Measurement of local Mr 97,000 and 250,000 protein antigen concentration in sections of human melanoma tumor using in vitro quantitative autoradiography

An assay method that uses 125I-labeled monoclonal antibody (MoAb) and in vitro quantitative autoradiography was developed to determine the local concentration of tumor-associated antigens in tissue sections. Human melanoma biopsy specimens were evaluated for the expression of the Mr 97,000 and 250,000 protein antigens using MoAb-96.5 and MoAb-9.2.27, respectively. Tissue sections were incubated in solutions of increasing concentration of 125I-labeled MoAb with or without an excess of unlabeled antibody. Quantitative autoradiography was performed on the sections and compared with 125I standards to determine tumor-bound radioactivity and calculate bound pmol of MoAb per g of tumor. The total binding, nonsaturable binding, and specific binding of 125I-labeled MoAb to tumor were then computed. Specific binding of MoAbs to tumor tissue was saturable in all antigen-positive tumors. The maximal concentration of specific binding of antibody to tissue (Bmax) represented the tissue antigen concentration. Estimates of the Ka of antigen/antibody binding were also made. The reliability of the measurements was confirmed by testing sections from mixtures of antigen-positive and antigen-negative cells.     

Differential expression and cytoplasm/membrane distribution of endoglin (CD105) in human tumour cell lines: Implications in the modulation of cell proliferation

Endoglin (CD105, an accessory component of the TGF-beta receptor complex) expression and distribution on different human tumour cells and its role in cellular proliferation were evaluated. We examined: 1) sixteen human carcinoma cell lines, 2) eight human sarcoma cell lines, 3) five miscellaneous tumour cell lines. HECV (endothelial cells) were employed as a positive control for endoglin expression. Normal Human Dermal Fibroblasts (NHDF) and 293 cells (epithelial kidney cells) were used as normal controls for connective and epithelial tissues, respectively. The results showed that CD105 was poorly expressed in the majority of human carcinoma cells (10/16), whereas it was highly expressed in most human sarcoma cells (7/8), and differently expressed by miscellaneous tumour cell lines. These data reflect endoglin expression by the normal counterparts of tumour cell lines, i.e. NHDF and 293 cells. However, CD105 levels in sarcoma cell lines, even though consistently lower than in NHDF, were significantly higher than those observed in carcinoma cells. Interestingly, CD105 presented a strong expression in the cytoplasm of MDA-MB-453 (breast carcinoma), NPA (papillary thyroid carcinoma), COLO-853 (melanoma) and SaOS-2 (osteosarcoma), but was weakly expressed on their cell membrane. This differential expression in the cytoplasm and on the membrane of some tumour cells, suggests a complex mechanism of translocation for this protein. The analysis of clonal growth in soft agar of some cell lines, characterized by high CD105 expression, showed an increased colony formation potential that was antagonized by the addition of anti-CD105 blocking mAb. The results indicated that endoglin is differentially expressed in human carcinoma and sarcoma cells and its overexpression modulates the proliferative rate of human solid tumour cells. Moreover, these data suggest that CD105 is involved in the regulation of TGF-beta effects in human solid malignancies, and therefore it could play an important role in tumour diagnosis and treatment.     

Public food service in Milan city and Hinterland: food-handlers training level (Part 2)

The prevention and control of foodborne diseases play an important role in public health and the responsibility of food-handlers is of great concern: their training on food safety is particularly required in the critical sector of public food service establishments. The food-handlers knowledge has been evaluated by a questionnaire filled up in two Public Health Units (PHU) in Milan City and Milan hinterland. Only 11.5% of food-handlers turned at to be good trained; the wrong answers are concentrated on the section titled "temperatures management" (68 and 59% in Milan City and in Milan hinterland, respectively). Only for 31.4% of food-handlers the attendance to training courses is well documented, although the knowledge level seems to be partially influenced by training activity: exclusively in Milan City food-handlers an highly significant difference has been found among "trained" and "no-trained" workers in correct answers about temperatures management (p= 0.0046). The frequency of exact answers isn't associated to the satisfaction level revealed during inspection of restaurants. Focusing the attention on the insufficient efficacy of training courses and the lacking connection between knowledge and behaviour, a critical revision of training activity quality seems to be necessary. In future some professional training activities in the field should be promoted.     

Carcinoma ex-pleomorphic adenoma of the breast. Report of three cases suggesting a relationship to metaplastic carcinoma of matrix-producing type

Three cases of carcinoma ex-pleomorphic adenoma of the breast are reported. Patients were 82, 60 and 56 years old and presented with a breast lump. All tumours showed areas of pleomorphic adenoma adjacent to typical areas of malignant transformation. These cases add to the spectrum of tumours shared by breast and salivary gland. The relationship between these neoplasms and metaplastic carcinoma of matrix-producing type is discussed.     

Human cortical responses during one-bit delayed-response tasks: an fMRI study

Neuroimaging study of cognition across aging requires simple tasks ensuring: (i) high rate of correct performances in neurophysiological settings; and (ii) significant modulation of cortical activity. As a preliminary step, the present functional magnetic resonance imaging (fMRI) study tested the hypothesis that very simple delayed-response tasks fit these requirements in normal young adults. The short-term memory (STM) variant included a sequence of cue stimulus (two vertical bars), delay period (blank screen for only 5s), go stimulus, and motor response compatible with the taller vertical bar. Noteworthy, the retention (only one bit) could be based on visuo-spatial, phonological, and somatomotor coding. In the control variant (no STM, NSTM), the cue stimulus was present during the delay period. Results showed high rate of correct performances in both tasks (about 95%). Compared to the NSTM task (delay period), the STM task enhanced cortical responses in bilateral dorsolateral prefrontal (Brodmann area 8-9 (BA 8-9)), lateral premotor (BA 6L), medial premotor (BA 6M), inferior parietal (BA 40), and superior parietal (BA 7) areas. In the STM task, cortical responses were stronger in right than left BA 8-9 and BA 6L. These results indicate that, in normal young adults, a simple STM variant of delayed-response tasks (one bit to be retained) is correctly performed and enhances bilateral fronto-parietal responses. Therefore, it may be used for future cognitive neuroimaging studies on aging.     

Persistent B-cell lymphopenia, multiorgan disease, and erythema multiforme caused by Mycoplasma pneumoniae infection

We report a 6-year-old girl in whom Mycoplasma pneumoniae infection presenting with erythema multiforme, multiorgan, and hematologic dysfunctions induced a long-standing, marked B-cell lymphopenia. An increase of CD8+ lymphocytes was also detected. We suggest that a selective cytotoxic T lymphocyte-dependent B cell lysis and the expansion of super-antigen activated CD8+ T cells may account for the multiorgan and hematologic disturbances triggered by M. pneumoniae.