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The percentage and the absolute numbers of T lymphocytes Fc receptors for IgG and IgM (T gamma and T mu lymphocytes, respectively) were evaluated in fourteen patients with active sarcoidosis and in a group of controls. A marked increase in the percentage of T gamma cells and a net decrease of T mu cells were found. Although sarcoidosis patients present a T lymphopenia, the absolute number of T gamma lymphocytes was still increased whereas the T mu decrease was even more pronounced. The possible causes of this imbalance in view of the recent interpretations of T suppressor and T helper lymphocytes are discussed.

To determine whether bronchoalveolar lavage reflects the histologic aspects of the lung histology in patients with sarcoidosis and hypersensitivity pneumonitis, cells recovered from lavage fluid were compared with tissue sections from transbronchial lung biopsies in 33 patients. The evaluation of cellular types and their topographic distribution in situ was determined by using monoclonal antibodies in combination with immunohistochemical techniques. Cell counts in bronchoalveolar lavage and lung biopsies were significantly correlated both in sarcoidosis and hypersensitivity pneumonitis. In fact, the relative proportions of inflammatory and immunocompetent cells recovered from lavage fluid accurately overlapped those observed in lung tissue sections. However, in patients with more pronounced alveolitis, the frequency of macrophages in tissue sections was higher than that observed in the bronchoalveolar lavage, and the degree of lymphocytes in the lavage was higher than that observed in the corresponding biopsy. Specifically, in these patients the lavage underestimated the amount of macrophages in the lung biopsies and overestimated the number of lymphocytes that were present in the lung parenchyma. This was more evident in patients with hypersensitivity pneumonitis, where the intensity of alveolitis was higher than in sarcoidosis. Our data support the idea that, at least in patients with sarcoidosis and hypersensitivity pneumonitis, bronchoalveolar lavage correctly samples the alveolitis. Discrepancies in patients with very high intensity alveolitis could be due to a more pronounced recirculation of lymphocytes from the parenchyma to the alveolar spaces.

Surface phenotype and functional in vitro activities were studied in 2 cases of lymphoproliferative disorders of granular lymphocytes. Cells from both patients presented the same, previously unreported, surface phenotype (i.e. T3+, T8+, T4-, HNK-1-, NK-15+, M1-), were unable to display either Natural Killer (NK) activity or suppressor function in a poke-weed-driven system, and showed a defective response to phytohemagglutinin (PHA). On the basis of available schemes for NK cells ontogenesis, we will discuss the phenotype and functional activities of patients' cells suggesting that the cell population expressing the T3+, T8+, HNK-1-, NK-15+, M1- phenotype might represent a discrete stage along the NK-cell differentiation pathway.

Seventeen patients with well compensated chronic renal failure undergoing periodic hemodialysis were studied with regard to absolute number of T and B lymphocytes, spontaneous and PHA induced lymphocyte blastogenesis both with autologous and homologous compatible plasma. A normal lymphocyte count as well as a normal relative and absolute number of T and B lymphocytes was found in most cases. Spontaneous blastogenesis was normal. Lymphocyte response to PHA was reduced both with autologous and homologous plasma, but the depression was more relevant when autologous plasma was used in culture. The authors discuss these findings with respect to available data, particularly concerning inhibitory factors in uraemic plasma.

High fever, spleen and lymph node enlargement, and joint pains that assumed the character of rheumatoid arthritis in the ensuing months were noted after a viral hepatitis episode in a 21-year-old woman. Serious anaemia and myocarditis also appeared when the picture was at its worst. A lymphoma was suspected, and the spleen and some abdominal lymph nodes were removed. These displayed signs of intense follicular reaction unaccompanied by atypia. The possibility that juvenile rheumatoid arthritis may be triggered by hepatitis is examined.

Peripheral blood lymphocytes from a patient with chronic lymphocytic leukaemia of T cell origin were studied. The thymus derived nature of these lymphocytes was confirmed by surface markers, mitogen cultures, mixed lymphocyte reaction, cytotoxicity studies, and cytochemical stains. This case is notable for several clinical and laboratory findings. Among these, the benign clinical course, the reduced rate of serum immunoglobulins, the elevated number of active E rosettes, the increased PHA-induced response to low mitogen doses, the absence of PHA mediated cellular cytotoxicity, and the thy-like positivity to ANAE should be pointed out. Emphasis should be placed, however, on the loss of stimulatory ability in MLR. This last feature supports the hypothesis that these cells proliferate as a clone.

A preliminary report on the immunological monitoring of primary intracranial neoplasms is presented. The most important findings concerning B-cells and T-cells mediated immunity and delayed hypersensitivity reactions in this kind of patients, are discussed. Among the fairly significant immunobiological pictures, the Authors stress the "normal behaviour" of the B-cells dependent pool, the undebatable depression of the delayed hypersensitivity reactions, and the noticeable failure of the T-cell dependent pool, particularly marked in malignant gliomas, which are also characterized by the presence of cells with natural cytotoxic activity.

