Investigation by gamma-ray diffraction of the crystalline quality of GaAs and InP single crystals.

The crystalline quality of GaAs and InP single crystals grown by the liquid-encapsulated Czochralski technique, was investigated by gamma-ray diffraction. In particular, the rocking curve was measured in different areas of each crystal, obtaining the mosaic spread, which characterises the grain disorientation around the average direction. The analytical technique which was used, proved useful for the non-destructive characterisation of nearly perfect crystals. In particular, the crystalline quality of Si-doped GaAs and S-doped InP single crystals was found to be very high, whereas the undoped InP crystal appeared to be of worst quality, with a mosaic of the order of few minutes and varying from place to place.

In vivo effect of chronic ethanol abuse on membrane alpha 1-glycoprotein of lymphocytes and immune response to various stimulating agents.

Data on the immune status of chronic alcoholic patients are rather conflicting probably due to the interference of liver disease and/or malnutrition on immune function. In order to avoid this kind of interference, peripheral lymphocytes from 12 chronic alcoholic patients in good nutritional status and without heavy liver damage and 15 healthy controls were examined in this study. Lymphocyte functional activity was evaluated by means of response to phytohemagglutinin, calcium ionophore A 23187, and autologous non-T-cells [autologous mixed lymphocyte reaction (AMLR)]. Phenotypical analysis was carried out by the indirect immunofluorescence technique using monoclonal antibodies specific to CD5 (mature T-lymphocytes), CD4 (helper/inducer T-lymphocytes), CD8 (suppressor/cytotoxic T-lymphocytes), glycoproteins, and an immunoglobulin fraction from rabbit directed to membrane alpha 1 acid glycoprotein (AGP) that is involved in T-cell activation process. Our results show significant impairment in AMLR while response to phytohemagglutinin, heterologous non-T-cells and carcinoma ionophore did not differ from controls. No differences were present in circulating T-lymphocytes expressing CD5, CD4, and CD8 on their membrane, whereas AGP-bearing lymphocytes were significantly lower in chronic alcoholics (14.4 +/- 8.6) than in controls (31.9 +/- 8.1; p less than 0.001). These results support the hypothesis of a direct action of alcohol on one of the pathways of lymphocyte activation and the role of the lymphocyte membrane AGP on the AMLR.

A possible cytotoxicity inducer role of 5/9 positive lymphocytes infiltrating the liver in CAH patients.

The presence, in chronic active hepatitis (CAH) patients, of an inflammatory infiltrate basically composed of T lymphocytes suggested the hypothesis that these lymphocytes could play a role in the pathogenesis of the disease. The aim of this study has been to characterize, in a group of carefully selected CAH patients, the liver-infiltrating T lymphocyte, utilizing commercial monoclonal antibody (anti-Leu 1, anti-Leu 2a, anti-Leu 3a) and 5/9 monoclonal antibody that recognizes a further lymphocyte subset within T4 cells. Our data show that both T4 positive subpopulation and T8 positive subpopulation are represented in the infiltrate in the same ratio; furthermore the distribution of 5/9 positive lymphocytes is prevalent where the infiltrate is mainly composed of T8 positive lymphocytes. Moreover, there is a positive correlation between 5/9 positive cells in the liver and GPT and the patients with high percentages of infiltrating 5/9 positive lymphocytes show a low T4/T8 ratio with respect to patients with low percentages of 5/9 positive cells. These data support the hypothesis that 5/9 positive lymphocytes may present an inducer role on cytotoxic cells.

Accuracy of an average ultrasonic laboratory in measurements of fetal biparietal diameter, head circumference and abdominal circumference.

Twenty patients between 14 and 28 gestational weeks were scanned on three occasions during a single day by six operators with different ultrasonic experience (three use a compound scanner and three a real-time equipment). On each occasion every operator had to measure in a "blind" manner the fetal biparietal diameter (BPD), head circumference and abdominal circumference (HC and AC); a coded copy of head and abdominal circumference was subsequently measured by one of the members of the staff. Statistical analysis was carried out on the 1800 measurements, and it was concluded that the accuracy was not dissimilar from that reported by pilot studies. The reproducibility of the parameters studied did not change throughout pregnancy and real-time and compound scanner yielded homogeneous results.