFG2, as methods for detecting this. The preservation of three of the 30 carcinomas assessed, all poorly differentiated, was poor after 3 days of culture. The viability of the other 27 was variable, and was greater in the better differentiated tumours and with the addition of insulin. Expression of the milk fat globule membrane epitopes was generally well maintained. Six of the carcinomas showed a significant change in antigen expression, with this being more frequent in tissues incubated with insulin. Hence, a small group of carcinomas have been identified which appear to have a greater capacity to undergo functional differentiation. Organ culture is considered to be a suitable method for maintaining the tissues in vitro for such evaluation, but the problems encountered in quantifying the immunohistochemical staining, because of antigenic heterogeneity, were such that it is suggested that other approaches be employed.     

Evidence of hypothalamic involvement in the mechanism of transplacental carcinogenesis by diethylstilbestrol.

Disruption of hypothalamic sex differentiation in the fetus is one hypothesis to explain female reproductive system anomalies and cancer arising from prenatal exposure to diethylstilbestrol (DES). To further test this hypothesis, breeding performance and behavior were monitored in a colony of mice exposed prenatally to DES, using a schedule previously shown to produce anomalies and cancer of the female reproductive system. Fertility decreased with age more rapidly in DES-exposed females than in control females. DES-exposed females were less accepting of the male than control females. These observations support the hypothesis of abnormal hypothalamic sex differentiation as a basic mechanism in DES transplacental carcinogenesis.     

Probiotics as flourishing benefactors for the human body.

This article provides a comprehensive review of the beneficial effects of various strains of probiotics in preventing and treating certain diseases. Currently, changed lifestyles as well as the increased use of antibiotics are significant factors challenging the preservation of a healthy intestinal microflora. The concept of probiotics is to restore and uphold a microflora advantageous for the human body. Probiotics are found in a number of fermented dairy products, infant formula, and dietary supplements. In the presence of prebiotics, which are nondigestible food ingredients favorable for probiotic growth, their survival in the intestine is ameliorated.