In twelve patients with active sarcoidosis we attempted to explain the nature of reduced release on interleukin-2 (IL-2) and the consequent impairment in lymphoproliferative in vitro responses. The addition of exogenous IL-2 containing supernatants was unable to completely restore the defective uptake of 3H-Thymidine suggesting that an impairment of IL-2 producer cells is not enough to explain the in vitro hyporesponsiveness of sarcoid lymphocytes. We also found a reduced number of precursors of IL-2 responder cells, as defined by peripheral blood lymphocytes bearing Tac determinant following in vitro stimulation with mitogens. The abnormalities of both IL-2 producer cells and precursors of IL-2 responder cells in peripheral blood of patients with sarcoidosis are discussed, stressing the importance of the concept of compartmentalization of T lymphocytes in this disease.

The lung is involved in more than 50 per cent of patients with the acquired immune deficiency syndrome (AIDS), and pulmonary abnormalities can be easily investigated using the bronchoalveolar lavage (BAL). Besides providing information on the type of infecting microorganism, BAL has been used to characterize immunocompetent cells from the lower respiratory tract in these patients. This allows new insights into the immunopathogenetic mechanism involved in the persistence of opportunistic pulmonary infections and in the uncontrolled viral replication. This paper emphasizes the value of BAL evaluation as a simple and useful method for investigating the involvement of the distal respiratory tract in AIDS patients. A particular attention is payed on the immunological pulmonary abnormalities of this epidemic immunodeficiency syndrome.

In 20 patients with lymphoproliferative disease of granular lymphocytes (LDGL) the cytotoxic in vitro function of peripheral blood mononuclear cells was studied against both NK sensitive (K-562) and NK resistant target cells (Daudi). Cytotoxicity was analysed at resting conditions and after in vitro pre-incubation with recombinant alpha 2-interferon, gamma-interferon and interleukin 2. At resting conditions, a heterogeneous cytotoxic picture was observed against the K-562 targets, with 11 of the 20 patients showing a normal or increased NK activity, and nine an impaired function. Against the Daudi targets, unstimulated cells from all patients displayed a normal cytotoxic activity. Following in vitro stimulation, an increased lytic function against K-562 cells was demonstrated in six of the nine patients with low basal values, in three after boosting with all lymphokines tested and in three with interleukin 2. In three of these six patients incubation with interleukin 2 also produced an increased cytotoxic function against Daudi target cells; this phenomenon may be associated to the lymphokine-activated killer (LAK) system. The importance of investigating the cytotoxic in vitro function in LDGL patients to further characterize the biological features of GL and its relevance to better define the nature of this disease are discussed.

The Moon is characterized by extremely harsh conditions due to ultraviolet irradiation, wide temperature extremes, vacuum resulting from the absence of an atmosphere and high ionizing radiation. Therefore, its surface may provide a unique platform to investigate the effects of such conditions. For lunar exploration with the Lunar Gateway platform, exposure experiments in Low Earth Orbit are useful testbeds to prepare for lunar space experiments and to understand how and if potential biomarkers are influenced by extra-terrestrial conditions. During the BIOMEX (BIOlogy and Mars EXperiment) project, dried colonies of the fungus Cryomyces antarcticus grown on Lunar Regolith Analogue (LRA) were exposed to space conditions for 16 months aboard the EXPOSE-R2 payload outside the International Space Station. In this study, we investigated the stability/degradation of fungal biomarkers in LRA after exposure to (i) simulated space and (ii) real space conditions, using Raman spectroscopy, gas chromatography-mass spectrometry and DNA amplification. The results demonstrated that fungal biomarkers were detectable after 16 months of real space exposure. This work will contribute to the interpretation of data from future biological experiments in the Cislunar orbit with the Lunar Gateway platform and/or on the lunar surface, in preparation for the next step of human exploration.

Objectives To evaluate the in vitro effectiveness on dentine permeability and dentine morphology of a calcium silicate treatment based on Portland cement (DSC). Methods The experimental treatment consisted of a calcium silicate paste based on Portland cement that was applied on dentine surface for 3 min. A professional re-mineralizing treatment (GC Tooth Mousse), two in office desensitizing agents (D/Sense Crystal, and By Sealant) and a commercial toothpaste Dentosan S were studied as comparison materials. All materials were applied accordingly with manufacturer directions on wet dentine. The quantitative changes in the hydraulic conductance i.e., permeability through tubules of dentine discs samples produced by treatment were quantified in vitro using a hydrostatic device working at 6.9 kPa. SEM/EDX analyses of dentine were carried out to obtain qualitative information on dentine morphology and surface deposits and to study their relationship with the hydraulic conductance. After treatment, each dentine sample was immersed in artificial saliva and permeability re-evaluated. Finally, each sample was exposed to 0.02 M citric acid solution and the final permeability was assessed. Results The experimental treatment and both oxalate-based products (D/Sense Crystal and By Sealant) significantly decreased dentine permeability and created crystals and precipitates on the dentine surface that reduced the diameter of dentinal tubules. Artificial saliva immersion and citric acid challenge increased dentine permeability and partially modified the treated surfaces. Dentosan S and GC Tooth Mousse treatments partially reduced dentine permeability and created small amount of precipitates that were removed by saliva immersion and citric acid exposure. EDX revealed the presence of calcium-rich layer after DSC experimental treatment. Conclusions The application of the experimental calcium silicate paste and oxalate-based treatments was determined to be effective on dentine permeability reduction and tubules occlusion. The clinical use as desensitizing agent of materials derived from Portland cement as desensitizing agent should be considered for dentine hypersensitivity treatment.